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Rename mm (memory manager) to pm (process manager), involved renaming

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This commit is contained in:
Ben Gras 2005-05-03 15:35:52 +00:00
parent 83ef55e301
commit 0e9261ed5a
21 changed files with 3402 additions and 1 deletions
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2
servers/Makefile
View file

@ -14,7 +14,7 @@ usage:
build: all
all install clean:
cd ./mm && $(MAKE) $@
cd ./pm && $(MAKE) $@
cd ./fs && $(MAKE) $@
cd ./is && $(MAKE) $@
cd ./init && $(MAKE) $@

134
servers/pm/Makefile Normal file
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@ -0,0 +1,134 @@
# Makefile for Process Manager (PM)
SERVER = pm
# directories
u = /usr
i = $u/include
s = $i/sys
h = $i/minix
k = $u/src/kernel
# programs, flags, etc.
CC = exec cc
CFLAGS = -I$i
LDFLAGS = -i
OBJ = main.o forkexit.o break.o exec.o procutils.o \
signal.o alloc.o utility.o table.o trace.o getset.o misc.o
# build local binary
all build: $(SERVER)
$(SERVER): $(OBJ)
$(CC) -o $@ $(LDFLAGS) $(OBJ) -lsys -lutils
install -S 256w $@
# install with other servers
install: /usr/sbin/servers/$(SERVER)
/usr/sbin/servers/$(SERVER): $(SERVER)
install -o root -cs $? $@
# clean up local files
clean:
rm -f $(SERVER) *.o *.bak
# dependencies
a = mm.h $h/config.h $s/types.h $h/const.h $h/type.h \
$i/ansi.h $i/fcntl.h $i/unistd.h $h/syslib.h \
$i/limits.h $i/errno.h const.h type.h proto.h glo.h
alloc.o: $a
alloc.o: $i/signal.h
alloc.o: $h/com.h
alloc.o: $h/callnr.h
alloc.o: mproc.h
alloc.o: $k/type.h
alloc.o: $k/const.h
break.o: $a
break.o: $i/signal.h
break.o: mproc.h
break.o: param.h
exec.o: $a
exec.o: $s/stat.h
exec.o: $h/callnr.h
exec.o: $h/com.h
exec.o: $i/a.out.h
exec.o: $i/signal.h
exec.o: $i/string.h
exec.o: mproc.h
exec.o: param.h
forkexit.o: $a
forkexit.o: $s/wait.h
forkexit.o: $h/callnr.h
forkexit.o: $h/com.h
forkexit.o: $h/utils.h
forkexit.o: $i/signal.h
forkexit.o: mproc.h
forkexit.o: param.h
getset.o: $a
getset.o: $h/callnr.h
getset.o: $i/signal.h
getset.o: mproc.h
getset.o: param.h
main.o: $a
main.o: $h/callnr.h
main.o: $h/com.h
main.o: $i/signal.h
main.o: $i/fcntl.h
main.o: $h/ioctl.h
main.o: $s/ioc_memory.h
main.o: $h/utils.h
main.o: mproc.h
main.o: param.h
misc.o: $a
misc.o: $h/callnr.h
misc.o: $h/utils.h
misc.o: $i/signal.h
misc.o: $h/ioctl.h
misc.o: $s/svrctl.h
misc.o: mproc.h
misc.o: param.h
procutils.o: $a
procutils.o: $i/timers.h
procutils.o: $i/string.h
procutils.o: $k/const.h
procutils.o: $k/type.h
procutils.o: $k/proc.h
signal.o: $a
signal.o: $s/stat.h
signal.o: $h/callnr.h
signal.o: $h/utils.h
signal.o: $h/com.h
signal.o: $i/signal.h
signal.o: $s/sigcontext.h
signal.o: $i/string.h
signal.o: mproc.h
signal.o: param.h
table.o: $a
table.o: $h/callnr.h
table.o: $i/signal.h
table.o: mproc.h
table.o: param.h
trace.o: $a
trace.o: $h/com.h
trace.o: $s/ptrace.h
trace.o: $i/signal.h
trace.o: mproc.h
trace.o: param.h
utility.o: $a
utility.o: $s/stat.h
utility.o: $h/callnr.h
utility.o: $h/com.h
utility.o: $i/fcntl.h
utility.o: $i/signal.h
utility.o: mproc.h

428
servers/pm/alloc.c Normal file
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@ -0,0 +1,428 @@
/* This file is concerned with allocating and freeing arbitrary-size blocks of
* physical memory on behalf of the FORK and EXEC system calls. The key data
* structure used is the hole table, which maintains a list of holes in memory.
* It is kept sorted in order of increasing memory address. The addresses
* it contains refers to physical memory, starting at absolute address 0
* (i.e., they are not relative to the start of MM). During system
* initialization, that part of memory containing the interrupt vectors,
* kernel, and MM are "allocated" to mark them as not available and to
* remove them from the hole list.
*
* The entry points into this file are:
* alloc_mem: allocate a given sized chunk of memory
* free_mem: release a previously allocated chunk of memory
* mem_init: initialize the tables when MM start up
* max_hole: returns the largest hole currently available
*/
#include "mm.h"
#include <minix/com.h>
#include <minix/callnr.h>
#include <signal.h>
#include "mproc.h"
#include "../../kernel/const.h"
#include "../../kernel/type.h"
#define NR_HOLES (2*NR_PROCS) /* max # entries in hole table */
#define NIL_HOLE (struct hole *) 0
PRIVATE struct hole {
struct hole *h_next; /* pointer to next entry on the list */
phys_clicks h_base; /* where does the hole begin? */
phys_clicks h_len; /* how big is the hole? */
} hole[NR_HOLES];
PRIVATE struct hole *hole_head; /* pointer to first hole */
PRIVATE struct hole *free_slots;/* ptr to list of unused table slots */
#if ENABLE_SWAP
PRIVATE int swap_fd = -1; /* file descriptor of open swap file/device */
PRIVATE u32_t swap_offset; /* offset to start of swap area on swap file */
PRIVATE phys_clicks swap_base; /* memory offset chosen as swap base */
PRIVATE phys_clicks swap_maxsize;/* maximum amount of swap "memory" possible */
PRIVATE struct mproc *in_queue; /* queue of processes wanting to swap in */
PRIVATE struct mproc *outswap = &mproc[LOW_USER]; /* outswap candidate? */
#else /* !SWAP */
#define swap_base ((phys_clicks) -1)
#endif /* !SWAP */
FORWARD _PROTOTYPE( void del_slot, (struct hole *prev_ptr, struct hole *hp) );
FORWARD _PROTOTYPE( void merge, (struct hole *hp) );
#if ENABLE_SWAP
FORWARD _PROTOTYPE( int swap_out, (void) );
#else
#define swap_out() (0)
#endif
/*===========================================================================*
* alloc_mem *
*===========================================================================*/
PUBLIC phys_clicks alloc_mem(clicks)
phys_clicks clicks; /* amount of memory requested */
{
/* Allocate a block of memory from the free list using first fit. The block
* consists of a sequence of contiguous bytes, whose length in clicks is
* given by 'clicks'. A pointer to the block is returned. The block is
* always on a click boundary. This procedure is called when memory is
* needed for FORK or EXEC. Swap other processes out if needed.
*/
register struct hole *hp, *prev_ptr;
phys_clicks old_base;
do {
hp = hole_head;
while (hp != NIL_HOLE && hp->h_base < swap_base) {
if (hp->h_len >= clicks) {
/* We found a hole that is big enough. Use it. */
old_base = hp->h_base; /* remember where it started */
hp->h_base += clicks; /* bite a piece off */
hp->h_len -= clicks; /* ditto */
/* Delete the hole if used up completely. */
if (hp->h_len == 0) del_slot(prev_ptr, hp);
/* Return the start address of the acquired block. */
return(old_base);
}
prev_ptr = hp;
hp = hp->h_next;
}
} while (swap_out()); /* try to swap some other process out */
return(NO_MEM);
}
/*===========================================================================*
* free_mem *
*===========================================================================*/
PUBLIC void free_mem(base, clicks)
phys_clicks base; /* base address of block to free */
phys_clicks clicks; /* number of clicks to free */
{
/* Return a block of free memory to the hole list. The parameters tell where
* the block starts in physical memory and how big it is. The block is added
* to the hole list. If it is contiguous with an existing hole on either end,
* it is merged with the hole or holes.
*/
register struct hole *hp, *new_ptr, *prev_ptr;
if (clicks == 0) return;
if ( (new_ptr = free_slots) == NIL_HOLE) panic("Hole table full", NO_NUM);
new_ptr->h_base = base;
new_ptr->h_len = clicks;
free_slots = new_ptr->h_next;
hp = hole_head;
/* If this block's address is numerically less than the lowest hole currently
* available, or if no holes are currently available, put this hole on the
* front of the hole list.
*/
if (hp == NIL_HOLE || base <= hp->h_base) {
/* Block to be freed goes on front of the hole list. */
new_ptr->h_next = hp;
hole_head = new_ptr;
merge(new_ptr);
return;
}
/* Block to be returned does not go on front of hole list. */
while (hp != NIL_HOLE && base > hp->h_base) {
prev_ptr = hp;
hp = hp->h_next;
}
/* We found where it goes. Insert block after 'prev_ptr'. */
new_ptr->h_next = prev_ptr->h_next;
prev_ptr->h_next = new_ptr;
merge(prev_ptr); /* sequence is 'prev_ptr', 'new_ptr', 'hp' */
}
/*===========================================================================*
* del_slot *
*===========================================================================*/
PRIVATE void del_slot(prev_ptr, hp)
register struct hole *prev_ptr; /* pointer to hole entry just ahead of 'hp' */
register struct hole *hp; /* pointer to hole entry to be removed */
{
/* Remove an entry from the hole list. This procedure is called when a
* request to allocate memory removes a hole in its entirety, thus reducing
* the numbers of holes in memory, and requiring the elimination of one
* entry in the hole list.
*/
if (hp == hole_head)
hole_head = hp->h_next;
else
prev_ptr->h_next = hp->h_next;
hp->h_next = free_slots;
free_slots = hp;
}
/*===========================================================================*
* merge *
*===========================================================================*/
PRIVATE void merge(hp)
register struct hole *hp; /* ptr to hole to merge with its successors */
{
/* Check for contiguous holes and merge any found. Contiguous holes can occur
* when a block of memory is freed, and it happens to abut another hole on
* either or both ends. The pointer 'hp' points to the first of a series of
* three holes that can potentially all be merged together.
*/
register struct hole *next_ptr;
/* If 'hp' points to the last hole, no merging is possible. If it does not,
* try to absorb its successor into it and free the successor's table entry.
*/
if ( (next_ptr = hp->h_next) == NIL_HOLE) return;
if (hp->h_base + hp->h_len == next_ptr->h_base) {
hp->h_len += next_ptr->h_len; /* first one gets second one's mem */
del_slot(hp, next_ptr);
} else {
hp = next_ptr;
}
/* If 'hp' now points to the last hole, return; otherwise, try to absorb its
* successor into it.
*/
if ( (next_ptr = hp->h_next) == NIL_HOLE) return;
if (hp->h_base + hp->h_len == next_ptr->h_base) {
hp->h_len += next_ptr->h_len;
del_slot(hp, next_ptr);
}
}
/*===========================================================================*
* mem_init *
*===========================================================================*/
PUBLIC void mem_init(free)
phys_clicks *free; /* memory size summaries */
{
/* Initialize hole lists. There are two lists: 'hole_head' points to a linked
* list of all the holes (unused memory) in the system; 'free_slots' points to
* a linked list of table entries that are not in use. Initially, the former
* list has one entry for each chunk of physical memory, and the second
* list links together the remaining table slots. As memory becomes more
* fragmented in the course of time (i.e., the initial big holes break up into
* smaller holes), new table slots are needed to represent them. These slots
* are taken from the list headed by 'free_slots'.
*/
struct memory mem[NR_MEMS]; /* chunks of physical memory */
int i;
register struct hole *hp;
phys_clicks base; /* base address of chunk */
phys_clicks size; /* size of chunk */
message mess;
/* Get a copy of the physical memory chunks found at the kernel. */
if ((i=sys_getmemchunks(mem)) != OK)
panic("MM couldn't get mem chunks",i);
/* Put all holes on the free list. */
for (hp = &hole[0]; hp < &hole[NR_HOLES]; hp++) hp->h_next = hp + 1;
hole[NR_HOLES-1].h_next = NIL_HOLE;
hole_head = NIL_HOLE;
free_slots = &hole[0];
/* Ask the kernel for chunks of physical memory and allocate holes. */
*free = 0;
for (i=0; i<NR_MEMS; i++) {
if (mem[i].size > 0) {
free_mem(mem[i].base, mem[i].size);
*free += mem[i].size;
#if ENABLE_SWAP
if (swap_base < mem[i].base + mem[i].size)
swap_base = mem[i].base+mem[i].size;
#endif
}
}
#if ENABLE_SWAP
/* The swap area is represented as a hole above and separate of regular
* memory. A hole at the size of the swap file is allocated on "swapon".
*/
swap_base++; /* make separate */
swap_maxsize = 0 - swap_base; /* maximum we can possibly use */
#endif
}
#if ENABLE_SWAP
/*===========================================================================*
* swap_on *
*===========================================================================*/
PUBLIC int swap_on(file, offset, size)
char *file; /* file to swap on */
u32_t offset, size; /* area on swap file to use */
{
/* Turn swapping on. */
if (swap_fd != -1) return(EBUSY); /* already have swap? */
tell_fs(CHDIR, who, FALSE, 0); /* be like the caller for open() */
if ((swap_fd = open(file, O_RDWR)) < 0) return(-errno);
swap_offset = offset;
size >>= CLICK_SHIFT;
if (size > swap_maxsize) size = swap_maxsize;
if (size > 0) free_mem(swap_base, (phys_clicks) size);
}
/*===========================================================================*
* swap_off *
*===========================================================================*/
PUBLIC int swap_off()
{
/* Turn swapping off. */
struct mproc *rmp;
struct hole *hp, *prev_ptr;
if (swap_fd == -1) return(OK); /* can't turn off what isn't on */
/* Put all swapped out processes on the inswap queue and swap in. */
for (rmp = &mproc[LOW_USER]; rmp < &mproc[NR_PROCS]; rmp++) {
if (rmp->mp_flags & ONSWAP) swap_inqueue(rmp);
}
swap_in();
/* All in memory? */
for (rmp = &mproc[LOW_USER]; rmp < &mproc[NR_PROCS]; rmp++) {
if (rmp->mp_flags & ONSWAP) return(ENOMEM);
}
/* Yes. Remove the swap hole and close the swap file descriptor. */
for (hp = hole_head; hp != NIL_HOLE; prev_ptr = hp, hp = hp->h_next) {
if (hp->h_base >= swap_base) {
del_slot(prev_ptr, hp);
hp = hole_head;
}
}
close(swap_fd);
swap_fd = -1;
return(OK);
}
/*===========================================================================*
* swap_inqueue *
*===========================================================================*/
PUBLIC void swap_inqueue(rmp)
register struct mproc *rmp; /* process to add to the queue */
{
/* Put a swapped out process on the queue of processes to be swapped in. This
* happens when such a process gets a signal, or if a reply message must be
* sent, like when a process doing a wait() has a child that exits.
*/
struct mproc **pmp;
if (rmp->mp_flags & SWAPIN) return; /* already queued */
for (pmp = &in_queue; *pmp != NULL; pmp = &(*pmp)->mp_swapq) {}
*pmp = rmp;
rmp->mp_swapq = NULL;
rmp->mp_flags |= SWAPIN;
}
/*===========================================================================*
* swap_in *
*===========================================================================*/
PUBLIC void swap_in()
{
/* Try to swap in a process on the inswap queue. We want to send it a message,
* interrupt it, or something.
*/
struct mproc **pmp, *rmp;
phys_clicks old_base, new_base, size;
off_t off;
int proc_nr;
pmp = &in_queue;
while ((rmp = *pmp) != NULL) {
proc_nr = (rmp - mproc);
size = rmp->mp_seg[S].mem_vir + rmp->mp_seg[S].mem_len
- rmp->mp_seg[D].mem_vir;
if (!(rmp->mp_flags & SWAPIN)) {
/* Guess it got killed. (Queue is cleaned here.) */
*pmp = rmp->mp_swapq;
continue;
} else
if ((new_base = alloc_mem(size)) == NO_MEM) {
/* No memory for this one, try the next. */
pmp = &rmp->mp_swapq;
} else {
/* We've found memory. Update map and swap in. */
old_base = rmp->mp_seg[D].mem_phys;
rmp->mp_seg[D].mem_phys = new_base;
rmp->mp_seg[S].mem_phys = rmp->mp_seg[D].mem_phys +
(rmp->mp_seg[S].mem_vir - rmp->mp_seg[D].mem_vir);
sys_newmap(proc_nr, rmp->mp_seg);
off = swap_offset + ((off_t) (old_base-swap_base)<<CLICK_SHIFT);
lseek(swap_fd, off, SEEK_SET);
rw_seg(0, swap_fd, proc_nr, D, (phys_bytes)size << CLICK_SHIFT);
free_mem(old_base, size);
rmp->mp_flags &= ~(ONSWAP|SWAPIN);
*pmp = rmp->mp_swapq;
check_pending(rmp); /* a signal may have waked this one */
}
}
}
/*===========================================================================*
* swap_out *
*===========================================================================*/
PRIVATE int swap_out()
{
/* Try to find a process that can be swapped out. Candidates are those blocked
* on a system call that MM handles, like wait(), pause() or sigsuspend().
*/
struct mproc *rmp;
struct hole *hp, *prev_ptr;
phys_clicks old_base, new_base, size;
off_t off;
int proc_nr;
rmp = outswap;
do {
if (++rmp == &mproc[NR_PROCS]) rmp = &mproc[LOW_USER];
/* A candidate? */
if (!(rmp->mp_flags & (PAUSED | WAITING | SIGSUSPENDED))) continue;
/* Already on swap or otherwise to be avoided? */
if (rmp->mp_flags & (TRACED | REPLY | ONSWAP)) continue;
/* Got one, find a swap hole and swap it out. */
proc_nr = (rmp - mproc);
size = rmp->mp_seg[S].mem_vir + rmp->mp_seg[S].mem_len
- rmp->mp_seg[D].mem_vir;
prev_ptr = NIL_HOLE;
for (hp = hole_head; hp != NIL_HOLE; prev_ptr = hp, hp = hp->h_next) {
if (hp->h_base >= swap_base && hp->h_len >= size) break;
}
if (hp == NIL_HOLE) continue; /* oops, not enough swapspace */
new_base = hp->h_base;
hp->h_base += size;
hp->h_len -= size;
if (hp->h_len == 0) del_slot(prev_ptr, hp);
off = swap_offset + ((off_t) (new_base - swap_base) << CLICK_SHIFT);
lseek(swap_fd, off, SEEK_SET);
rw_seg(1, swap_fd, proc_nr, D, (phys_bytes)size << CLICK_SHIFT);
old_base = rmp->mp_seg[D].mem_phys;
rmp->mp_seg[D].mem_phys = new_base;
rmp->mp_seg[S].mem_phys = rmp->mp_seg[D].mem_phys +
(rmp->mp_seg[S].mem_vir - rmp->mp_seg[D].mem_vir);
sys_newmap(proc_nr, rmp->mp_seg);
free_mem(old_base, size);
rmp->mp_flags |= ONSWAP;
outswap = rmp; /* next time start here */
return(TRUE);
} while (rmp != outswap);
return(FALSE); /* no candidate found */
}
#endif /* SWAP */

170
servers/pm/break.c Normal file
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@ -0,0 +1,170 @@
/* The MINIX model of memory allocation reserves a fixed amount of memory for
* the combined text, data, and stack segments. The amount used for a child
* process created by FORK is the same as the parent had. If the child does
* an EXEC later, the new size is taken from the header of the file EXEC'ed.
*
* The layout in memory consists of the text segment, followed by the data
* segment, followed by a gap (unused memory), followed by the stack segment.
* The data segment grows upward and the stack grows downward, so each can
* take memory from the gap. If they meet, the process must be killed. The
* procedures in this file deal with the growth of the data and stack segments.
*
* The entry points into this file are:
* do_brk: BRK/SBRK system calls to grow or shrink the data segment
* adjust: see if a proposed segment adjustment is allowed
* size_ok: see if the segment sizes are feasible
*/
#include "mm.h"
#include <signal.h>
#include "mproc.h"
#include "param.h"
#define DATA_CHANGED 1 /* flag value when data segment size changed */
#define STACK_CHANGED 2 /* flag value when stack size changed */
/*===========================================================================*
* do_brk *
*===========================================================================*/
PUBLIC int do_brk()
{
/* Perform the brk(addr) system call.
*
* The call is complicated by the fact that on some machines (e.g., 8088),
* the stack pointer can grow beyond the base of the stack segment without
* anybody noticing it.
* The parameter, 'addr' is the new virtual address in D space.
*/
register struct mproc *rmp;
int r;
vir_bytes v, new_sp;
vir_clicks new_clicks;
rmp = mp;
v = (vir_bytes) m_in.addr;
new_clicks = (vir_clicks) ( ((long) v + CLICK_SIZE - 1) >> CLICK_SHIFT);
if (new_clicks < rmp->mp_seg[D].mem_vir) {
rmp->mp_reply.reply_ptr = (char *) -1;
return(ENOMEM);
}
new_clicks -= rmp->mp_seg[D].mem_vir;
if ((r=p_getsp(who, &new_sp)) != OK) /* ask kernel for current sp value */
panic("MM couldn't get stack pointer", r);
r = adjust(rmp, new_clicks, new_sp);
rmp->mp_reply.reply_ptr = (r == OK ? m_in.addr : (char *) -1);
return(r); /* return new address or -1 */
}
/*===========================================================================*
* adjust *
*===========================================================================*/
PUBLIC int adjust(rmp, data_clicks, sp)
register struct mproc *rmp; /* whose memory is being adjusted? */
vir_clicks data_clicks; /* how big is data segment to become? */
vir_bytes sp; /* new value of sp */
{
/* See if data and stack segments can coexist, adjusting them if need be.
* Memory is never allocated or freed. Instead it is added or removed from the
* gap between data segment and stack segment. If the gap size becomes
* negative, the adjustment of data or stack fails and ENOMEM is returned.
*/
register struct mem_map *mem_sp, *mem_dp;
vir_clicks sp_click, gap_base, lower, old_clicks;
int changed, r, ft;
long base_of_stack, delta; /* longs avoid certain problems */
mem_dp = &rmp->mp_seg[D]; /* pointer to data segment map */
mem_sp = &rmp->mp_seg[S]; /* pointer to stack segment map */
changed = 0; /* set when either segment changed */
if (mem_sp->mem_len == 0) return(OK); /* don't bother init */
/* See if stack size has gone negative (i.e., sp too close to 0xFFFF...) */
base_of_stack = (long) mem_sp->mem_vir + (long) mem_sp->mem_len;
sp_click = sp >> CLICK_SHIFT; /* click containing sp */
if (sp_click >= base_of_stack) return(ENOMEM); /* sp too high */
/* Compute size of gap between stack and data segments. */
delta = (long) mem_sp->mem_vir - (long) sp_click;
lower = (delta > 0 ? sp_click : mem_sp->mem_vir);
/* Add a safety margin for future stack growth. Impossible to do right. */
#define SAFETY_BYTES (384 * sizeof(char *))
#define SAFETY_CLICKS ((SAFETY_BYTES + CLICK_SIZE - 1) / CLICK_SIZE)
gap_base = mem_dp->mem_vir + data_clicks + SAFETY_CLICKS;
if (lower < gap_base) return(ENOMEM); /* data and stack collided */
/* Update data length (but not data orgin) on behalf of brk() system call. */
old_clicks = mem_dp->mem_len;
if (data_clicks != mem_dp->mem_len) {
mem_dp->mem_len = data_clicks;
changed |= DATA_CHANGED;
}
/* Update stack length and origin due to change in stack pointer. */
if (delta > 0) {
mem_sp->mem_vir -= delta;
mem_sp->mem_phys -= delta;
mem_sp->mem_len += delta;
changed |= STACK_CHANGED;
}
/* Do the new data and stack segment sizes fit in the address space? */
ft = (rmp->mp_flags & SEPARATE);
r = size_ok(ft, rmp->mp_seg[T].mem_len, rmp->mp_seg[D].mem_len,
rmp->mp_seg[S].mem_len, rmp->mp_seg[D].mem_vir, rmp->mp_seg[S].mem_vir);
if (r == OK) {
if (changed) sys_newmap((int)(rmp - mproc), rmp->mp_seg);
return(OK);
}
/* New sizes don't fit or require too many page/segment registers. Restore.*/
if (changed & DATA_CHANGED) mem_dp->mem_len = old_clicks;
if (changed & STACK_CHANGED) {
mem_sp->mem_vir += delta;
mem_sp->mem_phys += delta;
mem_sp->mem_len -= delta;
}
return(ENOMEM);
}
/*===========================================================================*
* size_ok *
*===========================================================================*/
PUBLIC int size_ok(file_type, tc, dc, sc, dvir, s_vir)
int file_type; /* SEPARATE or 0 */
vir_clicks tc; /* text size in clicks */
vir_clicks dc; /* data size in clicks */
vir_clicks sc; /* stack size in clicks */
vir_clicks dvir; /* virtual address for start of data seg */
vir_clicks s_vir; /* virtual address for start of stack seg */
{
/* Check to see if the sizes are feasible and enough segmentation registers
* exist. On a machine with eight 8K pages, text, data, stack sizes of
* (32K, 16K, 16K) will fit, but (33K, 17K, 13K) will not, even though the
* former is bigger (64K) than the latter (63K). Even on the 8088 this test
* is needed, since the data and stack may not exceed 4096 clicks.
*/
#if (CHIP == INTEL && _WORD_SIZE == 2)
int pt, pd, ps; /* segment sizes in pages */
pt = ( (tc << CLICK_SHIFT) + PAGE_SIZE - 1)/PAGE_SIZE;
pd = ( (dc << CLICK_SHIFT) + PAGE_SIZE - 1)/PAGE_SIZE;
ps = ( (sc << CLICK_SHIFT) + PAGE_SIZE - 1)/PAGE_SIZE;
if (file_type == SEPARATE) {
if (pt > MAX_PAGES || pd + ps > MAX_PAGES) return(ENOMEM);
} else {
if (pt + pd + ps > MAX_PAGES) return(ENOMEM);
}
#endif
if (dvir + dc > s_vir) return(ENOMEM);
return(OK);
}

14
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/* Constants used by the Memory Manager. */
#define NO_MEM ((phys_clicks) 0) /* returned by alloc_mem() with mem is up */
#if (CHIP == INTEL && _WORD_SIZE == 2)
/* These definitions are used in size_ok and are not needed for 386.
* The 386 segment granularity is 1 for segments smaller than 1M and 4096
* above that.
*/
#define PAGE_SIZE 16 /* how many bytes in a page (s.b.HCLICK_SIZE)*/
#define MAX_PAGES 4096 /* how many pages in the virtual addr space */
#endif
#define INIT_PID 1 /* init's process id number */

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/* This file handles the EXEC system call. It performs the work as follows:
* - see if the permissions allow the file to be executed
* - read the header and extract the sizes
* - fetch the initial args and environment from the user space
* - allocate the memory for the new process
* - copy the initial stack from MM to the process
* - read in the text and data segments and copy to the process
* - take care of setuid and setgid bits
* - fix up 'mproc' table
* - tell kernel about EXEC
* - save offset to initial argc (for ps)
*
* The entry points into this file are:
* do_exec: perform the EXEC system call
* rw_seg: read or write a segment from or to a file
* find_share: find a process whose text segment can be shared
*/
#include "mm.h"
#include <sys/stat.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <a.out.h>
#include <signal.h>
#include <string.h>
#include "mproc.h"
#include "param.h"
FORWARD _PROTOTYPE( int new_mem, (struct mproc *sh_mp, vir_bytes text_bytes,
vir_bytes data_bytes, vir_bytes bss_bytes,
vir_bytes stk_bytes, phys_bytes tot_bytes) );
FORWARD _PROTOTYPE( void patch_ptr, (char stack[ARG_MAX], vir_bytes base) );
FORWARD _PROTOTYPE( int insert_arg, (char stack[ARG_MAX],
vir_bytes *stk_bytes, char *arg, int replace) );
FORWARD _PROTOTYPE( char *patch_stack, (int fd, char stack[ARG_MAX],
vir_bytes *stk_bytes, char *script) );
FORWARD _PROTOTYPE( int read_header, (int fd, int *ft, vir_bytes *text_bytes,
vir_bytes *data_bytes, vir_bytes *bss_bytes,
phys_bytes *tot_bytes, long *sym_bytes, vir_clicks sc,
vir_bytes *pc) );
#define ESCRIPT (-2000) /* Returned by read_header for a #! script. */
#define PTRSIZE sizeof(char *) /* Size of pointers in argv[] and envp[]. */
/*===========================================================================*
* do_exec *
*===========================================================================*/
PUBLIC int do_exec()
{
/* Perform the execve(name, argv, envp) call. The user library builds a
* complete stack image, including pointers, args, environ, etc. The stack
* is copied to a buffer inside MM, and then to the new core image.
*/
register struct mproc *rmp;
struct mproc *sh_mp;
int m, r, fd, ft, sn;
static char mbuf[ARG_MAX]; /* buffer for stack and zeroes */
static char name_buf[PATH_MAX]; /* the name of the file to exec */
char *new_sp, *name, *basename;
vir_bytes src, dst, text_bytes, data_bytes, bss_bytes, stk_bytes, vsp;
phys_bytes tot_bytes; /* total space for program, including gap */
long sym_bytes;
vir_clicks sc;
struct stat s_buf[2], *s_p;
vir_bytes pc;
/* Do some validity checks. */
rmp = mp;
stk_bytes = (vir_bytes) m_in.stack_bytes;
if (stk_bytes > ARG_MAX) return(ENOMEM); /* stack too big */
if (m_in.exec_len <= 0 || m_in.exec_len > PATH_MAX) return(EINVAL);
/* Get the exec file name and see if the file is executable. */
src = (vir_bytes) m_in.exec_name;
dst = (vir_bytes) name_buf;
r = sys_datacopy(who, (vir_bytes) src,
PM_PROC_NR, (vir_bytes) dst, (phys_bytes) m_in.exec_len);
if (r != OK) return(r); /* file name not in user data segment */
/* Fetch the stack from the user before destroying the old core image. */
src = (vir_bytes) m_in.stack_ptr;
dst = (vir_bytes) mbuf;
r = sys_datacopy(who, (vir_bytes) src,
PM_PROC_NR, (vir_bytes) dst, (phys_bytes)stk_bytes);
if (r != OK) return(EACCES); /* can't fetch stack (e.g. bad virtual addr) */
r = 0; /* r = 0 (first attempt), or 1 (interpreted script) */
name = name_buf; /* name of file to exec. */
do {
s_p = &s_buf[r];
tell_fs(CHDIR, who, FALSE, 0); /* switch to the user's FS environ */
fd = allowed(name, s_p, X_BIT); /* is file executable? */
if (fd < 0) return(fd); /* file was not executable */
/* Read the file header and extract the segment sizes. */
sc = (stk_bytes + CLICK_SIZE - 1) >> CLICK_SHIFT;
m = read_header(fd, &ft, &text_bytes, &data_bytes, &bss_bytes,
&tot_bytes, &sym_bytes, sc, &pc);
if (m != ESCRIPT || ++r > 1) break;
} while ((name = patch_stack(fd, mbuf, &stk_bytes, name_buf)) != NULL);
if (m < 0) {
close(fd); /* something wrong with header */
return(stk_bytes > ARG_MAX ? ENOMEM : ENOEXEC);
}
/* Can the process' text be shared with that of one already running? */
sh_mp = find_share(rmp, s_p->st_ino, s_p->st_dev, s_p->st_ctime);
/* Allocate new memory and release old memory. Fix map and tell kernel. */
r = new_mem(sh_mp, text_bytes, data_bytes, bss_bytes, stk_bytes, tot_bytes);
if (r != OK) {
close(fd); /* insufficient core or program too big */
return(r);
}
/* Save file identification to allow it to be shared. */
rmp->mp_ino = s_p->st_ino;
rmp->mp_dev = s_p->st_dev;
rmp->mp_ctime = s_p->st_ctime;
/* Patch up stack and copy it from MM to new core image. */
vsp = (vir_bytes) rmp->mp_seg[S].mem_vir << CLICK_SHIFT;
vsp += (vir_bytes) rmp->mp_seg[S].mem_len << CLICK_SHIFT;
vsp -= stk_bytes;
patch_ptr(mbuf, vsp);
src = (vir_bytes) mbuf;
r = sys_datacopy(PM_PROC_NR, (vir_bytes) src,
who, (vir_bytes) vsp, (phys_bytes)stk_bytes);
if (r != OK) panic("do_exec stack copy err on", who);
/* Read in text and data segments. */
if (sh_mp != NULL) {
lseek(fd, (off_t) text_bytes, SEEK_CUR); /* shared: skip text */
} else {
rw_seg(0, fd, who, T, text_bytes);
}
rw_seg(0, fd, who, D, data_bytes);
close(fd); /* don't need exec file any more */
/* Take care of setuid/setgid bits. */
if ((rmp->mp_flags & TRACED) == 0) { /* suppress if tracing */
if (s_buf[0].st_mode & I_SET_UID_BIT) {
rmp->mp_effuid = s_buf[0].st_uid;
tell_fs(SETUID,who, (int)rmp->mp_realuid, (int)rmp->mp_effuid);
}
if (s_buf[0].st_mode & I_SET_GID_BIT) {
rmp->mp_effgid = s_buf[0].st_gid;
tell_fs(SETGID,who, (int)rmp->mp_realgid, (int)rmp->mp_effgid);
}
}
/* Save offset to initial argc (for ps) */
rmp->mp_procargs = vsp;
/* Fix 'mproc' fields, tell kernel that exec is done, reset caught sigs. */
for (sn = 1; sn <= _NSIG; sn++) {
if (sigismember(&rmp->mp_catch, sn)) {
sigdelset(&rmp->mp_catch, sn);
rmp->mp_sigact[sn].sa_handler = SIG_DFL;
sigemptyset(&rmp->mp_sigact[sn].sa_mask);
}
}
rmp->mp_flags &= ~SEPARATE; /* turn off SEPARATE bit */
rmp->mp_flags |= ft; /* turn it on for separate I & D files */
new_sp = (char *) vsp;
tell_fs(EXEC, who, 0, 0); /* allow FS to handle FD_CLOEXEC files */
/* System will save command line for debugging, ps(1) output, etc. */
basename = strrchr(name, '/');
if (basename == NULL) basename = name; else basename++;
strncpy(rmp->mp_name, basename, PROC_NAME_LEN-1);
rmp->mp_name[PROC_NAME_LEN] = '\0';
sys_exec(who, new_sp, rmp->mp_flags & TRACED, basename, pc);
return(SUSPEND); /* no reply, new program just runs */
}
/*===========================================================================*
* read_header *
*===========================================================================*/
PRIVATE int read_header(fd, ft, text_bytes, data_bytes, bss_bytes,
tot_bytes, sym_bytes, sc, pc)
int fd; /* file descriptor for reading exec file */
int *ft; /* place to return ft number */
vir_bytes *text_bytes; /* place to return text size */
vir_bytes *data_bytes; /* place to return initialized data size */
vir_bytes *bss_bytes; /* place to return bss size */
phys_bytes *tot_bytes; /* place to return total size */
long *sym_bytes; /* place to return symbol table size */
vir_clicks sc; /* stack size in clicks */
vir_bytes *pc; /* program entry point (initial PC) */
{
/* Read the header and extract the text, data, bss and total sizes from it. */
int m, ct;
vir_clicks tc, dc, s_vir, dvir;
phys_clicks totc;
struct exec hdr; /* a.out header is read in here */
/* Read the header and check the magic number. The standard MINIX header
* is defined in <a.out.h>. It consists of 8 chars followed by 6 longs.
* Then come 4 more longs that are not used here.
* Byte 0: magic number 0x01
* Byte 1: magic number 0x03
* Byte 2: normal = 0x10 (not checked, 0 is OK), separate I/D = 0x20
* Byte 3: CPU type, Intel 16 bit = 0x04, Intel 32 bit = 0x10,
* Motorola = 0x0B, Sun SPARC = 0x17
* Byte 4: Header length = 0x20
* Bytes 5-7 are not used.
*
* Now come the 6 longs
* Bytes 8-11: size of text segments in bytes
* Bytes 12-15: size of initialized data segment in bytes
* Bytes 16-19: size of bss in bytes
* Bytes 20-23: program entry point
* Bytes 24-27: total memory allocated to program (text, data + stack)
* Bytes 28-31: size of symbol table in bytes
* The longs are represented in a machine dependent order,
* little-endian on the 8088, big-endian on the 68000.
* The header is followed directly by the text and data segments, and the
* symbol table (if any). The sizes are given in the header. Only the
* text and data segments are copied into memory by exec. The header is
* used here only. The symbol table is for the benefit of a debugger and
* is ignored here.
*/
if ((m= read(fd, &hdr, A_MINHDR)) < 2) return(ENOEXEC);
/* Interpreted script? */
if (((char *) &hdr)[0] == '#' && ((char *) &hdr)[1] == '!') return(ESCRIPT);
if (m != A_MINHDR) return(ENOEXEC);
/* Check magic number, cpu type, and flags. */
if (BADMAG(hdr)) return(ENOEXEC);
#if (CHIP == INTEL && _WORD_SIZE == 2)
if (hdr.a_cpu != A_I8086) return(ENOEXEC);
#endif
#if (CHIP == INTEL && _WORD_SIZE == 4)
if (hdr.a_cpu != A_I80386) return(ENOEXEC);
#endif
if ((hdr.a_flags & ~(A_NSYM | A_EXEC | A_SEP)) != 0) return(ENOEXEC);
*ft = ( (hdr.a_flags & A_SEP) ? SEPARATE : 0); /* separate I & D or not */
/* Get text and data sizes. */
*text_bytes = (vir_bytes) hdr.a_text; /* text size in bytes */
*data_bytes = (vir_bytes) hdr.a_data; /* data size in bytes */
*bss_bytes = (vir_bytes) hdr.a_bss; /* bss size in bytes */
*tot_bytes = hdr.a_total; /* total bytes to allocate for prog */
*sym_bytes = hdr.a_syms; /* symbol table size in bytes */
if (*tot_bytes == 0) return(ENOEXEC);
if (*ft != SEPARATE) {
/* If I & D space is not separated, it is all considered data. Text=0*/
*data_bytes += *text_bytes;
*text_bytes = 0;
}
*pc = hdr.a_entry; /* initial address to start execution */
/* Check to see if segment sizes are feasible. */
tc = ((unsigned long) *text_bytes + CLICK_SIZE - 1) >> CLICK_SHIFT;
dc = (*data_bytes + *bss_bytes + CLICK_SIZE - 1) >> CLICK_SHIFT;
totc = (*tot_bytes + CLICK_SIZE - 1) >> CLICK_SHIFT;
if (dc >= totc) return(ENOEXEC); /* stack must be at least 1 click */
dvir = (*ft == SEPARATE ? 0 : tc);
s_vir = dvir + (totc - sc);
m = size_ok(*ft, tc, dc, sc, dvir, s_vir);
ct = hdr.a_hdrlen & BYTE; /* header length */
if (ct > A_MINHDR) lseek(fd, (off_t) ct, SEEK_SET); /* skip unused hdr */
return(m);
}
/*===========================================================================*
* new_mem *
*===========================================================================*/
PRIVATE int new_mem(sh_mp, text_bytes, data_bytes,bss_bytes,stk_bytes,tot_bytes)
struct mproc *sh_mp; /* text can be shared with this process */
vir_bytes text_bytes; /* text segment size in bytes */
vir_bytes data_bytes; /* size of initialized data in bytes */
vir_bytes bss_bytes; /* size of bss in bytes */
vir_bytes stk_bytes; /* size of initial stack segment in bytes */
phys_bytes tot_bytes; /* total memory to allocate, including gap */
{
/* Allocate new memory and release the old memory. Change the map and report
* the new map to the kernel. Zero the new core image's bss, gap and stack.
*/
register struct mproc *rmp;
vir_clicks text_clicks, data_clicks, gap_clicks, stack_clicks, tot_clicks;
phys_clicks new_base;
static char zero[1024]; /* used to zero bss */
phys_bytes bytes, base, count, bss_offset;
/* No need to allocate text if it can be shared. */
if (sh_mp != NULL) text_bytes = 0;
/* Allow the old data to be swapped out to make room. (Which is really a
* waste of time, because we are going to throw it away anyway.)
*/
rmp->mp_flags |= WAITING;
/* Acquire the new memory. Each of the 4 parts: text, (data+bss), gap,
* and stack occupies an integral number of clicks, starting at click
* boundary. The data and bss parts are run together with no space.
*/
text_clicks = ((unsigned long) text_bytes + CLICK_SIZE - 1) >> CLICK_SHIFT;
data_clicks = (data_bytes + bss_bytes + CLICK_SIZE - 1) >> CLICK_SHIFT;
stack_clicks = (stk_bytes + CLICK_SIZE - 1) >> CLICK_SHIFT;
tot_clicks = (tot_bytes + CLICK_SIZE - 1) >> CLICK_SHIFT;
gap_clicks = tot_clicks - data_clicks - stack_clicks;
if ( (int) gap_clicks < 0) return(ENOMEM);
/* Try to allocate memory for the new process. */
new_base = alloc_mem(text_clicks + tot_clicks);
if (new_base == NO_MEM) return(ENOMEM);
/* We've got memory for the new core image. Release the old one. */
rmp = mp;
if (find_share(rmp, rmp->mp_ino, rmp->mp_dev, rmp->mp_ctime) == NULL) {
/* No other process shares the text segment, so free it. */
free_mem(rmp->mp_seg[T].mem_phys, rmp->mp_seg[T].mem_len);
}
/* Free the data and stack segments. */
free_mem(rmp->mp_seg[D].mem_phys,
rmp->mp_seg[S].mem_vir + rmp->mp_seg[S].mem_len - rmp->mp_seg[D].mem_vir);
/* We have now passed the point of no return. The old core image has been
* forever lost, memory for a new core image has been allocated. Set up
* and report new map.
*/
if (sh_mp != NULL) {
/* Share the text segment. */
rmp->mp_seg[T] = sh_mp->mp_seg[T];
} else {
rmp->mp_seg[T].mem_phys = new_base;
rmp->mp_seg[T].mem_vir = 0;
rmp->mp_seg[T].mem_len = text_clicks;
}
rmp->mp_seg[D].mem_phys = new_base + text_clicks;
rmp->mp_seg[D].mem_vir = 0;
rmp->mp_seg[D].mem_len = data_clicks;
rmp->mp_seg[S].mem_phys = rmp->mp_seg[D].mem_phys + data_clicks + gap_clicks;
rmp->mp_seg[S].mem_vir = rmp->mp_seg[D].mem_vir + data_clicks + gap_clicks;
rmp->mp_seg[S].mem_len = stack_clicks;
#if (CHIP == M68000)
rmp->mp_seg[T].mem_vir = 0;
rmp->mp_seg[D].mem_vir = rmp->mp_seg[T].mem_len;
rmp->mp_seg[S].mem_vir = rmp->mp_seg[D].mem_vir + rmp->mp_seg[D].mem_len + gap_clicks;
#endif
sys_newmap(who, rmp->mp_seg); /* report new map to the kernel */
/* The old memory may have been swapped out, but the new memory is real. */
rmp->mp_flags &= ~(WAITING|ONSWAP|SWAPIN);
/* Zero the bss, gap, and stack segment. */
bytes = (phys_bytes)(data_clicks + gap_clicks + stack_clicks) << CLICK_SHIFT;
base = (phys_bytes) rmp->mp_seg[D].mem_phys << CLICK_SHIFT;
bss_offset = (data_bytes >> CLICK_SHIFT) << CLICK_SHIFT;
base += bss_offset;
bytes -= bss_offset;
while (bytes > 0) {
count = MIN(bytes, (phys_bytes) sizeof(zero));
if (sys_physcopy(PM_PROC_NR, D, (phys_bytes) zero,
NONE, PHYS_SEG, base, count) != OK) {
panic("new_mem can't zero", NO_NUM);
}
base += count;
bytes -= count;
}
return(OK);
}
/*===========================================================================*
* patch_ptr *
*===========================================================================*/
PRIVATE void patch_ptr(stack, base)
char stack[ARG_MAX]; /* pointer to stack image within MM */
vir_bytes base; /* virtual address of stack base inside user */
{
/* When doing an exec(name, argv, envp) call, the user builds up a stack
* image with arg and env pointers relative to the start of the stack. Now
* these pointers must be relocated, since the stack is not positioned at
* address 0 in the user's address space.
*/
char **ap, flag;
vir_bytes v;
flag = 0; /* counts number of 0-pointers seen */
ap = (char **) stack; /* points initially to 'nargs' */
ap++; /* now points to argv[0] */
while (flag < 2) {
if (ap >= (char **) &stack[ARG_MAX]) return; /* too bad */
if (*ap != NULL) {
v = (vir_bytes) *ap; /* v is relative pointer */
v += base; /* relocate it */
*ap = (char *) v; /* put it back */
} else {
flag++;
}
ap++;
}
}
/*===========================================================================*
* insert_arg *
*===========================================================================*/
PRIVATE int insert_arg(stack, stk_bytes, arg, replace)
char stack[ARG_MAX]; /* pointer to stack image within MM */
vir_bytes *stk_bytes; /* size of initial stack */
char *arg; /* argument to prepend/replace as new argv[0] */
int replace;
{
/* Patch the stack so that arg will become argv[0]. Be careful, the stack may
* be filled with garbage, although it normally looks like this:
* nargs argv[0] ... argv[nargs-1] NULL envp[0] ... NULL
* followed by the strings "pointed" to by the argv[i] and the envp[i]. The
* pointers are really offsets from the start of stack.
* Return true iff the operation succeeded.
*/
int offset, a0, a1, old_bytes = *stk_bytes;
/* Prepending arg adds at least one string and a zero byte. */
offset = strlen(arg) + 1;
a0 = (int) ((char **) stack)[1]; /* argv[0] */
if (a0 < 4 * PTRSIZE || a0 >= old_bytes) return(FALSE);
a1 = a0; /* a1 will point to the strings to be moved */
if (replace) {
/* Move a1 to the end of argv[0][] (argv[1] if nargs > 1). */
do {
if (a1 == old_bytes) return(FALSE);
--offset;
} while (stack[a1++] != 0);
} else {
offset += PTRSIZE; /* new argv[0] needs new pointer in argv[] */
a0 += PTRSIZE; /* location of new argv[0][]. */
}
/* stack will grow by offset bytes (or shrink by -offset bytes) */
if ((*stk_bytes += offset) > ARG_MAX) return(FALSE);
/* Reposition the strings by offset bytes */
memmove(stack + a1 + offset, stack + a1, old_bytes - a1);
strcpy(stack + a0, arg); /* Put arg in the new space. */
if (!replace) {
/* Make space for a new argv[0]. */
memmove(stack + 2 * PTRSIZE, stack + 1 * PTRSIZE, a0 - 2 * PTRSIZE);
((char **) stack)[0]++; /* nargs++; */
}
/* Now patch up argv[] and envp[] by offset. */
patch_ptr(stack, (vir_bytes) offset);
((char **) stack)[1] = (char *) a0; /* set argv[0] correctly */
return(TRUE);
}
/*===========================================================================*
* patch_stack *
*===========================================================================*/
PRIVATE char *patch_stack(fd, stack, stk_bytes, script)
int fd; /* file descriptor to open script file */
char stack[ARG_MAX]; /* pointer to stack image within MM */
vir_bytes *stk_bytes; /* size of initial stack */
char *script; /* name of script to interpret */
{
/* Patch the argument vector to include the path name of the script to be
* interpreted, and all strings on the #! line. Returns the path name of
* the interpreter.
*/
char *sp, *interp = NULL;
int n;
enum { INSERT=FALSE, REPLACE=TRUE };
/* Make script[] the new argv[0]. */
if (!insert_arg(stack, stk_bytes, script, REPLACE)) return(NULL);
if (lseek(fd, 2L, 0) == -1 /* just behind the #! */
|| (n= read(fd, script, PATH_MAX)) < 0 /* read line one */
|| (sp= memchr(script, '\n', n)) == NULL) /* must be a proper line */
return(NULL);
/* Move sp backwards through script[], prepending each string to stack. */
for (;;) {
/* skip spaces behind argument. */
while (sp > script && (*--sp == ' ' || *sp == '\t')) {}
if (sp == script) break;
sp[1] = 0;
/* Move to the start of the argument. */
while (sp > script && sp[-1] != ' ' && sp[-1] != '\t') --sp;
interp = sp;
if (!insert_arg(stack, stk_bytes, sp, INSERT)) return(NULL);
}
/* Round *stk_bytes up to the size of a pointer for alignment contraints. */
*stk_bytes= ((*stk_bytes + PTRSIZE - 1) / PTRSIZE) * PTRSIZE;
close(fd);
return(interp);
}
/*===========================================================================*
* rw_seg *
*===========================================================================*/
PUBLIC void rw_seg(rw, fd, proc, seg, seg_bytes0)
int rw; /* 0 = read, 1 = write */
int fd; /* file descriptor to read from / write to */
int proc; /* process number */
int seg; /* T, D, or S */
phys_bytes seg_bytes0; /* how much is to be transferred? */
{
/* Transfer text or data from/to a file and copy to/from a process segment.
* This procedure is a little bit tricky. The logical way to transfer a
* segment would be block by block and copying each block to/from the user
* space one at a time. This is too slow, so we do something dirty here,
* namely send the user space and virtual address to the file system in the
* upper 10 bits of the file descriptor, and pass it the user virtual address
* instead of a MM address. The file system extracts these parameters when
* gets a read or write call from the memory manager, which is the only process
* that is permitted to use this trick. The file system then copies the whole
* segment directly to/from user space, bypassing MM completely.
*
* The byte count on read is usually smaller than the segment count, because
* a segment is padded out to a click multiple, and the data segment is only
* partially initialized.
*/
int new_fd, bytes, r;
char *ubuf_ptr;
struct mem_map *sp = &mproc[proc].mp_seg[seg];
phys_bytes seg_bytes = seg_bytes0;
new_fd = (proc << 7) | (seg << 5) | fd;
ubuf_ptr = (char *) ((vir_bytes) sp->mem_vir << CLICK_SHIFT);
while (seg_bytes != 0) {
#define MM_CHUNK_SIZE 8192
bytes = MIN((INT_MAX / MM_CHUNK_SIZE) * MM_CHUNK_SIZE, seg_bytes);
if (rw == 0) {
r = read(new_fd, ubuf_ptr, bytes);
} else {
r = write(new_fd, ubuf_ptr, bytes);
}
if (r != bytes) break;
ubuf_ptr += bytes;
seg_bytes -= bytes;
}
}
/*===========================================================================*
* find_share *
*===========================================================================*/
PUBLIC struct mproc *find_share(mp_ign, ino, dev, ctime)
struct mproc *mp_ign; /* process that should not be looked at */
ino_t ino; /* parameters that uniquely identify a file */
dev_t dev;
time_t ctime;
{
/* Look for a process that is the file <ino, dev, ctime> in execution. Don't
* accidentally "find" mp_ign, because it is the process on whose behalf this
* call is made.
*/
struct mproc *sh_mp;
for (sh_mp = &mproc[INIT_PROC_NR]; sh_mp < &mproc[NR_PROCS]; sh_mp++) {
if (!(sh_mp->mp_flags & SEPARATE)) continue;
if (sh_mp == mp_ign) continue;
if (sh_mp->mp_ino != ino) continue;
if (sh_mp->mp_dev != dev) continue;
if (sh_mp->mp_ctime != ctime) continue;
return sh_mp;
}
return(NULL);
}

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/* This file deals with creating processes (via FORK) and deleting them (via
* EXIT/WAIT). When a process forks, a new slot in the 'mproc' table is
* allocated for it, and a copy of the parent's core image is made for the
* child. Then the kernel and file system are informed. A process is removed
* from the 'mproc' table when two events have occurred: (1) it has exited or
* been killed by a signal, and (2) the parent has done a WAIT. If the process
* exits first, it continues to occupy a slot until the parent does a WAIT.
*
* The entry points into this file are:
* do_fork: perform the FORK system call
* do_mm_exit: perform the EXIT system call (by calling mm_exit())
* mm_exit: actually do the exiting
* do_wait: perform the WAITPID or WAIT system call
*/
#include "mm.h"
#include <sys/wait.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/utils.h>
#include <signal.h>
#include "mproc.h"
#include "param.h"
#define LAST_FEW 2 /* last few slots reserved for superuser */
PRIVATE pid_t next_pid = INIT_PID+1; /* next pid to be assigned */
FORWARD _PROTOTYPE (void cleanup, (register struct mproc *child) );
/*===========================================================================*
* do_fork *
*===========================================================================*/
PUBLIC int do_fork()
{
/* The process pointed to by 'mp' has forked. Create a child process. */
register struct mproc *rmp; /* pointer to parent */
register struct mproc *rmc; /* pointer to child */
int i, child_nr, t;
phys_clicks prog_clicks, child_base;
phys_bytes prog_bytes, parent_abs, child_abs; /* Intel only */
/* If tables might fill up during FORK, don't even start since recovery half
* way through is such a nuisance.
*/
rmp = mp;
if ((procs_in_use == NR_PROCS) ||
(procs_in_use >= NR_PROCS-LAST_FEW && rmp->mp_effuid != 0))
{
printf("MM: proc table full!\n");
return(EAGAIN);
}
/* Determine how much memory to allocate. Only the data and stack need to
* be copied, because the text segment is either shared or of zero length.
*/
prog_clicks = (phys_clicks) rmp->mp_seg[S].mem_len;
prog_clicks += (rmp->mp_seg[S].mem_vir - rmp->mp_seg[D].mem_vir);
prog_bytes = (phys_bytes) prog_clicks << CLICK_SHIFT;
if ( (child_base = alloc_mem(prog_clicks)) == NO_MEM) return(ENOMEM);
/* Create a copy of the parent's core image for the child. */
child_abs = (phys_bytes) child_base << CLICK_SHIFT;
parent_abs = (phys_bytes) rmp->mp_seg[D].mem_phys << CLICK_SHIFT;
i = sys_abscopy(parent_abs, child_abs, prog_bytes);
if (i < 0) panic("do_fork can't copy", i);
/* Find a slot in 'mproc' for the child process. A slot must exist. */
for (rmc = &mproc[0]; rmc < &mproc[NR_PROCS]; rmc++)
if ( (rmc->mp_flags & IN_USE) == 0) break;
/* Set up the child and its memory map; copy its 'mproc' slot from parent. */
child_nr = (int)(rmc - mproc); /* slot number of the child */
procs_in_use++;
*rmc = *rmp; /* copy parent's process slot to child's */
rmc->mp_parent = who; /* record child's parent */
rmc->mp_flags &= (IN_USE|SEPARATE); /* inherit only these flags */
/* A separate I&D child keeps the parents text segment. The data and stack
* segments must refer to the new copy.
*/
if (!(rmc->mp_flags & SEPARATE)) rmc->mp_seg[T].mem_phys = child_base;
rmc->mp_seg[D].mem_phys = child_base;
rmc->mp_seg[S].mem_phys = rmc->mp_seg[D].mem_phys +
(rmp->mp_seg[S].mem_vir - rmp->mp_seg[D].mem_vir);
rmc->mp_exitstatus = 0;
rmc->mp_sigstatus = 0;
/* Find a free pid for the child and put it in the table. */
do {
t = 0; /* 't' = 0 means pid still free */
next_pid = (next_pid < 30000 ? next_pid + 1 : INIT_PID + 1);
for (rmp = &mproc[0]; rmp < &mproc[NR_PROCS]; rmp++)
if (rmp->mp_pid == next_pid || rmp->mp_procgrp == next_pid) {
t = 1;
break;
}
rmc->mp_pid = next_pid; /* assign pid to child */
} while (t);
/* Tell kernel and file system about the (now successful) FORK. */
sys_fork(who, child_nr, rmc->mp_pid);
tell_fs(FORK, who, child_nr, rmc->mp_pid);
/* Report child's memory map to kernel. */
sys_newmap(child_nr, rmc->mp_seg);
/* Reply to child to wake it up. */
setreply(child_nr, 0);
return(next_pid); /* child's pid */
}
/*===========================================================================*
* do_mm_exit *
*===========================================================================*/
PUBLIC int do_mm_exit()
{
/* Perform the exit(status) system call. The real work is done by mm_exit(),
* which is also called when a process is killed by a signal.
*/
mm_exit(mp, m_in.status);
return(SUSPEND); /* can't communicate from beyond the grave */
}
/*===========================================================================*
* mm_exit *
*===========================================================================*/
PUBLIC void mm_exit(rmp, exit_status)
register struct mproc *rmp; /* pointer to the process to be terminated */
int exit_status; /* the process' exit status (for parent) */
{
/* A process is done. Release most of the process' possessions. If its
* parent is waiting, release the rest, else keep the process slot and
* become a zombie.
*/
register int proc_nr;
int parent_waiting, right_child;
pid_t pidarg, procgrp;
struct mproc *p_mp;
proc_nr = (int) (rmp - mproc); /* get process slot number */
/* Remember a session leader's process group. */
procgrp = (rmp->mp_pid == mp->mp_procgrp) ? mp->mp_procgrp : 0;
/* If the exited process has a timer pending, kill it. */
if (rmp->mp_flags & ALARM_ON) set_alarm(proc_nr, (unsigned) 0);
/* Tell the kernel and FS that the process is no longer runnable. */
tell_fs(EXIT, proc_nr, 0, 0); /* file system can free the proc slot */
sys_xit(rmp->mp_parent, proc_nr);
/* Release the memory occupied by the child. */
if (find_share(rmp, rmp->mp_ino, rmp->mp_dev, rmp->mp_ctime) == NULL) {
/* No other process shares the text segment, so free it. */
free_mem(rmp->mp_seg[T].mem_phys, rmp->mp_seg[T].mem_len);
}
/* Free the data and stack segments. */
free_mem(rmp->mp_seg[D].mem_phys,
rmp->mp_seg[S].mem_vir + rmp->mp_seg[S].mem_len - rmp->mp_seg[D].mem_vir);
/* The process slot can only be freed if the parent has done a WAIT. */
rmp->mp_exitstatus = (char) exit_status;
p_mp = &mproc[rmp->mp_parent]; /* process' parent */
pidarg = p_mp->mp_wpid; /* who's being waited for? */
parent_waiting = p_mp->mp_flags & WAITING;
right_child = /* child meets one of the 3 tests? */
(pidarg == -1 || pidarg == rmp->mp_pid || -pidarg == rmp->mp_procgrp);
if (parent_waiting && right_child) {
cleanup(rmp); /* tell parent and release child slot */
} else {
rmp->mp_flags = IN_USE|ZOMBIE; /* parent not waiting, zombify child */
sig_proc(p_mp, SIGCHLD); /* send parent a "child died" signal */
}
/* If the process has children, disinherit them. INIT is the new parent. */
for (rmp = &mproc[0]; rmp < &mproc[NR_PROCS]; rmp++) {
if (rmp->mp_flags & IN_USE && rmp->mp_parent == proc_nr) {
/* 'rmp' now points to a child to be disinherited. */
rmp->mp_parent = INIT_PROC_NR;
parent_waiting = mproc[INIT_PROC_NR].mp_flags & WAITING;
if (parent_waiting && (rmp->mp_flags & ZOMBIE)) cleanup(rmp);
}
}
/* Send a hangup to the process' process group if it was a session leader. */
if (procgrp != 0) check_sig(-procgrp, SIGHUP);
}
/*===========================================================================*
* do_waitpid *
*===========================================================================*/
PUBLIC int do_waitpid()
{
/* A process wants to wait for a child to terminate. If one is already waiting,
* go clean it up and let this WAIT call terminate. Otherwise, really wait.
* Both WAIT and WAITPID are handled by this code.
*/
register struct mproc *rp;
int pidarg, options, children;
/* A process calling WAIT never gets a reply in the usual way at the end
* of the main loop (unless WNOHANG is set or no qualifying child exists).
* If a child has already exited, the routine cleanup() sends the reply
* to awaken the caller.
*/
/* Set internal variables, depending on whether this is WAIT or WAITPID. */
pidarg = (call_nr == WAIT ? -1 : m_in.pid); /* 1st param of waitpid */
options = (call_nr == WAIT ? 0 : m_in.sig_nr); /* 3rd param of waitpid */
if (pidarg == 0) pidarg = -mp->mp_procgrp; /* pidarg < 0 ==> proc grp */
/* Is there a child waiting to be collected? At this point, pidarg != 0:
* pidarg > 0 means pidarg is pid of a specific process to wait for
* pidarg == -1 means wait for any child
* pidarg < -1 means wait for any child whose process group = -pidarg
*/
children = 0;
for (rp = &mproc[0]; rp < &mproc[NR_PROCS]; rp++) {
if ( (rp->mp_flags & IN_USE) && rp->mp_parent == who) {
/* The value of pidarg determines which children qualify. */
if (pidarg > 0 && pidarg != rp->mp_pid) continue;
if (pidarg < -1 && -pidarg != rp->mp_procgrp) continue;
children++; /* this child is acceptable */
if (rp->mp_flags & ZOMBIE) {
/* This child meets the pid test and has exited. */
cleanup(rp); /* this child has already exited */
return(SUSPEND);
}
if ((rp->mp_flags & STOPPED) && rp->mp_sigstatus) {
/* This child meets the pid test and is being traced.*/
mp->mp_reply.reply_res2 = 0177|(rp->mp_sigstatus << 8);
rp->mp_sigstatus = 0;
return(rp->mp_pid);
}
}
}
/* No qualifying child has exited. Wait for one, unless none exists. */
if (children > 0) {
/* At least 1 child meets the pid test exists, but has not exited. */
if (options & WNOHANG) return(0); /* parent does not want to wait */
mp->mp_flags |= WAITING; /* parent wants to wait */
mp->mp_wpid = (pid_t) pidarg; /* save pid for later */
return(SUSPEND); /* do not reply, let it wait */
} else {
/* No child even meets the pid test. Return error immediately. */
return(ECHILD); /* no - parent has no children */
}
}
/*===========================================================================*
* cleanup *
*===========================================================================*/
PRIVATE void cleanup(child)
register struct mproc *child; /* tells which process is exiting */
{
/* Finish off the exit of a process. The process has exited or been killed
* by a signal, and its parent is waiting.
*/
struct mproc *parent = &mproc[child->mp_parent];
int exitstatus;
/* Wake up the parent. */
exitstatus = (child->mp_exitstatus << 8) | (child->mp_sigstatus & 0377);
parent->mp_reply.reply_res2 = exitstatus;
setreply(child->mp_parent, child->mp_pid);
parent->mp_flags &= ~WAITING; /* parent no longer waiting */
/* Release the process table entry. */
child->mp_flags = 0;
procs_in_use--;
}

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/* This file handles the 4 system calls that get and set uids and gids.
* It also handles getpid(), setsid(), and getpgrp(). The code for each
* one is so tiny that it hardly seemed worthwhile to make each a separate
* function.
*/
#include "mm.h"
#include <minix/callnr.h>
#include <signal.h>
#include "mproc.h"
#include "param.h"
/*===========================================================================*
* do_getset *
*===========================================================================*/
PUBLIC int do_getset()
{
/* Handle GETUID, GETGID, GETPID, GETPGRP, SETUID, SETGID, SETSID. The four
* GETs and SETSID return their primary results in 'r'. GETUID, GETGID, and
* GETPID also return secondary results (the effective IDs, or the parent
* process ID) in 'reply_res2', which is returned to the user.
*/
register struct mproc *rmp = mp;
register int r;
switch(call_nr) {
case GETUID:
r = rmp->mp_realuid;
rmp->mp_reply.reply_res2 = rmp->mp_effuid;
break;
case GETGID:
r = rmp->mp_realgid;
rmp->mp_reply.reply_res2 = rmp->mp_effgid;
break;
case GETPID:
r = mproc[who].mp_pid;
rmp->mp_reply.reply_res2 = mproc[rmp->mp_parent].mp_pid;
break;
case SETUID:
if (rmp->mp_realuid != (uid_t) m_in.usr_id &&
rmp->mp_effuid != SUPER_USER)
return(EPERM);
rmp->mp_realuid = (uid_t) m_in.usr_id;
rmp->mp_effuid = (uid_t) m_in.usr_id;
tell_fs(SETUID, who, rmp->mp_realuid, rmp->mp_effuid);
r = OK;
break;
case SETGID:
if (rmp->mp_realgid != (gid_t) m_in.grp_id &&
rmp->mp_effuid != SUPER_USER)
return(EPERM);
rmp->mp_realgid = (gid_t) m_in.grp_id;
rmp->mp_effgid = (gid_t) m_in.grp_id;
tell_fs(SETGID, who, rmp->mp_realgid, rmp->mp_effgid);
r = OK;
break;
case SETSID:
if (rmp->mp_procgrp == rmp->mp_pid) return(EPERM);
rmp->mp_procgrp = rmp->mp_pid;
tell_fs(SETSID, who, 0, 0);
/*FALL THROUGH*/
case GETPGRP:
r = rmp->mp_procgrp;
break;
default:
r = EINVAL;
break;
}
return(r);
}

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/* EXTERN should be extern except in table.c */
#ifdef _TABLE
#undef EXTERN
#define EXTERN
#endif
/* Global variables. */
EXTERN struct mproc *mp; /* ptr to 'mproc' slot of current process */
EXTERN int procs_in_use; /* how many processes are marked as IN_USE */
/* The parameters of the call are kept here. */
EXTERN message m_in; /* the incoming message itself is kept here. */
EXTERN int who; /* caller's proc number */
EXTERN int call_nr; /* system call number */
extern _PROTOTYPE (int (*call_vec[]), (void) ); /* system call handlers */
extern char core_name[]; /* file name where core images are produced */
EXTERN sigset_t core_sset; /* which signals cause core images */
EXTERN sigset_t ign_sset; /* which signals are by default ignored */

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/* This file contains the main program of the memory manager and some related
* procedures. When MINIX starts up, the kernel runs for a little while,
* initializing itself and its tasks, and then it runs MM and FS. Both MM
* and FS initialize themselves as far as they can. FS then makes a call to
* MM, because MM has to wait for FS to acquire a RAM disk. MM asks the
* kernel for all free memory and starts serving requests.
*
* The entry points into this file are:
* main: starts MM running
* setreply: set the reply to be sent to process making an MM system call
*/
#include "mm.h"
#include <minix/utils.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/ioc_memory.h>
#include "mproc.h"
#include "param.h"
FORWARD _PROTOTYPE( void get_work, (void) );
FORWARD _PROTOTYPE( void mm_init, (void) );
#define click_to_round_k(n) \
((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC void main()
{
/* Main routine of the memory manager. */
int result, proc_nr;
struct mproc *rmp;
mm_init(); /* initialize memory manager tables */
/* This is MM's main loop- get work and do it, forever and forever. */
while (TRUE) {
get_work(); /* wait for an MM system call */
/* Check for system notifications first. Special cases. */
if (call_nr == HARD_STOP) { /* MINIX is shutting down */
check_sig(-1, SIGKILL); /* kill all processes */
sys_exit(0);
/* never reached */
} else if (call_nr == KSIG_PENDING) { /* signals pending */
(void) ksig_pending();
result = SUSPEND; /* don't reply */
}
/* Else, if the system call number is valid, perform the call. */
else if ((unsigned) call_nr >= NCALLS) {
result = ENOSYS;
} else {
result = (*call_vec[call_nr])();
}
/* Send the results back to the user to indicate completion. */
if (result != SUSPEND) setreply(who, result);
swap_in(); /* maybe a process can be swapped in? */
/* Send out all pending reply messages, including the answer to
* the call just made above. The processes must not be swapped out.
*/
for (proc_nr=0, rmp=mproc; proc_nr < NR_PROCS; proc_nr++, rmp++) {
if ((rmp->mp_flags & (REPLY | ONSWAP)) == REPLY) {
if (send(proc_nr, &rmp->mp_reply) != OK)
panic("MM can't reply to", proc_nr);
rmp->mp_flags &= ~REPLY;
}
}
}
}
/*===========================================================================*
* get_work *
*===========================================================================*/
PRIVATE void get_work()
{
/* Wait for the next message and extract useful information from it. */
if (receive(ANY, &m_in) != OK) panic("MM receive error", NO_NUM);
who = m_in.m_source; /* who sent the message */
call_nr = m_in.m_type; /* system call number */
/* Process slot of caller. Misuse MM's own process slot if the kernel is
* calling. The can happen in case of pending kernel signals.
*/
mp = &mproc[who < 0 ? PM_PROC_NR : who];
}
/*===========================================================================*
* setreply *
*===========================================================================*/
PUBLIC void setreply(proc_nr, result)
int proc_nr; /* process to reply to */
int result; /* result of the call (usually OK or error #)*/
{
/* Fill in a reply message to be sent later to a user process. System calls
* may occasionally fill in other fields, this is only for the main return
* value, and for setting the "must send reply" flag.
*/
register struct mproc *rmp = &mproc[proc_nr];
rmp->mp_reply.reply_res = result;
rmp->mp_flags |= REPLY; /* reply pending */
if (rmp->mp_flags & ONSWAP)
swap_inqueue(rmp); /* must swap this process back in */
}
/*===========================================================================*
* mm_init *
*===========================================================================*/
PRIVATE void mm_init()
{
/* Initialize the memory manager. */
int s;
static char core_sigs[] = { SIGQUIT, SIGILL, SIGTRAP, SIGABRT,
SIGEMT, SIGFPE, SIGUSR1, SIGSEGV, SIGUSR2 };
static char ign_sigs[] = { SIGCHLD };
register int proc_nr;
register struct mproc *rmp;
register char *sig_ptr;
phys_clicks ram_clicks, total_clicks, minix_clicks, free_clicks;
message mess;
struct mem_map kernel_map[NR_LOCAL_SEGS];
int mem;
/* Build the set of signals which cause core dumps, and the set of signals
* that are by default ignored.
*/
sigemptyset(&core_sset);
for (sig_ptr = core_sigs; sig_ptr < core_sigs+sizeof(core_sigs); sig_ptr++)
sigaddset(&core_sset, *sig_ptr);
sigemptyset(&ign_sset);
for (sig_ptr = ign_sigs; sig_ptr < ign_sigs+sizeof(ign_sigs); sig_ptr++)
sigaddset(&ign_sset, *sig_ptr);
/* Get the memory map of the kernel to see how much memory it uses. */
if ((s=p_getmap(SYSTASK, kernel_map)) != OK)
panic("MM couldn't get proc entry of SYSTASK",s);
minix_clicks = (kernel_map[S].mem_phys + kernel_map[S].mem_len)
- kernel_map[T].mem_phys;
/* Initialize MM's tables. Request a copy of the system image table that
* is defined at the kernel level to see which slots to fill in.
*/
for (proc_nr = 0; proc_nr <= INIT_PROC_NR; proc_nr++) {
rmp = &mproc[proc_nr];
rmp->mp_flags |= IN_USE;
if ((s=p_getmap(proc_nr, rmp->mp_seg)) != OK)
panic("MM couldn't get proc entry",s);
if (rmp->mp_seg[T].mem_len != 0) rmp->mp_flags |= SEPARATE;
minix_clicks += (rmp->mp_seg[S].mem_phys + rmp->mp_seg[S].mem_len)
- rmp->mp_seg[T].mem_phys;
}
mproc[INIT_PROC_NR].mp_pid = INIT_PID;
sigemptyset(&mproc[INIT_PROC_NR].mp_ignore);
sigemptyset(&mproc[INIT_PROC_NR].mp_catch);
procs_in_use = LOW_USER + 1;
/* Wait for FS to send a message telling the RAM disk size then go "on-line".
*/
if (receive(FS_PROC_NR, &mess) != OK)
panic("MM can't obtain RAM disk size from FS", NO_NUM);
ram_clicks = mess.MEM_CHUNK_SIZE;
/* Initialize tables to all physical mem. */
mem_init(&free_clicks);
total_clicks = minix_clicks + ram_clicks + free_clicks;
/* Print memory information. */
printf("Memory size=%uK ", click_to_round_k(total_clicks));
printf("MINIX=%uK ", click_to_round_k(minix_clicks));
printf("RAM disk=%uK ", click_to_round_k(ram_clicks));
printf("Available=%uK\n\n", click_to_round_k(free_clicks));
/* Tell FS to continue. */
if (send(FS_PROC_NR, &mess) != OK)
panic("MM can't sync up with FS", NO_NUM);
/* Tell the memory task where my process table is for the sake of ps(1). */
if ((mem = open("/dev/ram", O_RDWR)) != -1) {
ioctl(mem, MIOCSPSINFO, (void *) mproc);
close(mem);
}
}

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/* Miscellaneous system calls. Author: Kees J. Bot
* 31 Mar 2000
* The entry points into this file are:
* do_reboot: kill all processes, then reboot system
* do_svrctl: memory manager control
* do_getsysinfo: request copy of MM data structure
*/
#include "mm.h"
#include <minix/callnr.h>
#include <signal.h>
#include <sys/svrctl.h>
#include <minix/com.h>
#include <minix/utils.h>
#include <string.h>
#include "mproc.h"
#include "param.h"
FORWARD _PROTOTYPE( char *find_key, (const char *params, const char *key));
/* MM gets a copy of all boot monitor parameters. */
PRIVATE char monitor_params[128*sizeof(char *)];
/*=====================================================================*
* do_getsysinfo *
*=====================================================================*/
PUBLIC int do_getsysinfo()
{
return(OK);
}
/*=====================================================================*
* do_reboot *
*=====================================================================*/
PUBLIC int do_reboot()
{
register struct mproc *rmp = mp;
char monitor_code[32*sizeof(char *)];
if (rmp->mp_effuid != SUPER_USER) return(EPERM);
switch (m_in.reboot_flag) {
case RBT_HALT:
case RBT_REBOOT:
case RBT_PANIC:
case RBT_RESET:
break;
case RBT_MONITOR:
if (m_in.reboot_size >= sizeof(monitor_code)) return(EINVAL);
if (sys_datacopy(who, (vir_bytes) m_in.reboot_code,
PM_PROC_NR, (vir_bytes) monitor_code,
(phys_bytes) (m_in.reboot_size+1)) != OK) return(EFAULT);
if (monitor_code[m_in.reboot_size] != 0) return(EINVAL);
break;
default:
return(EINVAL);
}
check_sig(-1, SIGKILL); /* kill all processes except init */
tell_fs(REBOOT,0,0,0); /* tell FS to prepare for shutdown */
sys_abort(m_in.reboot_flag, PM_PROC_NR, monitor_code, m_in.reboot_size);
sys_exit(0);
}
/*=====================================================================*
* do_svrctl *
*=====================================================================*/
PUBLIC int do_svrctl()
{
static int initialized = 0;
int s, req;
vir_bytes ptr;
req = m_in.svrctl_req;
ptr = (vir_bytes) m_in.svrctl_argp;
/* Initialize private copy of monitor parameters on first call. */
if (! initialized) {
if ((s=sys_getmonparams(monitor_params, sizeof(monitor_params))) != OK)
printf("MM: Warning couldn't get copy of monitor params: %d\n",s);
else
initialized = 1;
}
/* Binary compatibility check. */
if (req == SYSGETENV) {
#if DEAD_CODE
printf("SYSGETENV by %d (fix!)\n", who);
#endif
req = MMGETPARAM;
}
/* Is the request for the kernel? Forward it, except for SYSGETENV. */
if (((req >> 8) & 0xFF) == 'S') {
/* Simply forward call to the SYSTEM task. */
return(sys_svrctl(who, req, mp->mp_effuid == SUPER_USER, ptr));
}
/* Control operations local to the MM. */
switch(req) {
case MMGETPARAM: {
struct sysgetenv sysgetenv;
char search_key[64];
char *val_start;
size_t val_len;
size_t copy_len;
/* Check if boot monitor parameters are in place. */
if (! initialized) return(EAGAIN);
/* Copy sysgetenv structure to MM. */
if (sys_datacopy(who, ptr, SELF, (vir_bytes) &sysgetenv,
sizeof(sysgetenv)) != OK) return(EFAULT);
if (sysgetenv.keylen == 0) { /* copy all parameters */
val_start = monitor_params;
val_len = sizeof(monitor_params);
}
else { /* lookup value for key */
/* Try to get a copy of the requested key. */
if (sysgetenv.keylen > sizeof(search_key)) return(EINVAL);
if ((s = sys_datacopy(who, (vir_bytes) sysgetenv.key,
SELF, (vir_bytes) search_key, sysgetenv.keylen)) != OK)
return(s);
/* Make sure key is null-terminated and lookup value. */
search_key[sysgetenv.keylen-1]= '\0';
if ((val_start = find_key(monitor_params, search_key)) == NULL)
return(ESRCH);
val_len = strlen(val_start) + 1;
}
/* Value found, make the actual copy (as far as possible). */
copy_len = MAX(val_len, sysgetenv.vallen);
if ((s=sys_datacopy(SELF, (vir_bytes) val_start,
who, (vir_bytes) sysgetenv.val, copy_len)) != OK)
return(s);
/* See if it fits in the client's buffer. */
return (copy_len > sysgetenv.vallen) ? E2BIG : OK;
}
case MMSIGNON: {
/* A user process becomes a task. Simulate an exit by
* releasing a waiting parent and disinheriting children.
*/
struct mproc *rmp;
pid_t pidarg;
if (mp->mp_effuid != SUPER_USER) return(EPERM);
rmp = &mproc[mp->mp_parent];
tell_fs(EXIT, who, 0, 0);
pidarg = rmp->mp_wpid;
if ((rmp->mp_flags & WAITING) && (pidarg == -1
|| pidarg == mp->mp_pid || -pidarg == mp->mp_procgrp))
{
/* Wake up the parent. */
rmp->mp_reply.reply_res2 = 0;
setreply(mp->mp_parent, mp->mp_pid);
rmp->mp_flags &= ~WAITING;
}
/* Disinherit children. */
for (rmp = &mproc[0]; rmp < &mproc[NR_PROCS]; rmp++) {
if (rmp->mp_flags & IN_USE && rmp->mp_parent == who) {
rmp->mp_parent = INIT_PROC_NR;
}
}
/* Become like MM and FS. */
mp->mp_pid = mp->mp_procgrp = 0;
mp->mp_parent = 0;
return(OK); }
#if ENABLE_SWAP
case MMSWAPON: {
struct mmswapon swapon;
if (mp->mp_effuid != SUPER_USER) return(EPERM);
if (sys_datacopy(who, (phys_bytes) ptr,
PM_PROC_NR, (phys_bytes) &swapon,
(phys_bytes) sizeof(swapon)) != OK) return(EFAULT);
return(swap_on(swapon.file, swapon.offset, swapon.size)); }
case MMSWAPOFF: {
if (mp->mp_effuid != SUPER_USER) return(EPERM);
return(swap_off()); }
#endif /* SWAP */
default:
return(EINVAL);
}
}
/*==========================================================================*
* find_key *
*==========================================================================*/
PRIVATE char *find_key(params,name)
const char *params;
const char *name;
{
register const char *namep;
register char *envp;
for (envp = (char *) params; *envp != 0;) {
for (namep = name; *namep != 0 && *namep == *envp; namep++, envp++)
;
if (*namep == '\0' && *envp == '=')
return(envp + 1);
while (*envp++ != 0)
;
}
return(NULL);
}

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/* This is the master header for mm. It includes some other files
* and defines the principal constants.
*/
#define _POSIX_SOURCE 1 /* tell headers to include POSIX stuff */
#define _MINIX 1 /* tell headers to include MINIX stuff */
#define _SYSTEM 1 /* tell headers that this is the kernel */
/* The following are so basic, all the *.c files get them automatically. */
#include <minix/config.h> /* MUST be first */
#include <ansi.h> /* MUST be second */
#include <sys/types.h>
#include <minix/const.h>
#include <minix/type.h>
#include <fcntl.h>
#include <unistd.h>
#include <minix/syslib.h>
#include <limits.h>
#include <errno.h>
#include "const.h"
#include "type.h"
#include "proto.h"
#include "glo.h"

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/* This table has one slot per process. It contains all the memory management
* information for each process. Among other things, it defines the text, data
* and stack segments, uids and gids, and various flags. The kernel and file
* systems have tables that are also indexed by process, with the contents
* of corresponding slots referring to the same process in all three.
*/
EXTERN struct mproc {
struct mem_map mp_seg[NR_LOCAL_SEGS]; /* points to text, data, stack */
char mp_exitstatus; /* storage for status when process exits */
char mp_sigstatus; /* storage for signal # for killed procs */
pid_t mp_pid; /* process id */
pid_t mp_procgrp; /* pid of process group (used for signals) */
pid_t mp_wpid; /* pid this process is waiting for */
int mp_parent; /* index of parent process */
/* Real and effective uids and gids. */
uid_t mp_realuid; /* process' real uid */
uid_t mp_effuid; /* process' effective uid */
gid_t mp_realgid; /* process' real gid */
gid_t mp_effgid; /* process' effective gid */
/* File identification for sharing. */
ino_t mp_ino; /* inode number of file */
dev_t mp_dev; /* device number of file system */
time_t mp_ctime; /* inode changed time */
/* Signal handling information. */
sigset_t mp_ignore; /* 1 means ignore the signal, 0 means don't */
sigset_t mp_catch; /* 1 means catch the signal, 0 means don't */
sigset_t mp_sigmask; /* signals to be blocked */
sigset_t mp_sigmask2; /* saved copy of mp_sigmask */
sigset_t mp_sigpending; /* signals being blocked */
struct sigaction mp_sigact[_NSIG + 1]; /* as in sigaction(2) */
vir_bytes mp_sigreturn; /* address of C library __sigreturn function */
/* Backwards compatibility for signals. */
sighandler_t mp_func; /* all sigs vectored to a single user fcn */
unsigned mp_flags; /* flag bits */
vir_bytes mp_procargs; /* ptr to proc's initial stack arguments */
struct mproc *mp_swapq; /* queue of procs waiting to be swapped in */
message mp_reply; /* reply message to be sent to one */
char mp_name[PROC_NAME_LEN]; /* process name */
} mproc[NR_PROCS];
/* Flag values */
#define IN_USE 0x001 /* set when 'mproc' slot in use */
#define WAITING 0x002 /* set by WAIT system call */
#define ZOMBIE 0x004 /* set by EXIT, cleared by WAIT */
#define PAUSED 0x008 /* set by PAUSE system call */
#define ALARM_ON 0x010 /* set when SIGALRM timer started */
#define SEPARATE 0x020 /* set if file is separate I & D space */
#define TRACED 0x040 /* set if process is to be traced */
#define STOPPED 0x080 /* set if process stopped for tracing */
#define SIGSUSPENDED 0x100 /* set by SIGSUSPEND system call */
#define REPLY 0x200 /* set if a reply message is pending */
#define ONSWAP 0x400 /* set if data segment is swapped out */
#define SWAPIN 0x800 /* set if on the "swap this in" queue */
#define NIL_MPROC ((struct mproc *) 0)

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/* The following names are synonyms for the variables in the input message. */
#define addr m1_p1
#define exec_name m1_p1
#define exec_len m1_i1
#define func m6_f1
#define grp_id m1_i1
#define namelen m1_i1
#define pid m1_i1
#define seconds m1_i1
#define sig m6_i1
#define stack_bytes m1_i2
#define stack_ptr m1_p2
#define status m1_i1
#define usr_id m1_i1
#define request m2_i2
#define taddr m2_l1
#define data m2_l2
#define sig_nr m1_i2
#define sig_nsa m1_p1
#define sig_osa m1_p2
#define sig_ret m1_p3
#define sig_set m2_l1
#define sig_how m2_i1
#define sig_flags m2_i2
#define sig_context m2_p1
#ifdef _SIGMESSAGE
#define sig_msg m1_i1
#endif
#define reboot_flag m1_i1
#define reboot_code m1_p1
#define reboot_size m1_i2
#define svrctl_req m2_i1
#define svrctl_argp m2_p1
/* The following names are synonyms for the variables in a reply message. */
#define reply_res m_type
#define reply_res2 m2_i1
#define reply_ptr m2_p1
#define reply_mask m2_l1
#define reply_trace m2_l2
/* The following names are used to inform the FS about certain events. */
#define tell_fs_arg1 m1_i1
#define tell_fs_arg2 m1_i2
#define tell_fs_arg3 m1_i3

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#include "mm.h"
#include <minix/config.h>
#include <timers.h>
#include <string.h>
#include "../../kernel/const.h"
#include "../../kernel/type.h"
#include "../../kernel/proc.h"
/* The entry points into this file are:
* p_getmap: get memory map of given process
* p_getsp: get stack pointer of given process
*/
/*===========================================================================*
* p_getmap *
*===========================================================================*/
PUBLIC int p_getmap(proc_nr, mem_map)
int proc_nr; /* process to get map of */
struct mem_map *mem_map; /* put memory map here */
{
struct proc p;
int s;
if ((s=sys_getproc(&p, proc_nr)) != OK)
return(s);
memcpy(mem_map, p.p_memmap, sizeof(p.p_memmap));
return(OK);
}
/*===========================================================================*
* p_getsp *
*===========================================================================*/
PUBLIC int p_getsp(proc_nr, sp)
int proc_nr; /* process to get sp of */
vir_bytes *sp; /* put stack pointer here */
{
struct proc p;
int s;
if ((s=sys_getproc(&p, proc_nr)) != OK)
return(s);
*sp = p.p_reg.sp;
return(OK);
}

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/* Function prototypes. */
struct mproc;
struct stat;
struct mem_map;
/* alloc.c */
_PROTOTYPE( phys_clicks alloc_mem, (phys_clicks clicks) );
_PROTOTYPE( void free_mem, (phys_clicks base, phys_clicks clicks) );
_PROTOTYPE( void mem_init, (phys_clicks *free) );
#if ENABLE_SWAP
_PROTOTYPE( int swap_on, (char *file, u32_t offset, u32_t size) );
_PROTOTYPE( int swap_off, (void) );
_PROTOTYPE( void swap_in, (void) );
_PROTOTYPE( void swap_inqueue, (struct mproc *rmp) );
#else /* !SWAP */
#define swap_in() ((void)0)
#define swap_inqueue(rmp) ((void)0)
#endif /* !SWAP */
/* break.c */
_PROTOTYPE( int adjust, (struct mproc *rmp,
vir_clicks data_clicks, vir_bytes sp) );
_PROTOTYPE( int do_brk, (void) );
_PROTOTYPE( int size_ok, (int file_type, vir_clicks tc, vir_clicks dc,
vir_clicks sc, vir_clicks dvir, vir_clicks s_vir) );
/* devio.c */
_PROTOTYPE( int do_dev_io, (void) );
_PROTOTYPE( int do_dev_io, (void) );
/* exec.c */
_PROTOTYPE( int do_exec, (void) );
_PROTOTYPE( void rw_seg, (int rw, int fd, int proc, int seg,
phys_bytes seg_bytes) );
_PROTOTYPE( struct mproc *find_share, (struct mproc *mp_ign, Ino_t ino,
Dev_t dev, time_t ctime) );
/* forkexit.c */
_PROTOTYPE( int do_fork, (void) );
_PROTOTYPE( int do_mm_exit, (void) );
_PROTOTYPE( int do_waitpid, (void) );
_PROTOTYPE( void mm_exit, (struct mproc *rmp, int exit_status) );
/* getset.c */
_PROTOTYPE( int do_getset, (void) );
/* main.c */
_PROTOTYPE( void main, (void) );
/* misc.c */
_PROTOTYPE( int do_reboot, (void) );
_PROTOTYPE( int do_getsysinfo, (void) );
_PROTOTYPE( int do_svrctl, (void) );
_PROTOTYPE( int do_mstats, (void) );
#if (MACHINE == MACINTOSH)
_PROTOTYPE( phys_clicks start_click, (void) );
#endif
_PROTOTYPE( void setreply, (int proc_nr, int result) );
/* signal.c */
_PROTOTYPE( int do_alarm, (void) );
_PROTOTYPE( int do_kill, (void) );
_PROTOTYPE( int ksig_pending, (void) );
_PROTOTYPE( int do_ksig, (void) );
_PROTOTYPE( int do_pause, (void) );
_PROTOTYPE( int set_alarm, (int proc_nr, int sec) );
_PROTOTYPE( int check_sig, (pid_t proc_id, int signo) );
_PROTOTYPE( void sig_proc, (struct mproc *rmp, int sig_nr) );
_PROTOTYPE( int do_sigaction, (void) );
_PROTOTYPE( int do_sigpending, (void) );
_PROTOTYPE( int do_sigprocmask, (void) );
_PROTOTYPE( int do_sigreturn, (void) );
_PROTOTYPE( int do_sigsuspend, (void) );
_PROTOTYPE( void check_pending, (struct mproc *rmp) );
/* trace.c */
_PROTOTYPE( int do_trace, (void) );
_PROTOTYPE( void stop_proc, (struct mproc *rmp, int sig_nr) );
/* utility.c */
_PROTOTYPE( int allowed, (char *name_buf, struct stat *s_buf, int mask) );
_PROTOTYPE( int no_sys, (void) );
_PROTOTYPE( void panic, (char *format, int num) );
_PROTOTYPE( void tell_fs, (int what, int p1, int p2, int p3) );
/* procutils.c */
_PROTOTYPE( int p_getsp, (int proc_nr, vir_bytes *sp) );
_PROTOTYPE( int p_getmap, (int proc_nr, struct mem_map *mem_map) );

646
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/* This file handles signals, which are asynchronous events and are generally
* a messy and unpleasant business. Signals can be generated by the KILL
* system call, or from the keyboard (SIGINT) or from the clock (SIGALRM).
* In all cases control eventually passes to check_sig() to see which processes
* can be signaled. The actual signaling is done by sig_proc().
*
* The entry points into this file are:
* do_sigaction: perform the SIGACTION system call
* do_sigpending: perform the SIGPENDING system call
* do_sigprocmask: perform the SIGPROCMASK system call
* do_sigreturn: perform the SIGRETURN system call
* do_sigsuspend: perform the SIGSUSPEND system call
* do_kill: perform the KILL system call
* do_ksig: accept a signal originating in the kernel (e.g., SIGINT)
* do_alarm: perform the ALARM system call by calling set_alarm()
* set_alarm: tell the clock task to start or stop a timer
* do_pause: perform the PAUSE system call
* ksig_pending: the kernel notified about pending signals
* sig_proc: interrupt or terminate a signaled process
* check_sig: check which processes to signal with sig_proc()
* check_pending: check if a pending signal can now be delivered
*/
#include "mm.h"
#include <minix/utils.h>
#include <sys/stat.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <signal.h>
#include <sys/sigcontext.h>
#include <string.h>
#include "mproc.h"
#include "param.h"
#define CORE_MODE 0777 /* mode to use on core image files */
#define DUMPED 0200 /* bit set in status when core dumped */
FORWARD _PROTOTYPE( void dump_core, (struct mproc *rmp) );
FORWARD _PROTOTYPE( void unpause, (int pro) );
FORWARD _PROTOTYPE( void handle_ksig, (int proc_nr, sigset_t sig_map) );
/*===========================================================================*
* do_sigaction *
*===========================================================================*/
PUBLIC int do_sigaction()
{
int r;
struct sigaction svec;
struct sigaction *svp;
if (m_in.sig_nr == SIGKILL) return(OK);
if (m_in.sig_nr < 1 || m_in.sig_nr > _NSIG) return (EINVAL);
svp = &mp->mp_sigact[m_in.sig_nr];
if ((struct sigaction *) m_in.sig_osa != (struct sigaction *) NULL) {
r = sys_datacopy(PM_PROC_NR,(vir_bytes) svp,
who, (vir_bytes) m_in.sig_osa, (phys_bytes) sizeof(svec));
if (r != OK) return(r);
}
if ((struct sigaction *) m_in.sig_nsa == (struct sigaction *) NULL)
return(OK);
/* Read in the sigaction structure. */
r = sys_datacopy(who, (vir_bytes) m_in.sig_nsa,
PM_PROC_NR, (vir_bytes) &svec, (phys_bytes) sizeof(svec));
if (r != OK) return(r);
if (svec.sa_handler == SIG_IGN) {
sigaddset(&mp->mp_ignore, m_in.sig_nr);
sigdelset(&mp->mp_sigpending, m_in.sig_nr);
sigdelset(&mp->mp_catch, m_in.sig_nr);
} else {
sigdelset(&mp->mp_ignore, m_in.sig_nr);
if (svec.sa_handler == SIG_DFL)
sigdelset(&mp->mp_catch, m_in.sig_nr);
else
sigaddset(&mp->mp_catch, m_in.sig_nr);
}
mp->mp_sigact[m_in.sig_nr].sa_handler = svec.sa_handler;
sigdelset(&svec.sa_mask, SIGKILL);
mp->mp_sigact[m_in.sig_nr].sa_mask = svec.sa_mask;
mp->mp_sigact[m_in.sig_nr].sa_flags = svec.sa_flags;
mp->mp_sigreturn = (vir_bytes) m_in.sig_ret;
return(OK);
}
/*===========================================================================*
* do_sigpending *
*===========================================================================*/
PUBLIC int do_sigpending()
{
mp->mp_reply.reply_mask = (long) mp->mp_sigpending;
return OK;
}
/*===========================================================================*
* do_sigprocmask *
*===========================================================================*/
PUBLIC int do_sigprocmask()
{
/* Note that the library interface passes the actual mask in sigmask_set,
* not a pointer to the mask, in order to save a copy. Similarly,
* the old mask is placed in the return message which the library
* interface copies (if requested) to the user specified address.
*
* The library interface must set SIG_INQUIRE if the 'act' argument
* is NULL.
*/
int i;
mp->mp_reply.reply_mask = (long) mp->mp_sigmask;
switch (m_in.sig_how) {
case SIG_BLOCK:
sigdelset((sigset_t *)&m_in.sig_set, SIGKILL);
for (i = 1; i <= _NSIG; i++) {
if (sigismember((sigset_t *)&m_in.sig_set, i))
sigaddset(&mp->mp_sigmask, i);
}
break;
case SIG_UNBLOCK:
for (i = 1; i <= _NSIG; i++) {
if (sigismember((sigset_t *)&m_in.sig_set, i))
sigdelset(&mp->mp_sigmask, i);
}
check_pending(mp);
break;
case SIG_SETMASK:
sigdelset((sigset_t *) &m_in.sig_set, SIGKILL);
mp->mp_sigmask = (sigset_t) m_in.sig_set;
check_pending(mp);
break;
case SIG_INQUIRE:
break;
default:
return(EINVAL);
break;
}
return OK;
}
/*===========================================================================*
* do_sigsuspend *
*===========================================================================*/
PUBLIC int do_sigsuspend()
{
mp->mp_sigmask2 = mp->mp_sigmask; /* save the old mask */
mp->mp_sigmask = (sigset_t) m_in.sig_set;
sigdelset(&mp->mp_sigmask, SIGKILL);
mp->mp_flags |= SIGSUSPENDED;
check_pending(mp);
return(SUSPEND);
}
/*===========================================================================*
* do_sigreturn *
*===========================================================================*/
PUBLIC int do_sigreturn()
{
/* A user signal handler is done. Restore context and check for
* pending unblocked signals.
*/
int r;
mp->mp_sigmask = (sigset_t) m_in.sig_set;
sigdelset(&mp->mp_sigmask, SIGKILL);
r = sys_sigreturn(who, (struct sigmsg *) m_in.sig_context, m_in.sig_flags);
check_pending(mp);
return(r);
}
/*===========================================================================*
* do_kill *
*===========================================================================*/
PUBLIC int do_kill()
{
/* Perform the kill(pid, signo) system call. */
return check_sig(m_in.pid, m_in.sig_nr);
}
/*===========================================================================*
* do_ksig_pending *
*===========================================================================*/
PUBLIC int ksig_pending()
{
/* The kernel has notified the MM about pending signals. Request pending
* signals until all signals are handled. If there are no more signals,
* NONE is returned in the process number field.
*/
int proc_nr;
sigset_t sig_map;
while (TRUE) {
sys_getsig(&proc_nr, &sig_map); /* get an arbitrary pending signal */
if (NONE == proc_nr) { /* stop if no more pending signals */
break;
} else {
handle_ksig(proc_nr, sig_map); /* handle the receive signal */
}
}
return(SUSPEND); /* prevents sending reply */
}
/*===========================================================================*
* do_ksig *
*===========================================================================*/
PUBLIC int do_ksig()
{
/* Certain signals, such as segmentation violations and DEL, originate in the
* kernel. When the kernel detects such signals, it sets bits in a bit map.
* As soon as MM is awaiting new work, the kernel sends MM a message containing
* the process slot and bit map. That message comes here. The File System
* also uses this mechanism to signal writing on broken pipes (SIGPIPE).
*/
int proc_nr;
sigset_t sig_map;
/* Only kernel may make this call. */
if (who != HARDWARE) return(EPERM);
proc_nr = m_in.SIG_PROC;
sig_map = (sigset_t) m_in.SIG_MAP;
handle_ksig(proc_nr, sig_map);
return(SUSPEND);
}
/*===========================================================================*
* handle_ksig *
*===========================================================================*/
PRIVATE void handle_ksig(proc_nr, sig_map)
int proc_nr;
sigset_t sig_map;
{
register struct mproc *rmp;
int i;
pid_t proc_id, id;
rmp = &mproc[proc_nr];
if ((rmp->mp_flags & (IN_USE | ZOMBIE)) != IN_USE) return;
proc_id = rmp->mp_pid;
mp = &mproc[0]; /* pretend kernel signals are from MM */
mp->mp_procgrp = rmp->mp_procgrp; /* get process group right */
/* Check each bit in turn to see if a signal is to be sent. Unlike
* kill(), the kernel may collect several unrelated signals for a
* process and pass them to MM in one blow. Thus loop on the bit
* map. For SIGINT and SIGQUIT, use proc_id 0 to indicate a broadcast
* to the recipient's process group. For SIGKILL, use proc_id -1 to
* indicate a systemwide broadcast.
*/
for (i = 1; i <= _NSIG; i++) {
if (!sigismember(&sig_map, i)) continue;
switch (i) {
case SIGINT:
case SIGQUIT:
id = 0; break; /* broadcast to process group */
case SIGKILL:
id = -1; break; /* broadcast to all except INIT */
case SIGALRM:
/* Disregard SIGALRM when the target process has not
* requested an alarm. This only applies for a KERNEL
* generated signal.
*/
if ((rmp->mp_flags & ALARM_ON) == 0) continue;
rmp->mp_flags &= ~ALARM_ON;
/* fall through */
default:
id = proc_id;
break;
}
check_sig(id, i);
sys_endsig(proc_nr); /* tell kernel it's done */
}
}
/*===========================================================================*
* do_alarm *
*===========================================================================*/
PUBLIC int do_alarm()
{
/* Perform the alarm(seconds) system call. */
return(set_alarm(who, m_in.seconds));
}
/*===========================================================================*
* set_alarm *
*===========================================================================*/
PUBLIC int set_alarm(proc_nr, sec)
int proc_nr; /* process that wants the alarm */
int sec; /* how many seconds delay before the signal */
{
/* This routine is used by do_alarm() to set the alarm timer. It is also used
* to turn the timer off when a process exits with the timer still on.
*/
clock_t ticks; /* number of ticks for alarm */
int remaining; /* previous time left in seconds */
int s;
if (sec != 0) mproc[proc_nr].mp_flags |= ALARM_ON;
else mproc[proc_nr].mp_flags &= ~ALARM_ON;
/* Tell the clock task to provide a signal message when the time comes.
*
* Large delays cause a lot of problems. First, the alarm system call
* takes an unsigned seconds count and the library has cast it to an int.
* That probably works, but on return the library will convert "negative"
* unsigneds to errors. Presumably no one checks for these errors, so
* force this call through. Second, If unsigned and long have the same
* size, converting from seconds to ticks can easily overflow. Finally,
* the kernel has similar overflow bugs adding ticks.
*
* Fixing this requires a lot of ugly casts to fit the wrong interface
* types and to avoid overflow traps. ALRM_EXP_TIME has the right type
* (clock_t) although it is declared as long. How can variables like
* this be declared properly without combinatorial explosion of message
* types?
*/
ticks = (clock_t) (HZ * (unsigned long) (unsigned) sec);
if ( (unsigned long) ticks / HZ != (unsigned) sec)
ticks = LONG_MAX; /* eternity (really TMR_NEVER) */
if ((s=sys_signalrm(proc_nr, &ticks)) != OK)
panic("MM couldn't set signal alarm", s);
remaining = (int) ((ticks + (HZ-1))/HZ);
if (remaining < 0) remaining = INT_MAX; /* true value is too large */
return(remaining);
}
/*===========================================================================*
* do_pause *
*===========================================================================*/
PUBLIC int do_pause()
{
/* Perform the pause() system call. */
mp->mp_flags |= PAUSED;
return(SUSPEND);
}
/*===========================================================================*
* sig_proc *
*===========================================================================*/
PUBLIC void sig_proc(rmp, signo)
register struct mproc *rmp; /* pointer to the process to be signaled */
int signo; /* signal to send to process (1 to _NSIG) */
{
/* Send a signal to a process. Check to see if the signal is to be caught,
* ignored, or blocked. If the signal is to be caught, coordinate with
* KERNEL to push a sigcontext structure and a sigframe structure onto
* the catcher's stack. Also, KERNEL will reset the program counter and
* stack pointer, so that when the process next runs, it will be executing
* the signal handler. When the signal handler returns, sigreturn(2)
* will be called. Then KERNEL will restore the signal context from the
* sigcontext structure.
*
* If there is insufficient stack space, kill the process.
*/
vir_bytes new_sp;
int s;
int slot;
int sigflags;
struct sigmsg sm;
slot = (int) (rmp - mproc);
if ((rmp->mp_flags & (IN_USE | ZOMBIE)) != IN_USE) {
printf("MM: signal %d sent to %s process %d\n",
(rmp->mp_flags & ZOMBIE) ? "zombie" : "dead", signo, slot);
panic("", NO_NUM);
}
if ((rmp->mp_flags & TRACED) && signo != SIGKILL) {
/* A traced process has special handling. */
unpause(slot);
stop_proc(rmp, signo); /* a signal causes it to stop */
return;
}
/* Some signals are ignored by default. */
if (sigismember(&rmp->mp_ignore, signo)) return;
if (sigismember(&rmp->mp_sigmask, signo)) {
/* Signal should be blocked. */
sigaddset(&rmp->mp_sigpending, signo);
return;
}
sigflags = rmp->mp_sigact[signo].sa_flags;
if (sigismember(&rmp->mp_catch, signo)) {
if (rmp->mp_flags & ONSWAP) {
/* Process is swapped out, leave signal pending. */
sigaddset(&rmp->mp_sigpending, signo);
swap_inqueue(rmp);
return;
}
if (rmp->mp_flags & SIGSUSPENDED)
sm.sm_mask = rmp->mp_sigmask2;
else
sm.sm_mask = rmp->mp_sigmask;
sm.sm_signo = signo;
sm.sm_sighandler = (vir_bytes) rmp->mp_sigact[signo].sa_handler;
sm.sm_sigreturn = rmp->mp_sigreturn;
if ((s=p_getsp(slot, &new_sp)) != OK)
panic("MM couldn't get new stack pointer",s);
sm.sm_stkptr = new_sp;
/* Make room for the sigcontext and sigframe struct. */
new_sp -= sizeof(struct sigcontext)
+ 3 * sizeof(char *) + 2 * sizeof(int);
if (adjust(rmp, rmp->mp_seg[D].mem_len, new_sp) != OK)
goto doterminate;
rmp->mp_sigmask |= rmp->mp_sigact[signo].sa_mask;
if (sigflags & SA_NODEFER)
sigdelset(&rmp->mp_sigmask, signo);
else
sigaddset(&rmp->mp_sigmask, signo);
if (sigflags & SA_RESETHAND) {
sigdelset(&rmp->mp_catch, signo);
rmp->mp_sigact[signo].sa_handler = SIG_DFL;
}
sys_sigsend(slot, &sm);
sigdelset(&rmp->mp_sigpending, signo);
/* If process is hanging on PAUSE, WAIT, SIGSUSPEND, tty, pipe, etc.,
* release it.
*/
unpause(slot);
return;
}
doterminate:
/* Signal should not or cannot be caught. Take default action. */
if (sigismember(&ign_sset, signo)) return;
rmp->mp_sigstatus = (char) signo;
if (sigismember(&core_sset, signo)) {
if (rmp->mp_flags & ONSWAP) {
/* Process is swapped out, leave signal pending. */
sigaddset(&rmp->mp_sigpending, signo);
swap_inqueue(rmp);
return;
}
/* Switch to the user's FS environment and dump core. */
tell_fs(CHDIR, slot, FALSE, 0);
dump_core(rmp);
}
mm_exit(rmp, 0); /* terminate process */
}
/*===========================================================================*
* check_sig *
*===========================================================================*/
PUBLIC int check_sig(proc_id, signo)
pid_t proc_id; /* pid of proc to sig, or 0 or -1, or -pgrp */
int signo; /* signal to send to process (0 to _NSIG) */
{
/* Check to see if it is possible to send a signal. The signal may have to be
* sent to a group of processes. This routine is invoked by the KILL system
* call, and also when the kernel catches a DEL or other signal.
*/
register struct mproc *rmp;
int count; /* count # of signals sent */
int error_code;
if (signo < 0 || signo > _NSIG) return(EINVAL);
/* Return EINVAL for attempts to send SIGKILL to INIT alone. */
if (proc_id == INIT_PID && signo == SIGKILL) return(EINVAL);
/* Search the proc table for processes to signal. (See forkexit.c about
* pid magic.)
*/
count = 0;
error_code = ESRCH;
for (rmp = &mproc[INIT_PROC_NR]; rmp < &mproc[NR_PROCS]; rmp++) {
if (!(rmp->mp_flags & IN_USE)) continue;
if ((rmp->mp_flags & ZOMBIE) && signo != 0) continue;
/* Check for selection. */
if (proc_id > 0 && proc_id != rmp->mp_pid) continue;
if (proc_id == 0 && mp->mp_procgrp != rmp->mp_procgrp) continue;
if (proc_id == -1 && rmp->mp_pid <= INIT_PID) continue;
if (proc_id < -1 && rmp->mp_procgrp != -proc_id) continue;
/* Check for permission. */
if (mp->mp_effuid != SUPER_USER
&& mp->mp_realuid != rmp->mp_realuid
&& mp->mp_effuid != rmp->mp_realuid
&& mp->mp_realuid != rmp->mp_effuid
&& mp->mp_effuid != rmp->mp_effuid) {
error_code = EPERM;
continue;
}
count++;
if (signo == 0) continue;
/* 'sig_proc' will handle the disposition of the signal. The
* signal may be caught, blocked, ignored, or cause process
* termination, possibly with core dump.
*/
sig_proc(rmp, signo);
if (proc_id > 0) break; /* only one process being signaled */
}
/* If the calling process has killed itself, don't reply. */
if ((mp->mp_flags & (IN_USE | ZOMBIE)) != IN_USE) return(SUSPEND);
return(count > 0 ? OK : error_code);
}
/*===========================================================================*
* check_pending *
*===========================================================================*/
PUBLIC void check_pending(rmp)
register struct mproc *rmp;
{
/* Check to see if any pending signals have been unblocked. The
* first such signal found is delivered.
*
* If multiple pending unmasked signals are found, they will be
* delivered sequentially.
*
* There are several places in this file where the signal mask is
* changed. At each such place, check_pending() should be called to
* check for newly unblocked signals.
*/
int i;
for (i = 1; i <= _NSIG; i++) {
if (sigismember(&rmp->mp_sigpending, i) &&
!sigismember(&rmp->mp_sigmask, i)) {
sigdelset(&rmp->mp_sigpending, i);
sig_proc(rmp, i);
break;
}
}
}
/*===========================================================================*
* unpause *
*===========================================================================*/
PRIVATE void unpause(pro)
int pro; /* which process number */
{
/* A signal is to be sent to a process. If that process is hanging on a
* system call, the system call must be terminated with EINTR. Possible
* calls are PAUSE, WAIT, READ and WRITE, the latter two for pipes and ttys.
* First check if the process is hanging on an MM call. If not, tell FS,
* so it can check for READs and WRITEs from pipes, ttys and the like.
*/
register struct mproc *rmp;
rmp = &mproc[pro];
/* Check to see if process is hanging on a PAUSE, WAIT or SIGSUSPEND call. */
if (rmp->mp_flags & (PAUSED | WAITING | SIGSUSPENDED)) {
rmp->mp_flags &= ~(PAUSED | WAITING | SIGSUSPENDED);
setreply(pro, EINTR);
return;
}
/* Process is not hanging on an MM call. Ask FS to take a look. */
tell_fs(UNPAUSE, pro, 0, 0);
}
/*===========================================================================*
* dump_core *
*===========================================================================*/
PRIVATE void dump_core(rmp)
register struct mproc *rmp; /* whose core is to be dumped */
{
/* Make a core dump on the file "core", if possible. */
int s, fd, fake_fd, nr_written, seg, slot;
char *buf;
vir_bytes current_sp;
phys_bytes left; /* careful; 64K might overflow vir_bytes */
unsigned nr_to_write; /* unsigned for arg to write() but < INT_MAX */
long trace_data, trace_off;
slot = (int) (rmp - mproc);
/* Can core file be written? We are operating in the user's FS environment,
* so no special permission checks are needed.
*/
if (rmp->mp_realuid != rmp->mp_effuid) return;
if ( (fd = open(core_name, O_WRONLY | O_CREAT | O_TRUNC | O_NONBLOCK,
CORE_MODE)) < 0) return;
rmp->mp_sigstatus |= DUMPED;
/* Make sure the stack segment is up to date.
* We don't want adjust() to fail unless current_sp is preposterous,
* but it might fail due to safety checking. Also, we don't really want
* the adjust() for sending a signal to fail due to safety checking.
* Maybe make SAFETY_BYTES a parameter.
*/
if ((s=p_getsp(slot, &current_sp)) != OK)
panic("MM couldn't get new stack pointer",s);
adjust(rmp, rmp->mp_seg[D].mem_len, current_sp);
/* Write the memory map of all segments to begin the core file. */
if (write(fd, (char *) rmp->mp_seg, (unsigned) sizeof rmp->mp_seg)
!= (unsigned) sizeof rmp->mp_seg) {
close(fd);
return;
}
/* Write out the whole kernel process table entry to get the regs. */
trace_off = 0;
while (sys_trace(3, slot, trace_off, &trace_data) == OK) {
if (write(fd, (char *) &trace_data, (unsigned) sizeof (long))
!= (unsigned) sizeof (long)) {
close(fd);
return;
}
trace_off += sizeof (long);
}
/* Loop through segments and write the segments themselves out. */
for (seg = 0; seg < NR_LOCAL_SEGS; seg++) {
rw_seg(1, fd, slot, seg,
(phys_bytes) rmp->mp_seg[seg].mem_len << CLICK_SHIFT);
}
close(fd);
}

108
servers/pm/table.c Normal file
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/* This file contains the table used to map system call numbers onto the
* routines that perform them.
*/
#define _TABLE
#include "mm.h"
#include <minix/callnr.h>
#include <signal.h>
#include "mproc.h"
#include "param.h"
/* Miscellaneous */
char core_name[] = "core"; /* file name where core images are produced */
_PROTOTYPE (int (*call_vec[NCALLS]), (void) ) = {
no_sys, /* 0 = unused */
do_mm_exit, /* 1 = exit */
do_fork, /* 2 = fork */
no_sys, /* 3 = read */
no_sys, /* 4 = write */
no_sys, /* 5 = open */
no_sys, /* 6 = close */
do_waitpid, /* 7 = wait */
no_sys, /* 8 = creat */
no_sys, /* 9 = link */
no_sys, /* 10 = unlink */
do_waitpid, /* 11 = waitpid */
no_sys, /* 12 = chdir */
no_sys, /* 13 = time */
no_sys, /* 14 = mknod */
no_sys, /* 15 = chmod */
no_sys, /* 16 = chown */
do_brk, /* 17 = break */
no_sys, /* 18 = stat */
no_sys, /* 19 = lseek */
do_getset, /* 20 = getpid */
no_sys, /* 21 = mount */
no_sys, /* 22 = umount */
do_getset, /* 23 = setuid */
do_getset, /* 24 = getuid */
no_sys, /* 25 = stime */
do_trace, /* 26 = ptrace */
do_alarm, /* 27 = alarm */
no_sys, /* 28 = fstat */
do_pause, /* 29 = pause */
no_sys, /* 30 = utime */
no_sys, /* 31 = (stty) */
no_sys, /* 32 = (gtty) */
no_sys, /* 33 = access */
no_sys, /* 34 = (nice) */
no_sys, /* 35 = (ftime) */
no_sys, /* 36 = sync */
do_kill, /* 37 = kill */
no_sys, /* 38 = rename */
no_sys, /* 39 = mkdir */
no_sys, /* 40 = rmdir */
no_sys, /* 41 = dup */
no_sys, /* 42 = pipe */
no_sys, /* 43 = times */
no_sys, /* 44 = (prof) */
no_sys, /* 45 = unused */
do_getset, /* 46 = setgid */
do_getset, /* 47 = getgid */
no_sys, /* 48 = (signal)*/
no_sys, /* 49 = unused */
no_sys, /* 50 = unused */
no_sys, /* 51 = (acct) */
no_sys, /* 52 = (phys) */
no_sys, /* 53 = (lock) */
no_sys, /* 54 = ioctl */
no_sys, /* 55 = fcntl */
no_sys, /* 56 = (mpx) */
no_sys, /* 57 = unused */
no_sys, /* 58 = unused */
do_exec, /* 59 = execve */
no_sys, /* 60 = umask */
no_sys, /* 61 = chroot */
do_getset, /* 62 = setsid */
do_getset, /* 63 = getpgrp */
do_ksig, /* 64 = KSIG: signals originating in the kernel */
no_sys, /* 65 = UNPAUSE */
no_sys, /* 66 = unused */
no_sys, /* 67 = REVIVE */
no_sys, /* 68 = TASK_REPLY */
no_sys, /* 69 = unused */
no_sys, /* 70 = unused */
do_sigaction, /* 71 = sigaction */
do_sigsuspend, /* 72 = sigsuspend */
do_sigpending, /* 73 = sigpending */
do_sigprocmask, /* 74 = sigprocmask */
do_sigreturn, /* 75 = sigreturn */
do_reboot, /* 76 = reboot */
do_svrctl, /* 77 = svrctl */
no_sys, /* 78 = cmostime */
do_getsysinfo, /* 79 = getsysinfo */
#if ENABLE_MESSAGE_STATS
do_mstats, /* 80 = mstats */
#else
no_sys,
#endif
no_sys, /* 81 = unused */
no_sys, /* 82 = unused */
};
/* This should not fail with "array size is negative": */
extern int dummy[sizeof(call_vec) == NCALLS * sizeof(call_vec[0]) ? 1 : -1];

111
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/* This file handles the memory manager's part of debugging, using the
* ptrace system call. Most of the commands are passed on to the system
* task for completion.
*
* The debugging commands available are:
* T_STOP stop the process
* T_OK enable tracing by parent for this process
* T_GETINS return value from instruction space
* T_GETDATA return value from data space
* T_GETUSER return value from user process table
* T_SETINS set value in instruction space
* T_SETDATA set value in data space
* T_SETUSER set value in user process table
* T_RESUME resume execution
* T_EXIT exit
* T_STEP set trace bit
*
* The T_OK and T_EXIT commands are handled here, and the T_RESUME and
* T_STEP commands are partially handled here and completed by the system
* task. The rest are handled entirely by the system task.
*/
#include "mm.h"
#include <minix/com.h>
#include <sys/ptrace.h>
#include <signal.h>
#include "mproc.h"
#include "param.h"
#define NIL_MPROC ((struct mproc *) 0)
FORWARD _PROTOTYPE( struct mproc *findproc, (pid_t lpid) );
/*===========================================================================*
* do_trace *
*===========================================================================*/
PUBLIC int do_trace()
{
register struct mproc *child;
/* the T_OK call is made by the child fork of the debugger before it execs
* the process to be traced
*/
if (m_in.request == T_OK) { /* enable tracing by parent for this proc */
mp->mp_flags |= TRACED;
mp->mp_reply.reply_trace = 0;
return(OK);
}
if ((child=findproc(m_in.pid))==NIL_MPROC || !(child->mp_flags & STOPPED)) {
return(ESRCH);
}
/* all the other calls are made by the parent fork of the debugger to
* control execution of the child
*/
switch (m_in.request) {
case T_EXIT: /* exit */
mm_exit(child, (int) m_in.data);
mp->mp_reply.reply_trace = 0;
return(OK);
case T_RESUME:
case T_STEP: /* resume execution */
if (m_in.data < 0 || m_in.data > _NSIG) return(EIO);
if (m_in.data > 0) { /* issue signal */
child->mp_flags &= ~TRACED; /* so signal is not diverted */
sig_proc(child, (int) m_in.data);
child->mp_flags |= TRACED;
}
child->mp_flags &= ~STOPPED;
break;
}
if (sys_trace(m_in.request,(int)(child-mproc),m_in.taddr,&m_in.data) != OK)
return(-errno);
mp->mp_reply.reply_trace = m_in.data;
return(OK);
}
/*===========================================================================*
* findproc *
*===========================================================================*/
PRIVATE struct mproc *findproc(lpid)
pid_t lpid;
{
register struct mproc *rmp;
for (rmp = &mproc[INIT_PROC_NR + 1]; rmp < &mproc[NR_PROCS]; rmp++)
if (rmp->mp_flags & IN_USE && rmp->mp_pid == lpid) return(rmp);
return(NIL_MPROC);
}
/*===========================================================================*
* stop_proc *
*===========================================================================*/
PUBLIC void stop_proc(rmp, signo)
register struct mproc *rmp;
int signo;
{
/* A traced process got a signal so stop it. */
register struct mproc *rpmp = mproc + rmp->mp_parent;
if (sys_trace(-1, (int) (rmp - mproc), 0L, (long *) 0) != OK) return;
rmp->mp_flags |= STOPPED;
if (rpmp->mp_flags & WAITING) {
rpmp->mp_flags &= ~WAITING; /* parent is no longer waiting */
rpmp->mp_reply.reply_res2 = 0177 | (signo << 8);
setreply(rmp->mp_parent, rmp->mp_pid);
} else {
rmp->mp_sigstatus = signo;
}
return;
}

5
servers/pm/type.h Normal file
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/* If there were any type definitions local to the Memory Manager, they would
* be here. This file is included only for symmetry with the kernel and File
* System, which do have some local type definitions.
*/

114
servers/pm/utility.c Normal file
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/* This file contains some utility routines for MM.
*
* The entry points are:
* allowed: see if an access is permitted
* no_sys: this routine is called for invalid system call numbers
* panic: MM has run aground of a fatal error and cannot continue
* tell_fs: interface to FS
*/
#include "mm.h"
#include <sys/stat.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <fcntl.h>
#include <signal.h> /* needed only because mproc.h needs it */
#include "mproc.h"
#include "param.h"
/*===========================================================================*
* allowed *
*===========================================================================*/
PUBLIC int allowed(name_buf, s_buf, mask)
char *name_buf; /* pointer to file name to be EXECed */
struct stat *s_buf; /* buffer for doing and returning stat struct*/
int mask; /* R_BIT, W_BIT, or X_BIT */
{
/* Check to see if file can be accessed. Return EACCES or ENOENT if the access
* is prohibited. If it is legal open the file and return a file descriptor.
*/
int fd;
int save_errno;
/* Use the fact that mask for access() is the same as the permissions mask.
* E.g., X_BIT in <minix/const.h> is the same as X_OK in <unistd.h> and
* S_IXOTH in <sys/stat.h>. tell_fs(DO_CHDIR, ...) has set MM's real ids
* to the user's effective ids, so access() works right for setuid programs.
*/
if (access(name_buf, mask) < 0) return(-errno);
/* The file is accessible but might not be readable. Make it readable. */
tell_fs(SETUID, PM_PROC_NR, (int) SUPER_USER, (int) SUPER_USER);
/* Open the file and fstat it. Restore the ids early to handle errors. */
fd = open(name_buf, O_RDONLY | O_NONBLOCK);
save_errno = errno; /* open might fail, e.g. from ENFILE */
tell_fs(SETUID, PM_PROC_NR, (int) mp->mp_effuid, (int) mp->mp_effuid);
if (fd < 0) return(-save_errno);
if (fstat(fd, s_buf) < 0) panic("allowed: fstat failed", NO_NUM);
/* Only regular files can be executed. */
if (mask == X_BIT && (s_buf->st_mode & I_TYPE) != I_REGULAR) {
close(fd);
return(EACCES);
}
return(fd);
}
/*===========================================================================*
* no_sys *
*===========================================================================*/
PUBLIC int no_sys()
{
/* A system call number not implemented by MM has been requested. */
return(EINVAL);
}
/*===========================================================================*
* panic *
*===========================================================================*/
PUBLIC void panic(format, num)
char *format; /* format string */
int num; /* number to go with format string */
{
/* Something awful has happened. Panics are caused when an internal
* inconsistency is detected, e.g., a programming error or illegal value of a
* defined constant.
*/
printf("Memory manager panic: %s ", format);
if (num != NO_NUM) printf("%d",num);
printf("\n");
tell_fs(SYNC, 0, 0, 0); /* flush the cache to the disk */
sys_abort(RBT_PANIC);
}
/*===========================================================================*
* tell_fs *
*===========================================================================*/
PUBLIC void tell_fs(what, p1, p2, p3)
int what, p1, p2, p3;
{
/* This routine is only used by MM to inform FS of certain events:
* tell_fs(CHDIR, slot, dir, 0)
* tell_fs(EXEC, proc, 0, 0)
* tell_fs(EXIT, proc, 0, 0)
* tell_fs(FORK, parent, child, pid)
* tell_fs(SETGID, proc, realgid, effgid)
* tell_fs(SETSID, proc, 0, 0)
* tell_fs(SETUID, proc, realuid, effuid)
* tell_fs(SYNC, 0, 0, 0)
* tell_fs(UNPAUSE, proc, signr, 0)
*/
message m;
m.tell_fs_arg1 = p1;
m.tell_fs_arg2 = p2;
m.tell_fs_arg3 = p3;
_taskcall(FS_PROC_NR, what, &m);
}