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minix/servers/vm/exec.c
Evgeniy Ivanov ef0a265086 New stat structure. 
* VFS and installed MFSes must be in sync before and after this change *

Use struct stat from NetBSD. It requires adding new STAT, FSTAT and LSTAT
syscalls. Libc modification is both backward and forward compatible.

Also new struct stat uses modern field sizes to avoid ABI
incompatibility, when we update uid_t, gid_t and company.
Exceptions are ino_t and off_t in old libc (though paddings added).
2011-07-12 16:39:55 +02:00

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#define _SYSTEM 1
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/ds.h>
#include <minix/endpoint.h>
#include <minix/keymap.h>
#include <minix/minlib.h>
#include <minix/type.h>
#include <minix/ipc.h>
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/const.h>
#include <minix/bitmap.h>
#include <errno.h>
#include <assert.h>
#include <env.h>
#include <pagetable.h>
#include <sys/param.h>
#include "glo.h"
#include "proto.h"
#include "util.h"
#include "vm.h"
#include "region.h"
#include "sanitycheck.h"
#include "memory.h"
FORWARD _PROTOTYPE( int new_mem, (struct vmproc *vmp,
vir_bytes text_addr, vir_bytes text_bytes,
vir_bytes data_addr, vir_bytes data_bytes,
vir_bytes stk_bytes, phys_bytes tot_bytes, vir_bytes *stack_top,
int is_elf));
/*===========================================================================*
* exec_newmem *
*===========================================================================*/
PUBLIC int do_exec_newmem(message *msg)
{
int r, proc_e, proc_n;
vir_bytes stack_top;
vir_clicks tc, dc, sc, totc, dvir, s_vir;
struct vmproc *vmp;
char *ptr;
struct exec_newmem args;
SANITYCHECK(SCL_FUNCTIONS);
proc_e= msg->VMEN_ENDPOINT;
if (vm_isokendpt(proc_e, &proc_n) != OK)
{
printf("VM: exec_newmem: bad endpoint %d from %d\n",
proc_e, msg->m_source);
return ESRCH;
}
vmp= &vmproc[proc_n];
ptr= msg->VMEN_ARGSPTR;
if(msg->VMEN_ARGSSIZE != sizeof(args)) {
printf("VM: exec_newmem: args size %d != %u\n",
msg->VMEN_ARGSSIZE, sizeof(args));
return EINVAL;
}
SANITYCHECK(SCL_DETAIL);
r= sys_datacopy(msg->m_source, (vir_bytes)ptr,
SELF, (vir_bytes)&args, sizeof(args));
if (r != OK)
panic("exec_newmem: sys_datacopy failed: %d", r);
/* Minimum stack region (not preallocated)
* Stopgap for better rlimit-based stack size system
*/
if(args.tot_bytes < MINSTACKREGION) {
args.tot_bytes = MINSTACKREGION;
}
/* Check to see if segment sizes are feasible. */
tc = (vir_clicks) (CLICK_CEIL(args.text_bytes) >> CLICK_SHIFT);
dc = (vir_clicks) (CLICK_CEIL(args.data_bytes) >> CLICK_SHIFT);
totc = (vir_clicks) (CLICK_CEIL(args.tot_bytes) >> CLICK_SHIFT);
sc = (vir_clicks) (CLICK_CEIL(args.args_bytes) >> CLICK_SHIFT);
if (dc >= totc) {
printf("VM: newmem: no stack?\n");
return(ENOEXEC); /* stack must be at least 1 click */
}
dvir = (args.sep_id ? 0 : tc);
s_vir = dvir + (totc - sc);
r = (dvir + dc > s_vir) ? ENOMEM : OK;
if (r != OK) {
printf("VM: newmem: no virtual space?\n");
return r;
}
/* Allocate new memory and release old memory. Fix map and tell
* kernel.
*/
r = new_mem(vmp, args.text_addr, args.text_bytes,
args.data_addr, args.data_bytes,
args.args_bytes, args.tot_bytes, &stack_top,
args.is_elf);
if (r != OK) {
printf("VM: newmem: new_mem failed\n");
return(r);
}
/* Save file identification to allow it to be shared. */
vmp->vm_ino = args.st_ino;
vmp->vm_dev = args.st_dev;
vmp->vm_ctime = args.enst_ctime;
/* set/clear separate I&D flag */
if (args.sep_id)
vmp->vm_flags |= VMF_SEPARATE;
else
vmp->vm_flags &= ~VMF_SEPARATE;
msg->VMEN_STACK_TOP = (void *) stack_top;
msg->VMEN_FLAGS = 0;
msg->VMEN_FLAGS |= EXC_NM_RF_LOAD_TEXT;
return OK;
}
/*===========================================================================*
* new_mem *
*===========================================================================*/
PRIVATE int new_mem(
struct vmproc *rmp, /* process to get a new memory map */
vir_bytes text_addr, /* text segement load address */
vir_bytes text_bytes, /* text segment size in bytes */
vir_bytes data_addr, /* data segment load address */
vir_bytes data_bytes, /* size of data (incl bss) in bytes */
vir_bytes stk_bytes, /* size of initial stack segment in bytes */
phys_bytes tot_bytes, /* total memory to allocate, including gap */
vir_bytes *stack_top, /* top of process stack */
int is_elf
)
{
/* 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.
*/
vir_clicks text_clicks, data_clicks, gap_clicks, stack_clicks, tot_clicks;
int r, hadpt = 0;
struct vmproc *vmpold = &vmproc[VMP_EXECTMP];
int ptok = 1;
SANITYCHECK(SCL_FUNCTIONS);
assert(rmp->vm_flags & VMF_HASPT);
/* 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 = (vir_clicks) (CLICK_CEIL(text_bytes) >> CLICK_SHIFT);
data_clicks = (vir_clicks) (CLICK_CEIL(data_bytes) >> CLICK_SHIFT);
stack_clicks = (vir_clicks) (CLICK_CEIL(stk_bytes) >> CLICK_SHIFT);
tot_clicks = (vir_clicks) (CLICK_CEIL(tot_bytes) >> CLICK_SHIFT);
gap_clicks = tot_clicks - data_clicks - stack_clicks;
if ( (int) gap_clicks < 0) {
printf("VM: new_mem: no gap?\n");
return(ENOMEM);
}
/* Keep previous process state for recovery; the sanity check functions
* know about the 'vmpold' slot, so the memory that the exec()ing
* process is still holding is referenced there.
*
* Throw away the old page table to avoid having two process slots
* using the same vm_pt.
* Just recreate it in the case that we have to revert.
*/
SANITYCHECK(SCL_DETAIL);
rmp->vm_flags &= ~VMF_HASPT;
pt_free(&rmp->vm_pt);
assert(!(vmpold->vm_flags & VMF_INUSE));
*vmpold = *rmp; /* copy current state. */
#if SANITYCHECKS
map_setparent(vmpold);
#endif
region_init(&rmp->vm_regions_avl); /* exec()ing process regions thrown out. */
rmp->vm_region_top = 0;
SANITYCHECK(SCL_DETAIL);
/* Build new process in current slot, without freeing old
* one. If it fails, revert.
*/
SANITYCHECK(SCL_DETAIL);
if((r=pt_new(&rmp->vm_pt)) != OK) {
ptok = 0;
printf("exec_newmem: no new pagetable\n");
}
SANITYCHECK(SCL_DETAIL);
if(r != OK || (r=proc_new(rmp,
VM_PROCSTART, /* where to start the process in the page table */
text_addr, /* text load address */
CLICK2ABS(text_clicks),/* how big is the text in bytes, page-aligned */
data_addr, /* data load address */
CLICK2ABS(data_clicks),/* how big is data+bss, page-aligned */
CLICK2ABS(stack_clicks),/* how big is stack, page-aligned */
CLICK2ABS(gap_clicks), /* how big is gap, page-aligned */
0,0, /* not preallocated */
VM_STACKTOP, /* regular stack top */
0, is_elf)) != OK) {
SANITYCHECK(SCL_DETAIL);
printf("VM: new_mem: failed\n");
if(ptok) {
rmp->vm_flags &= ~VMF_HASPT;
pt_free(&rmp->vm_pt);
}
*rmp = *vmpold; /* undo. */
map_setparent(rmp);
clear_proc(vmpold); /* disappear. */
SANITYCHECK(SCL_DETAIL);
if(hadpt) {
if(pt_new(&rmp->vm_pt) != OK) {
/* We secretly know that making a new pagetable
* in the same slot if one was there will never fail.
*/
panic("new_mem: pt_new failed: %d", ENOMEM);
}
rmp->vm_flags |= VMF_HASPT;
SANITYCHECK(SCL_DETAIL);
if(map_writept(rmp) != OK) {
printf("VM: warning: exec undo failed\n");
}
SANITYCHECK(SCL_DETAIL);
}
return r;
}
SANITYCHECK(SCL_DETAIL);
/* new process is made; free and unreference
* page table and memory still held by exec()ing process.
*/
SANITYCHECK(SCL_DETAIL);
free_proc(vmpold);
clear_proc(vmpold); /* disappear. */
SANITYCHECK(SCL_DETAIL);
*stack_top = VM_STACKTOP;
SANITYCHECK(SCL_FUNCTIONS);
return(OK);
}
/*===========================================================================*
* find_kernel_top *
*===========================================================================*/
PUBLIC phys_bytes find_kernel_top(void)
{
/* Find out where the kernel is, so we know where to start mapping
* user processes.
*/
u32_t kernel_top = 0;
#define MEMTOP(v, i) \
(vmproc[v].vm_arch.vm_seg[i].mem_phys + vmproc[v].vm_arch.vm_seg[i].mem_len)
assert(vmproc[VMP_SYSTEM].vm_flags & VMF_INUSE);
kernel_top = MEMTOP(VMP_SYSTEM, T);
kernel_top = MAX(kernel_top, MEMTOP(VMP_SYSTEM, D));
kernel_top = MAX(kernel_top, MEMTOP(VMP_SYSTEM, S));
assert(kernel_top);
return CLICK2ABS(kernel_top);
}
/*===========================================================================*
* proc_new *
*===========================================================================*/
PUBLIC int proc_new(struct vmproc *vmp,
phys_bytes vstart, /* where to start the process in page table */
phys_bytes text_addr, /* address at which to load code */
phys_bytes text_bytes, /* how much code, in bytes but page aligned */
phys_bytes data_addr, /* address at which to load data */
phys_bytes data_bytes, /* how much data + bss, in bytes but page aligned */
phys_bytes stack_bytes, /* stack space to reserve, in bytes, page aligned */
phys_bytes gap_bytes, /* gap bytes, page aligned */
phys_bytes text_start, /* text starts here, if preallocated, otherwise 0 */
phys_bytes data_start, /* data starts here, if preallocated, otherwise 0 */
phys_bytes stacktop,
int prealloc_stack,
int is_elf
)
{
int s;
vir_bytes hole_bytes;
struct vir_region *reg;
phys_bytes map_text_addr, map_data_addr, map_stack_addr;
assert(!(vstart % VM_PAGE_SIZE));
assert(!(text_addr % VM_PAGE_SIZE));
assert(!(text_bytes % VM_PAGE_SIZE));
assert(!(data_addr % VM_PAGE_SIZE));
assert(!(data_bytes % VM_PAGE_SIZE));
assert(!(stack_bytes % VM_PAGE_SIZE));
assert(!(gap_bytes % VM_PAGE_SIZE));
assert(!(text_start % VM_PAGE_SIZE));
assert(!(data_start % VM_PAGE_SIZE));
assert((!text_start && !data_start) || (text_start && data_start));
/* Place text at start of process. */
map_text_addr = vstart + text_addr;
vmp->vm_arch.vm_seg[T].mem_phys = ABS2CLICK(map_text_addr);
vmp->vm_arch.vm_seg[T].mem_vir = ABS2CLICK(text_addr);
vmp->vm_arch.vm_seg[T].mem_len = ABS2CLICK(text_bytes);
vmp->vm_offset = vstart;
/* page mapping flags for code */
#define TEXTFLAGS (PTF_PRESENT | PTF_USER)
SANITYCHECK(SCL_DETAIL);
if(text_bytes > 0) {
if(!(reg=map_page_region(vmp, map_text_addr, 0, text_bytes,
text_start ? text_start : MAP_NONE,
VR_ANON | VR_WRITABLE, text_start ? 0 : MF_PREALLOC))) {
SANITYCHECK(SCL_DETAIL);
printf("VM: proc_new: map_page_region failed (text)\n");
map_free_proc(vmp);
SANITYCHECK(SCL_DETAIL);
return(ENOMEM);
}
map_region_set_tag(reg, VRT_TEXT);
SANITYCHECK(SCL_DETAIL);
}
SANITYCHECK(SCL_DETAIL);
/* Allocate memory for data (including bss, but not including gap
* or stack), make sure it's cleared, and map it in after text
* (if any).
*/
if (is_elf) {
map_data_addr = vstart + data_addr;
} else {
map_data_addr = vstart + text_bytes;
}
if(!(vmp->vm_heap = map_page_region(vmp, map_data_addr, 0,
data_bytes, data_start ? data_start : MAP_NONE, VR_ANON | VR_WRITABLE,
data_start ? 0 : MF_PREALLOC))) {
printf("VM: exec: map_page_region for data failed\n");
map_free_proc(vmp);
SANITYCHECK(SCL_DETAIL);
return ENOMEM;
}
/* Tag the heap so brk() call knows which region to extend. */
map_region_set_tag(vmp->vm_heap, VRT_HEAP);
/* How many address space clicks between end of data
* and start of stack?
* stacktop is the first address after the stack, as addressed
* from within the user process.
*/
hole_bytes = stacktop - data_bytes - stack_bytes
- gap_bytes - data_addr;
map_stack_addr = map_data_addr + data_bytes + hole_bytes;
if(!(reg=map_page_region(vmp,
map_stack_addr,
0, stack_bytes + gap_bytes, MAP_NONE,
VR_ANON | VR_WRITABLE, prealloc_stack ? MF_PREALLOC : 0)) != OK) {
panic("map_page_region failed for stack");
}
map_region_set_tag(reg, VRT_STACK);
vmp->vm_arch.vm_seg[D].mem_phys = ABS2CLICK(map_data_addr);
vmp->vm_arch.vm_seg[D].mem_vir = ABS2CLICK(data_addr);
vmp->vm_arch.vm_seg[D].mem_len = ABS2CLICK(data_bytes);
vmp->vm_arch.vm_seg[S].mem_phys = ABS2CLICK(map_data_addr +
data_bytes + gap_bytes + hole_bytes);
vmp->vm_arch.vm_seg[S].mem_vir = ABS2CLICK(data_addr +
data_bytes + gap_bytes + hole_bytes);
/* Where are we allowed to start using the rest of the virtual
* address space?
*/
vmp->vm_stacktop = stacktop;
vmp->vm_flags |= VMF_HASPT;
if(vmp->vm_endpoint != NONE) {
/* Pretend the stack is the full size of the data segment, so
* we get a full-sized data segment, up to VM_DATATOP.
* After sys_newmap(), change the stack to what we know the
* stack to be (up to stacktop).
*/
vmp->vm_arch.vm_seg[S].mem_len = (VM_DATATOP >> CLICK_SHIFT) -
vmp->vm_arch.vm_seg[S].mem_vir - ABS2CLICK(map_data_addr);
/* What is the final size of the data segment in bytes? */
vmp->vm_arch.vm_data_top =
(vmp->vm_arch.vm_seg[S].mem_vir +
vmp->vm_arch.vm_seg[S].mem_len) << CLICK_SHIFT;
if((s=sys_newmap(vmp->vm_endpoint, vmp->vm_arch.vm_seg)) != OK)
panic("sys_newmap (vm) failed: %d", s);
if((s=pt_bind(&vmp->vm_pt, vmp)) != OK)
panic("exec_newmem: pt_bind failed: %d", s);
}
return OK;
}
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