431 lines
12 KiB
C
431 lines
12 KiB
C
#include "inc.h"
|
|
#include <a.out.h>
|
|
|
|
#define BLOCK_SIZE 1024
|
|
|
|
static void do_exec(int proc_e, char *exec, size_t exec_len, char *progname,
|
|
char *frame, int frame_len);
|
|
FORWARD _PROTOTYPE( int read_header, (char *exec, size_t exec_len, int *sep_id,
|
|
vir_bytes *text_bytes, vir_bytes *data_bytes,
|
|
vir_bytes *bss_bytes, phys_bytes *tot_bytes, vir_bytes *pc,
|
|
int *hdrlenp) );
|
|
FORWARD _PROTOTYPE( int exec_newmem, (int proc_e, vir_bytes text_bytes,
|
|
vir_bytes data_bytes, vir_bytes bss_bytes, vir_bytes tot_bytes,
|
|
vir_bytes frame_len, int sep_id,
|
|
Dev_t st_dev, ino_t st_ino, time_t st_ctime, char *progname,
|
|
int new_uid, int new_gid,
|
|
vir_bytes *stack_topp, int *load_textp, int *allow_setuidp) );
|
|
FORWARD _PROTOTYPE( int exec_restart, (int proc_e, int result) );
|
|
FORWARD _PROTOTYPE( void patch_ptr, (char stack[ARG_MAX],
|
|
vir_bytes base) );
|
|
FORWARD _PROTOTYPE( int read_seg, (char *exec, size_t exec_len, off_t off,
|
|
int proc_e, int seg, phys_bytes seg_bytes) );
|
|
|
|
static int self_e= NONE;
|
|
|
|
int dev_execve(int proc_e, char *exec, size_t exec_len, char **argv,
|
|
char **Xenvp)
|
|
{
|
|
char * const *ap;
|
|
char * const *ep;
|
|
char *frame;
|
|
char **vp;
|
|
char *sp, *progname;
|
|
size_t argc;
|
|
size_t frame_size;
|
|
size_t string_off;
|
|
size_t n;
|
|
int ov;
|
|
message m;
|
|
|
|
/* Assumptions: size_t and char *, it's all the same thing. */
|
|
|
|
/* Create a stack image that only needs to be patched up slightly
|
|
* by the kernel to be used for the process to be executed.
|
|
*/
|
|
|
|
ov= 0; /* No overflow yet. */
|
|
frame_size= 0; /* Size of the new initial stack. */
|
|
string_off= 0; /* Offset to start of the strings. */
|
|
argc= 0; /* Argument count. */
|
|
|
|
for (ap= argv; *ap != NULL; ap++) {
|
|
n = sizeof(*ap) + strlen(*ap) + 1;
|
|
frame_size+= n;
|
|
if (frame_size < n) ov= 1;
|
|
string_off+= sizeof(*ap);
|
|
argc++;
|
|
}
|
|
|
|
#if 0
|
|
printf("here: %s, %d\n", __FILE__, __LINE__);
|
|
for (ep= envp; *ep != NULL; ep++) {
|
|
n = sizeof(*ep) + strlen(*ep) + 1;
|
|
frame_size+= n;
|
|
if (frame_size < n) ov= 1;
|
|
string_off+= sizeof(*ap);
|
|
}
|
|
#endif
|
|
|
|
/* Add an argument count and two terminating nulls. */
|
|
frame_size+= sizeof(argc) + sizeof(*ap) + sizeof(*ep);
|
|
string_off+= sizeof(argc) + sizeof(*ap) + sizeof(*ep);
|
|
|
|
/* Align. */
|
|
frame_size= (frame_size + sizeof(char *) - 1) & ~(sizeof(char *) - 1);
|
|
|
|
/* The party is off if there is an overflow. */
|
|
if (ov || frame_size < 3 * sizeof(char *)) {
|
|
errno= E2BIG;
|
|
return -1;
|
|
}
|
|
|
|
/* Allocate space for the stack frame. */
|
|
if ((frame = (char *) sbrk(frame_size)) == (char *) -1) {
|
|
errno = E2BIG;
|
|
return -1;
|
|
}
|
|
|
|
/* Set arg count, init pointers to vector and string tables. */
|
|
* (size_t *) frame = argc;
|
|
vp = (char **) (frame + sizeof(argc));
|
|
sp = frame + string_off;
|
|
|
|
/* Load the argument vector and strings. */
|
|
for (ap= argv; *ap != NULL; ap++) {
|
|
*vp++= (char *) (sp - frame);
|
|
n= strlen(*ap) + 1;
|
|
memcpy(sp, *ap, n);
|
|
sp+= n;
|
|
}
|
|
*vp++= NULL;
|
|
|
|
#if 0
|
|
/* Load the environment vector and strings. */
|
|
for (ep= envp; *ep != NULL; ep++) {
|
|
*vp++= (char *) (sp - frame);
|
|
n= strlen(*ep) + 1;
|
|
memcpy(sp, *ep, n);
|
|
sp+= n;
|
|
}
|
|
#endif
|
|
*vp++= NULL;
|
|
|
|
/* Padding. */
|
|
while (sp < frame + frame_size) *sp++= 0;
|
|
|
|
(progname=strrchr(argv[0], '/')) ? progname++ : (progname=argv[0]);
|
|
do_exec(proc_e, exec, exec_len, progname, frame, frame_size);
|
|
|
|
/* Failure, return the memory used for the frame and exit. */
|
|
(void) sbrk(-frame_size);
|
|
return -1;
|
|
}
|
|
|
|
static void do_exec(int proc_e, char *exec, size_t exec_len, char *progname,
|
|
char *frame, int frame_len)
|
|
{
|
|
int r;
|
|
int hdrlen, sep_id, load_text, allow_setuid;
|
|
int need_restart, error;
|
|
vir_bytes stack_top, vsp;
|
|
vir_bytes text_bytes, data_bytes, bss_bytes, pc;
|
|
phys_bytes tot_bytes;
|
|
off_t off;
|
|
uid_t new_uid;
|
|
gid_t new_gid;
|
|
|
|
need_restart= 0;
|
|
error= 0;
|
|
|
|
self_e = getnprocnr(getpid());
|
|
|
|
/* Read the file header and extract the segment sizes. */
|
|
r = read_header(exec, exec_len, &sep_id,
|
|
&text_bytes, &data_bytes, &bss_bytes,
|
|
&tot_bytes, &pc, &hdrlen);
|
|
if (r != OK)
|
|
{
|
|
printf("do_exec: read_header failed\n");
|
|
goto fail;
|
|
}
|
|
need_restart= 1;
|
|
|
|
new_uid= getuid();
|
|
new_gid= getgid();
|
|
/* XXX what should we use to identify the executable? */
|
|
r= exec_newmem(proc_e, text_bytes, data_bytes, bss_bytes, tot_bytes,
|
|
frame_len, sep_id, 0 /*dev*/, proc_e /*inum*/, 0 /*ctime*/,
|
|
progname, new_uid, new_gid, &stack_top, &load_text,
|
|
&allow_setuid);
|
|
if (r != OK)
|
|
{
|
|
printf("do_exec: exec_newmap failed: %d\n", r);
|
|
error= r;
|
|
goto fail;
|
|
}
|
|
|
|
/* Patch up stack and copy it from FS to new core image. */
|
|
vsp = stack_top;
|
|
vsp -= frame_len;
|
|
patch_ptr(frame, vsp);
|
|
r = sys_datacopy(SELF, (vir_bytes) frame,
|
|
proc_e, (vir_bytes) vsp, (phys_bytes)frame_len);
|
|
if (r != OK) panic(__FILE__,"pm_exec stack copy err on", proc_e);
|
|
|
|
off = hdrlen;
|
|
|
|
/* Read in text and data segments. */
|
|
if (load_text) {
|
|
r= read_seg(exec, exec_len, off, proc_e, T, text_bytes);
|
|
if (r != OK)
|
|
{
|
|
printf("do_exec: read_seg failed: %d\n", r);
|
|
error= r;
|
|
goto fail;
|
|
}
|
|
}
|
|
else
|
|
printf("do_exec: not loading text segment\n");
|
|
|
|
off += text_bytes;
|
|
r= read_seg(exec, exec_len, off, proc_e, D, data_bytes);
|
|
if (r != OK)
|
|
{
|
|
printf("do_exec: read_seg failed: %d\n", r);
|
|
error= r;
|
|
goto fail;
|
|
}
|
|
|
|
exec_restart(proc_e, OK);
|
|
|
|
return;
|
|
|
|
fail:
|
|
printf("do_exec(fail): error = %d\n", error);
|
|
if (need_restart)
|
|
exec_restart(proc_e, error);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* exec_newmem *
|
|
*===========================================================================*/
|
|
PRIVATE int exec_newmem(proc_e, text_bytes, data_bytes, bss_bytes, tot_bytes,
|
|
frame_len, sep_id, st_dev, st_ino, st_ctime, progname,
|
|
new_uid, new_gid, stack_topp, load_textp, allow_setuidp)
|
|
int proc_e;
|
|
vir_bytes text_bytes;
|
|
vir_bytes data_bytes;
|
|
vir_bytes bss_bytes;
|
|
vir_bytes tot_bytes;
|
|
vir_bytes frame_len;
|
|
int sep_id;
|
|
dev_t st_dev;
|
|
ino_t st_ino;
|
|
time_t st_ctime;
|
|
int new_uid;
|
|
int new_gid;
|
|
char *progname;
|
|
vir_bytes *stack_topp;
|
|
int *load_textp;
|
|
int *allow_setuidp;
|
|
{
|
|
int r;
|
|
struct exec_newmem e;
|
|
message m;
|
|
|
|
e.text_bytes= text_bytes;
|
|
e.data_bytes= data_bytes;
|
|
e.bss_bytes= bss_bytes;
|
|
e.tot_bytes= tot_bytes;
|
|
e.args_bytes= frame_len;
|
|
e.sep_id= sep_id;
|
|
e.st_dev= st_dev;
|
|
e.st_ino= st_ino;
|
|
e.st_ctime= st_ctime;
|
|
e.new_uid= new_uid;
|
|
e.new_gid= new_gid;
|
|
strncpy(e.progname, progname, sizeof(e.progname)-1);
|
|
e.progname[sizeof(e.progname)-1]= '\0';
|
|
|
|
m.m_type= EXEC_NEWMEM;
|
|
m.EXC_NM_PROC= proc_e;
|
|
m.EXC_NM_PTR= (char *)&e;
|
|
r= sendrec(PM_PROC_NR, &m);
|
|
if (r != OK)
|
|
return r;
|
|
#if 0
|
|
printf("exec_newmem: r = %d, m_type = %d\n", r, m.m_type);
|
|
#endif
|
|
*stack_topp= m.m1_i1;
|
|
*load_textp= !!(m.m1_i2 & EXC_NM_RF_LOAD_TEXT);
|
|
*allow_setuidp= !!(m.m1_i2 & EXC_NM_RF_ALLOW_SETUID);
|
|
#if 0
|
|
printf("exec_newmem: stack_top = 0x%x\n", *stack_topp);
|
|
printf("exec_newmem: load_text = %d\n", *load_textp);
|
|
#endif
|
|
return m.m_type;
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* exec_restart *
|
|
*===========================================================================*/
|
|
PRIVATE int exec_restart(proc_e, result)
|
|
int proc_e;
|
|
int result;
|
|
{
|
|
int r;
|
|
message m;
|
|
|
|
m.m_type= EXEC_RESTART;
|
|
m.EXC_RS_PROC= proc_e;
|
|
m.EXC_RS_RESULT= result;
|
|
r= sendrec(PM_PROC_NR, &m);
|
|
if (r != OK)
|
|
return r;
|
|
return m.m_type;
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* read_header *
|
|
*===========================================================================*/
|
|
PRIVATE int read_header(exec, exec_len, sep_id, text_bytes, data_bytes,
|
|
bss_bytes, tot_bytes, pc, hdrlenp)
|
|
char *exec; /* executable image */
|
|
size_t exec_len; /* size of the image */
|
|
int *sep_id; /* true iff sep I&D */
|
|
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 */
|
|
vir_bytes *pc; /* program entry point (initial PC) */
|
|
int *hdrlenp;
|
|
{
|
|
/* Read the header and extract the text, data, bss and total sizes from it. */
|
|
off_t pos;
|
|
block_t b;
|
|
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.
|
|
*/
|
|
int r;
|
|
|
|
pos= 0; /* Read from the start of the file */
|
|
|
|
if (exec_len < sizeof(hdr)) return(ENOEXEC);
|
|
|
|
memcpy(&hdr, exec, sizeof(hdr));
|
|
|
|
/* 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);
|
|
|
|
*sep_id = !!(hdr.a_flags & A_SEP); /* 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 */
|
|
if (*tot_bytes == 0) return(ENOEXEC);
|
|
|
|
if (!*sep_id) {
|
|
/* 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 */
|
|
*hdrlenp = hdr.a_hdrlen & BYTE; /* header length */
|
|
|
|
return(OK);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* patch_ptr *
|
|
*===========================================================================*/
|
|
PRIVATE void patch_ptr(stack, base)
|
|
char stack[ARG_MAX]; /* pointer to stack image within PM */
|
|
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++;
|
|
}
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* read_seg *
|
|
*===========================================================================*/
|
|
PRIVATE int read_seg(exec, exec_len, off, proc_e, seg, seg_bytes)
|
|
char *exec; /* executable image */
|
|
size_t exec_len; /* size of the image */
|
|
off_t off; /* offset in file */
|
|
int proc_e; /* process number (endpoint) */
|
|
int seg; /* T, D, or S */
|
|
phys_bytes seg_bytes; /* how much is to be transferred? */
|
|
{
|
|
/*
|
|
* 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 r;
|
|
off_t n, o, b_off, seg_off;
|
|
|
|
if (off+seg_bytes > exec_len) return ENOEXEC;
|
|
r= sys_vircopy(SELF, D, (vir_bytes)exec+off, proc_e, seg, 0, seg_bytes);
|
|
return r;
|
|
}
|
|
|