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freebsd/sys/kern/imgact_gzip.c
John Dyson 5856e12e69 Fully implement vfork. Vfork is now much much faster than even our
fork. (On my machine, fork is about 240usecs, vfork is 78usecs.)

Implement rfork(!RFPROC !RFMEM), which allows a thread to divorce its memory
	from the other threads of a group.

Implement rfork(!RFPROC RFCFDG), which closes all file descriptors, eliminating
	possible existing shares with other threads/processes.

Implement rfork(!RFPROC RFFDG), which divorces the file descriptors for a
	thread from the rest of the group.

Fix the case where a thread does an exec.  It is almost nonsense for a thread
	to modify the other threads address space by an exec, so we
	now automatically divorce the address space before modifying it.
1997-04-13 01:48:35 +00:00

381 lines
9.4 KiB
C

/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@login.dkuug.dk> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* $Id: imgact_gzip.c,v 1.28 1997/02/22 09:38:57 peter Exp $
*
* This module handles execution of a.out files which have been run through
* "gzip". This saves diskspace, but wastes cpu-cycles and VM.
*
* TODO:
* text-segments should be made R/O after being filled
* is the vm-stuff safe ?
* should handle the entire header of gzip'ed stuff.
* inflate isn't quite reentrant yet...
* error-handling is a mess...
* so is the rest...
* tidy up unnecesary includes
*/
#include "opt_rlimit.h"
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/imgact.h>
#include <sys/imgact_aout.h>
#include <sys/kernel.h>
#include <sys/mman.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/sysent.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/inflate.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <sys/lock.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
struct imgact_gzip {
struct image_params *ip;
struct exec a_out;
int error;
int where;
u_char *inbuf;
u_long offset;
u_long output;
u_long len;
int idx;
u_long virtual_offset, file_offset, file_end, bss_size;
};
static int exec_gzip_imgact __P((struct image_params *imgp));
static int NextByte __P((void *vp));
static int do_aout_hdr __P((struct imgact_gzip *));
static int Flush __P((void *vp, u_char *, u_long siz));
static int
exec_gzip_imgact(imgp)
struct image_params *imgp;
{
int error, error2 = 0;
const u_char *p = (const u_char *) imgp->image_header;
struct imgact_gzip igz;
struct inflate infl;
struct vmspace *vmspace;
/* If these four are not OK, it isn't a gzip file */
if (p[0] != 0x1f)
return -1; /* 0 Simply magic */
if (p[1] != 0x8b)
return -1; /* 1 Simply magic */
if (p[2] != 0x08)
return -1; /* 2 Compression method */
if (p[9] != 0x03)
return -1; /* 9 OS compressed on */
/*
* If this one contains anything but a comment or a filename marker,
* we don't want to chew on it
*/
if (p[3] & ~(0x18))
return ENOEXEC; /* 3 Flags */
/* These are of no use to us */
/* 4-7 Timestamp */
/* 8 Extra flags */
bzero(&igz, sizeof igz);
bzero(&infl, sizeof infl);
infl.gz_private = (void *) &igz;
infl.gz_input = NextByte;
infl.gz_output = Flush;
igz.ip = imgp;
igz.idx = 10;
if (p[3] & 0x08) { /* skip a filename */
while (p[igz.idx++])
if (igz.idx >= PAGE_SIZE)
return ENOEXEC;
}
if (p[3] & 0x10) { /* skip a comment */
while (p[igz.idx++])
if (igz.idx >= PAGE_SIZE)
return ENOEXEC;
}
igz.len = imgp->attr->va_size;
error = inflate(&infl);
if ( !error ) {
vmspace = imgp->proc->p_vmspace;
error = vm_map_protect(&vmspace->vm_map,
(vm_offset_t) vmspace->vm_taddr,
(vm_offset_t) (vmspace->vm_taddr +
(vmspace->vm_tsize << PAGE_SHIFT)) ,
VM_PROT_READ|VM_PROT_EXECUTE,0);
}
if (igz.inbuf) {
error2 =
vm_map_remove(kernel_map, (vm_offset_t) igz.inbuf,
(vm_offset_t) igz.inbuf + PAGE_SIZE);
}
if (igz.error || error || error2) {
printf("Output=%lu ", igz.output);
printf("Inflate_error=%d igz.error=%d error2=%d where=%d\n",
error, igz.error, error2, igz.where);
}
if (igz.error)
return igz.error;
if (error)
return ENOEXEC;
if (error2)
return error2;
return 0;
}
static int
do_aout_hdr(struct imgact_gzip * gz)
{
int error;
struct vmspace *vmspace;
vm_offset_t vmaddr;
/*
* Set file/virtual offset based on a.out variant. We do two cases:
* host byte order and network byte order (for NetBSD compatibility)
*/
switch ((int) (gz->a_out.a_magic & 0xffff)) {
case ZMAGIC:
gz->virtual_offset = 0;
if (gz->a_out.a_text) {
gz->file_offset = PAGE_SIZE;
} else {
/* Bill's "screwball mode" */
gz->file_offset = 0;
}
break;
case QMAGIC:
gz->virtual_offset = PAGE_SIZE;
gz->file_offset = 0;
break;
default:
/* NetBSD compatibility */
switch ((int) (ntohl(gz->a_out.a_magic) & 0xffff)) {
case ZMAGIC:
case QMAGIC:
gz->virtual_offset = PAGE_SIZE;
gz->file_offset = 0;
break;
default:
gz->where = __LINE__;
return (-1);
}
}
gz->bss_size = roundup(gz->a_out.a_bss, PAGE_SIZE);
/*
* Check various fields in header for validity/bounds.
*/
if ( /* entry point must lay with text region */
gz->a_out.a_entry < gz->virtual_offset ||
gz->a_out.a_entry >= gz->virtual_offset + gz->a_out.a_text ||
/* text and data size must each be page rounded */
gz->a_out.a_text & PAGE_MASK || gz->a_out.a_data & PAGE_MASK) {
gz->where = __LINE__;
return (-1);
}
/*
* text/data/bss must not exceed limits
*/
if ( /* text can't exceed maximum text size */
gz->a_out.a_text > MAXTSIZ ||
/* data + bss can't exceed maximum data size */
gz->a_out.a_data + gz->bss_size > MAXDSIZ ||
/* data + bss can't exceed rlimit */
gz->a_out.a_data + gz->bss_size >
gz->ip->proc->p_rlimit[RLIMIT_DATA].rlim_cur) {
gz->where = __LINE__;
return (ENOMEM);
}
/* Find out how far we should go */
gz->file_end = gz->file_offset + gz->a_out.a_text + gz->a_out.a_data;
/* copy in arguments and/or environment from old process */
error = exec_extract_strings(gz->ip);
if (error) {
gz->where = __LINE__;
return (error);
}
/*
* Destroy old process VM and create a new one (with a new stack)
*/
exec_new_vmspace(gz->ip);
vmspace = gz->ip->proc->p_vmspace;
vmaddr = gz->virtual_offset;
error = vm_mmap(&vmspace->vm_map,
&vmaddr,
gz->a_out.a_text + gz->a_out.a_data,
VM_PROT_ALL, VM_PROT_ALL, MAP_ANON | MAP_FIXED,
0,
0);
if (error) {
gz->where = __LINE__;
return (error);
}
if (gz->bss_size != 0) {
/*
* Allocate demand-zeroed area for uninitialized data.
* "bss" = 'block started by symbol' - named after the
* IBM 7090 instruction of the same name.
*/
vmaddr = gz->virtual_offset + gz->a_out.a_text +
gz->a_out.a_data;
error = vm_map_find(&vmspace->vm_map,
NULL,
0,
&vmaddr,
gz->bss_size,
FALSE, VM_PROT_ALL, VM_PROT_ALL, 0);
if (error) {
gz->where = __LINE__;
return (error);
}
}
/* Fill in process VM information */
vmspace->vm_tsize = gz->a_out.a_text >> PAGE_SHIFT;
vmspace->vm_dsize = (gz->a_out.a_data + gz->bss_size) >> PAGE_SHIFT;
vmspace->vm_taddr = (caddr_t) gz->virtual_offset;
vmspace->vm_daddr = (caddr_t) gz->virtual_offset + gz->a_out.a_text;
/* Fill in image_params */
gz->ip->interpreted = 0;
gz->ip->entry_addr = gz->a_out.a_entry;
gz->ip->proc->p_sysent = &aout_sysvec;
return 0;
}
static int
NextByte(void *vp)
{
int error;
struct imgact_gzip *igz = (struct imgact_gzip *) vp;
if (igz->idx >= igz->len) {
igz->where = __LINE__;
return GZ_EOF;
}
if (igz->inbuf && igz->idx < (igz->offset + PAGE_SIZE)) {
return igz->inbuf[(igz->idx++) - igz->offset];
}
if (igz->inbuf) {
error = vm_map_remove(kernel_map, (vm_offset_t) igz->inbuf,
(vm_offset_t) igz->inbuf + PAGE_SIZE);
if (error) {
igz->where = __LINE__;
igz->error = error;
return GZ_EOF;
}
}
igz->offset = igz->idx & ~PAGE_MASK;
error = vm_mmap(kernel_map, /* map */
(vm_offset_t *) & igz->inbuf, /* address */
PAGE_SIZE, /* size */
VM_PROT_READ, /* protection */
VM_PROT_READ, /* max protection */
0, /* flags */
(caddr_t) igz->ip->vp, /* vnode */
igz->offset); /* offset */
if (error) {
igz->where = __LINE__;
igz->error = error;
return GZ_EOF;
}
return igz->inbuf[(igz->idx++) - igz->offset];
}
static int
Flush(void *vp, u_char * ptr, u_long siz)
{
struct imgact_gzip *gz = (struct imgact_gzip *) vp;
u_char *p = ptr, *q;
int i;
/* First, find a a.out-header */
if (gz->output < sizeof gz->a_out) {
q = (u_char *) & gz->a_out;
i = min(siz, sizeof gz->a_out - gz->output);
bcopy(p, q + gz->output, i);
gz->output += i;
p += i;
siz -= i;
if (gz->output == sizeof gz->a_out) {
i = do_aout_hdr(gz);
if (i == -1) {
if (!gz->where)
gz->where = __LINE__;
gz->error = ENOEXEC;
return ENOEXEC;
} else if (i) {
gz->where = __LINE__;
gz->error = i;
return ENOEXEC;
}
if (gz->file_offset < sizeof gz->a_out) {
q = (u_char *) gz->virtual_offset + gz->output - gz->file_offset;
bcopy(&gz->a_out, q, sizeof gz->a_out - gz->file_offset);
}
}
}
/* Skip over zero-padded first PAGE if needed */
if (gz->output < gz->file_offset && (gz->output + siz) > gz->file_offset) {
i = min(siz, gz->file_offset - gz->output);
gz->output += i;
p += i;
siz -= i;
}
if (gz->output >= gz->file_offset && gz->output < gz->file_end) {
i = min(siz, gz->file_end - gz->output);
q = (u_char *) gz->virtual_offset + gz->output - gz->file_offset;
bcopy(p, q, i);
gz->output += i;
p += i;
siz -= i;
}
gz->output += siz;
return 0;
}
/*
* Tell kern_execve.c about it, with a little help from the linker.
* Since `const' objects end up in the text segment, TEXT_SET is the
* correct directive to use.
*/
static const struct execsw gzip_execsw = {exec_gzip_imgact, "gzip"};
TEXT_SET(execsw_set, gzip_execsw);