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Write protect the text segment of gzip'ed programs.

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Various other cleanups by phk.

Reviewed by:	phk
Submitted by:	Igor Khasilev <igor@jabber.paco.odessa.ua>
This commit is contained in:
Poul-Henning Kamp 1996-08-01 22:00:14 +00:00
parent a2970ccbcf
commit 5e9ed9c990
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=17386
1 changed files with 21 additions and 27 deletions
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48
sys/kern/imgact_gzip.c
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@ -6,7 +6,7 @@
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* $Id: imgact_gzip.c,v 1.21 1996/05/01 02:42:50 bde Exp $
* $Id: imgact_gzip.c,v 1.22 1996/05/02 10:43:16 phk Exp $
*
* This module handles execution of a.out files which have been run through
* "gzip". This saves diskspace, but wastes cpu-cycles and VM.
@ -69,6 +69,7 @@ exec_gzip_imgact(imgp)
u_char *p = (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)
@ -110,10 +111,19 @@ exec_gzip_imgact(imgp)
if (igz.idx >= PAGE_SIZE)
return ENOEXEC;
}
igz.len = igz.ip->attr->va_size;
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,
@ -217,31 +227,10 @@ do_aout_hdr(struct imgact_gzip * gz)
vmaddr = gz->virtual_offset;
error = vm_mmap(&vmspace->vm_map, /* map */
&vmaddr,/* address */
gz->a_out.a_text, /* size */
VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_WRITE, /* protection */
VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_WRITE,
MAP_ANON | MAP_FIXED, /* flags */
0, /* vnode */
0); /* offset */
if (error) {
gz->where = __LINE__;
return (error);
}
vmaddr = gz->virtual_offset + gz->a_out.a_text;
/*
* Map data read/write (if text is 0, assume text is in data area
* [Bill's screwball mode])
*/
error = vm_mmap(&vmspace->vm_map,
&vmaddr,
gz->a_out.a_data,
VM_PROT_READ | VM_PROT_WRITE | (gz->a_out.a_text ? 0 : VM_PROT_EXECUTE),
VM_PROT_ALL, MAP_ANON | MAP_FIXED,
gz->a_out.a_text + gz->a_out.a_data,
VM_PROT_ALL, VM_PROT_ALL, MAP_ANON | MAP_FIXED,
0,
0);
@ -249,6 +238,7 @@ do_aout_hdr(struct imgact_gzip * gz)
gz->where = __LINE__;
return (error);
}
if (gz->bss_size != 0) {
/*
* Allocate demand-zeroed area for uninitialized data.
@ -257,8 +247,12 @@ do_aout_hdr(struct imgact_gzip * gz)
*/
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);
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);