d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Refactor ELF interpreter loading into a separate function.

Browse Source 
Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D19741
This commit is contained in:
Edward Tomasz Napierala 2019-04-08 14:31:07 +00:00
parent de0b14f2db
commit 9274fb3599
1 changed files with 41 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
sys/kern/imgact_elf.c
View File

@ -945,6 +945,41 @@ __elfN(get_interp)(struct image_params *imgp, const Elf_Phdr *phdr,
return (0);
}
static int
__elfN(load_interp)(struct image_params *imgp, const Elf_Brandinfo *brand_info,
const char *interp, u_long *addr, u_long *entry)
{
char *path;
int error;
if (brand_info->emul_path != NULL &&
brand_info->emul_path[0] != '\0') {
path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
snprintf(path, MAXPATHLEN, "%s%s",
brand_info->emul_path, interp);
error = __elfN(load_file)(imgp->proc, path, addr, entry);
free(path, M_TEMP);
if (error == 0)
return (0);
}
if (brand_info->interp_newpath != NULL &&
(brand_info->interp_path == NULL ||
strcmp(interp, brand_info->interp_path) == 0)) {
error = __elfN(load_file)(imgp->proc,
brand_info->interp_newpath, addr, entry);
if (error == 0)
return (0);
}
error = __elfN(load_file)(imgp->proc, interp, addr, entry);
if (error == 0)
return (0);
uprintf("ELF interpreter %s not found, error %d\n", interp, error);
return (error);
}
/*
* Impossible et_dyn_addr initial value indicating that the real base
* must be calculated later with some randomization applied.
@ -960,8 +995,7 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
Elf_Auxargs *elf_auxargs;
struct vmspace *vmspace;
vm_map_t map;
const char *newinterp;
char *interp, *path;
char *interp;
Elf_Brandinfo *brand_info;
struct sysentvec *sv;
vm_prot_t prot;
@ -970,7 +1004,7 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
uint32_t fctl0;
int32_t osrel;
bool free_interp;
int error, i, n, have_interp;
int error, i, n;
hdr = (const Elf_Ehdr *)imgp->image_header;
@ -1006,7 +1040,7 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
osrel = 0;
fctl0 = 0;
entry = proghdr = 0;
newinterp = interp = NULL;
interp = NULL;
free_interp = false;
td = curthread;
maxalign = PAGE_SIZE;
@ -1074,8 +1108,6 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
et_dyn_addr = ET_DYN_LOAD_ADDR;
}
}
if (interp != NULL && brand_info->interp_newpath != NULL)
newinterp = brand_info->interp_newpath;
/*
* Avoid a possible deadlock if the current address space is destroyed
@ -1200,7 +1232,6 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
imgp->entry_addr = entry;
if (interp != NULL) {
have_interp = FALSE;
VOP_UNLOCK(imgp->vp, 0);
if ((map->flags & MAP_ASLR) != 0) {
/* Assume that interpeter fits into 1/4 of AS */
@ -1209,35 +1240,11 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
addr = __CONCAT(rnd_, __elfN(base))(map, addr,
maxv1, PAGE_SIZE);
}
if (brand_info->emul_path != NULL &&
brand_info->emul_path[0] != '\0') {
path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
snprintf(path, MAXPATHLEN, "%s%s",
brand_info->emul_path, interp);
error = __elfN(load_file)(imgp->proc, path, &addr,
&imgp->entry_addr);
free(path, M_TEMP);
if (error == 0)
have_interp = TRUE;
}
if (!have_interp && newinterp != NULL &&
(brand_info->interp_path == NULL ||
strcmp(interp, brand_info->interp_path) == 0)) {
error = __elfN(load_file)(imgp->proc, newinterp, &addr,
&imgp->entry_addr);
if (error == 0)
have_interp = TRUE;
}
if (!have_interp) {
error = __elfN(load_file)(imgp->proc, interp, &addr,
&imgp->entry_addr);
}
error = __elfN(load_interp)(imgp, brand_info, interp, &addr,
&imgp->entry_addr);
vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
if (error != 0) {
uprintf("ELF interpreter %s not found, error %d\n",
interp, error);
if (error != 0)
goto ret;
}
} else
addr = et_dyn_addr;