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Moved elf brand identification into a function. Fully identify the

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brand early in the process of loading an elf file, so that we can
identify the sysentvec, and so that we do not continue if we do not
have a brand (and thus a sysentvec).  Use the values in the sysentvec
for the page size and vm ranges unconditionally, since they are all
filled in now.
This commit is contained in:
Jake Burkholder 2002-09-02 04:50:57 +00:00
parent 8a59b15cd4
commit 5fe3ed629a
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=102836
1 changed files with 75 additions and 105 deletions
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180
sys/kern/imgact_elf.c
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@ -71,6 +71,8 @@ __ElfType(Brandinfo);
__ElfType(Auxargs);
static int __elfN(check_header)(const Elf_Ehdr *hdr);
static Elf_Brandinfo *__elfN(get_brandinfo)(const Elf_Ehdr *hdr,
const char *interp);
static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
u_long *entry, size_t pagesize);
static int __elfN(load_section)(struct proc *p,
@ -87,6 +89,7 @@ SYSCTL_INT(_debug, OID_AUTO, elf64_trace, CTLFLAG_RW, &elf_trace, 0, "");
#endif
static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
extern int fallback_elf_brand;
int
__elfN(insert_brand_entry)(Elf_Brandinfo *entry)
@ -138,6 +141,50 @@ __elfN(brand_inuse)(Elf_Brandinfo *entry)
return (rval);
}
static Elf_Brandinfo *
__elfN(get_brandinfo)(const Elf_Ehdr *hdr, const char *interp)
{
Elf_Brandinfo *bi;
int i;
/*
* We support three types of branding -- (1) the ELF EI_OSABI field
* that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
* branding w/in the ELF header, and (3) path of the `interp_path'
* field. We should also look for an ".note.ABI-tag" ELF section now
* in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones.
*/
/* If the executable has a brand, search for it in the brand list. */
for (i = 0; i < MAX_BRANDS; i++) {
bi = elf_brand_list[i];
if (bi != NULL && hdr->e_machine == bi->machine &&
(hdr->e_ident[EI_OSABI] == bi->brand ||
strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0))
return (bi);
}
/* Lacking a known brand, search for a recognized interpreter. */
if (interp != NULL) {
for (i = 0; i < MAX_BRANDS; i++) {
bi = elf_brand_list[i];
if (bi != NULL && hdr->e_machine == bi->machine &&
strcmp(interp, bi->interp_path) == 0)
return (bi);
}
}
/* Lacking a recognized interpreter, try the default brand */
for (i = 0; i < MAX_BRANDS; i++) {
bi = elf_brand_list[i];
if (bi != NULL && hdr->e_machine == bi->machine &&
fallback_elf_brand == bi->brand)
return (bi);
}
return (NULL);
}
static int
__elfN(check_header)(const Elf_Ehdr *hdr)
{
@ -578,8 +625,6 @@ __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
return (error);
}
extern int fallback_elf_brand;
static int
__CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
{
@ -592,12 +637,12 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
u_long text_addr = 0, data_addr = 0;
u_long seg_size, seg_addr;
u_long addr, entry = 0, proghdr = 0;
vm_offset_t maxuser, usrstack, pagesize;
int error, i;
const char *interp = NULL;
Elf_Brandinfo *brand_info;
char *path;
struct thread *td = curthread;
struct sysentvec *sv;
GIANT_REQUIRED;
@ -625,41 +670,35 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
VOP_UNLOCK(imgp->vp, 0, td);
if ((error = exec_extract_strings(imgp)) != 0)
goto fail;
/*
* Tentatively identify the brand based on the machine so that
* we can figure out VM ranges and page sizes.
*/
brand_info = NULL;
for (i = 0; i < MAX_BRANDS; i++) {
Elf_Brandinfo *bi = elf_brand_list[i];
if (bi != NULL &&
hdr->e_machine == bi->machine &&
(hdr->e_ident[EI_OSABI] == bi->brand
|| 0 ==
strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
bi->compat_3_brand, strlen(bi->compat_3_brand)))) {
brand_info = bi;
for (i = 0; i < hdr->e_phnum; i++) {
switch (phdr[i].p_type) {
case PT_INTERP: /* Path to interpreter */
if (phdr[i].p_filesz > MAXPATHLEN ||
phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) {
error = ENOEXEC;
goto fail;
}
interp = imgp->image_header + phdr[i].p_offset;
break;
default:
break;
}
}
pagesize = PAGE_SIZE;
maxuser = VM_MAXUSER_ADDRESS;
usrstack = USRSTACK;
if (brand_info) {
if (brand_info->sysvec->sv_pagesize)
pagesize = brand_info->sysvec->sv_pagesize;
if (brand_info->sysvec->sv_maxuser)
maxuser = brand_info->sysvec->sv_maxuser;
if (brand_info->sysvec->sv_usrstack)
usrstack = brand_info->sysvec->sv_usrstack;
brand_info = __elfN(get_brandinfo)(hdr, interp);
if (brand_info == NULL) {
uprintf("ELF binary type \"%u\" not known.\n",
hdr->e_ident[EI_OSABI]);
error = ENOEXEC;
goto fail;
}
sv = brand_info->sysvec;
exec_new_vmspace(imgp, VM_MIN_ADDRESS, maxuser, usrstack);
if ((error = exec_extract_strings(imgp)) != 0)
goto fail;
exec_new_vmspace(imgp, sv->sv_minuser, sv->sv_maxuser,
sv->sv_usrstack);
vmspace = imgp->proc->p_vmspace;
@ -687,7 +726,7 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
imgp->vp, imgp->object, phdr[i].p_offset,
(caddr_t)(uintptr_t)phdr[i].p_vaddr,
phdr[i].p_memsz, phdr[i].p_filesz, prot,
pagesize)) != 0)
sv->sv_pagesize)) != 0)
goto fail;
seg_addr = trunc_page(phdr[i].p_vaddr);
@ -730,14 +769,6 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
entry = (u_long)hdr->e_entry;
}
break;
case PT_INTERP: /* Path to interpreter */
if (phdr[i].p_filesz > MAXPATHLEN ||
phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) {
error = ENOEXEC;
goto fail;
}
interp = imgp->image_header + phdr[i].p_offset;
break;
case PT_PHDR: /* Program header table info */
proghdr = phdr[i].p_vaddr;
break;
@ -755,76 +786,15 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
imgp->entry_addr = entry;
brand_info = NULL;
/* We support three types of branding -- (1) the ELF EI_OSABI field
* that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
* branding w/in the ELF header, and (3) path of the `interp_path'
* field. We should also look for an ".note.ABI-tag" ELF section now
* in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones.
*/
/* If the executable has a brand, search for it in the brand list. */
if (brand_info == NULL) {
for (i = 0; i < MAX_BRANDS; i++) {
Elf_Brandinfo *bi = elf_brand_list[i];
if (bi != NULL &&
hdr->e_machine == bi->machine &&
(hdr->e_ident[EI_OSABI] == bi->brand
|| 0 ==
strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
bi->compat_3_brand, strlen(bi->compat_3_brand)))) {
brand_info = bi;
break;
}
}
}
/* Lacking a known brand, search for a recognized interpreter. */
if (brand_info == NULL && interp != NULL) {
for (i = 0; i < MAX_BRANDS; i++) {
Elf_Brandinfo *bi = elf_brand_list[i];
if (bi != NULL &&
hdr->e_machine == bi->machine &&
strcmp(interp, bi->interp_path) == 0) {
brand_info = bi;
break;
}
}
}
/* Lacking a recognized interpreter, try the default brand */
if (brand_info == NULL) {
for (i = 0; i < MAX_BRANDS; i++) {
Elf_Brandinfo *bi = elf_brand_list[i];
if (bi != NULL &&
hdr->e_machine == bi->machine &&
fallback_elf_brand == bi->brand) {
brand_info = bi;
break;
}
}
}
if (brand_info == NULL) {
uprintf("ELF binary type \"%u\" not known.\n",
hdr->e_ident[EI_OSABI]);
error = ENOEXEC;
goto fail;
}
imgp->proc->p_sysent = brand_info->sysvec;
imgp->proc->p_sysent = sv;
if (interp != NULL) {
path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
snprintf(path, MAXPATHLEN, "%s%s", brand_info->emul_path,
interp);
if ((error = __elfN(load_file)(imgp->proc, path, &addr,
&imgp->entry_addr, pagesize)) != 0) {
&imgp->entry_addr, sv->sv_pagesize)) != 0) {
if ((error = __elfN(load_file)(imgp->proc, interp,
&addr, &imgp->entry_addr, pagesize)) != 0) {
&addr, &imgp->entry_addr, sv->sv_pagesize)) != 0) {
uprintf("ELF interpreter %s not found\n",
path);
free(path, M_TEMP);