kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Use list_head in binfmt handling

Browse source 
Switch single-linked binfmt formats list to usual list_head's.  This leads
to one-liners in register_binfmt() and unregister_binfmt().  The downside
is one pointer more in struct linux_binfmt.  This is not a problem, since
the set of registered binfmts on typical box is very small -- (ELF +
something distro enabled for you).

Test-booted, played with executable .txt files, modprobe/rmmod binfmt_misc.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexey Dobriyan 2007-10-16 23:26:03 -07:00 committed by Linus Torvalds
parent deba0f49b9
commit e4dc1b14d8
4 changed files with 17 additions and 33 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
arch/mips/kernel/irixelf.c
View file

@ -47,8 +47,11 @@ static int irix_core_dump(long signr, struct pt_regs * regs,
struct file *file);
static struct linux_binfmt irix_format = {
NULL, THIS_MODULE, load_irix_binary, load_irix_library,
irix_core_dump, PAGE_SIZE
.module = THIS_MODULE,
.load_binary = load_irix_binary,
.load_shlib = load_irix_library,
.core_dump = irix_core_dump,
.min_coredump = PAGE_SIZE,
};
/* Debugging routines. */

7
arch/sparc64/kernel/binfmt_aout32.c
View file

@ -38,8 +38,11 @@ static int load_aout32_library(struct file*);
static int aout32_core_dump(long signr, struct pt_regs * regs, struct file *file);
static struct linux_binfmt aout32_format = {
NULL, THIS_MODULE, load_aout32_binary, load_aout32_library, aout32_core_dump,
PAGE_SIZE
.module = THIS_MODULE,
.load_binary = load_aout32_binary,
.load_shlib = load_aout32_library,
.core_dump = aout32_core_dump,
.min_coredump = PAGE_SIZE,
};
static void set_brk(unsigned long start, unsigned long end)

32
fs/exec.c
View file

@ -66,27 +66,15 @@ int suid_dumpable = 0;
EXPORT_SYMBOL(suid_dumpable);
/* The maximal length of core_pattern is also specified in sysctl.c */
static struct linux_binfmt *formats;
static LIST_HEAD(formats);
static DEFINE_RWLOCK(binfmt_lock);
int register_binfmt(struct linux_binfmt * fmt)
{
struct linux_binfmt ** tmp = &formats;
if (!fmt)
return -EINVAL;
if (fmt->next)
return -EBUSY;
write_lock(&binfmt_lock);
while (*tmp) {
if (fmt == *tmp) {
write_unlock(&binfmt_lock);
return -EBUSY;
}
tmp = &(*tmp)->next;
}
fmt->next = formats;
formats = fmt;
list_add(&fmt->lh, &formats);
write_unlock(&binfmt_lock);
return 0;
}
@ -95,20 +83,10 @@ EXPORT_SYMBOL(register_binfmt);
int unregister_binfmt(struct linux_binfmt * fmt)
{
struct linux_binfmt ** tmp = &formats;
write_lock(&binfmt_lock);
while (*tmp) {
if (fmt == *tmp) {
*tmp = fmt->next;
fmt->next = NULL;
list_del(&fmt->lh);
write_unlock(&binfmt_lock);
return 0;
}
tmp = &(*tmp)->next;
}
write_unlock(&binfmt_lock);
return -EINVAL;
}
EXPORT_SYMBOL(unregister_binfmt);
@ -155,7 +133,7 @@ asmlinkage long sys_uselib(const char __user * library)
struct linux_binfmt * fmt;
read_lock(&binfmt_lock);
for (fmt = formats ; fmt ; fmt = fmt->next) {
list_for_each_entry(fmt, &formats, lh) {
if (!fmt->load_shlib)
continue;
if (!try_module_get(fmt->module))
@ -1284,7 +1262,7 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
retval = -ENOENT;
for (try=0; try<2; try++) {
read_lock(&binfmt_lock);
for (fmt = formats ; fmt ; fmt = fmt->next) {
list_for_each_entry(fmt, &formats, lh) {
int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary;
if (!fn)
continue;

2
include/linux/binfmts.h
View file

@ -63,7 +63,7 @@ struct linux_binprm{
* linux accepts.
*/
struct linux_binfmt {
struct linux_binfmt * next;
struct list_head lh;
struct module *module;
int (*load_binary)(struct linux_binprm *, struct pt_regs * regs);
int (*load_shlib)(struct file *);