Use list_head in binfmt handling
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>
diff --git a/arch/mips/kernel/irixelf.c b/arch/mips/kernel/irixelf.c
index 8ef5cf4..5a3fe43 100644
--- a/arch/mips/kernel/irixelf.c
+++ b/arch/mips/kernel/irixelf.c
@@ -47,8 +47,11 @@
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. */
diff --git a/arch/sparc64/kernel/binfmt_aout32.c b/arch/sparc64/kernel/binfmt_aout32.c
index d208cc7..c8acbea 100644
--- a/arch/sparc64/kernel/binfmt_aout32.c
+++ b/arch/sparc64/kernel/binfmt_aout32.c
@@ -38,8 +38,11 @@
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)
diff --git a/fs/exec.c b/fs/exec.c
index 073b0b8..65825bd 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -66,27 +66,15 @@
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 @@
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;
- write_unlock(&binfmt_lock);
- return 0;
- }
- tmp = &(*tmp)->next;
- }
+ list_del(&fmt->lh);
write_unlock(&binfmt_lock);
- return -EINVAL;
+ return 0;
}
EXPORT_SYMBOL(unregister_binfmt);
@@ -155,7 +133,7 @@
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 @@
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;
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index 91c8c07..6b834dc 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -63,7 +63,7 @@
* 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 *);
