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>
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@ -47,8 +47,11 @@ static int irix_core_dump(long signr, struct pt_regs * regs,
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struct file *file);
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static struct linux_binfmt irix_format = {
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NULL, THIS_MODULE, load_irix_binary, load_irix_library,
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irix_core_dump, PAGE_SIZE
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.module = THIS_MODULE,
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.load_binary = load_irix_binary,
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.load_shlib = load_irix_library,
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.core_dump = irix_core_dump,
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.min_coredump = PAGE_SIZE,
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};
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/* Debugging routines. */
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@ -38,8 +38,11 @@ static int load_aout32_library(struct file*);
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static int aout32_core_dump(long signr, struct pt_regs * regs, struct file *file);
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static struct linux_binfmt aout32_format = {
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NULL, THIS_MODULE, load_aout32_binary, load_aout32_library, aout32_core_dump,
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PAGE_SIZE
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.module = THIS_MODULE,
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.load_binary = load_aout32_binary,
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.load_shlib = load_aout32_library,
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.core_dump = aout32_core_dump,
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.min_coredump = PAGE_SIZE,
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};
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static void set_brk(unsigned long start, unsigned long end)
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34
fs/exec.c
34
fs/exec.c
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@ -66,27 +66,15 @@ int suid_dumpable = 0;
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EXPORT_SYMBOL(suid_dumpable);
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/* The maximal length of core_pattern is also specified in sysctl.c */
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static struct linux_binfmt *formats;
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static LIST_HEAD(formats);
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static DEFINE_RWLOCK(binfmt_lock);
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int register_binfmt(struct linux_binfmt * fmt)
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{
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struct linux_binfmt ** tmp = &formats;
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if (!fmt)
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return -EINVAL;
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if (fmt->next)
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return -EBUSY;
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write_lock(&binfmt_lock);
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while (*tmp) {
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if (fmt == *tmp) {
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write_unlock(&binfmt_lock);
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return -EBUSY;
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}
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tmp = &(*tmp)->next;
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}
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fmt->next = formats;
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formats = fmt;
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list_add(&fmt->lh, &formats);
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write_unlock(&binfmt_lock);
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return 0;
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}
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@ -95,20 +83,10 @@ EXPORT_SYMBOL(register_binfmt);
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int unregister_binfmt(struct linux_binfmt * fmt)
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{
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struct linux_binfmt ** tmp = &formats;
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write_lock(&binfmt_lock);
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while (*tmp) {
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if (fmt == *tmp) {
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*tmp = fmt->next;
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fmt->next = NULL;
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write_unlock(&binfmt_lock);
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return 0;
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}
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tmp = &(*tmp)->next;
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}
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list_del(&fmt->lh);
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write_unlock(&binfmt_lock);
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return -EINVAL;
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return 0;
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}
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EXPORT_SYMBOL(unregister_binfmt);
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@ -155,7 +133,7 @@ asmlinkage long sys_uselib(const char __user * library)
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struct linux_binfmt * fmt;
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read_lock(&binfmt_lock);
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for (fmt = formats ; fmt ; fmt = fmt->next) {
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list_for_each_entry(fmt, &formats, lh) {
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if (!fmt->load_shlib)
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continue;
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if (!try_module_get(fmt->module))
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@ -1284,7 +1262,7 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
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retval = -ENOENT;
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for (try=0; try<2; try++) {
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read_lock(&binfmt_lock);
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for (fmt = formats ; fmt ; fmt = fmt->next) {
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list_for_each_entry(fmt, &formats, lh) {
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int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary;
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if (!fn)
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continue;
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@ -63,7 +63,7 @@ struct linux_binprm{
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* linux accepts.
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*/
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struct linux_binfmt {
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struct linux_binfmt * next;
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struct list_head lh;
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struct module *module;
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int (*load_binary)(struct linux_binprm *, struct pt_regs * regs);
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int (*load_shlib)(struct file *);
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