From 74641f584da8eccf30becfbb5507ab457187db22 Mon Sep 17 00:00:00 2001 From: Ivan Kokshaysky Date: Thu, 30 Apr 2009 15:08:49 -0700 Subject: [PATCH] alpha: binfmt_aout fix This fixes the problem introduced by commit 3bfacef412 (get rid of special-casing the /sbin/loader on alpha): osf/1 ecoff binary segfaults when binfmt_aout built as module. That happens because aout binary handler gets on the top of the binfmt list due to late registration, and kernel attempts to execute the binary without preparatory work that must be done by binfmt_loader. Fixed by changing the registration order of the default binfmt handlers using list_add_tail() and introducing insert_binfmt() function which places new handler on the top of the binfmt list. This might be generally useful for installing arch-specific frontends for default handlers or just for overriding them. Signed-off-by: Ivan Kokshaysky Cc: Al Viro Cc: Richard Henderson Signed-off-by: Linus Torvalds --- arch/alpha/kernel/Makefile | 6 +++++- arch/alpha/kernel/binfmt_loader.c | 2 +- fs/exec.c | 7 ++++--- include/linux/binfmts.h | 14 +++++++++++++- 4 files changed, 23 insertions(+), 6 deletions(-) diff --git a/arch/alpha/kernel/Makefile b/arch/alpha/kernel/Makefile index a427538252f8..7739a62440a7 100644 --- a/arch/alpha/kernel/Makefile +++ b/arch/alpha/kernel/Makefile @@ -8,7 +8,7 @@ EXTRA_CFLAGS := -Werror -Wno-sign-compare obj-y := entry.o traps.o process.o init_task.o osf_sys.o irq.o \ irq_alpha.o signal.o setup.o ptrace.o time.o \ - alpha_ksyms.o systbls.o err_common.o io.o binfmt_loader.o + alpha_ksyms.o systbls.o err_common.o io.o obj-$(CONFIG_VGA_HOSE) += console.o obj-$(CONFIG_SMP) += smp.o @@ -43,6 +43,10 @@ else # Misc support obj-$(CONFIG_ALPHA_SRM) += srmcons.o +ifdef CONFIG_BINFMT_AOUT +obj-y += binfmt_loader.o +endif + # Core logic support obj-$(CONFIG_ALPHA_APECS) += core_apecs.o obj-$(CONFIG_ALPHA_CIA) += core_cia.o diff --git a/arch/alpha/kernel/binfmt_loader.c b/arch/alpha/kernel/binfmt_loader.c index 4a0af906b00a..3fcfad410130 100644 --- a/arch/alpha/kernel/binfmt_loader.c +++ b/arch/alpha/kernel/binfmt_loader.c @@ -46,6 +46,6 @@ static struct linux_binfmt loader_format = { static int __init init_loader_binfmt(void) { - return register_binfmt(&loader_format); + return insert_binfmt(&loader_format); } arch_initcall(init_loader_binfmt); diff --git a/fs/exec.c b/fs/exec.c index a3a8ce83940f..639177b0eeac 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -69,17 +69,18 @@ int suid_dumpable = 0; static LIST_HEAD(formats); static DEFINE_RWLOCK(binfmt_lock); -int register_binfmt(struct linux_binfmt * fmt) +int __register_binfmt(struct linux_binfmt * fmt, int insert) { if (!fmt) return -EINVAL; write_lock(&binfmt_lock); - list_add(&fmt->lh, &formats); + insert ? list_add(&fmt->lh, &formats) : + list_add_tail(&fmt->lh, &formats); write_unlock(&binfmt_lock); return 0; } -EXPORT_SYMBOL(register_binfmt); +EXPORT_SYMBOL(__register_binfmt); void unregister_binfmt(struct linux_binfmt * fmt) { diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 6638b8148de7..61ee18c1bdb4 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -82,7 +82,19 @@ struct linux_binfmt { int hasvdso; }; -extern int register_binfmt(struct linux_binfmt *); +extern int __register_binfmt(struct linux_binfmt *fmt, int insert); + +/* Registration of default binfmt handlers */ +static inline int register_binfmt(struct linux_binfmt *fmt) +{ + return __register_binfmt(fmt, 0); +} +/* Same as above, but adds a new binfmt at the top of the list */ +static inline int insert_binfmt(struct linux_binfmt *fmt) +{ + return __register_binfmt(fmt, 1); +} + extern void unregister_binfmt(struct linux_binfmt *); extern int prepare_binprm(struct linux_binprm *); -- 2.20.1