path: root/lib
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-05 11:29:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-05 11:29:27 -0700
commit5336377d6225959624146629ce3fc88ee8ecda3d (patch)
tree571b9db75d1ba50faa1e399509563f367fd5694f /lib
parent2f6b3aa7a563d05453c4d73ccf88191aee84333f (diff)
modules: Fix module_bug_list list corruption race
With all the recent module loading cleanups, we've minimized the code that sits under module_mutex, fixing various deadlocks and making it possible to do most of the module loading in parallel. However, that whole conversion totally missed the rather obscure code that adds a new module to the list for BUG() handling. That code was doubly obscure because (a) the code itself lives in lib/bugs.c (for dubious reasons) and (b) it gets called from the architecture-specific "module_finalize()" rather than from generic code. Calling it from arch-specific code makes no sense what-so-ever to begin with, and is now actively wrong since that code isn't protected by the module loading lock any more. So this commit moves the "module_bug_{finalize,cleanup}()" calls away from the arch-specific code, and into the generic code - and in the process protects it with the module_mutex so that the list operations are now safe. Future fixups: - move the module list handling code into kernel/module.c where it belongs. - get rid of 'module_bug_list' and just use the regular list of modules (called 'modules' - imagine that) that we already create and maintain for other reasons. Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Adrian Bunk <bunk@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
1 files changed, 2 insertions, 4 deletions
diff --git a/lib/bug.c b/lib/bug.c
index 7cdfad88128..19552096d16 100644
--- a/lib/bug.c
+++ b/lib/bug.c
@@ -72,8 +72,8 @@ static const struct bug_entry *module_find_bug(unsigned long bugaddr)
return NULL;
-int module_bug_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
- struct module *mod)
+void module_bug_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
+ struct module *mod)
char *secstrings;
unsigned int i;
@@ -97,8 +97,6 @@ int module_bug_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
* could potentially lead to deadlock and thus be counter-productive.
list_add(&mod->bug_list, &module_bug_list);
- return 0;
void module_bug_cleanup(struct module *mod)