diff options
| author | Arjan van de Ven <arjan@linux.intel.com> | 2008-08-15 15:29:38 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-09-10 09:08:53 +0200 |
| commit | ab7476cf76e560f0efda2a631a70aabe93009025 (patch) | |
| tree | d4e843760774d7099692950a6ac49ccdbc8b0d55 /kernel | |
| parent | fb822db465bd9fd4208eef1af4490539b236c54e (diff) | |
debug: add notifier chain debugging, v2
- unbreak ia64 (and powerpc) where function pointers dont
point at code but at data (reported by Tony Luck)
[ mingo@elte.hu: various cleanups ]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/extable.c | 16 | ||||
| -rw-r--r-- | kernel/notifier.c | 10 |
2 files changed, 17 insertions, 9 deletions
diff --git a/kernel/extable.c b/kernel/extable.c index a26cb2e1702..adf0cc9c02d 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -66,3 +66,19 @@ int kernel_text_address(unsigned long addr) return 1; return module_text_address(addr) != NULL; } + +/* + * On some architectures (PPC64, IA64) function pointers + * are actually only tokens to some data that then holds the + * real function address. As a result, to find if a function + * pointer is part of the kernel text, we need to do some + * special dereferencing first. + */ +int func_ptr_is_kernel_text(void *ptr) +{ + unsigned long addr; + addr = (unsigned long) dereference_function_descriptor(ptr); + if (core_kernel_text(addr)) + return 1; + return module_text_address(addr) != NULL; +} diff --git a/kernel/notifier.c b/kernel/notifier.c index 143fdd77dbf..0f39e398ef6 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -21,10 +21,6 @@ BLOCKING_NOTIFIER_HEAD(reboot_notifier_list); static int notifier_chain_register(struct notifier_block **nl, struct notifier_block *n) { - if (!kernel_text_address((unsigned long)n->notifier_call)) { - WARN(1, "Invalid notifier registered!"); - return 0; - } while ((*nl) != NULL) { if (n->priority > (*nl)->priority) break; @@ -38,10 +34,6 @@ static int notifier_chain_register(struct notifier_block **nl, static int notifier_chain_cond_register(struct notifier_block **nl, struct notifier_block *n) { - if (!kernel_text_address((unsigned long)n->notifier_call)) { - WARN(1, "Invalid notifier registered!"); - return 0; - } while ((*nl) != NULL) { if ((*nl) == n) return 0; @@ -92,7 +84,7 @@ static int __kprobes notifier_call_chain(struct notifier_block **nl, next_nb = rcu_dereference(nb->next); #ifdef CONFIG_DEBUG_NOTIFIERS - if (!kernel_text_address((unsigned long)nb->notifier_call)) { + if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) { WARN(1, "Invalid notifier called!"); nb = next_nb; continue; |