Commit-ID: d81b4253b0f0f1e7b7e03b0cd0f80cab18bc4d7b Gitweb: http://git.kernel.org/tip/d81b4253b0f0f1e7b7e03b0cd0f80cab18bc4d7b Author: Masami Hiramatsu <[email protected]> AuthorDate: Thu, 17 Jul 2014 11:44:11 +0000 Committer: Ingo Molnar <[email protected]> CommitDate: Fri, 18 Jul 2014 06:23:40 +0200
kprobes: Fix "Failed to find blacklist" probing errors on ia64 and ppc64 On ia64 and ppc64, function pointers do not point to the entry address of the function, but to the address of a function descriptor (which contains the entry address and misc data). Since the kprobes code passes the function pointer stored by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for initalizing its blacklist, it fails and reports many errors, such as: Failed to find blacklist 0001013168300000 Failed to find blacklist 0001013000f0a000 [...] To fix this bug, use arch_deref_entry_point() to get the function entry address for kallsyms_lookup_size_offset() instead of the raw function pointer. Suzuki also pointed out that blacklist entries should also be updated as well. Reported-by: Tony Luck <[email protected]> Fixed-by: Suzuki K. Poulose <[email protected]> Tested-by: Tony Luck <[email protected]> Tested-by: Michael Ellerman <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Acked-by: Michael Ellerman <[email protected]> (for powerpc) Acked-by: Benjamin Herrenschmidt <[email protected]> Cc: Jeremy Fitzhardinge <[email protected]> Cc: [email protected] Cc: Paul Mackerras <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Fenghua Yu <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Rusty Russell <[email protected]> Cc: Chris Wright <[email protected]> Cc: [email protected] Cc: Kevin Hao <[email protected]> Cc: Ananth N Mavinakayanahalli <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Linus Torvalds <[email protected]> Cc: David S. Miller <[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- kernel/kprobes.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 3214289..734e9a7 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2037,19 +2037,23 @@ static int __init populate_kprobe_blacklist(unsigned long *start, { unsigned long *iter; struct kprobe_blacklist_entry *ent; - unsigned long offset = 0, size = 0; + unsigned long entry, offset = 0, size = 0; for (iter = start; iter < end; iter++) { - if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) { - pr_err("Failed to find blacklist %p\n", (void *)*iter); + entry = arch_deref_entry_point((void *)*iter); + + if (!kernel_text_address(entry) || + !kallsyms_lookup_size_offset(entry, &size, &offset)) { + pr_err("Failed to find blacklist at %p\n", + (void *)entry); continue; } ent = kmalloc(sizeof(*ent), GFP_KERNEL); if (!ent) return -ENOMEM; - ent->start_addr = *iter; - ent->end_addr = *iter + size; + ent->start_addr = entry; + ent->end_addr = entry + size; INIT_LIST_HEAD(&ent->list); list_add_tail(&ent->list, &kprobe_blacklist); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
