| Message ID | 1352958613-17599-1-git-send-email-herton.krzesinski@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c index f4546e9..23817a6 100644 --- a/arch/mips/kernel/kgdb.c +++ b/arch/mips/kernel/kgdb.c @@ -283,6 +283,15 @@ static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd, struct pt_regs *regs = args->regs; int trap = (regs->cp0_cause & 0x7c) >> 2; +#ifdef CONFIG_KPROBES + /* + * Return immediately if the kprobes fault notifier has set + * DIE_PAGE_FAULT. + */ + if (cmd == DIE_PAGE_FAULT) + return NOTIFY_DONE; +#endif /* CONFIG_KPROBES */ + /* Userspace events, ignore. */ if (user_mode(regs)) return NOTIFY_DONE;
This is a note to let you know that I have just added a patch titled mips,kgdb: fix recursive page fault with CONFIG_KPROBES to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.yuz tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From eb7ed4610e1414991c1225c0c497476fd1140487 Mon Sep 17 00:00:00 2001 From: Jason Wessel <jason.wessel@windriver.com> Date: Fri, 10 Aug 2012 12:21:15 -0500 Subject: [PATCH] mips,kgdb: fix recursive page fault with CONFIG_KPROBES commit f0a996eeeda214f4293e234df33b29bec003b536 upstream. This fault was detected using the kgdb test suite on boot and it crashes recursively due to the fact that CONFIG_KPROBES on mips adds an extra die notifier in the page fault handler. The crash signature looks like this: kgdbts:RUN bad memory access test KGDB: re-enter exception: ALL breakpoints killed Call Trace: [<807b7548>] dump_stack+0x20/0x54 [<807b7548>] dump_stack+0x20/0x54 The fix for now is to have kgdb return immediately if the fault type is DIE_PAGE_FAULT and allow the kprobe code to decide what is supposed to happen. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- arch/mips/kernel/kgdb.c | 9 +++++++++ 1 file changed, 9 insertions(+) -- 1.7.9.5