Messages in this thread Patch in this message | | | From | Petr Mladek <> | Subject | [PATCH 2/2] kprobes/x86: Check for invalid ftrace location in __recover_probed_insn() | Date | Fri, 20 Feb 2015 11:16:42 +0100 |
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__recover_probed_insn() should always be called from an address where an instructions starts. The check for ftrace_location() might help to discover a potential inconsistency. Something goes terribly wrong when an address inside the ftrace location is checked. Let's BUG() in this case.
Suggested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> --- arch/x86/kernel/kprobes/core.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 2f464b56766a..124577dcf768 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -228,6 +228,12 @@ __recover_probed_insn(kprobe_opcode_t *buf, unsigned long addr) kp = get_kprobe((void *)addr); faddr = ftrace_location(addr); /* + * Addresses inside the ftrace location are refused by + * arch_check_ftrace_location(). Something went terribly wrong + * if such an address is checked here. + */ + BUG_ON(faddr && faddr != addr); + /* * Use the current code if it is not modified by Kprobe * and it cannot be modified by ftrace. */ -- 1.8.5.6
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