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| author | Peter Zijlstra <peterz@infradead.org> | 2022-03-08 16:30:29 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-03-15 10:32:37 +0100 |
| commit | aebfd12521d9c7d0b502cf6d06314cfbcdccfe3b (patch) | |
| tree | 32b122cd707b1a26aef2d1ac5612f013ee2821e4 /arch/x86/kernel/kprobes/core.c | |
| parent | 6649fa876da4c505548b8e8945a6fc48e62e427c (diff) | |
| download | linux-aebfd12521d9c7d0b502cf6d06314cfbcdccfe3b.tar.bz2 | |
x86/ibt,ftrace: Search for __fentry__ location
Currently a lot of ftrace code assumes __fentry__ is at sym+0. However
with Intel IBT enabled the first instruction of a function will most
likely be ENDBR.
Change ftrace_location() to not only return the __fentry__ location
when called for the __fentry__ location, but also when called for the
sym+0 location.
Then audit/update all callsites of this function to consistently use
these new semantics.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154318.227581603@infradead.org
Diffstat (limited to 'arch/x86/kernel/kprobes/core.c')
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 11 |
1 files changed, 2 insertions, 9 deletions
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 6290712cb36d..4d8086a1627e 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -193,17 +193,10 @@ static unsigned long __recover_probed_insn(kprobe_opcode_t *buf, unsigned long addr) { struct kprobe *kp; - unsigned long faddr; + bool faddr; 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. - */ - if (WARN_ON(faddr && faddr != addr)) - return 0UL; + faddr = ftrace_location(addr) == addr; /* * Use the current code if it is not modified by Kprobe * and it cannot be modified by ftrace. |