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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2017-02-13 18:03:38 +0300 |
|---|---|---|
| committer | Jon Medhurst <tixy@linaro.org> | 2017-03-21 19:24:18 +0300 |
| commit | f3fbd7ec62dec1528fb8044034e2885f2b257941 (patch) | |
| tree | 5e14e41e31c5716f061c3c6b04c5d333880b5b3c /arch/arm/probes/kprobes | |
| parent | 4495c08e84729385774601b5146d51d9e5849f81 (diff) | |
| download | linux-f3fbd7ec62dec1528fb8044034e2885f2b257941.tar.xz | |
arm: kprobes: Allow to handle reentered kprobe on single-stepping
This is arm port of commit 6a5022a56ac3 ("kprobes/x86: Allow to
handle reentered kprobe on single-stepping")
Since the FIQ handlers can interrupt in the single stepping
(or preparing the single stepping, do_debug etc.), we should
consider a kprobe is hit in the NMI handler. Even in that
case, the kprobe is allowed to be reentered as same as the
kprobes hit in kprobe handlers
(KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE).
The real issue will happen when a kprobe hit while another
reentered kprobe is processing (KPROBE_REENTER), because
we already consumed a saved-area for the previous kprobe.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Diffstat (limited to 'arch/arm/probes/kprobes')
| -rw-r--r-- | arch/arm/probes/kprobes/core.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index b6dc9d838a9a..35148b46c4f5 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -271,6 +271,7 @@ void __kprobes kprobe_handler(struct pt_regs *regs) switch (kcb->kprobe_status) { case KPROBE_HIT_ACTIVE: case KPROBE_HIT_SSDONE: + case KPROBE_HIT_SS: /* A pre- or post-handler probe got us here. */ kprobes_inc_nmissed_count(p); save_previous_kprobe(kcb); @@ -279,6 +280,11 @@ void __kprobes kprobe_handler(struct pt_regs *regs) singlestep(p, regs, kcb); restore_previous_kprobe(kcb); break; + case KPROBE_REENTER: + /* A nested probe was hit in FIQ, it is a BUG */ + pr_warn("Unrecoverable kprobe detected at %p.\n", + p->addr); + /* fall through */ default: /* impossible cases */ BUG(); |