diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2017-02-14 00:03:38 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-11 12:45:27 +0200 |
| commit | f780f3fc81d54916d94ffef7282be5ca09b5017e (patch) | |
| tree | 082042162b562ee7756604946ea2f81483f99f7e /arch/arm/probes | |
| parent | 478791754649395287a5a8e3048784f4b2cc79a6 (diff) | |
arm: kprobes: Allow to handle reentered kprobe on single-stepping
commit f3fbd7ec62dec1528fb8044034e2885f2b257941 upstream.
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>
Fixes: 24ba613c9d6c ("ARM kprobes: core code")
Cc: stable@vger.kernel.org #v2.6.25~v4.11
Signed-off-by: huangshaobo <huangshaobo6@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/probes')
| -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 3eb018fa1a1f..c3362ddd6c4c 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -270,6 +270,7 @@ 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); @@ -278,6 +279,11 @@ 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(); |