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| author | Jisheng Zhang <jszhang@kernel.org> | 2021-03-29 21:14:40 +0300 |
|---|---|---|
| committer | Palmer Dabbelt <palmerdabbelt@google.com> | 2021-04-16 07:32:34 +0300 |
| commit | e31be8d343e64e7ab17aef55c1d1b36dc504da67 (patch) | |
| tree | ddaad7d4e24b5d2ff2f63069e0be6482a5d0af14 /arch/riscv | |
| parent | 2349a3b26e29b8d860466bafda2e02b4b87a9e40 (diff) | |
| download | linux-e31be8d343e64e7ab17aef55c1d1b36dc504da67.tar.xz | |
riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
Currently, the riscv's kprobes(powerred by ftrace) handler is
preemptible. Futher check indicates we miss something similar as the
commit c536aa1c5b17 ("kprobes/ftrace: Add recursion protection to the
ftrace callback"), so do similar modifications as the commit does.
Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported")
Cc: stable@vger.kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/kernel/probes/ftrace.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/riscv/kernel/probes/ftrace.c b/arch/riscv/kernel/probes/ftrace.c index 17ca5e923bb0..aab85a82f419 100644 --- a/arch/riscv/kernel/probes/ftrace.c +++ b/arch/riscv/kernel/probes/ftrace.c @@ -9,10 +9,16 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct kprobe *p; struct pt_regs *regs; struct kprobe_ctlblk *kcb; + int bit; + bit = ftrace_test_recursion_trylock(ip, parent_ip); + if (bit < 0) + return; + + preempt_disable_notrace(); p = get_kprobe((kprobe_opcode_t *)ip); if (unlikely(!p) || kprobe_disabled(p)) - return; + goto out; regs = ftrace_get_regs(fregs); kcb = get_kprobe_ctlblk(); @@ -45,6 +51,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, */ __this_cpu_write(current_kprobe, NULL); } +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); |