Re: [PATCH v3 1/4] rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Date: 2023-05-17 12:00:07
Also in:
bpf, linux-riscv, linux-s390, lkml, stable
Hi Ze Gao, On Wed, 17 May 2023 11:45:06 +0800 Ze Gao [off-list ref] wrote:
This patch replaces preempt_{disable, enable} with its corresponding
notrace version in rethook_trampoline_handler so no worries about stack
recursion or overflow introduced by preempt_count_{add, sub} under
fprobe + rethook context.
Fixes: 54ecbe6f1ed5 ("rethook: Add a generic return hook")
Signed-off-by: Ze Gao <redacted>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: <redacted>
Link: https://lore.kernel.org/linux-trace-kernel/20230516071830.8190-2-zegao@tencent.com (local)Note that you don't need to add Link tag of the previous version for each patch. I'll add it when I pick it :) Thank you,
quoted hunk ↗ jump to hunk
--- kernel/trace/rethook.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c index 32c3dfdb4d6a..60f6cb2b486b 100644 --- a/kernel/trace/rethook.c +++ b/kernel/trace/rethook.c@@ -288,7 +288,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs, * These loops must be protected from rethook_free_rcu() because those * are accessing 'rhn->rethook'. */ - preempt_disable(); + preempt_disable_notrace(); /* * Run the handler on the shadow stack. Do not unlink the list here because@@ -321,7 +321,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs, first = first->next; rethook_recycle(rhn); } - preempt_enable(); + preempt_enable_notrace(); return correct_ret_addr; }-- 2.40.1
-- Masami Hiramatsu (Google) [off-list ref]