From: Song Liu <song@kernel.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
live-patching@vger.kernel.org
Cc: rostedt@goodmis.org, mhiramat@kernel.org, mark.rutland@arm.com,
kernel-team@meta.com, Song Liu <song@kernel.org>
Subject: [PATCH v2 09/16] arm64: Mark the preempt count helpers notrace
Date: Thu, 22 Oct 2026 18:10:42 -0700 [thread overview]
Message-ID: <20261023011049.1164625-10-song@kernel.org> (raw)
In-Reply-To: <20261023011049.1164625-1-song@kernel.org>
ftrace_test_recursion_trylock() reads preempt_count() to find the
current context, and preempt_disable_notrace() and
preempt_enable_notrace() use __preempt_count_add(),
__preempt_count_sub(), __preempt_count_dec_and_test() and
should_resched(). On arm64 these are plain inline functions. If the
compiler emits one of them out of line, that copy is untraced only
because inline implies notrace, and tracing it would recurse before the
recursion check takes effect.
Mark them, and preempt_count_set(), notrace explicitly. The x86 and
generic versions are __always_inline. No functional change.
Assisted-by: Claude:claude-opus-5
Signed-off-by: Song Liu <song@kernel.org>
---
arch/arm64/include/asm/preempt.h | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h
index 932ea4b62042..0441938c9e7e 100644
--- a/arch/arm64/include/asm/preempt.h
+++ b/arch/arm64/include/asm/preempt.h
@@ -7,12 +7,12 @@
#define PREEMPT_NEED_RESCHED BIT(32)
#define PREEMPT_ENABLED (PREEMPT_NEED_RESCHED)
-static inline int preempt_count(void)
+static inline int notrace preempt_count(void)
{
return READ_ONCE(current_thread_info()->preempt.count);
}
-static inline void preempt_count_set(u64 pc)
+static inline void notrace preempt_count_set(u64 pc)
{
/* Preserve existing value of PREEMPT_NEED_RESCHED */
WRITE_ONCE(current_thread_info()->preempt.count, pc);
@@ -41,21 +41,21 @@ static inline bool test_preempt_need_resched(void)
return !current_thread_info()->preempt.need_resched;
}
-static inline void __preempt_count_add(int val)
+static inline void notrace __preempt_count_add(int val)
{
u32 pc = READ_ONCE(current_thread_info()->preempt.count);
pc += val;
WRITE_ONCE(current_thread_info()->preempt.count, pc);
}
-static inline void __preempt_count_sub(int val)
+static inline void notrace __preempt_count_sub(int val)
{
u32 pc = READ_ONCE(current_thread_info()->preempt.count);
pc -= val;
WRITE_ONCE(current_thread_info()->preempt.count, pc);
}
-static inline bool __preempt_count_dec_and_test(void)
+static inline bool notrace __preempt_count_dec_and_test(void)
{
struct thread_info *ti = current_thread_info();
u64 pc = READ_ONCE(ti->preempt_count);
@@ -73,7 +73,7 @@ static inline bool __preempt_count_dec_and_test(void)
return !pc || !READ_ONCE(ti->preempt_count);
}
-static inline bool should_resched(int preempt_offset)
+static inline bool notrace should_resched(int preempt_offset)
{
u64 pc = READ_ONCE(current_thread_info()->preempt_count);
return pc == preempt_offset;
--
2.53.0-Meta
next prev parent reply other threads:[~2026-10-23 1:11 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-23 1:10 [PATCH v2 00/16] Move notrace from inline to __always_inline Song Liu
2026-10-23 1:10 ` [PATCH v2 01/16] x86/paravirt: Mark native pv_ops helpers notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 02/16] x86: Mark CPU state helpers used by resume and kexec notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 03/16] bpf: Mark bpf_spin_lock helpers notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 04/16] bpf: Mark the BPF trampoline " Song Liu
2026-10-23 1:10 ` [PATCH v2 05/16] bpf: Mark the bpf_mem_alloc fast path " Song Liu
2026-10-23 1:10 ` [PATCH v2 06/16] u64_stats: Mark the update helpers used by BPF notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 07/16] tracepoint: Mark __do_trace_##name() notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 08/16] srcu: Mark the fast notrace read-side helpers notrace Song Liu
2026-10-23 1:10 ` Song Liu [this message]
2026-10-23 1:10 ` [PATCH v2 10/16] powerpc, csky, mips, sh: Mark the accessors behind current notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 11/16] rcu: Mark the Tiny RCU rcu_is_watching() notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 12/16] tracing: Mark the tracing_gen_ctx helpers notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 13/16] ktime: Mark ktime_to_ns() notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 14/16] kallsyms: Mark the kernel text address checks notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 15/16] uaccess: Mark pagefault_disable() and pagefault_enable() notrace Song Liu
2026-10-23 1:10 ` [PATCH v2 16/16] compiler_types: Move notrace from inline to __always_inline Song Liu
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