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Message-Id: <20220613094922.100865784@linuxfoundation.org>
Date: Mon, 13 Jun 2022 12:11:42 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, kernel test robot <lkp@...el.com>,
"Peter Zijlstra (Intel)" <peterz@...radead.org>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.10 142/172] jump_label,noinstr: Avoid instrumentation for JUMP_LABEL=n builds
From: Peter Zijlstra <peterz@...radead.org>
[ Upstream commit 656d054e0a15ec327bd82801ccd58201e59f6896 ]
When building x86_64 with JUMP_LABEL=n it's possible for
instrumentation to sneak into noinstr:
vmlinux.o: warning: objtool: exit_to_user_mode+0x14: call to static_key_count.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: syscall_exit_to_user_mode+0x2d: call to static_key_count.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: irqentry_exit_to_user_mode+0x1b: call to static_key_count.constprop.0() leaves .noinstr.text section
Switch to arch_ prefixed atomic to avoid the explicit instrumentation.
Reported-by: kernel test robot <lkp@...el.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
include/linux/jump_label.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index 32809624d422..e67ee4d7318f 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -249,9 +249,9 @@ extern void static_key_disable_cpuslocked(struct static_key *key);
#include <linux/atomic.h>
#include <linux/bug.h>
-static inline int static_key_count(struct static_key *key)
+static __always_inline int static_key_count(struct static_key *key)
{
- return atomic_read(&key->enabled);
+ return arch_atomic_read(&key->enabled);
}
static __always_inline void jump_label_init(void)
--
2.35.1
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