From: Jisheng Zhang <jszhang@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>,
Alexander Potapenko <glider@google.com>,
Andrey Konovalov <andreyknvl@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Tejun Heo <tj@kernel.org>, Dennis Zhou <dennis@kernel.org>,
Christoph Lameter <cl@gentwo.org>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
linux-mm@kvack.org
Subject: [PATCH 3/4] arm64: stacktrace: Always inline internal stack boundary helpers
Date: Sat, 7 Nov 2026 15:13:38 +0800 [thread overview]
Message-ID: <20261107071339.17467-4-jszhang@kernel.org> (raw)
In-Reply-To: <20261107071339.17467-1-jszhang@kernel.org>
The noinstr stack walkers reach the stack boundary and frame-record
helpers through an __always_inline call chain. However, these shared
helpers do not themselves guarantee inlining.
With CONFIG_CC_OPTIMIZE_FOR_SIZE=y, GCC emitted several stack
information helpers and unwind_find_stack() out of line in .text.
Mark the shared stack boundary and frame-record helpers
__always_inline to keep their instructions in the non-instrumentable
walkers
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Assisted-by: LLM
---
arch/arm64/include/asm/stacktrace.h | 16 ++++++++--------
arch/arm64/include/asm/stacktrace/common.h | 12 ++++++------
2 files changed, 14 insertions(+), 14 deletions(-)
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 6d3280932bf5..b370c0e1e337 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -22,7 +22,7 @@ extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
-static inline struct stack_info stackinfo_get_irq(void)
+static __always_inline struct stack_info stackinfo_get_irq(void)
{
unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
unsigned long high = low + IRQ_STACK_SIZE;
@@ -33,13 +33,13 @@ static inline struct stack_info stackinfo_get_irq(void)
};
}
-static inline bool on_irq_stack(unsigned long sp, unsigned long size)
+static __always_inline bool on_irq_stack(unsigned long sp, unsigned long size)
{
struct stack_info info = stackinfo_get_irq();
return stackinfo_on_stack(&info, sp, size);
}
-static inline struct stack_info stackinfo_get_task(const struct task_struct *tsk)
+static __always_inline struct stack_info stackinfo_get_task(const struct task_struct *tsk)
{
unsigned long low = (unsigned long)task_stack_page(tsk);
unsigned long high = low + THREAD_SIZE;
@@ -50,7 +50,7 @@ static inline struct stack_info stackinfo_get_task(const struct task_struct *tsk
};
}
-static inline bool on_task_stack(const struct task_struct *tsk,
+static __always_inline bool on_task_stack(const struct task_struct *tsk,
unsigned long sp, unsigned long size)
{
struct stack_info info = stackinfo_get_task(tsk);
@@ -61,7 +61,7 @@ static inline bool on_task_stack(const struct task_struct *tsk,
DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
-static inline struct stack_info stackinfo_get_overflow(void)
+static __always_inline struct stack_info stackinfo_get_overflow(void)
{
unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
unsigned long high = low + OVERFLOW_STACK_SIZE;
@@ -76,7 +76,7 @@ static inline struct stack_info stackinfo_get_overflow(void)
DECLARE_PER_CPU(unsigned long *, sdei_stack_normal_ptr);
DECLARE_PER_CPU(unsigned long *, sdei_stack_critical_ptr);
-static inline struct stack_info stackinfo_get_sdei_normal(void)
+static __always_inline struct stack_info stackinfo_get_sdei_normal(void)
{
unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr);
unsigned long high = low + SDEI_STACK_SIZE;
@@ -87,7 +87,7 @@ static inline struct stack_info stackinfo_get_sdei_normal(void)
};
}
-static inline struct stack_info stackinfo_get_sdei_critical(void)
+static __always_inline struct stack_info stackinfo_get_sdei_critical(void)
{
unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr);
unsigned long high = low + SDEI_STACK_SIZE;
@@ -105,7 +105,7 @@ static inline struct stack_info stackinfo_get_sdei_critical(void)
#ifdef CONFIG_EFI
extern u64 *efi_rt_stack_top;
-static inline struct stack_info stackinfo_get_efi(void)
+static __always_inline struct stack_info stackinfo_get_efi(void)
{
unsigned long high = (u64)efi_rt_stack_top;
unsigned long low = high - THREAD_SIZE;
diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h
index 821a8fdd31af..7c502ae276b9 100644
--- a/arch/arm64/include/asm/stacktrace/common.h
+++ b/arch/arm64/include/asm/stacktrace/common.h
@@ -35,7 +35,7 @@ struct unwind_state {
int nr_stacks;
};
-static inline struct stack_info stackinfo_get_unknown(void)
+static __always_inline struct stack_info stackinfo_get_unknown(void)
{
return (struct stack_info) {
.low = 0,
@@ -43,7 +43,7 @@ static inline struct stack_info stackinfo_get_unknown(void)
};
}
-static inline bool stackinfo_on_stack(const struct stack_info *info,
+static __always_inline bool stackinfo_on_stack(const struct stack_info *info,
unsigned long sp, unsigned long size)
{
if (!info->low)
@@ -55,7 +55,7 @@ static inline bool stackinfo_on_stack(const struct stack_info *info,
return true;
}
-static inline void unwind_init_common(struct unwind_state *state)
+static __always_inline void unwind_init_common(struct unwind_state *state)
{
state->stack = stackinfo_get_unknown();
}
@@ -70,7 +70,7 @@ static inline void unwind_init_common(struct unwind_state *state)
*
* Return: a pointer to the relevant stack_info if found; NULL otherwise.
*/
-static struct stack_info *unwind_find_stack(struct unwind_state *state,
+static __always_inline struct stack_info *unwind_find_stack(struct unwind_state *state,
unsigned long sp,
unsigned long size)
{
@@ -99,7 +99,7 @@ static struct stack_info *unwind_find_stack(struct unwind_state *state,
*
* Return: 0 upon success, an error code otherwise.
*/
-static inline void unwind_consume_stack(struct unwind_state *state,
+static __always_inline void unwind_consume_stack(struct unwind_state *state,
struct stack_info *info,
unsigned long sp,
unsigned long size)
@@ -142,7 +142,7 @@ static inline void unwind_consume_stack(struct unwind_state *state,
*
* Return: 0 upon success, an error code otherwise.
*/
-static inline int
+static __always_inline int
unwind_next_frame_record(struct unwind_state *state)
{
struct stack_info *info;
--
2.55.0
next prev parent reply other threads:[~2026-11-07 7:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-07 7:13 [PATCH 0/4] arm64: Fix instrumentation escapes from noinstr path Jisheng Zhang
2026-11-07 7:13 ` [PATCH 1/4] arm64: percpu: Always inline helpers used by noinstr code Jisheng Zhang
2026-11-07 7:13 ` [PATCH 2/4] arm64: entry: Always inline helpers used by non-instrumentable paths Jisheng Zhang
2026-11-07 7:13 ` Jisheng Zhang [this message]
2026-11-07 7:13 ` [PATCH 4/4] arm64: alternatives: Make branch and ADRP offset helpers noinst Jisheng Zhang
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