[PATCH v2 05/10] arm64: use a common struct frame_record
Mark Rutland
mark.rutland at arm.com
Thu Oct 17 02:25:33 PDT 2024
Currently the signal handling code has its own struct frame_record,
the definition of struct pt_regs open-codes a frame record as an array,
and the kernel unwinder hard-codes frame record offsets.
Move to a common struct frame_record that can be used throughout the
kernel.
Signed-off-by: Mark Rutland <mark.rutland at arm.com>
Reviewed-by: Mark Brown <broonie at kernel.org>
Reviewed-by: Miroslav Benes <mbenes at suse.cz>
Reviewed-by: Puranjay Mohan <puranjay12 at gmail.com>
Cc: Ard Biesheuvel <ardb at kernel.org>
Cc: Josh Poimboeuf <jpoimboe at kernel.org>
Cc: Kalesh Singh <kaleshsingh at google.com>
Cc: Madhavan T. Venkataraman <madvenka at linux.microsoft.com>
Cc: Marc Zyngier <maz at kernel.org>
Cc: Will Deacon <will at kernel.org>
---
arch/arm64/include/asm/ptrace.h | 4 +++-
arch/arm64/include/asm/stacktrace/common.h | 8 +++++---
arch/arm64/include/asm/stacktrace/frame.h | 13 +++++++++++++
arch/arm64/kernel/process.c | 2 +-
arch/arm64/kernel/signal.c | 5 -----
arch/arm64/kernel/stacktrace.c | 2 +-
6 files changed, 23 insertions(+), 11 deletions(-)
create mode 100644 arch/arm64/include/asm/stacktrace/frame.h
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index 92531aeba5310..89c02f85f4b11 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -98,6 +98,8 @@
#include <linux/bug.h>
#include <linux/types.h>
+#include <asm/stacktrace/frame.h>
+
/* sizeof(struct user) for AArch32 */
#define COMPAT_USER_SZ 296
@@ -168,7 +170,7 @@ struct pt_regs {
u64 sdei_ttbr1;
u64 unused;
- u64 stackframe[2];
+ struct frame_record stackframe;
/* Only valid for some EL1 exceptions. */
u64 lockdep_hardirqs;
diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h
index f63dc654e545f..7fab6876e4970 100644
--- a/arch/arm64/include/asm/stacktrace/common.h
+++ b/arch/arm64/include/asm/stacktrace/common.h
@@ -137,21 +137,23 @@ static inline int unwind_consume_stack(struct unwind_state *state,
static inline int
unwind_next_frame_record(struct unwind_state *state)
{
+ struct frame_record *record;
unsigned long fp = state->fp;
int err;
if (fp & 0x7)
return -EINVAL;
- err = unwind_consume_stack(state, fp, 16);
+ err = unwind_consume_stack(state, fp, sizeof(*record));
if (err)
return err;
/*
* Record this frame record's values.
*/
- state->fp = READ_ONCE(*(unsigned long *)(fp));
- state->pc = READ_ONCE(*(unsigned long *)(fp + 8));
+ record = (struct frame_record *)fp;
+ state->fp = READ_ONCE(record->fp);
+ state->pc = READ_ONCE(record->lr);
return 0;
}
diff --git a/arch/arm64/include/asm/stacktrace/frame.h b/arch/arm64/include/asm/stacktrace/frame.h
new file mode 100644
index 0000000000000..6397bc847f147
--- /dev/null
+++ b/arch/arm64/include/asm/stacktrace/frame.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_STACKTRACE_FRAME_H
+#define __ASM_STACKTRACE_FRAME_H
+
+/*
+ * A standard AAPCS64 frame record.
+ */
+struct frame_record {
+ u64 fp;
+ u64 lr;
+};
+
+#endif /* __ASM_STACKTRACE_FRAME_H */
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index c722c1be6fa59..d45fd114eac3f 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -419,7 +419,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
* For the benefit of the unwinder, set up childregs->stackframe
* as the final frame for the new task.
*/
- p->thread.cpu_context.fp = (unsigned long)childregs->stackframe;
+ p->thread.cpu_context.fp = (unsigned long)&childregs->stackframe;
ptrace_hw_copy_thread(p);
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 5619869475304..2c47f9a0e40ba 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -42,11 +42,6 @@ struct rt_sigframe {
struct ucontext uc;
};
-struct frame_record {
- u64 fp;
- u64 lr;
-};
-
struct rt_sigframe_user_layout {
struct rt_sigframe __user *sigframe;
struct frame_record __user *next_frame;
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 2729faaee4b4c..ffe8e4f549566 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -145,7 +145,7 @@ kunwind_next(struct kunwind_state *state)
int err;
/* Final frame; nothing to unwind */
- if (fp == (unsigned long)task_pt_regs(tsk)->stackframe)
+ if (fp == (unsigned long)&task_pt_regs(tsk)->stackframe)
return -ENOENT;
err = unwind_next_frame_record(&state->common);
--
2.30.2
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