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in repository https://gitbox.apache.org/repos/asf/nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new 3c4b099189c arch/arm/armv8-m: stack pointer should be 8-byte aligned
in signal context
3c4b099189c is described below
commit 3c4b099189cb4f46df09bc26b3b0d6330c5bb1e2
Author: chao an <anchao.arc...@bytedance.com>
AuthorDate: Thu Sep 11 13:54:53 2025 +0800
arch/arm/armv8-m: stack pointer should be 8-byte aligned in signal context
Since the alignment of the signal context is affected by XCPTCONTEXT_SIZE in
different Kconfig, sometimes the stack pointer is not aligned to 8 bytes,
this
is not what the software and compiler expect, for example, if va_list()
obtains
wide data of type long long, the offset will be wrong, So in this commit,
we set
stack-aligned the base offset so that the correct offset will be set during
context
restoration.
1. test code:
| void signal_handler(int signo, siginfo_t *info, void *context)
{
| long long ttt = 1024000;
| printf("%lld\n", ttt);
| }
|
| struct itimerspec its = { .it_value.tv_sec = 1,
| .it_value.tv_nsec = 0,
| .it_interval.tv_sec = 1,
| .it_interval.tv_nsec = 0
| };
|
| int main(int argc, FAR char *argv[])
| {
| struct sigevent evp;
| timer_t timer_id;
|
| memset(&evp, 0, sizeof(evp));
| evp.sigev_notify = SIGEV_SIGNAL | SIGEV_THREAD_ID;
| evp.sigev_signo = SIGALRM;
| evp.sigev_notify_thread_id = gettid();
|
| timer_create(CLOCK_REALTIME, &evp, &timer_id);
|
|
| struct sigaction sa;
| memset(&sa, 0, sizeof(sa));
| sa.sa_sigaction = signal_handler;
| sa.sa_flags = SA_SIGINFO;
| sigemptyset(&sa.sa_mask);
|
| sigaction(SIGALRM, &sa, NULL);
|
| timer_settime(timer_id, 0, &its, NULL);
|
| while (1)
| sleep(1);
|
| return 0;
| }
2. before this change:
| NuttShell (NSH) NuttX-12.10.0
| nsh> hello
| 4398046527890440
| 4398046527890472
| 4398046527890504
| 4398046527890536
3. after this change:
| NuttShell (NSH) NuttX-12.10.0
| nsh> hello
| 1024000
| 1024000
| 1024000
| 1024000
Signed-off-by: chao an <anchao.arc...@bytedance.com>
---
arch/arm/src/armv8-m/arm_schedulesigaction.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/arm/src/armv8-m/arm_schedulesigaction.c
b/arch/arm/src/armv8-m/arm_schedulesigaction.c
index 523082806c9..5de5c439d9c 100644
--- a/arch/arm/src/armv8-m/arm_schedulesigaction.c
+++ b/arch/arm/src/armv8-m/arm_schedulesigaction.c
@@ -119,6 +119,11 @@ void up_schedule_sigaction(struct tcb_s *tcb)
tcb->xcp.saved_regs = tcb->xcp.regs;
+ /* Stack pointer should be 8-byte aligned */
+
+ tcb->xcp.regs = (void *)STACK_ALIGN_DOWN(
+ (uint32_t)tcb->xcp.regs);
+
/* Duplicate the register context. These will be
* restored by the signal trampoline after the signal has been
* delivered.
