From 41f83a0271daab9a9bba6afbe5f7dd99000c5af5 Mon Sep 17 00:00:00 2001
From: zhangyuan21 <zhangyuan21@xiaomi.com>
Date: Thu, 6 Apr 2023 13:48:28 +0800
Subject: [PATCH] arch/arm64: change up_saveusercontext to assembly code

minidump will backtrace failure when use C code to save user context,
because the stack push operation in C code can disrupt the stack information.

Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
---
 arch/arm64/src/common/arm64_internal.h   |  1 -
 arch/arm64/src/common/arm64_task_sched.c | 38 ------------------------
 arch/arm64/src/common/arm64_vectors.S    |  6 ++--
 3 files changed, 3 insertions(+), 42 deletions(-)

diff --git a/arch/arm64/src/common/arm64_internal.h b/arch/arm64/src/common/arm64_internal.h
index 081908cffb..98c4e79c00 100644
--- a/arch/arm64/src/common/arm64_internal.h
+++ b/arch/arm64/src/common/arm64_internal.h
@@ -254,7 +254,6 @@ void arm64_secondary_start(void);
 
 void arm64_fullcontextrestore(uint64_t *restoreregs) noreturn_function;
 void arm64_switchcontext(uint64_t **saveregs, uint64_t *restoreregs);
-void arm64_context_snapshot(void *savereg);
 
 /* Signal handling **********************************************************/
 
diff --git a/arch/arm64/src/common/arm64_task_sched.c b/arch/arm64/src/common/arm64_task_sched.c
index bb5254345a..69f27df8c1 100644
--- a/arch/arm64/src/common/arm64_task_sched.c
+++ b/arch/arm64/src/common/arm64_task_sched.c
@@ -44,44 +44,6 @@
  * Public Functions
  ****************************************************************************/
 
-/****************************************************************************
- * Name: up_saveusercontext
- *
- * Description:
- *   Save the current thread context.  Full prototype is:
- *
- *   int  up_saveusercontext(void *saveregs);
- *
- * Returned Value:
- *   0: Normal return
- *   1: Context switch return
- *
- ****************************************************************************/
-#ifdef CONFIG_BUILD_FLAT
-
-int up_saveusercontext(void *saveregs)
-{
-  irqstate_t flags;
-
-  /* Take a snapshot of the thread context right now */
-
-  flags = enter_critical_section();
-
-  arm64_context_snapshot(saveregs);
-
-  leave_critical_section(flags);
-  return 0;
-}
-
-#else
-
-int up_saveusercontext(void *saveregs)
-{
-  return sys_call1(SYS_save_context, (uintptr_t)saveregs);
-}
-
-#endif
-
 /****************************************************************************
  * Name: arm64_fullcontextrestore
  *
diff --git a/arch/arm64/src/common/arm64_vectors.S b/arch/arm64/src/common/arm64_vectors.S
index 14c6f61ada..77507cfad9 100644
--- a/arch/arm64/src/common/arm64_vectors.S
+++ b/arch/arm64/src/common/arm64_vectors.S
@@ -60,15 +60,15 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Function: arm64_context_snapshot
+ * Function: up_saveusercontext
  *
  * Description:
  *   Take a snapshot of the thread GP registers context
  *   x0 --- pointer to struct regs_context
  *
  ****************************************************************************/
-GTEXT(arm64_context_snapshot)
-SECTION_FUNC(text, arm64_context_snapshot)
+GTEXT(up_saveusercontext)
+SECTION_FUNC(text, up_saveusercontext)
     str    x0, [sp, #-16]!
 
     stp    x0,  x1,  [x0, #8 * REG_X0]