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armv6/7/8-m: use ISB instruction immediately after the MSR instruction

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when changing the stack pointer, software must use an
ISB instruction immediately after the MSR instruction.
This ensures that instructions after the ISB instruction
execute using the new stack pointer.

https://developer.arm.com/documentation/101928/0101/The-Cortex-M85-Processor--Reference-Material/Programmer-s-model/Core-registers/CONTROL-register?lang=en

" When changing the stack pointer, software must use an ISB instruction immediately after the MSR instruction. This ensures that instructions after the ISB instruction execute using the new stack pointer."

Signed-off-by: hujun5 <hujun5@xiaomi.com>
This commit is contained in:
hujun5 2024-01-24 13:36:59 +08:00 committed by Alan Carvalho de Assis
parent 105b97d799
commit c06c10f6f3
6 changed files with 12 additions and 0 deletions
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4
arch/arm/src/armv6-m/arm_exception.S
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@ -100,6 +100,7 @@ exception_common:
mrs r1, msp /* R1=The main stack pointer */ mrs r1, msp /* R1=The main stack pointer */
subs r1, #SW_XCPT_SIZE /* R1=Beginning of context array on the stack */ subs r1, #SW_XCPT_SIZE /* R1=Beginning of context array on the stack */
msr msp, r1 /* Reserved stack space */ msr msp, r1 /* Reserved stack space */
isb sy
b 2f b 2f
1: 1:
@ -160,6 +161,7 @@ exception_common:
mov r2, r1 /* Reserve signal context */ mov r2, r1 /* Reserve signal context */
subs r2, r2, #XCPTCONTEXT_SIZE subs r2, r2, #XCPTCONTEXT_SIZE
msr msp, r2 /* We are using the main stack pointer */ msr msp, r2 /* We are using the main stack pointer */
isb sy
3: 3:
#endif #endif
@ -197,10 +199,12 @@ exception_common:
lsls r0, #(31 - EXC_RETURN_PROCESS_BITNO) /* Move to bit 31 */ lsls r0, #(31 - EXC_RETURN_PROCESS_BITNO) /* Move to bit 31 */
bmi 4f /* Test bit 31 */ bmi 4f /* Test bit 31 */
msr msp, r1 /* R1=The main stack pointer */ msr msp, r1 /* R1=The main stack pointer */
isb sy
b 5f b 5f
4: 4:
msr psp, r1 /* R1=The process stack pointer */ msr psp, r1 /* R1=The process stack pointer */
isb sy
5: 5:

2
arch/arm/src/armv6-m/arm_initialstate.c
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@ -168,6 +168,7 @@ noinline_function void arm_initialize_stack(void)
"mov %1, sp\n" "mov %1, sp\n"
"msr psp, %1\n" "msr psp, %1\n"
"isb sy\n"
/* Select PSP */ /* Select PSP */
@ -179,6 +180,7 @@ noinline_function void arm_initialize_stack(void)
/* Initialize MSP */ /* Initialize MSP */
"msr msp, %0\n" "msr msp, %0\n"
"isb sy\n"
: :
: "r" (stack), "r" (tempa), "r" (tempb) : "r" (stack), "r" (tempa), "r" (tempb)
: "memory"); : "memory");

1
arch/arm/src/armv7-m/arm_exception.S
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@ -138,6 +138,7 @@ exception_common:
mrs r1, msp /* R1=The main stack pointer (MSP) */ mrs r1, msp /* R1=The main stack pointer (MSP) */
sub r2, r1, #SW_XCPT_SIZE /* Reserved stack space */ sub r2, r1, #SW_XCPT_SIZE /* Reserved stack space */
msr msp, r2 msr msp, r2
isb sy
2: 2:
mov r2, r1 /* R2=Copy of the main/process stack pointer */ mov r2, r1 /* R2=Copy of the main/process stack pointer */

2
arch/arm/src/armv7-m/arm_initialstate.c
View File

@ -190,6 +190,7 @@ noinline_function void arm_initialize_stack(void)
"mov %1, sp\n" "mov %1, sp\n"
"msr psp, %1\n" "msr psp, %1\n"
"isb sy\n"
/* Select PSP */ /* Select PSP */
@ -201,6 +202,7 @@ noinline_function void arm_initialize_stack(void)
/* Initialize MSP */ /* Initialize MSP */
"msr msp, %0\n" "msr msp, %0\n"
"isb sy\n"
: :
: "r" (stack), "r" (temp) : "r" (stack), "r" (temp)
: "memory"); : "memory");

1
arch/arm/src/armv8-m/arm_exception.S
View File

@ -137,6 +137,7 @@ exception_common:
mrs r1, msp /* R1=The main stack pointer (MSP) */ mrs r1, msp /* R1=The main stack pointer (MSP) */
sub r2, r1, #SW_XCPT_SIZE /* Reserve the stack space */ sub r2, r1, #SW_XCPT_SIZE /* Reserve the stack space */
msr msp, r2 msr msp, r2
isb sy
2: 2:
mov r2, r1 /* R2=Copy of the main/process stack pointer */ mov r2, r1 /* R2=Copy of the main/process stack pointer */
add r2, #HW_XCPT_SIZE /* R2=MSP/PSP before the interrupt was taken */ add r2, #HW_XCPT_SIZE /* R2=MSP/PSP before the interrupt was taken */

2
arch/arm/src/armv8-m/arm_initialstate.c
View File

@ -204,6 +204,7 @@ noinline_function void arm_initialize_stack(void)
"mrs %1, msplim\n" "mrs %1, msplim\n"
"msr psplim, %1\n" "msr psplim, %1\n"
#endif #endif
"isb sy\n"
/* Select PSP */ /* Select PSP */
@ -219,6 +220,7 @@ noinline_function void arm_initialize_stack(void)
#ifdef CONFIG_ARMV8M_STACKCHECK_HARDWARE #ifdef CONFIG_ARMV8M_STACKCHECK_HARDWARE
"msr msplim, %2\n" "msr msplim, %2\n"
#endif #endif
"isb sy\n"
: :
#ifdef CONFIG_ARMV8M_STACKCHECK_HARDWARE #ifdef CONFIG_ARMV8M_STACKCHECK_HARDWARE
: "r" (stack), "r" (temp), "r" (stacklim) : "r" (stack), "r" (temp), "r" (stacklim)