6.9-stable review patch. If anyone has any objections, please let me know.
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From: Heiko Carstens hca@linux.ibm.com
[ Upstream commit be72ea09c1a5273abf8c6c52ef53e36c701cbf6a ]
Introduce and use struct stack_frame_vdso_wrapper within vdso user wrapper code. With this structure it is possible to automatically generate an asm-offset define which can be used to save and restore the return address of the calling function.
Also use STACK_FRAME_USER_OVERHEAD instead of STACK_FRAME_OVERHEAD to document that the code works with user space stack frames with the standard stack frame layout.
Fixes: aa44433ac4ee ("s390: add USER_STACKTRACE support") Reviewed-by: Jens Remus jremus@linux.ibm.com Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/include/asm/stacktrace.h | 5 +++++ arch/s390/kernel/asm-offsets.c | 4 ++++ arch/s390/kernel/vdso64/vdso_user_wrapper.S | 18 ++++++++---------- 3 files changed, 17 insertions(+), 10 deletions(-)
diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h index 4aefbe32265d8..85b6738b826af 100644 --- a/arch/s390/include/asm/stacktrace.h +++ b/arch/s390/include/asm/stacktrace.h @@ -13,6 +13,11 @@ struct stack_frame_user { unsigned long empty2[4]; };
+struct stack_frame_vdso_wrapper { + struct stack_frame_user sf; + unsigned long return_address; +}; + struct perf_callchain_entry_ctx;
void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *cookie, diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index fa5f6885c74aa..28017c418442b 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -66,6 +66,10 @@ int main(void) OFFSET(__SF_SIE_CONTROL_PHYS, stack_frame, sie_control_block_phys); DEFINE(STACK_FRAME_OVERHEAD, sizeof(struct stack_frame)); BLANK(); + DEFINE(STACK_FRAME_USER_OVERHEAD, sizeof(struct stack_frame_user)); + OFFSET(__SFVDSO_RETURN_ADDRESS, stack_frame_vdso_wrapper, return_address); + DEFINE(STACK_FRAME_VDSO_OVERHEAD, sizeof(struct stack_frame_vdso_wrapper)); + BLANK(); /* idle data offsets */ OFFSET(__CLOCK_IDLE_ENTER, s390_idle_data, clock_idle_enter); OFFSET(__TIMER_IDLE_ENTER, s390_idle_data, timer_idle_enter); diff --git a/arch/s390/kernel/vdso64/vdso_user_wrapper.S b/arch/s390/kernel/vdso64/vdso_user_wrapper.S index 85247ef5a41b8..deee8ca9cdbf0 100644 --- a/arch/s390/kernel/vdso64/vdso_user_wrapper.S +++ b/arch/s390/kernel/vdso64/vdso_user_wrapper.S @@ -6,8 +6,6 @@ #include <asm/dwarf.h> #include <asm/ptrace.h>
-#define WRAPPER_FRAME_SIZE (STACK_FRAME_OVERHEAD+8) - /* * Older glibc version called vdso without allocating a stackframe. This wrapper * is just used to allocate a stackframe. See @@ -20,16 +18,16 @@ __ALIGN __kernel_\func: CFI_STARTPROC - aghi %r15,-WRAPPER_FRAME_SIZE - CFI_DEF_CFA_OFFSET (STACK_FRAME_OVERHEAD + WRAPPER_FRAME_SIZE) - CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD - stg %r14,STACK_FRAME_OVERHEAD(%r15) - CFI_REL_OFFSET 14, STACK_FRAME_OVERHEAD + aghi %r15,-STACK_FRAME_VDSO_OVERHEAD + CFI_DEF_CFA_OFFSET (STACK_FRAME_USER_OVERHEAD + STACK_FRAME_VDSO_OVERHEAD) + CFI_VAL_OFFSET 15,-STACK_FRAME_USER_OVERHEAD + stg %r14,__SFVDSO_RETURN_ADDRESS(%r15) + CFI_REL_OFFSET 14,__SFVDSO_RETURN_ADDRESS brasl %r14,__s390_vdso_\func - lg %r14,STACK_FRAME_OVERHEAD(%r15) + lg %r14,__SFVDSO_RETURN_ADDRESS(%r15) CFI_RESTORE 14 - aghi %r15,WRAPPER_FRAME_SIZE - CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD + aghi %r15,STACK_FRAME_VDSO_OVERHEAD + CFI_DEF_CFA_OFFSET STACK_FRAME_USER_OVERHEAD CFI_RESTORE 15 br %r14 CFI_ENDPROC