From b961ec10b9f9719987470236feb50c967db5a652 Mon Sep 17 00:00:00 2001 From: Jens Remus Date: Tue, 23 Apr 2024 17:35:52 +0200 Subject: s390/vdso: Add CFI for RA register to asm macro vdso_func The return-address (RA) register r14 is specified as volatile in the s390x ELF ABI [1]. Nevertheless proper CFI directives must be provided for an unwinder to restore the return address, if the RA register value is changed from its value at function entry, as it is the case. [1]: s390x ELF ABI, https://github.com/IBM/s390x-abi/releases Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO") Signed-off-by: Jens Remus Acked-by: Heiko Carstens Signed-off-by: Alexander Gordeev --- arch/s390/include/asm/dwarf.h | 1 + arch/s390/kernel/vdso64/vdso_user_wrapper.S | 2 ++ 2 files changed, 3 insertions(+) (limited to 'arch/s390') diff --git a/arch/s390/include/asm/dwarf.h b/arch/s390/include/asm/dwarf.h index 4f21ae561e4d..390906b8e386 100644 --- a/arch/s390/include/asm/dwarf.h +++ b/arch/s390/include/asm/dwarf.h @@ -9,6 +9,7 @@ #define CFI_DEF_CFA_OFFSET .cfi_def_cfa_offset #define CFI_ADJUST_CFA_OFFSET .cfi_adjust_cfa_offset #define CFI_RESTORE .cfi_restore +#define CFI_REL_OFFSET .cfi_rel_offset #ifdef CONFIG_AS_CFI_VAL_OFFSET #define CFI_VAL_OFFSET .cfi_val_offset diff --git a/arch/s390/kernel/vdso64/vdso_user_wrapper.S b/arch/s390/kernel/vdso64/vdso_user_wrapper.S index 57f62596e53b..85247ef5a41b 100644 --- a/arch/s390/kernel/vdso64/vdso_user_wrapper.S +++ b/arch/s390/kernel/vdso64/vdso_user_wrapper.S @@ -24,8 +24,10 @@ __kernel_\func: 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 brasl %r14,__s390_vdso_\func lg %r14,STACK_FRAME_OVERHEAD(%r15) + CFI_RESTORE 14 aghi %r15,WRAPPER_FRAME_SIZE CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD CFI_RESTORE 15 -- cgit v1.2.3