On s390 64-bit the s390x ELF ABI [1] designates register 11 as the "preferred" frame pointer (FP) register in user space.
While at it convert instruction_pointer() and user_stack_pointer() from macros to inline functions, to align their definition with x86 and arm64. Use const qualifier on struct pt_regs pointers to prevent compiler warnings: arch/s390/kernel/stacktrace.c: In function ‘arch_stack_walk_user_common’: arch/s390/kernel/stacktrace.c:114:34: warning: passing argument 1 of ‘instruction_pointer’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers] ... arch/s390/kernel/stacktrace.c:117:48: warning: passing argument 1 of ‘user_stack_pointer’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers] ... [1]: s390x ELF ABI, https://github.com/IBM/s390x-abi/releases Signed-off-by: Jens Remus <[email protected]> --- Notes (jremus): Changes in RFC v2: - Separate provide frame_pointer() into this new commit. arch/s390/include/asm/ptrace.h | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h index dfa770b15fad..455c119167fc 100644 --- a/arch/s390/include/asm/ptrace.h +++ b/arch/s390/include/asm/ptrace.h @@ -212,8 +212,6 @@ void update_cr_regs(struct task_struct *task); #define arch_has_block_step() (1) #define user_mode(regs) (((regs)->psw.mask & PSW_MASK_PSTATE) != 0) -#define instruction_pointer(regs) ((regs)->psw.addr) -#define user_stack_pointer(regs)((regs)->gprs[15]) #define profile_pc(regs) instruction_pointer(regs) static inline long regs_return_value(struct pt_regs *regs) @@ -235,6 +233,22 @@ static __always_inline unsigned long kernel_stack_pointer(struct pt_regs *regs) return regs->gprs[15]; } +static __always_inline unsigned long instruction_pointer(const struct pt_regs *regs) +{ + return regs->psw.addr; +} + +static __always_inline unsigned long frame_pointer(const struct pt_regs *regs) +{ + /* Return ABI-designated "preferred" frame-pointer register value. */ + return regs->gprs[11]; +} + +static __always_inline unsigned long user_stack_pointer(const struct pt_regs *regs) +{ + return regs->gprs[15]; +} + static __always_inline unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset) { if (offset >= NUM_GPRS) -- 2.51.0
