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| author | Vasily Gorbik <gor@linux.ibm.com> | 2019-10-28 15:17:42 +0100 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2019-10-31 17:20:53 +0100 |
| commit | 6756dd9b890fe50c01a6e7546bd498d57ddb98ae (patch) | |
| tree | 6ad029cd2859334de46d9616374a33d682946fa5 /arch/s390/kernel | |
| parent | ea3f6dcfa71afb51753ad3729c29570f90d6abbc (diff) | |
| download | linux-6756dd9b890fe50c01a6e7546bd498d57ddb98ae.tar.bz2 | |
s390/process: avoid custom stack unwinding in get_wchan
Currently get_wchan uses custom stack unwinding implementation which
relies on back_chain presence. Replace it with more abstract stack
unwinding api usage.
Suggested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel')
| -rw-r--r-- | arch/s390/kernel/process.c | 36 |
1 files changed, 16 insertions, 20 deletions
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index b0afec673f77..6ccef5f29761 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -40,6 +40,7 @@ #include <asm/stacktrace.h> #include <asm/switch_to.h> #include <asm/runtime_instr.h> +#include <asm/unwind.h> #include "entry.h" asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); @@ -178,9 +179,8 @@ EXPORT_SYMBOL(dump_fpu); unsigned long get_wchan(struct task_struct *p) { - struct stack_frame *sf, *low, *high; - unsigned long return_address; - int count; + struct unwind_state state; + unsigned long ip = 0; if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) return 0; @@ -188,26 +188,22 @@ unsigned long get_wchan(struct task_struct *p) if (!try_get_task_stack(p)) return 0; - low = task_stack_page(p); - high = (struct stack_frame *) task_pt_regs(p); - sf = (struct stack_frame *) p->thread.ksp; - if (sf <= low || sf > high) { - return_address = 0; - goto out; - } - for (count = 0; count < 16; count++) { - sf = (struct stack_frame *)READ_ONCE_NOCHECK(sf->back_chain); - if (sf <= low || sf > high) { - return_address = 0; - goto out; + unwind_for_each_frame(&state, p, NULL, 0) { + if (state.stack_info.type != STACK_TYPE_TASK) { + ip = 0; + break; } - return_address = READ_ONCE_NOCHECK(sf->gprs[8]); - if (!in_sched_functions(return_address)) - goto out; + + ip = unwind_get_return_address(&state); + if (!ip) + break; + + if (!in_sched_functions(ip)) + break; } -out: + put_task_stack(p); - return return_address; + return ip; } unsigned long arch_align_stack(unsigned long sp) |