s390/process: avoid custom stack unwinding in get_wchan (6756dd9b) · Commits · 戴 / test

arch/s390/kernel/process.c

+16 −20

Original line number	Diff line number	Diff line
		@@ -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;
		unwind_for_each_frame(&state, p, NULL, 0) {
		if (state.stack_info.type != STACK_TYPE_TASK) {
		ip = 0;
		break;
		}
		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;
		}
		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)