Commit 5d1ceb39 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

x86: Fix __get_wchan() for !STACKTRACE 



Use asm/unwind.h to implement wchan, since we cannot always rely on
STACKTRACE=y.

Fixes: bc9bbb81 ("x86: Fix get_wchan() to support the ORC unwinder")
Reported-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20211022152104.137058575@infradead.org
parent 55409ac5

arch/x86/kernel/process.c

+14 −3
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include <asm/io_bitmap.h>

#include <asm/proto.h>

#include <asm/frame.h>

#include <asm/unwind.h>



#include "process.h"
@@ -944,10 +945,20 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) 
 */

unsigned long __get_wchan(struct task_struct *p)

{

	unsigned long entry = 0;

	struct unwind_state state;

	unsigned long addr = 0;



	stack_trace_save_tsk(p, &entry, 1, 0);

	return entry;

	for (unwind_start(&state, p, NULL, NULL); !unwind_done(&state);

	     unwind_next_frame(&state)) {

		addr = unwind_get_return_address(&state);

		if (!addr)

			break;

		if (in_sched_functions(addr))

			continue;

		break;

	}



	return addr;

}



long do_arch_prctl_common(struct task_struct *task, int option,