Commit 49cf34c0 authored by Josh Poimboeuf's avatar Josh Poimboeuf Committed by Peter Zijlstra
Browse files

unwind_user/x86: Enable frame pointer unwinding on x86 



Use ARCH_INIT_USER_FP_FRAME to describe how frame pointers are unwound
on x86, and enable CONFIG_HAVE_UNWIND_USER_FP accordingly so the
unwind_user interfaces can be used.

Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20250827193828.347397433@kernel.org
parent c79dd946

arch/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -297,6 +297,7 @@ config X86 
	select HAVE_SYSCALL_TRACEPOINTS

	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL

	select HAVE_UNSTABLE_SCHED_CLOCK

	select HAVE_UNWIND_USER_FP		if X86_64

	select HAVE_USER_RETURN_NOTIFIER

	select HAVE_GENERIC_VDSO

	select VDSO_GETRANDOM			if X86_64

arch/x86/include/asm/unwind_user.h

0 → 100644
+25 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_X86_UNWIND_USER_H

#define _ASM_X86_UNWIND_USER_H



#include <asm/ptrace.h>



#define ARCH_INIT_USER_FP_FRAME(ws)			\

	.cfa_off	=  2*(ws),			\

	.ra_off		= -1*(ws),			\

	.fp_off		= -2*(ws),			\

	.use_fp		= true,



static inline int unwind_user_word_size(struct pt_regs *regs)

{

	/* We can't unwind VM86 stacks */

	if (regs->flags & X86_VM_MASK)

		return 0;

#ifdef CONFIG_X86_64

	if (!user_64bit_mode(regs))

		return sizeof(int);

#endif

	return sizeof(long);

}



#endif /* _ASM_X86_UNWIND_USER_H */