[linux-2.6-block.git] / arch / x86 / include / asm / frame.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_FRAME_H
#define _ASM_X86_FRAME_H

#include <asm/asm.h>

/*
 * These are stack frame creation macros.  They should be used by every
 * callable non-leaf asm function to make kernel stack traces more reliable.
 */

#ifdef CONFIG_FRAME_POINTER

#ifdef __ASSEMBLER__

.macro FRAME_BEGIN
	push %_ASM_BP
	_ASM_MOV %_ASM_SP, %_ASM_BP
.endm

.macro FRAME_END
	pop %_ASM_BP
.endm

#ifdef CONFIG_X86_64
/*
 * This is a sneaky trick to help the unwinder find pt_regs on the stack.  The
 * frame pointer is replaced with an encoded pointer to pt_regs.  The encoding
 * is just setting the LSB, which makes it an invalid stack address and is also
 * a signal to the unwinder that it's a pt_regs pointer in disguise.
 *
 * NOTE: This macro must be used *after* PUSH_AND_CLEAR_REGS because it corrupts
 * the original rbp.
 */
.macro ENCODE_FRAME_POINTER ptregs_offset=0
	leaq 1+\ptregs_offset(%rsp), %rbp
.endm
#else /* !CONFIG_X86_64 */
/*
 * This is a sneaky trick to help the unwinder find pt_regs on the stack.  The
 * frame pointer is replaced with an encoded pointer to pt_regs.  The encoding
 * is just clearing the MSB, which makes it an invalid stack address and is also
 * a signal to the unwinder that it's a pt_regs pointer in disguise.
 *
 * NOTE: This macro must be used *after* SAVE_ALL because it corrupts the
 * original ebp.
 */
.macro ENCODE_FRAME_POINTER
	mov %esp, %ebp
	andl $0x7fffffff, %ebp
.endm
#endif /* CONFIG_X86_64 */

#else /* !__ASSEMBLER__ */

#define FRAME_BEGIN				\
	"push %" _ASM_BP "\n"			\
	_ASM_MOV "%" _ASM_SP ", %" _ASM_BP "\n"

#define FRAME_END "pop %" _ASM_BP "\n"

#ifdef CONFIG_X86_64

#define ENCODE_FRAME_POINTER			\
	"lea 1(%rsp), %rbp\n\t"

static inline unsigned long encode_frame_pointer(struct pt_regs *regs)
{
	return (unsigned long)regs + 1;
}

#else /* !CONFIG_X86_64 */

#define ENCODE_FRAME_POINTER			\
	"movl %esp, %ebp\n\t"			\
	"andl $0x7fffffff, %ebp\n\t"

static inline unsigned long encode_frame_pointer(struct pt_regs *regs)
{
	return (unsigned long)regs & 0x7fffffff;
}

#endif /* CONFIG_X86_64 */

#endif /* __ASSEMBLER__ */

#define FRAME_OFFSET __ASM_SEL(4, 8)

#else /* !CONFIG_FRAME_POINTER */

#ifdef __ASSEMBLER__

.macro ENCODE_FRAME_POINTER ptregs_offset=0
.endm

#else /* !__ASSEMBLER__ */

#define ENCODE_FRAME_POINTER

static inline unsigned long encode_frame_pointer(struct pt_regs *regs)
{
	return 0;
}

#endif

#define FRAME_BEGIN
#define FRAME_END
#define FRAME_OFFSET 0

#endif /* CONFIG_FRAME_POINTER */

#endif /* _ASM_X86_FRAME_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _ASM_X86_FRAME_H
	3	#define _ASM_X86_FRAME_H
	4
	5	#include <asm/asm.h>
	6
	7	/*
	8	* These are stack frame creation macros. They should be used by every
	9	* callable non-leaf asm function to make kernel stack traces more reliable.
	10	*/
	11
	12	#ifdef CONFIG_FRAME_POINTER
	13
	14	#ifdef __ASSEMBLER__
	15
	16	.macro FRAME_BEGIN
	17	push %_ASM_BP
	18	_ASM_MOV %_ASM_SP, %_ASM_BP
	19	.endm
	20
	21	.macro FRAME_END
	22	pop %_ASM_BP
	23	.endm
	24
	25	#ifdef CONFIG_X86_64
	26	/*
	27	* This is a sneaky trick to help the unwinder find pt_regs on the stack. The
	28	* frame pointer is replaced with an encoded pointer to pt_regs. The encoding
	29	* is just setting the LSB, which makes it an invalid stack address and is also
	30	* a signal to the unwinder that it's a pt_regs pointer in disguise.
	31	*
	32	* NOTE: This macro must be used after PUSH_AND_CLEAR_REGS because it corrupts
	33	* the original rbp.
	34	*/
	35	.macro ENCODE_FRAME_POINTER ptregs_offset=0
	36	leaq 1+\ptregs_offset(%rsp), %rbp
	37	.endm
	38	#else /* !CONFIG_X86_64 */
	39	/*
	40	* This is a sneaky trick to help the unwinder find pt_regs on the stack. The
	41	* frame pointer is replaced with an encoded pointer to pt_regs. The encoding
	42	* is just clearing the MSB, which makes it an invalid stack address and is also
	43	* a signal to the unwinder that it's a pt_regs pointer in disguise.
	44	*
	45	* NOTE: This macro must be used after SAVE_ALL because it corrupts the
	46	* original ebp.
	47	*/
	48	.macro ENCODE_FRAME_POINTER
	49	mov %esp, %ebp
	50	andl $0x7fffffff, %ebp
	51	.endm
	52	#endif /* CONFIG_X86_64 */
	53
	54	#else /* !__ASSEMBLER__ */
	55
	56	#define FRAME_BEGIN \
	57	"push %" _ASM_BP "\n" \
	58	_ASM_MOV "%" _ASM_SP ", %" _ASM_BP "\n"
	59
	60	#define FRAME_END "pop %" _ASM_BP "\n"
	61
	62	#ifdef CONFIG_X86_64
	63
	64	#define ENCODE_FRAME_POINTER \
	65	"lea 1(%rsp), %rbp\n\t"
	66
	67	static inline unsigned long encode_frame_pointer(struct pt_regs *regs)
	68	{
	69	return (unsigned long)regs + 1;
	70	}
	71
	72	#else /* !CONFIG_X86_64 */
	73
	74	#define ENCODE_FRAME_POINTER \
	75	"movl %esp, %ebp\n\t" \
	76	"andl $0x7fffffff, %ebp\n\t"
	77
	78	static inline unsigned long encode_frame_pointer(struct pt_regs *regs)
	79	{
	80	return (unsigned long)regs & 0x7fffffff;
	81	}
	82
	83	#endif /* CONFIG_X86_64 */
	84
	85	#endif /* __ASSEMBLER__ */
	86
	87	#define FRAME_OFFSET __ASM_SEL(4, 8)
	88
	89	#else /* !CONFIG_FRAME_POINTER */
	90
	91	#ifdef __ASSEMBLER__
	92
	93	.macro ENCODE_FRAME_POINTER ptregs_offset=0
	94	.endm
	95
	96	#else /* !__ASSEMBLER__ */
	97
	98	#define ENCODE_FRAME_POINTER
	99
	100	static inline unsigned long encode_frame_pointer(struct pt_regs *regs)
	101	{
	102	return 0;
	103	}
	104
	105	#endif
	106
	107	#define FRAME_BEGIN
	108	#define FRAME_END
	109	#define FRAME_OFFSET 0
	110
	111	#endif /* CONFIG_FRAME_POINTER */
	112
	113	#endif /* _ASM_X86_FRAME_H */