cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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frame.h (2555B)

      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 __ASSEMBLY__
     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 /* !__ASSEMBLY__ */
     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
     67static 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
     78static 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 /* __ASSEMBLY__ */
     86
     87#define FRAME_OFFSET __ASM_SEL(4, 8)
     88
     89#else /* !CONFIG_FRAME_POINTER */
     90
     91#ifdef __ASSEMBLY__
     92
     93.macro ENCODE_FRAME_POINTER ptregs_offset=0
     94.endm
     95
     96#else /* !__ASSEMBLY */
     97
     98#define ENCODE_FRAME_POINTER
     99
    100static 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 */