linux/arch/x86/include/asm/text-patching.h
Nadav Amit 0a203df5cf x86/alternatives: Remove the return value of text_poke_*()
The return value of text_poke_early() and text_poke_bp() is useless.
Remove it.

Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <ard.biesheuvel@linaro.org>
Cc: <deneen.t.dock@intel.com>
Cc: <kernel-hardening@lists.openwall.com>
Cc: <kristen@linux.intel.com>
Cc: <linux_dti@icloud.com>
Cc: <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190426001143.4983-14-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30 12:37:56 +02:00

46 lines
1.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_TEXT_PATCHING_H
#define _ASM_X86_TEXT_PATCHING_H
#include <linux/types.h>
#include <linux/stddef.h>
#include <asm/ptrace.h>
struct paravirt_patch_site;
#ifdef CONFIG_PARAVIRT
void apply_paravirt(struct paravirt_patch_site *start,
struct paravirt_patch_site *end);
#else
static inline void apply_paravirt(struct paravirt_patch_site *start,
struct paravirt_patch_site *end)
{}
#define __parainstructions NULL
#define __parainstructions_end NULL
#endif
extern void text_poke_early(void *addr, const void *opcode, size_t len);
/*
* Clear and restore the kernel write-protection flag on the local CPU.
* Allows the kernel to edit read-only pages.
* Side-effect: any interrupt handler running between save and restore will have
* the ability to write to read-only pages.
*
* Warning:
* Code patching in the UP case is safe if NMIs and MCE handlers are stopped and
* no thread can be preempted in the instructions being modified (no iret to an
* invalid instruction possible) or if the instructions are changed from a
* consistent state to another consistent state atomically.
* On the local CPU you need to be protected again NMI or MCE handlers seeing an
* inconsistent instruction while you patch.
*/
extern void *text_poke(void *addr, const void *opcode, size_t len);
extern void *text_poke_kgdb(void *addr, const void *opcode, size_t len);
extern int poke_int3_handler(struct pt_regs *regs);
extern void text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
extern int after_bootmem;
extern __ro_after_init struct mm_struct *poking_mm;
extern __ro_after_init unsigned long poking_addr;
#endif /* _ASM_X86_TEXT_PATCHING_H */