Files
linux-stable-mirror/include/linux/cfi.h
T
Nathan Chancellor 979c294509 cfi: Include uaccess.h for get_kernel_nofault()
After commit 0652a3daa7 ("tracing: Fix CFI violation in probestub
being called by tprobes"), there are many build errors when building
ARCH=arm multi_v7_defconfig + CONFIG_CFI=y like:

  In file included from drivers/base/devres.c:17:
  In file included from drivers/base/trace.h:16:
  In file included from include/linux/tracepoint.h:23:
  include/linux/cfi.h:44:6: error: call to undeclared function 'get_kernel_nofault'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     44 |         if (get_kernel_nofault(hash, func - cfi_get_offset()))
        |             ^
  1 error generated.

get_kernel_nofault() is called in the generic version of
cfi_get_func_hash() but nothing ensures uaccess.h is always included for
a proper expansion and prototype.  Include uaccess.h in cfi.h to clear
up the errors.

Cc: stable@vger.kernel.org
Fixes: 0652a3daa7 ("tracing: Fix CFI violation in probestub being called by tprobes")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-06-06 15:08:36 -07:00

88 lines
2.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Clang Control Flow Integrity (CFI) support.
*
* Copyright (C) 2022 Google LLC
*/
#ifndef _LINUX_CFI_H
#define _LINUX_CFI_H
#include <linux/bug.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <asm/cfi.h>
#ifdef CONFIG_CFI
extern bool cfi_warn;
enum bug_trap_type report_cfi_failure(struct pt_regs *regs, unsigned long addr,
unsigned long *target, u32 type);
static inline enum bug_trap_type report_cfi_failure_noaddr(struct pt_regs *regs,
unsigned long addr)
{
return report_cfi_failure(regs, addr, NULL, 0);
}
#ifndef cfi_get_offset
/*
* Returns the CFI prefix offset. By default, the compiler emits only
* a 4-byte CFI type hash before the function. If an architecture
* uses -fpatchable-function-entry=N,M where M>0 to change the prefix
* offset, they must override this function.
*/
static inline int cfi_get_offset(void)
{
return 4;
}
#endif
#ifndef cfi_get_func_hash
static inline u32 cfi_get_func_hash(void *func)
{
u32 hash;
if (get_kernel_nofault(hash, func - cfi_get_offset()))
return 0;
return hash;
}
#endif
/* CFI type hashes for BPF function types */
extern u32 cfi_bpf_hash;
extern u32 cfi_bpf_subprog_hash;
#else /* CONFIG_CFI */
static inline int cfi_get_offset(void) { return 0; }
static inline u32 cfi_get_func_hash(void *func) { return 0; }
#define cfi_bpf_hash 0U
#define cfi_bpf_subprog_hash 0U
#endif /* CONFIG_CFI */
#ifdef CONFIG_ARCH_USES_CFI_TRAPS
bool is_cfi_trap(unsigned long addr);
#else
static inline bool is_cfi_trap(unsigned long addr) { return false; }
#endif
#ifdef CONFIG_MODULES
#ifdef CONFIG_ARCH_USES_CFI_TRAPS
void module_cfi_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *mod);
#else
static inline void module_cfi_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *mod) {}
#endif /* CONFIG_ARCH_USES_CFI_TRAPS */
#endif /* CONFIG_MODULES */
#ifndef CFI_NOSEAL
#define CFI_NOSEAL(x)
#endif
#endif /* _LINUX_CFI_H */