From: Peter Zijlstra peterz@infradead.org
[ Upstream commit e9d13b9d2f99ccf7afeab490d97eaa5ac9846598 ]
Add a CFI_NOSEAL() helper to mark functions that need to retain their CFI information, despite not otherwise leaking their address.
Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lore.kernel.org/r/20231215092707.669401084@infradead.org Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/include/asm/cfi.h | 5 +++++ include/linux/cfi.h | 4 ++++ 2 files changed, 9 insertions(+)
diff --git a/arch/x86/include/asm/cfi.h b/arch/x86/include/asm/cfi.h index 58dacd90daef..67b010c224e4 100644 --- a/arch/x86/include/asm/cfi.h +++ b/arch/x86/include/asm/cfi.h @@ -9,6 +9,7 @@ */
#include <linux/cfi.h> +#include <asm/ibt.h>
#ifdef CONFIG_CFI_CLANG enum bug_trap_type handle_cfi_failure(struct pt_regs *regs); @@ -19,4 +20,8 @@ static inline enum bug_trap_type handle_cfi_failure(struct pt_regs *regs) } #endif /* CONFIG_CFI_CLANG */
+#if HAS_KERNEL_IBT == 1 +#define CFI_NOSEAL(x) asm(IBT_NOSEAL(__stringify(x))) +#endif + #endif /* _ASM_X86_CFI_H */ diff --git a/include/linux/cfi.h b/include/linux/cfi.h index 5e134f4ce8b7..f2f722c5aedd 100644 --- a/include/linux/cfi.h +++ b/include/linux/cfi.h @@ -36,4 +36,8 @@ static inline void module_cfi_finalize(const Elf_Ehdr *hdr, #endif /* CONFIG_ARCH_USES_CFI_TRAPS */ #endif /* CONFIG_MODULES */
+#ifndef CFI_NOSEAL +#define CFI_NOSEAL(x) +#endif + #endif /* _LINUX_CFI_H */