This is a note to let you know that I've just added the patch titled
cfi: Add CFI_NOSEAL()
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cfi-add-cfi_noseal.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bfe2ec28ec2b6bdd08895cac43c9ec27104096ed
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Fri Dec 15 10:12:21 2023 +0100
cfi: Add CFI_NOSEAL()
[ 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@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231215092707.669401084@xxxxxxxxxxxxx
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 */
