This is a note to let you know that I've just added the patch titled
x86/text-patching: Make text_gen_insn() play nice with ANNOTATE_NOENDBR
to the 5.15-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:
x86-text-patching-make-text_gen_insn-play-nice-with-annotate_noendbr.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c902f82a89101e4d65eee4fa63411f781ff51eba Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Tue, 8 Mar 2022 16:30:19 +0100
Subject: x86/text-patching: Make text_gen_insn() play nice with ANNOTATE_NOENDBR
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Upstream commit: bbf92368b0b1fe472d489e62d3340d7897e9c697
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220308154317.638561109@xxxxxxxxxxxxx
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/text-patching.h | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- a/arch/x86/include/asm/text-patching.h
+++ b/arch/x86/include/asm/text-patching.h
@@ -101,13 +101,21 @@ void *text_gen_insn(u8 opcode, const voi
static union text_poke_insn insn; /* per instance */
int size = text_opcode_size(opcode);
+ /*
+ * Hide the addresses to avoid the compiler folding in constants when
+ * referencing code, these can mess up annotations like
+ * ANNOTATE_NOENDBR.
+ */
+ OPTIMIZER_HIDE_VAR(addr);
+ OPTIMIZER_HIDE_VAR(dest);
+
insn.opcode = opcode;
if (size > 1) {
insn.disp = (long)dest - (long)(addr + size);
if (size == 2) {
/*
- * Ensure that for JMP9 the displacement
+ * Ensure that for JMP8 the displacement
* actually fits the signed byte.
*/
BUG_ON((insn.disp >> 31) != (insn.disp >> 7));
Patches currently in stable-queue which might be from peterz@xxxxxxxxxxxxx are
queue-5.15/x86-ftrace-use-alternative-ret-encoding.patch
queue-5.15/x86-text-patching-make-text_gen_insn-play-nice-with-annotate_noendbr.patch
queue-5.15/x86-alternative-make-custom-return-thunk-unconditional.patch
queue-5.15/x86-returnthunk-allow-different-return-thunks.patch
queue-5.15/x86-ibt-paravirt-use-text_gen_insn-for-paravirt_patch.patch
queue-5.15/sched-rt-fix-sysctl_sched_rr_timeslice-intial-value.patch
queue-5.15/sched-rt-sysctl_sched_rr_timeslice-show-default-timeslice-after-reset.patch
