FAILED: patch "[PATCH] objtool/x86: Fixup frame-pointer vs rethunk" failed to apply to 5.15-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x dbf46008775516f7f25c95b7760041c286299783
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023082723-bribe-sporty-3c8c@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

dbf460087755 ("objtool/x86: Fixup frame-pointer vs rethunk")
c6f5dc28fb3d ("objtool: Union instruction::{call_dest,jump_table}")
0932dbe1f568 ("objtool: Remove instruction::reloc")
8b2de412158e ("objtool: Shrink instruction::{type,visited}")
d54066546121 ("objtool: Make instruction::alts a single-linked list")
3ee88df1b063 ("objtool: Make instruction::stack_ops a single-linked list")
20a554638dd2 ("objtool: Change arch_decode_instruction() signature")
5f6e430f931d ("Merge tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From dbf46008775516f7f25c95b7760041c286299783 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Wed, 16 Aug 2023 13:59:21 +0200
Subject: [PATCH] objtool/x86: Fixup frame-pointer vs rethunk

For stack-validation of a frame-pointer build, objtool validates that
every CALL instruction is preceded by a frame-setup. The new SRSO
return thunks violate this with their RSB stuffing trickery.

Extend the __fentry__ exception to also cover the embedded_insn case
used for this. This cures:

  vmlinux.o: warning: objtool: srso_untrain_ret+0xd: call without frame pointer save/setup

Fixes: 4ae68b26c3ab ("objtool/x86: Fix SRSO mess")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230816115921.GH980931@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 7a9aaf400873..1384090530db 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2650,12 +2650,17 @@ static int decode_sections(struct objtool_file *file)
 	return 0;
 }
 
-static bool is_fentry_call(struct instruction *insn)
+static bool is_special_call(struct instruction *insn)
 {
-	if (insn->type == INSN_CALL &&
-	    insn_call_dest(insn) &&
-	    insn_call_dest(insn)->fentry)
-		return true;
+	if (insn->type == INSN_CALL) {
+		struct symbol *dest = insn_call_dest(insn);
+
+		if (!dest)
+			return false;
+
+		if (dest->fentry || dest->embedded_insn)
+			return true;
+	}
 
 	return false;
 }
@@ -3656,7 +3661,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 			if (ret)
 				return ret;
 
-			if (opts.stackval && func && !is_fentry_call(insn) &&
+			if (opts.stackval && func && !is_special_call(insn) &&
 			    !has_valid_stack_frame(&state)) {
 				WARN_INSN(insn, "call without frame pointer save/setup");
 				return 1;