The patch below does not apply to the 5.10-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@vger.kernel.org.

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-5.10.y git checkout FETCH_HEAD git cherry-pick -x dbf46008775516f7f25c95b7760041c286299783 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023082724-deflate-drinkable-54a1@gregkh' --subject-prefix 'PATCH 5.10.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@infradead.org 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@infradead.org Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Acked-by: Josh Poimboeuf jpoimboe@kernel.org Link: https://lore.kernel.org/r/20230816115921.GH980931@hirez.programming.kicks-as...

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;