From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C20BE24A06D; Wed, 25 Feb 2026 01:43:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983814; cv=none; b=qME6Y6bP2Ssh3m9/BLUTFHWmZ8knM/gvSYiw7yUgy4rwCfAGx2IG1YxLSfF9SSVTSFhEhBCej52fvxgYxImRXQDazppO0WFvsRpkmLErGYabhSkdVXW+viVadd6F0F2iH6xEKDF3ekJ/vDP9mvzlk+Q6ngRX7h3kSwlPdZDxdtM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983814; c=relaxed/simple; bh=SzMfllMWqY3bLf5AdGJ7zDZP/NmF/s8hbQk/KGSgDMc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rv9r7ihc017KMsJX4hMPuXFFi0ZaKf13HnQLXBtM0YZePXPBc/Bkn0A8xQTnfYg2fv6Z0YAgekU0UqkB0G6X3wJmjjPaGEG6/aADO4sBu/QhfU8fjtVcVRtoqq1kdJnzmoz7u/8aJvf4EPeN3I8ubfi0NsP+86Qvr4HJ+LXDynw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gQfm/+n3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gQfm/+n3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83048C19423; Wed, 25 Feb 2026 01:43:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771983814; bh=SzMfllMWqY3bLf5AdGJ7zDZP/NmF/s8hbQk/KGSgDMc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gQfm/+n3h27VCIEJluPOZrNIkBeJqMemUGv0q0lreK4XrvnOymY4mNOf8WKM7MHUd oZdNAj+5Uu0eMZpWI3gbSNxct1VSNqnEC/wRsNHz2ETWUnTUTQyCoshlHLD1t8EMjI /og9WX53i2bRKLNkKR8ZMFvKQGkIRX7UhpvjzjJ4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiri Olsa , Andrii Nakryiko , "Steven Rostedt (Google)" , Sasha Levin Subject: [PATCH 6.18 099/641] x86/fgraph: Fix return_to_handler regs.rsp value Date: Tue, 24 Feb 2026 17:17:05 -0800 Message-ID: <20260225012351.508799951@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260225012348.915798704@linuxfoundation.org> References: <20260225012348.915798704@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Olsa [ Upstream commit 8bc11700e0d23d4fdb7d8d5a73b2e95de427cabc ] The previous change (Fixes commit) messed up the rsp register value, which is wrong because it's already adjusted with FRAME_SIZE, we need the original rsp value. This change does not affect fprobe current kernel unwind, the !perf_hw_regs path perf_callchain_kernel: if (perf_hw_regs(regs)) { if (perf_callchain_store(entry, regs->ip)) return; unwind_start(&state, current, regs, NULL); } else { unwind_start(&state, current, NULL, (void *)regs->sp); } which uses pt_regs.sp as first_frame boundary (FRAME_SIZE shift makes no difference, unwind stil stops at the right frame). This change fixes the other path when we want to unwind directly from pt_regs sp/fp/ip state, which is coming in following change. Fixes: 20a0bc10272f ("x86/fgraph,bpf: Fix stack ORC unwind from kprobe_multi return probe") Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Reviewed-by: Steven Rostedt (Google) Link: https://lore.kernel.org/bpf/20260126211837.472802-2-jolsa@kernel.org Signed-off-by: Sasha Levin --- arch/x86/kernel/ftrace_64.S | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index 823dbdd0eb410..ae94f7b0fdf16 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -354,6 +354,9 @@ SYM_CODE_START(return_to_handler) UNWIND_HINT_UNDEFINED ANNOTATE_NOENDBR + /* Store original rsp for pt_regs.sp value. */ + movq %rsp, %rdi + /* Restore return_to_handler value that got eaten by previous ret instruction. */ subq $8, %rsp UNWIND_HINT_FUNC @@ -364,7 +367,7 @@ SYM_CODE_START(return_to_handler) movq %rax, RAX(%rsp) movq %rdx, RDX(%rsp) movq %rbp, RBP(%rsp) - movq %rsp, RSP(%rsp) + movq %rdi, RSP(%rsp) movq %rsp, %rdi call ftrace_return_to_handler -- 2.51.0