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 5C030250BF2; Mon, 26 Jan 2026 21:19:00 +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=1769462340; cv=none; b=YejQT+fujLmAWWFEgx3s5Q/AXx1vmRk0GfE3XdFqtWnbvjy0U/nqO522aDIYiPm3nANIOrl4ci7k4s+xqXNWE+TLmt896ULd6Oa/PMS1j1OD3ruqsjsps75p6gKRZYcPRAHtmVvdTfpUifxxnqxPM+Au9vfi8g2Xyz8hV2TZWSk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769462340; c=relaxed/simple; bh=RAYNDZM6TcEje/Rvo7pwq2pa5dI4dJ2Et1lajk1HJbw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=i6IwyieJeW0Y5dAY6tH3Gane0Ax9oweEfY4D+ZC5mv6pVS3H4DBJ+5gzCmh0eq3yFuNRsMI7hOesRWW0X9/x5O5AMtc+Gsh/H0GZU9/WWODsnuKMHZYnlmaGeEJBUQTGWzaxjzQFUoMswzhY+8i0dJbSfB3F2hqOocSwfGBALg0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WluEbgIe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WluEbgIe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67066C116C6; Mon, 26 Jan 2026 21:18:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769462340; bh=RAYNDZM6TcEje/Rvo7pwq2pa5dI4dJ2Et1lajk1HJbw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WluEbgIepl7Gg39oc6yNxTH6hrSH82gnMk/o4kVFw1TTac7FA7nwvGzqybjkyKVD5 r+PaIQhlCykZES26TNJUMuVaGgx6TvbOIUqlB+BmAVi4gCzfhAvC4rE/qDC7dRxF0r 3K61Fkj1iQmR1nUH7haapdTKrL5ah6AZRhHXlSRAsmE+zpztv+OKo2+6JkoIsaQgWX eSXJfg/FypT9mxvVgqnQE7tdxIGqAz+uOm/7i59hDrLZ7Qyg1hTuvIUxOI3O6NVxYw seA6NwQ5s1HeB1WVSnL5w5tKJ2TwU3rTiy7ftVv2IJ3OiVmnZp4xV4Cu17471vsCLz O4jr+PrQB1XDA== From: Jiri Olsa To: Masami Hiramatsu , Steven Rostedt , Josh Poimboeuf Cc: Peter Zijlstra , bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, Yonghong Song , Song Liu , Andrii Nakryiko , Mahe Tardy Subject: [PATCHv2 bpf-next 1/6] x86/fgraph: Fix return_to_handler regs.rsp value Date: Mon, 26 Jan 2026 22:18:32 +0100 Message-ID: <20260126211837.472802-2-jolsa@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260126211837.472802-1-jolsa@kernel.org> References: <20260126211837.472802-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 --- 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 a132608265f6..62c1c93aa1c6 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -364,6 +364,9 @@ 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 @@ -374,7 +377,7 @@ 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 -- 2.52.0