From nobody Wed Oct 8 09:06:16 2025 Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) (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 AA85F1D5ABF; Tue, 1 Jul 2025 00:54:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.16 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751331268; cv=none; b=Z3nk1JVR+WwXCdSqSwKVjKUCY/3+WyTadBpvaebveMuf27U9I7ymh/iNvCL0AUURpBjqrgVOKH0FNJ65NGsw3b1SAXVQ7w07xLwDWlkV9ZlBdJ/IpOYle6OTEKMP5SOs9YEywYK6lWL89+B+Ui3YuinorDTNSOSM1vMK7BZmWSA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751331268; c=relaxed/simple; bh=q2QsKEvtnIKsRdYt6OTQ9dXxhzHlZleBu1wcHPb4KmA=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=fdRTXlvTZCatZU98wf/UjNBhzDTW5QNwXW2hcUfFWQOwWIynGojaKxuh+PgkdO6BIkgPP1U6tZaR5dR3i88/MdJrKfz0h1chq0X31j52ZVGBR/U+bYUWczeD50eCYpya5qHwb3+4hTSBhw6C8aoqaBL+iti2rB7aWB7TuphaCvM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id BEF2A1D2D80; Tue, 1 Jul 2025 00:54:17 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: nevets@goodmis.org) by omf03.hostedemail.com (Postfix) with ESMTPA id 6CFE56000B; Tue, 1 Jul 2025 00:54:14 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uWPGt-00000007Nfl-0rbh; Mon, 30 Jun 2025 20:54:51 -0400 Message-ID: <20250701005451.055982038@goodmis.org> User-Agent: quilt/0.68 Date: Mon, 30 Jun 2025 20:53:24 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, x86@kernel.org Cc: Masami Hiramatsu , Mathieu Desnoyers , Josh Poimboeuf , Peter Zijlstra , Ingo Molnar , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Andrii Nakryiko , Indu Bhagat , "Jose E. Marchesi" , Beau Belgrave , Jens Remus , Linus Torvalds , Andrew Morton , Jens Axboe , Florian Weimer Subject: [PATCH v12 03/14] unwind_user: Add compat mode frame pointer support References: <20250701005321.942306427@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Stat-Signature: 5hpuu3emhuceecpm319cziywgnc1ygs9 X-Rspamd-Server: rspamout08 X-Rspamd-Queue-Id: 6CFE56000B X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX19k3B6nUg7dyH2F0CIW8f4HjMWdFjC0G5o= X-HE-Tag: 1751331254-312351 X-HE-Meta: U2FsdGVkX1/DSa5YrJ0EqUry+7RAgMfcXxUqCjstXSI5ukRGng9ZgNNxgrGk/YwqDao/Ro4lFJEFqz4L0LnbckzEagG/18D4Up9iuc1YwSGa1Z1sTGXvhyCAlf61vlU+qtaJ0IucN3D86xW10XDkW2mfFfD0ug/iHG9kSPuEZYz5dOsYUbS4DLjT4d4HRvG8qf8ZX16gv14+pbbAbU3OddcEjAqYbRLHIHon/qTdoS57X0ZThTx4Zy963MRatzUpPM/hliGsdDy9DANdbUb4hr3lKnpTyX0H/vlQL/kBIBSsCUtBGnVvc0WAR2l6NhZBhnUU+9/71gamt4qO9ljixls1lGHcDuWvZ4qu41UXuXZq+h36aR0RI7lDgml/S7X9poGAsT8Gmg5ra03jDoxU3mHHjWOKC5TQDujB4Yasr/g= Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Josh Poimboeuf Add optional support for user space compat mode frame pointer unwinding. If supported, the arch needs to enable CONFIG_HAVE_UNWIND_USER_COMPAT_FP and define ARCH_INIT_USER_COMPAT_FP_FRAME. Signed-off-by: Josh Poimboeuf Co-developed-by: Steven Rostedt (Google) Signed-off-by: Steven Rostedt (Google) --- arch/Kconfig | 4 ++++ include/asm-generic/Kbuild | 1 + include/asm-generic/unwind_user_types.h | 5 ++++ include/linux/unwind_user.h | 5 ++++ include/linux/unwind_user_types.h | 7 ++++++ kernel/unwind/user.c | 32 +++++++++++++++++++++---- 6 files changed, 50 insertions(+), 4 deletions(-) create mode 100644 include/asm-generic/unwind_user_types.h diff --git a/arch/Kconfig b/arch/Kconfig index 8e3fd723bd74..2c41d3072910 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -442,6 +442,10 @@ config HAVE_UNWIND_USER_FP bool select UNWIND_USER =20 +config HAVE_UNWIND_USER_COMPAT_FP + bool + depends on HAVE_UNWIND_USER_FP + config HAVE_PERF_REGS bool help diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild index 295c94a3ccc1..b797a2434396 100644 --- a/include/asm-generic/Kbuild +++ b/include/asm-generic/Kbuild @@ -60,6 +60,7 @@ mandatory-y +=3D topology.h mandatory-y +=3D trace_clock.h mandatory-y +=3D uaccess.h mandatory-y +=3D unwind_user.h +mandatory-y +=3D unwind_user_types.h mandatory-y +=3D vermagic.h mandatory-y +=3D vga.h mandatory-y +=3D video.h diff --git a/include/asm-generic/unwind_user_types.h b/include/asm-generic/= unwind_user_types.h new file mode 100644 index 000000000000..f568b82e52cd --- /dev/null +++ b/include/asm-generic/unwind_user_types.h @@ -0,0 +1,5 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_UNWIND_USER_TYPES_H +#define _ASM_GENERIC_UNWIND_USER_TYPES_H + +#endif /* _ASM_GENERIC_UNWIND_USER_TYPES_H */ diff --git a/include/linux/unwind_user.h b/include/linux/unwind_user.h index a405111c41b0..ac007363820a 100644 --- a/include/linux/unwind_user.h +++ b/include/linux/unwind_user.h @@ -9,6 +9,11 @@ #define ARCH_INIT_USER_FP_FRAME #endif =20 +#ifndef ARCH_INIT_USER_COMPAT_FP_FRAME + #define ARCH_INIT_USER_COMPAT_FP_FRAME + #define in_compat_mode(regs) false +#endif + int unwind_user_start(struct unwind_user_state *state); int unwind_user_next(struct unwind_user_state *state); =20 diff --git a/include/linux/unwind_user_types.h b/include/linux/unwind_user_= types.h index 65bd070eb6b0..0b6563951ca4 100644 --- a/include/linux/unwind_user_types.h +++ b/include/linux/unwind_user_types.h @@ -3,10 +3,16 @@ #define _LINUX_UNWIND_USER_TYPES_H =20 #include +#include + +#ifndef arch_unwind_user_state +struct arch_unwind_user_state {}; +#endif =20 enum unwind_user_type { UNWIND_USER_TYPE_NONE, UNWIND_USER_TYPE_FP, + UNWIND_USER_TYPE_COMPAT_FP, }; =20 struct unwind_stacktrace { @@ -25,6 +31,7 @@ struct unwind_user_state { unsigned long ip; unsigned long sp; unsigned long fp; + struct arch_unwind_user_state arch; enum unwind_user_type type; bool done; }; diff --git a/kernel/unwind/user.c b/kernel/unwind/user.c index 1201d655654a..3a0ac4346f5b 100644 --- a/kernel/unwind/user.c +++ b/kernel/unwind/user.c @@ -12,12 +12,32 @@ static struct unwind_user_frame fp_frame =3D { ARCH_INIT_USER_FP_FRAME }; =20 +static struct unwind_user_frame compat_fp_frame =3D { + ARCH_INIT_USER_COMPAT_FP_FRAME +}; + static inline bool fp_state(struct unwind_user_state *state) { return IS_ENABLED(CONFIG_HAVE_UNWIND_USER_FP) && state->type =3D=3D UNWIND_USER_TYPE_FP; } =20 +static inline bool compat_fp_state(struct unwind_user_state *state) +{ + return IS_ENABLED(CONFIG_HAVE_UNWIND_USER_COMPAT_FP) && + state->type =3D=3D UNWIND_USER_TYPE_COMPAT_FP; +} + +#define unwind_get_user_long(to, from, state) \ +({ \ + int __ret; \ + if (compat_fp_state(state)) \ + __ret =3D get_user(to, (u32 __user *)(from)); \ + else \ + __ret =3D get_user(to, (unsigned long __user *)(from)); \ + __ret; \ +}) + int unwind_user_next(struct unwind_user_state *state) { struct unwind_user_frame *frame; @@ -26,7 +46,9 @@ int unwind_user_next(struct unwind_user_state *state) if (state->done) return -EINVAL; =20 - if (fp_state(state)) + if (compat_fp_state(state)) + frame =3D &compat_fp_frame; + else if (fp_state(state)) frame =3D &fp_frame; else goto done; @@ -39,10 +61,10 @@ int unwind_user_next(struct unwind_user_state *state) goto done; =20 /* Find the Return Address (RA) */ - if (get_user(ra, (unsigned long *)(cfa + frame->ra_off))) + if (unwind_get_user_long(ra, cfa + frame->ra_off, state)) goto done; =20 - if (frame->fp_off && get_user(fp, (unsigned long __user *)(cfa + frame->f= p_off))) + if (frame->fp_off && unwind_get_user_long(fp, cfa + frame->fp_off, state)) goto done; =20 state->ip =3D ra; @@ -68,7 +90,9 @@ int unwind_user_start(struct unwind_user_state *state) return -EINVAL; } =20 - if (IS_ENABLED(CONFIG_HAVE_UNWIND_USER_FP)) + if (IS_ENABLED(CONFIG_HAVE_UNWIND_USER_COMPAT_FP) && in_compat_mode(regs)) + state->type =3D UNWIND_USER_TYPE_COMPAT_FP; + else if (IS_ENABLED(CONFIG_HAVE_UNWIND_USER_FP)) state->type =3D UNWIND_USER_TYPE_FP; else state->type =3D UNWIND_USER_TYPE_NONE; --=20 2.47.2