From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) (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 B56C42F49F8; Wed, 25 Jun 2025 22:57:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750892225; cv=none; b=g92Xh05DE9KAishneau6T5ul8PjDC4eOZnt0fiXg2c3bpmLQm/s03TLaN51yGu2CqtP5Zekz6WxWBRPgoTLCoWhNluce+5pTt8iX1kg7oiz/cOxvhkJwDRJ79+MYY+JQNYTjEvifmvCot4WSoI2kcmOkQ0fxoReaCY4ClzChVwc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750892225; c=relaxed/simple; bh=BTki9KcgQuBs03ZLixR3EfsIYgDN30ni9Vj+f0Agnh0=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=IWizK1PWHIsRqwICFQBcSOZwYiufYZxwzGKaJ3GRGTH1OdpdNw/t8mfxpbHXY/U58LLtWmKhUsvXWPsQPYBW6fMiEBRT8Gy/J7A1k5MrCvYzWWOVf7os7NxA1Cju3YHwVJNe6rd9a+kEaf4bJ3mWigBwgrDYN9G6YWqiKz3tGW8= 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=216.40.44.12 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 omf02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 897271047D0; Wed, 25 Jun 2025 22:56:53 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: nevets@goodmis.org) by omf02.hostedemail.com (Postfix) with ESMTPA id 4DF758000F; Wed, 25 Jun 2025 22:56:50 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uUZ3L-000000043eL-1xnh; Wed, 25 Jun 2025 18:57:15 -0400 Message-ID: <20250625225715.319252952@goodmis.org> User-Agent: quilt/0.68 Date: Wed, 25 Jun 2025 18:56:03 -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 Subject: [PATCH v11 03/14] unwind_user: Add compat mode frame pointer support References: <20250625225600.555017347@goodmis.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Stat-Signature: u71xmu1cznptucshk3bon4dmo8t6eszg X-Rspamd-Server: rspamout05 X-Rspamd-Queue-Id: 4DF758000F X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1/OmbiHdwR6oaDQqzTo3ytvVL/34RQqUa4= X-HE-Tag: 1750892210-797740 X-HE-Meta: U2FsdGVkX19ptLZDQbVnXH2MvdZXZdeYsg4h4/9amlJ4uuUMEppxK0Jw7m/KMg1PVjp50TUcgvwNahM/NyuPzb8hW2VJWu8FAJT+FrTLajgnzEofH9lx0HEk2r8a4D7bw7NxM6tM+0YzkJPl21HzK4O3BwaGfjQf/pJci+WC/Hm8zs/xaLVeNHrw2XB0xkKtHrSPLeJMZmplzAGGS94HJzddJEQsvYN4gsMOadXdNXGTT9uLXhF3/YEVyB19BN5bol1NX4mwrVdwHPSddBWcbAHOwZRbXDj8xMhfxGyZ+HXz9gRVA47NFW7ZSIsLdYUWoIz0+CLiWsYN0XTZ+ksF972n0nYHQ7A9KBhXPGuiAHKXAS9Z7NLFsO69BR4dUtn8ilPfRpkrjRRiVLX/5dUkzUQy7L3rmDdeZX3oVVAEXZU= 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) --- Changes since v10: https://lore.kernel.org/20250611010428.261095906@goodmis.org - Rename compat_state() to compat_fp_state() for consistency. (Peter Zijlstra) - Lowercase macro UNWIND_GET_USER_LONG() to unwind_get_user_long() (Peter Zijlstra and Linus Torvalds) - Remove currently unused arch_unwind_user_init() and arch_unwind_user_next() and add them in the later patches when they are used. (Peter Zijlstra) 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 +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 += topology.h mandatory-y += trace_clock.h mandatory-y += uaccess.h mandatory-y += unwind_user.h +mandatory-y += unwind_user_types.h mandatory-y += vermagic.h mandatory-y += vga.h mandatory-y += 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 +#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); 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 #include +#include + +#ifndef arch_unwind_user_state +struct arch_unwind_user_state {}; +#endif enum unwind_user_type { UNWIND_USER_TYPE_NONE, UNWIND_USER_TYPE_FP, + UNWIND_USER_TYPE_COMPAT_FP, }; 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 = { ARCH_INIT_USER_FP_FRAME }; +static struct unwind_user_frame compat_fp_frame = { + 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 == UNWIND_USER_TYPE_FP; } +static inline bool compat_fp_state(struct unwind_user_state *state) +{ + return IS_ENABLED(CONFIG_HAVE_UNWIND_USER_COMPAT_FP) && + state->type == UNWIND_USER_TYPE_COMPAT_FP; +} + +#define unwind_get_user_long(to, from, state) \ +({ \ + int __ret; \ + if (compat_fp_state(state)) \ + __ret = get_user(to, (u32 __user *)(from)); \ + else \ + __ret = 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; - if (fp_state(state)) + if (compat_fp_state(state)) + frame = &compat_fp_frame; + else if (fp_state(state)) frame = &fp_frame; else goto done; @@ -39,10 +61,10 @@ int unwind_user_next(struct unwind_user_state *state) goto done; /* 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; - if (frame->fp_off && get_user(fp, (unsigned long __user *)(cfa + frame->fp_off))) + if (frame->fp_off && unwind_get_user_long(fp, cfa + frame->fp_off, state)) goto done; state->ip = ra; @@ -68,7 +90,9 @@ int unwind_user_start(struct unwind_user_state *state) return -EINVAL; } - if (IS_ENABLED(CONFIG_HAVE_UNWIND_USER_FP)) + if (IS_ENABLED(CONFIG_HAVE_UNWIND_USER_COMPAT_FP) && in_compat_mode(regs)) + state->type = UNWIND_USER_TYPE_COMPAT_FP; + else if (IS_ENABLED(CONFIG_HAVE_UNWIND_USER_FP)) state->type = UNWIND_USER_TYPE_FP; else state->type = UNWIND_USER_TYPE_NONE; -- 2.47.2