From nobody Mon Feb 9 03:34:52 2026 Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) (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 7736818FDD5; Wed, 11 Jun 2025 01:03:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.10 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749603790; cv=none; b=G81XsHm0TJaMpRHqFWQ0/VqF+80dDXxgyGEmUBU6V15YpqNrkodW6dg6W6KEny/3vwW+3eq51g1Odt6xEGPs3VtflcEfhHMz1ID9VIZ0IhE+mi5FzkPRyTImQqX3oLOTNwk20ZqVa7tA+wqabpOMg29uApt7Y5xVx1qfdRI9apU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749603790; c=relaxed/simple; bh=FEdFYcHE9hiNNH0v0kJvOh5Nf4CYXvUN8o4+V7c20RE=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=M0RVb8uS4F253K8sMDnAZUHNnSraAqBz5hotfNjPWD0gw+W91IfWl4v7d144bIBkm3jvrqUaICeq42ayW8vENImG+UKdBUUxoauTRNOvkutaSqpRxGGyme5GcJgqMV3aiJHnC0ssdWYsMEuvI/iSWPk0IfJadLP9oze9liKbT3U= 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=216.40.44.10 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 omf16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 8A61B1A14A1; Wed, 11 Jun 2025 01:02:59 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: nevets@goodmis.org) by omf16.hostedemail.com (Postfix) with ESMTPA id 6516A20016; Wed, 11 Jun 2025 01:02:56 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uP9tE-00000000v8l-1ioR; Tue, 10 Jun 2025 21:04:28 -0400 Message-ID: <20250611010428.261095906@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 10 Jun 2025 20:54:24 -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 Subject: [PATCH v10 03/14] unwind_user: Add compat mode frame pointer support References: <20250611005421.144238328@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Server: rspamout03 X-Rspamd-Queue-Id: 6516A20016 X-Stat-Signature: qhubogz66cku8w11ugwsoq3j9m6qy8es X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX18D/Otjcnc4hYwtwLxywwau0hsT2HDNzLM= X-HE-Tag: 1749603776-935033 X-HE-Meta: U2FsdGVkX1/J/7m/TUWAbEfJ9dG/cOQggKjAX/hEMf3c78hTrVMRzh7huHhJZeFIgQI8h0aTIxT6aKfl2/5Ma8xfXolYVAo8BIE0LqzW56LhHAr+KQH7zXlpC3jHJkAZBSspDmCuyvEgyYYJNdgu14MklhD7pSy0/Z13ehZYh72R3TCjxr5EmZUSJneeUVsibB0TmbbixjvDVh4xNKrVepikGgw0n7xorksvCvX7oINWaQiqA7MiSP7q4R40s0gsB0rGuIxVtxZuyKArSGgtA2yWIPOmPAVTAJF5tX5aGejh6wAlcR7YgKCuAubXLTIDkiimtOI91SRflFS+nx5Aw+wdJBnxAgx5IC2lgepR2WiMPJmUm7LM0xzrAH4dIKqTv9YJLycyWuluqWqTtd0umm/i42GGSvD7Q9aSvY8I57I= 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) --- Changes since v9: https://lore.kernel.org/linux-trace-kernel/20250513223551= .459986355@goodmis.org/ As asm-generic headers are not included when an architecture defines the header, having more than one #ifndef and setting variables does not work with those checks in the asm-generic header and the architecture header does not define all the values. - Move #indef arch_unwind_user_state to linux/user_unwind_types.h - Move the following to linux/unwind_user.h: #ifndef ARCH_INIT_USER_COMPAT_FP_FRAME #ifndef arch_unwind_user_init #ifndef arch_unwind_user_next - Changed UNWIND_GET_USER_LONG() to use "unsigned long" instead of u64 as this can be called on 32 bit architectures and just because "compat_state()" returns false doesn't mean that the value is 64 bit. arch/Kconfig | 4 +++ include/asm-generic/Kbuild | 1 + include/asm-generic/unwind_user_types.h | 5 ++++ include/linux/unwind_user.h | 13 +++++++++ include/linux/unwind_user_types.h | 7 +++++ kernel/unwind/user.c | 36 ++++++++++++++++++++++--- 6 files changed, 62 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..c70da8f7e54c 100644 --- a/include/linux/unwind_user.h +++ b/include/linux/unwind_user.h @@ -9,6 +9,19 @@ #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 + +#ifndef arch_unwind_user_init +static inline void arch_unwind_user_init(struct unwind_user_state *state, = struct pt_regs *reg) {} +#endif + +#ifndef arch_unwind_user_next +static inline void arch_unwind_user_next(struct unwind_user_state *state) = {} +#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 4fc550356b33..29e1f497a26e 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_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_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_state(state)) + frame =3D &compat_fp_frame; + else if (fp_state(state)) frame =3D &fp_frame; else goto the_end; @@ -37,10 +59,10 @@ int unwind_user_next(struct unwind_user_state *state) if (cfa <=3D state->sp) goto the_end; =20 - if (get_user(ra, (unsigned long *)(cfa + frame->ra_off))) + if (UNWIND_GET_USER_LONG(ra, cfa + frame->ra_off, state)) goto the_end; =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 the_end; =20 state->ip =3D ra; @@ -48,6 +70,8 @@ int unwind_user_next(struct unwind_user_state *state) if (frame->fp_off) state->fp =3D fp; =20 + arch_unwind_user_next(state); + return 0; =20 the_end: @@ -66,7 +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; @@ -75,6 +101,8 @@ int unwind_user_start(struct unwind_user_state *state) state->sp =3D user_stack_pointer(regs); state->fp =3D frame_pointer(regs); =20 + arch_unwind_user_init(state, regs); + return 0; } =20 --=20 2.47.2