From nobody Tue Oct 7 21:50:20 2025 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 F326F238C27; Fri, 9 May 2025 16:51:38 +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=1746809499; cv=none; b=lKh6TQuri5Gw6vTRXNBpjaVdQheYHjB3GIxsqF/Z5rS9A1Au0qRSKDXnw/qTiBOBPTJs4D+524PoRXVOhe2iHHacb7XX2iT6KmPpnexr/sUJ2FTpOYOYllWLkLqlGy8lybBu+b7DtwCs8ebXVgaX+EuS/+aC3+H9YqsF3kpR15E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746809499; c=relaxed/simple; bh=/O8CQz956FRS/3j6BWFD/9/GKy/nCXhh68LzH+c4gKM=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=U3MJEm9nYkmChsc5VZArzyAhh1909ycFDkjnkQRYmrnV9wFXwqsuDnnZv2Ov2Ef6eLJsXwP4W4kmGI5I16RspZmmy/80QjVm39oxTM9OqkKeG5Cq+r8E2pIVMYjQPJmLcx6CTJTEEEIJAz/jpABUW2BMRlTdOS8v1Ou3LPcuTb0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC5ACC4CEF5; Fri, 9 May 2025 16:51:38 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uDQx0-00000002gFh-2WXW; Fri, 09 May 2025 12:51:54 -0400 Message-ID: <20250509165154.456665131@goodmis.org> User-Agent: quilt/0.68 Date: Fri, 09 May 2025 12:45:29 -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 Subject: [PATCH v8 05/18] unwind_user: Add compat mode frame pointer support References: <20250509164524.448387100@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 Signed-off-by: Steven Rostedt (Google) --- arch/Kconfig | 4 +++ include/asm-generic/Kbuild | 2 ++ include/asm-generic/unwind_user.h | 15 +++++++++++ include/asm-generic/unwind_user_types.h | 9 +++++++ include/linux/unwind_user_types.h | 3 +++ kernel/unwind/user.c | 36 ++++++++++++++++++++++--- 6 files changed, 65 insertions(+), 4 deletions(-) create mode 100644 include/asm-generic/unwind_user_types.h diff --git a/arch/Kconfig b/arch/Kconfig index 0e3844c0e200..dbb1cc89e040 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 8675b7b4ad23..b797a2434396 100644 --- a/include/asm-generic/Kbuild +++ b/include/asm-generic/Kbuild @@ -59,6 +59,8 @@ mandatory-y +=3D tlbflush.h 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.h b/include/asm-generic/unwind= _user.h index 832425502fb3..385638ce4aec 100644 --- a/include/asm-generic/unwind_user.h +++ b/include/asm-generic/unwind_user.h @@ -2,8 +2,23 @@ #ifndef _ASM_GENERIC_UNWIND_USER_H #define _ASM_GENERIC_UNWIND_USER_H =20 +#include + #ifndef ARCH_INIT_USER_FP_FRAME #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 + #endif /* _ASM_GENERIC_UNWIND_USER_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..ee803de7c998 --- /dev/null +++ b/include/asm-generic/unwind_user_types.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_UNWIND_USER_TYPES_H +#define _ASM_GENERIC_UNWIND_USER_TYPES_H + +#ifndef arch_unwind_user_state +struct arch_unwind_user_state {}; +#endif + +#endif /* _ASM_GENERIC_UNWIND_USER_TYPES_H */ diff --git a/include/linux/unwind_user_types.h b/include/linux/unwind_user_= types.h index 65bd070eb6b0..3ec4a097a3dd 100644 --- a/include/linux/unwind_user_types.h +++ b/include/linux/unwind_user_types.h @@ -3,10 +3,12 @@ #define _LINUX_UNWIND_USER_TYPES_H =20 #include +#include =20 enum unwind_user_type { UNWIND_USER_TYPE_NONE, UNWIND_USER_TYPE_FP, + UNWIND_USER_TYPE_COMPAT_FP, }; =20 struct unwind_stacktrace { @@ -25,6 +27,7 @@ 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 0671a81494d3..635cc04bb299 100644 --- a/kernel/unwind/user.c +++ b/kernel/unwind/user.c @@ -13,12 +13,32 @@ 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, (u64 __user *)(from)); \ + __ret; \ +}) + int unwind_user_next(struct unwind_user_state *state) { struct unwind_user_frame _frame; @@ -28,7 +48,9 @@ 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; @@ -39,10 +61,10 @@ 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; @@ -50,6 +72,8 @@ 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: @@ -68,7 +92,9 @@ 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; @@ -77,6 +103,8 @@ 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