From nobody Mon Feb 9 23:38:06 2026 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 9D123216E23; Tue, 13 May 2025 22:35:26 +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=1747175726; cv=none; b=CuhgfX4fLS/9pyTOUlW8OPOyKIcgmraS0Akqs7AIEyaiVtBbTxHUwhLWTtBbgRpvv8JWpNbYww95sStgpscrDLUvbRYx3mF8t1gR7sFKbY16n4T6r24vB6fhEAl3LaI+ENgYc5/DE6E031j6ozB2v+LVvO96Eiqa5Y6r5xx9GN8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747175726; c=relaxed/simple; bh=8bCsPjFcHdrJLyuXeb4ApJUZqTxHKkLiNotDnZk7s18=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=JjAk28qp4J3/O3vL0RTy+ME2dCBUiOmGGOdFz9Drlk732RvSYTFOf9JsqNFxZZspZWoqiL2Rqq5/U4hvACwJK6EmpG7qmFPh4gx6n4qbJW+9Fn++Rz14qdGSqAVBDL99kkVJ+rQCTL2eUIPpsM3msdVuqpcm5KhAa37Crq2Ilh4= 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 38894C4CEF3; Tue, 13 May 2025 22:35:26 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uEyE4-00000004sc4-0T1k; Tue, 13 May 2025 18:35:52 -0400 Message-ID: <20250513223551.966925463@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 13 May 2025 18:34:41 -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 , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Andrii Nakryiko Subject: [PATCH v9 06/13] unwind_user/x86: Enable compat mode frame pointer unwinding on x86 References: <20250513223435.636200356@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 Use ARCH_INIT_USER_COMPAT_FP_FRAME to describe how frame pointers are unwound on x86, and implement the hooks needed to add the segment base addresses. Enable HAVE_UNWIND_USER_COMPAT_FP if the system has compat mode compiled in. Signed-off-by: Josh Poimboeuf Signed-off-by: Steven Rostedt (Google) --- arch/x86/Kconfig | 1 + arch/x86/include/asm/unwind_user.h | 50 ++++++++++++++++++++++++ arch/x86/include/asm/unwind_user_types.h | 17 ++++++++ 3 files changed, 68 insertions(+) create mode 100644 arch/x86/include/asm/unwind_user_types.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 456e085263e1..90f055956fce 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -301,6 +301,7 @@ config X86 select HAVE_SYSCALL_TRACEPOINTS select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL select HAVE_UNSTABLE_SCHED_CLOCK + select HAVE_UNWIND_USER_COMPAT_FP if IA32_EMULATION select HAVE_UNWIND_USER_FP if X86_64 select HAVE_USER_RETURN_NOTIFIER select HAVE_GENERIC_VDSO diff --git a/arch/x86/include/asm/unwind_user.h b/arch/x86/include/asm/unwi= nd_user.h index 8597857bf896..bb1148111259 100644 --- a/arch/x86/include/asm/unwind_user.h +++ b/arch/x86/include/asm/unwind_user.h @@ -2,10 +2,60 @@ #ifndef _ASM_X86_UNWIND_USER_H #define _ASM_X86_UNWIND_USER_H =20 +#include +#include +#include + #define ARCH_INIT_USER_FP_FRAME \ .cfa_off =3D (s32)sizeof(long) * 2, \ .ra_off =3D (s32)sizeof(long) * -1, \ .fp_off =3D (s32)sizeof(long) * -2, \ .use_fp =3D true, =20 +#ifdef CONFIG_IA32_EMULATION + +#define ARCH_INIT_USER_COMPAT_FP_FRAME \ + .cfa_off =3D (s32)sizeof(u32) * 2, \ + .ra_off =3D (s32)sizeof(u32) * -1, \ + .fp_off =3D (s32)sizeof(u32) * -2, \ + .use_fp =3D true, + +#define in_compat_mode(regs) !user_64bit_mode(regs) + +static inline void arch_unwind_user_init(struct unwind_user_state *state, + struct pt_regs *regs) +{ + unsigned long cs_base, ss_base; + + if (state->type !=3D UNWIND_USER_TYPE_COMPAT_FP) + return; + + scoped_guard(irqsave) { + cs_base =3D segment_base_address(regs->cs); + ss_base =3D segment_base_address(regs->ss); + } + + state->arch.cs_base =3D cs_base; + state->arch.ss_base =3D ss_base; + + state->ip +=3D cs_base; + state->sp +=3D ss_base; + state->fp +=3D ss_base; +} +#define arch_unwind_user_init arch_unwind_user_init + +static inline void arch_unwind_user_next(struct unwind_user_state *state) +{ + if (state->type !=3D UNWIND_USER_TYPE_COMPAT_FP) + return; + + state->ip +=3D state->arch.cs_base; + state->fp +=3D state->arch.ss_base; +} +#define arch_unwind_user_next arch_unwind_user_next + +#endif /* CONFIG_IA32_EMULATION */ + +#include + #endif /* _ASM_X86_UNWIND_USER_H */ diff --git a/arch/x86/include/asm/unwind_user_types.h b/arch/x86/include/as= m/unwind_user_types.h new file mode 100644 index 000000000000..d7074dc5f0ce --- /dev/null +++ b/arch/x86/include/asm/unwind_user_types.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_UNWIND_USER_TYPES_H +#define _ASM_UNWIND_USER_TYPES_H + +#ifdef CONFIG_IA32_EMULATION + +struct arch_unwind_user_state { + unsigned long ss_base; + unsigned long cs_base; +}; +#define arch_unwind_user_state arch_unwind_user_state + +#endif /* CONFIG_IA32_EMULATION */ + +#include + +#endif /* _ASM_UNWIND_USER_TYPES_H */ --=20 2.47.2