From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE0E523A561 for ; Tue, 28 Apr 2026 18:37:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777401441; cv=none; b=hG+XqVIziCSh8Yq0Lo9cnAe/dhwPEH2w9sOyHIvp6vP5DTFAYa5sC5/bpwoJnIYsAc2vrk4+0iYofq2iJ3G/MMu0LS18LsN69eCak38JFY1qppN1eDsXiIgQWis6HTGyJctfx5ezdDU8YHFZtgKw7SGsNovazveNv3DCYrj17kM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777401441; c=relaxed/simple; bh=57pPL7fXM2OfA7mEwfEVfLeqPvT/qphbCXDrvxnSDNE=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=uCGRetA2/57+bFeIvoXvUashVuGREqY1FMLtu/z+qGIAc3S8Bw6X6oZutAX4979MvlWraFrpv9WIx5L+TeWR3T+81PPMP7hr3N08A0bTWSiumUg0/gLnUGTk70mKDUv2xfjBT12vj46XF6p7gaJ4fC9+OusWR0omPnMQ+BoybfY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--dylanbhatch.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=jTZeXEuC; arc=none smtp.client-ip=209.85.210.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--dylanbhatch.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="jTZeXEuC" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-82fa860e71eso5686507b3a.0 for ; Tue, 28 Apr 2026 11:37:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777401439; x=1778006239; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=uAHjM+ToD9UfswYHel5T1N/OddHAZ2XMTwnzhPtkH7g=; b=jTZeXEuCbG9Pm2ikTqnhd0sLrkgpkhCQACujYB1rEOmNwRO8oMPrVWTHLC/7eW3thJ /aD/55xNoMuVtZGi8n5T9Zd18qV9tyhRNkY9TWtm8FfSbeVp0WAeDk4II7Kts+sI5HbZ 0sCymuBjA628Z5JwfetWoherPzqy1hWo1YYa7X3AWoPlEWvzocPozBRBHBqroppVXQ2a fwC6t1lNY38mPJacSTanr4pDAkYIcwqK5Aen+n4twOLgWxAhdW+WMRk1VV80RR3JY5C0 l1KqdMncOiV80HfKU32yfMvFKrs4uIumYfjgcBcfXI2DH60eHyxpCIp/XP/CAJOdllxZ adfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777401439; x=1778006239; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=uAHjM+ToD9UfswYHel5T1N/OddHAZ2XMTwnzhPtkH7g=; b=JzZFy0YqIcNW5ITNAhHPGUQUMGUK8vCOAASsdFtvrRmAi0A8gK3LJRUcqQNaMfHFXx CeQ9ZjQse4UqvDs+PYtOmjLRQk6pxN4+5BghVoW2hSZwx/9Kuz0y45dJAYCwrQ1g8rF+ db22F/hg0ibNec8WmUNs7Es9BJKYNStxyZ+zQFGky3N0jdOdKyHOzrmT9uWAo5t5awZW iCq0PFbYof4idWgZGJYLaDeHono9I6zpwOXkxupngCeOLqk7Bcm6SYxLIGqQzpWC6ipG /oHimEMsnysxYD4zHTtVMy1wR8oWSJ7xzVKrIaF0sp72jR88IdpTOWSMQscrI+holHEq g5Ig== X-Forwarded-Encrypted: i=1; AFNElJ9+RCTvGlj+7UM6+jJ735XwRN8d1PtV+MqNAUwUK+H0zUjFbGDtspctfJj3jkGko38BRwtu0aPcnHoRs7P5@vger.kernel.org X-Gm-Message-State: AOJu0YyN+OBKrY7ogz/p+A6r7ZrEbXlyCZ+HPLr1pMtSgKk2LtIrov1V 9lf8BuezLuuvAovKlHLSDI1W5/0ahKr4PnuStD3X46L8V74p1+6+tleNiYgeddS6TSqgRCIDXlM N3gd4QN9YpbQI/qy+XZn0N3oVeg== X-Received: from pfblh13.prod.google.com ([2002:a05:6a00:710d:b0:82f:b5a0:b27]) (user=dylanbhatch job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:1789:b0:82c:9c47:fefb with SMTP id d2e1a72fcca58-834ddad2852mr4478288b3a.20.1777401438937; Tue, 28 Apr 2026 11:37:18 -0700 (PDT) Date: Tue, 28 Apr 2026 18:36:39 +0000 In-Reply-To: <20260428183643.3796063-1-dylanbhatch@google.com> Precedence: bulk X-Mailing-List: live-patching@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260428183643.3796063-1-dylanbhatch@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260428183643.3796063-5-dylanbhatch@google.com> Subject: [PATCH v5 4/8] sframe: Provide PC lookup for vmlinux .sframe section From: Dylan Hatch To: Roman Gushchin , Weinan Liu , Will Deacon , Josh Poimboeuf , Indu Bhagat , Peter Zijlstra , Steven Rostedt , Catalin Marinas , Jiri Kosina , Jens Remus Cc: Dylan Hatch , Mark Rutland , Prasanna Kumar T S M , Puranjay Mohan , Song Liu , joe.lawrence@redhat.com, linux-toolchains@vger.kernel.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Randy Dunlap Content-Type: text/plain; charset="UTF-8" With SFRAME_UNWINDER, read in the .sframe section at boot. This provides unwind data as an alternative/supplement to frame pointer-based unwinding. Reviewed-by: Jens Remus Signed-off-by: Dylan Hatch --- arch/arm64/kernel/setup.c | 2 ++ include/linux/sframe.h | 14 ++++++++++++++ kernel/unwind/sframe.c | 36 ++++++++++++++++++++++++++++++++++++ 3 files changed, 52 insertions(+) diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 23c05dc7a8f2..4a633bc7aefb 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -375,6 +376,7 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) "This indicates a broken bootloader or old kernel\n", boot_args[1], boot_args[2], boot_args[3]); } + init_sframe_table(); } static inline bool cpu_can_disable(unsigned int cpu) diff --git a/include/linux/sframe.h b/include/linux/sframe.h index 0cb2924367bc..5b7341b61a7c 100644 --- a/include/linux/sframe.h +++ b/include/linux/sframe.h @@ -69,4 +69,18 @@ static inline int sframe_find_user(unsigned long ip, struct unwind_frame *frame) #endif /* CONFIG_HAVE_UNWIND_USER_SFRAME */ +#ifdef CONFIG_HAVE_UNWIND_KERNEL_SFRAME + +void __init init_sframe_table(void); +void sframe_module_init(struct module *mod, void *sframe, size_t sframe_size, + void *text, size_t text_size); + +extern int sframe_find_kernel(unsigned long ip, struct unwind_frame *frame); + +#else + +static inline void __init init_sframe_table(void) {} + +#endif /* CONFIG_HAVE_UNWIND_KERNEL_SFRAME */ + #endif /* _LINUX_SFRAME_H */ diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c index 89dd8c5a6a10..430bff9533ee 100644 --- a/kernel/unwind/sframe.c +++ b/kernel/unwind/sframe.c @@ -14,10 +14,20 @@ #include #include #include +#ifdef CONFIG_HAVE_UNWIND_KERNEL_SFRAME +#include +#endif #include "sframe.h" #include "sframe_debug.h" +#ifdef CONFIG_HAVE_UNWIND_KERNEL_SFRAME + +static bool sframe_init __ro_after_init; +static struct sframe_section kernel_sfsec __ro_after_init; + +#endif /* CONFIG_HAVE_UNWIND_KERNEL_SFRAME */ + struct sframe_fde_internal { unsigned long func_addr; u32 func_size; @@ -930,3 +940,29 @@ void sframe_free_mm(struct mm_struct *mm) } #endif /* CONFIG_HAVE_UNWIND_USER_SFRAME */ + +#ifdef CONFIG_HAVE_UNWIND_KERNEL_SFRAME + +int sframe_find_kernel(unsigned long ip, struct unwind_frame *frame) +{ + if (!frame || !sframe_init) + return -EINVAL; + + return __sframe_find(&kernel_sfsec, ip, frame); +} + +void __init init_sframe_table(void) +{ + kernel_sfsec.sec_type = SFRAME_KERNEL; + kernel_sfsec.sframe_start = (unsigned long)__start_sframe; + kernel_sfsec.sframe_end = (unsigned long)__end_sframe; + kernel_sfsec.text_start = (unsigned long)_stext; + kernel_sfsec.text_end = (unsigned long)_etext; + + if (WARN_ON(sframe_read_header(&kernel_sfsec))) + return; + + sframe_init = true; +} + +#endif /* CONFIG_HAVE_UNWIND_KERNEL_SFRAME */ -- 2.54.0.545.g6539524ca2-goog