From patchwork Tue Mar 5 17:09:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Jones X-Patchwork-Id: 13582765 Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [95.215.58.182]) (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 7BC88175AB for ; Tue, 5 Mar 2024 17:09:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709658552; cv=none; b=UDQvd4oh1GlbI6t3gvRlmwaTStKgMRgBrnnuZ1Le11lqy3H8S7v9LpkxOc7ZxZDivRso74kYJ4ODdJtcCW/sF5sxSvpUYKhqvGCmJGsb4DHb38E5jGuJNGWLn+ekpx7s77ywBAyPuxMxb1MUkdt8jdvzyjLv2CGjdeyYtwKTU9E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709658552; c=relaxed/simple; bh=VkVxzzEu3nVElayvwDmLcanYxqP9mTejahFEjNfr+w8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-type; b=HZ0TaR0F42wtloxIa1kT2uPOYkkkzJVHuSHEVvEain/AzzAPArHmGM3xfoM9HbL1f42d7AEbwSHe2ZUs1C0qHoae6bRemD4ij9uhT7GqihMO54XO7F+Y8MCQGLtJTfKMYGEo+6DRdsnr6vEW6XOo+AIBLihuUzyE0Al7Hd4H3Uo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=smHoWrGm; arc=none smtp.client-ip=95.215.58.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="smHoWrGm" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1709658548; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MraLn1H3cyPePsk9ywys4sQEOsdtJQzZmf/lns7/wI4=; b=smHoWrGmsdeJ9o2I/sXSbb/8LrOQCi30nPSaXKPznf9whoa31DK/NUjgOwd/oOHU0Yv0Qw G4qnoj6qjFK2voml2hTSfzPkdMut9sSjfab/ZI0apVoInf2309MR4Sl/+hjrB3sN9wYPsq Ylm59PH0HRxlJqZhPy/f0XOjjZOwYk8= From: Andrew Jones To: kvm@vger.kernel.org, kvm-riscv@lists.infradead.org Cc: pbonzini@redhat.com, thuth@redhat.com, Claudio Imbrenda , Nicholas Piggin , kvmarm@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, lvivier@redhat.com, frankja@linux.ibm.com, nrb@linux.ibm.com Subject: [kvm-unit-tests PATCH v2 03/13] treewide: lib/stack: Fix backtrace Date: Tue, 5 Mar 2024 18:09:02 +0100 Message-ID: <20240305170858.395836-18-andrew.jones@linux.dev> In-Reply-To: <20240305170858.395836-15-andrew.jones@linux.dev> References: <20240305170858.395836-15-andrew.jones@linux.dev> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-type: text/plain X-Migadu-Flow: FLOW_OUT We should never pass the result of __builtin_frame_address(0) to another function since the compiler is within its rights to pop the frame to which it points before making the function call, as may be done for tail calls. Nobody has complained about backtrace(), so likely all compilations have been inlining backtrace_frame(), not dropping the frame on the tail call, or nobody is looking at traces. However, for riscv, when built for EFI, it does drop the frame on the tail call, and it was noticed. Preemptively fix backtrace() for all architectures. Fixes: 52266791750d ("lib: backtrace printing") Acked-by: Claudio Imbrenda Reviewed-by: Nicholas Piggin Signed-off-by: Andrew Jones --- lib/arm/stack.c | 13 +++++-------- lib/arm64/stack.c | 12 +++++------- lib/riscv/stack.c | 12 +++++------- lib/s390x/stack.c | 12 +++++------- lib/stack.h | 24 +++++++++++++++++------- lib/x86/stack.c | 12 +++++------- 6 files changed, 42 insertions(+), 43 deletions(-) diff --git a/lib/arm/stack.c b/lib/arm/stack.c index 7d081be7c6d0..66d18b47ea53 100644 --- a/lib/arm/stack.c +++ b/lib/arm/stack.c @@ -8,13 +8,16 @@ #include #include -int backtrace_frame(const void *frame, const void **return_addrs, - int max_depth) +int arch_backtrace_frame(const void *frame, const void **return_addrs, + int max_depth, bool current_frame) { static int walking; int depth; const unsigned long *fp = (unsigned long *)frame; + if (current_frame) + fp = __builtin_frame_address(0); + if (walking) { printf("RECURSIVE STACK WALK!!!\n"); return 0; @@ -33,9 +36,3 @@ int backtrace_frame(const void *frame, const void **return_addrs, walking = 0; return depth; } - -int backtrace(const void **return_addrs, int max_depth) -{ - return backtrace_frame(__builtin_frame_address(0), - return_addrs, max_depth); -} diff --git a/lib/arm64/stack.c b/lib/arm64/stack.c index 82611f4b1815..f5eb57fd8892 100644 --- a/lib/arm64/stack.c +++ b/lib/arm64/stack.c @@ -8,7 +8,8 @@ extern char vector_stub_start, vector_stub_end; -int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) +int arch_backtrace_frame(const void *frame, const void **return_addrs, + int max_depth, bool current_frame) { const void *fp = frame; static bool walking; @@ -17,6 +18,9 @@ int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) bool is_exception = false; unsigned long addr; + if (current_frame) + fp = __builtin_frame_address(0); + if (walking) { printf("RECURSIVE STACK WALK!!!\n"); return 0; @@ -54,9 +58,3 @@ int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) walking = false; return depth; } - -int backtrace(const void **return_addrs, int max_depth) -{ - return backtrace_frame(__builtin_frame_address(0), - return_addrs, max_depth); -} diff --git a/lib/riscv/stack.c b/lib/riscv/stack.c index 712a5478d547..d865594b9671 100644 --- a/lib/riscv/stack.c +++ b/lib/riscv/stack.c @@ -2,12 +2,16 @@ #include #include -int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) +int arch_backtrace_frame(const void *frame, const void **return_addrs, + int max_depth, bool current_frame) { static bool walking; const unsigned long *fp = (unsigned long *)frame; int depth; + if (current_frame) + fp = __builtin_frame_address(0); + if (walking) { printf("RECURSIVE STACK WALK!!!\n"); return 0; @@ -24,9 +28,3 @@ int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) walking = false; return depth; } - -int backtrace(const void **return_addrs, int max_depth) -{ - return backtrace_frame(__builtin_frame_address(0), - return_addrs, max_depth); -} diff --git a/lib/s390x/stack.c b/lib/s390x/stack.c index 9f234a12adf6..d194f654e94d 100644 --- a/lib/s390x/stack.c +++ b/lib/s390x/stack.c @@ -14,11 +14,15 @@ #include #include -int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) +int arch_backtrace_frame(const void *frame, const void **return_addrs, + int max_depth, bool current_frame) { int depth = 0; struct stack_frame *stack = (struct stack_frame *)frame; + if (current_frame) + stack = __builtin_frame_address(0); + for (depth = 0; stack && depth < max_depth; depth++) { return_addrs[depth] = (void *)stack->grs[8]; stack = stack->back_chain; @@ -28,9 +32,3 @@ int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) return depth; } - -int backtrace(const void **return_addrs, int max_depth) -{ - return backtrace_frame(__builtin_frame_address(0), - return_addrs, max_depth); -} diff --git a/lib/stack.h b/lib/stack.h index 10fc2f793354..6edc84344b51 100644 --- a/lib/stack.h +++ b/lib/stack.h @@ -11,17 +11,27 @@ #include #ifdef HAVE_ARCH_BACKTRACE_FRAME -extern int backtrace_frame(const void *frame, const void **return_addrs, - int max_depth); +extern int arch_backtrace_frame(const void *frame, const void **return_addrs, + int max_depth, bool current_frame); + +static inline int backtrace_frame(const void *frame, const void **return_addrs, + int max_depth) +{ + return arch_backtrace_frame(frame, return_addrs, max_depth, false); +} + +static inline int backtrace(const void **return_addrs, int max_depth) +{ + return arch_backtrace_frame(NULL, return_addrs, max_depth, true); +} #else -static inline int -backtrace_frame(const void *frame __unused, const void **return_addrs __unused, - int max_depth __unused) +extern int backtrace(const void **return_addrs, int max_depth); + +static inline int backtrace_frame(const void *frame, const void **return_addrs, + int max_depth) { return 0; } #endif -extern int backtrace(const void **return_addrs, int max_depth); - #endif diff --git a/lib/x86/stack.c b/lib/x86/stack.c index 5ecd97ce90b9..58ab6c4b293a 100644 --- a/lib/x86/stack.c +++ b/lib/x86/stack.c @@ -1,12 +1,16 @@ #include #include -int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) +int arch_backtrace_frame(const void *frame, const void **return_addrs, + int max_depth, bool current_frame) { static int walking; int depth = 0; const unsigned long *bp = (unsigned long *) frame; + if (current_frame) + bp = __builtin_frame_address(0); + if (walking) { printf("RECURSIVE STACK WALK!!!\n"); return 0; @@ -23,9 +27,3 @@ int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) walking = 0; return depth; } - -int backtrace(const void **return_addrs, int max_depth) -{ - return backtrace_frame(__builtin_frame_address(0), return_addrs, - max_depth); -}