From patchwork Thu Feb 13 17:07:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 38038 Received: (qmail 48817 invoked by alias); 13 Feb 2020 17:08:11 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 48807 invoked by uid 89); 13 Feb 2020 17:08:10 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-19.0 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 spammy=unwind.h, UD:unwind.h, unwindh X-HELO: us-smtp-delivery-1.mimecast.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581613687; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Qi3Tki3F0G/ySqFdVqFZoEh3/cECYjubRmPMHzsoa3U=; b=UJENTLjSEa/MOwOrQT1lQJQr9G9PTMPRNbjYbvvDe+uxeaZWVN1vkRv5HvDycf0TkI4Jdv 6NEtaNdxHw7YUHXZ/jXfczo7Fo20XqHM3UFbNvYrEpMNxSX4mJdIzTKmpdAN2RZ0aL5VrR UR1q9Rpg3omW3xGD1pDdNjAhhKH0jzw= From: Florian Weimer To: libc-alpha@sourceware.org Subject: [PATCH 02/11] backtrace: Implement on top of In-Reply-To: References: X-From-Line: 06a9064d46e3d3fb5e386bf87a4ae83d79d32a53 Mon Sep 17 00:00:00 2001 Message-Id: <06a9064d46e3d3fb5e386bf87a4ae83d79d32a53.1581613260.git.fweimer@redhat.com> Date: Thu, 13 Feb 2020 18:07:55 +0100 User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com This reimplements the generic version of backtrace. --- debug/backtrace.c | 86 ++++++++++------------------------------------- 1 file changed, 18 insertions(+), 68 deletions(-) diff --git a/debug/backtrace.c b/debug/backtrace.c index cc4b9a5c90..921c9053c8 100644 --- a/debug/backtrace.c +++ b/debug/backtrace.c @@ -17,57 +17,19 @@ License along with the GNU C Library; if not, see . */ -#include -#include #include -#include #include -#include +#include struct trace_arg { void **array; + struct unwind_link *unwind_link; _Unwind_Word cfa; int cnt; int size; }; -#ifdef SHARED -static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *); -static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *); -static _Unwind_Word (*unwind_getcfa) (struct _Unwind_Context *); -static void *libgcc_handle; - - -/* Dummy version in case libgcc_s does not contain the real code. */ -static _Unwind_Word -dummy_getcfa (struct _Unwind_Context *ctx __attribute__ ((unused))) -{ - return 0; -} - - -static void -init (void) -{ - libgcc_handle = __libc_dlopen (LIBGCC_S_SO); - - if (libgcc_handle == NULL) - return; - - unwind_backtrace = __libc_dlsym (libgcc_handle, "_Unwind_Backtrace"); - unwind_getip = __libc_dlsym (libgcc_handle, "_Unwind_GetIP"); - if (unwind_getip == NULL) - unwind_backtrace = NULL; - unwind_getcfa = (__libc_dlsym (libgcc_handle, "_Unwind_GetCFA") - ?: dummy_getcfa); -} -#else -# define unwind_backtrace _Unwind_Backtrace -# define unwind_getip _Unwind_GetIP -# define unwind_getcfa _Unwind_GetCFA -#endif - static _Unwind_Reason_Code backtrace_helper (struct _Unwind_Context *ctx, void *a) { @@ -77,10 +39,12 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a) Skip it. */ if (arg->cnt != -1) { - arg->array[arg->cnt] = (void *) unwind_getip (ctx); + arg->array[arg->cnt] + = (void *) UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetIP) (ctx); /* Check whether we make any progress. */ - _Unwind_Word cfa = unwind_getcfa (ctx); + _Unwind_Word cfa + = UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetCFA) (ctx); if (arg->cnt > 0 && arg->array[arg->cnt - 1] == arg->array[arg->cnt] && cfa == arg->cfa) @@ -95,20 +59,20 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a) int __backtrace (void **array, int size) { - struct trace_arg arg = { .array = array, .cfa = 0, .size = size, .cnt = -1 }; - - if (size <= 0) - return 0; - -#ifdef SHARED - __libc_once_define (static, once); - - __libc_once (once, init); - if (unwind_backtrace == NULL) + struct trace_arg arg = + { + .array = array, + .unwind_link = __libc_unwind_link_get (), + .cfa = 0, + .size = size, + .cnt = -1 + }; + + if (size <= 0 || arg.unwind_link == NULL) return 0; -#endif - unwind_backtrace (backtrace_helper, &arg); + UNWIND_LINK_PTR (arg.unwind_link, _Unwind_Backtrace) + (backtrace_helper, &arg); /* _Unwind_Backtrace seems to put NULL address above _start. Fix it up here. */ @@ -118,17 +82,3 @@ __backtrace (void **array, int size) } weak_alias (__backtrace, backtrace) libc_hidden_def (__backtrace) - - -#ifdef SHARED -/* Free all resources if necessary. */ -libc_freeres_fn (free_mem) -{ - unwind_backtrace = NULL; - if (libgcc_handle != NULL) - { - __libc_dlclose (libgcc_handle); - libgcc_handle = NULL; - } -} -#endif