From patchwork Wed Feb 17 16:02:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 1441270 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=sourceware.org (client-ip=2620:52:3:1:0:246e:9693:128c; helo=sourceware.org; envelope-from=libc-alpha-bounces@sourceware.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.a=rsa-sha256 header.s=default header.b=Rmwlfozr; dkim-atps=neutral Received: from sourceware.org (server2.sourceware.org [IPv6:2620:52:3:1:0:246e:9693:128c]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4DgjKc6mxjz9sRf for ; Thu, 18 Feb 2021 03:02:44 +1100 (AEDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 25D703945060; Wed, 17 Feb 2021 16:02:34 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 25D703945060 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1613577754; bh=Z2IdkWOPHWEYuSC+fropCPBYOOrqI2sgefYFZcz4PWo=; h=To:Subject:In-Reply-To:References:Date:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=RmwlfozrHmW6Gtp+v3tgqOpYhApVRs++Kx1kGUnv+LyN/JZ38jEsgT+z7OASXxeFL cKG0xQcBiYSdGvElBfRrqHbJvaDq+iDUynfOC1pl4yfZX6+xM0XVe6fCcdY79o3BlE Gx0vjwhXXhQ/+jWErdSeXlY/2myxZTpgZmk+wJWQ= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by sourceware.org (Postfix) with ESMTP id A7ABE3834416 for ; Wed, 17 Feb 2021 16:02:30 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A7ABE3834416 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-146-qKbi2C-_NF2STW3SbYZOQA-1; Wed, 17 Feb 2021 11:02:22 -0500 X-MC-Unique: qKbi2C-_NF2STW3SbYZOQA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9121D100CD1D for ; Wed, 17 Feb 2021 16:02:21 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-113-131.ams2.redhat.com [10.36.113.131]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B51D05D719 for ; Wed, 17 Feb 2021 16:02:20 +0000 (UTC) To: libc-alpha@sourceware.org Subject: [PATCH 02/10] backtrace: Implement on top of In-Reply-To: References: Message-Id: <5d751702e5e7ff0f502b447a0206326396e8be0b.1613577607.git.fweimer@redhat.com> Date: Wed, 17 Feb 2021 17:02:52 +0100 User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Florian Weimer via Libc-alpha From: Florian Weimer Reply-To: Florian Weimer Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" This reimplements the generic version of backtrace. Reviewed-by: Carlos O'Donell --- debug/backtrace.c | 84 ++++++++++------------------------------------- 1 file changed, 17 insertions(+), 67 deletions(-) diff --git a/debug/backtrace.c b/debug/backtrace.c index 5ded57bfc4..187d911a0d 100644 --- a/debug/backtrace.c +++ b/debug/backtrace.c @@ -17,10 +17,7 @@ License along with the GNU C Library; if not, see . */ -#include -#include #include -#include #include #include #include @@ -28,47 +25,12 @@ 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) { @@ -78,14 +40,16 @@ 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); if (arg->cnt > 0) arg->array[arg->cnt] = unwind_arch_adjustment (arg->array[arg->cnt - 1], arg->array[arg->cnt]); /* 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) @@ -100,20 +64,20 @@ 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. */ @@ -123,17 +87,3 @@ __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