From patchwork Wed Feb 17 16:03:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 1441271 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=8.43.85.97; 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=OcMjTH6S; dkim-atps=neutral Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (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 4DgjKj6skkz9sRf for ; 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Wed, 17 Feb 2021 11:02:32 -0500 X-MC-Unique: bMEhFTivPFSSAZ7397cFkw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 337EE801975 for ; Wed, 17 Feb 2021 16:02:31 +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 8A9025C1A3 for ; Wed, 17 Feb 2021 16:02:30 +0000 (UTC) To: libc-alpha@sourceware.org Subject: [PATCH 04/10] i386: Implement backtrace on top of In-Reply-To: References: Message-Id: Date: Wed, 17 Feb 2021 17:03:02 +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 10.5.11.16 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" --- sysdeps/i386/backtrace.c | 82 +++++++++------------------------------- 1 file changed, 18 insertions(+), 64 deletions(-) Reviewed-by: Carlos O'Donell diff --git a/sysdeps/i386/backtrace.c b/sysdeps/i386/backtrace.c index 124b0b73e3..4631f68fdc 100644 --- a/sysdeps/i386/backtrace.c +++ b/sysdeps/i386/backtrace.c @@ -17,52 +17,18 @@ License along with the GNU C Library; if not, see . */ -#include -#include #include #include -#include +#include struct trace_arg { void **array; + struct unwind_link *unwind_link; int cnt, size; void *lastebp, *lastesp; }; -#ifdef SHARED -static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *); -static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *); -static _Unwind_Ptr (*unwind_getcfa) (struct _Unwind_Context *); -static _Unwind_Ptr (*unwind_getgr) (struct _Unwind_Context *, int); -static void *libgcc_handle; - -static void -init (void) -{ - libgcc_handle = __libc_dlopen ("libgcc_s.so.1"); - - if (libgcc_handle == NULL) - return; - - unwind_backtrace = __libc_dlsym (libgcc_handle, "_Unwind_Backtrace"); - unwind_getip = __libc_dlsym (libgcc_handle, "_Unwind_GetIP"); - unwind_getcfa = __libc_dlsym (libgcc_handle, "_Unwind_GetCFA"); - unwind_getgr = __libc_dlsym (libgcc_handle, "_Unwind_GetGR"); - if (unwind_getip == NULL || unwind_getgr == NULL || unwind_getcfa == NULL) - { - unwind_backtrace = NULL; - __libc_dlclose (libgcc_handle); - libgcc_handle = NULL; - } -} -#else -# define unwind_backtrace _Unwind_Backtrace -# define unwind_getip _Unwind_GetIP -# define unwind_getcfa _Unwind_GetCFA -# define unwind_getgr _Unwind_GetGR -#endif - static _Unwind_Reason_Code backtrace_helper (struct _Unwind_Context *ctx, void *a) { @@ -71,13 +37,16 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a) /* We are first called with address in the __backtrace function. 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 == arg->size) return _URC_END_OF_STACK; /* %ebp is DWARF2 register 5 on IA-32. */ - arg->lastebp = (void *) unwind_getgr (ctx, 5); - arg->lastesp = (void *) unwind_getcfa (ctx); + arg->lastebp + = (void *) UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetGR) (ctx, 5); + arg->lastesp + = (void *) UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetCFA) (ctx); return _URC_NO_REASON; } @@ -111,20 +80,19 @@ struct layout int __backtrace (void **array, int size) { - struct trace_arg arg = { .array = array, .size = size, .cnt = -1 }; - - if (size <= 0) - return 0; - -#ifdef SHARED - __libc_once_define (static, once); + struct trace_arg arg = + { + .array = array, + .unwind_link = __libc_unwind_link_get (), + .size = size, + .cnt = -1, + }; - __libc_once (once, init); - if (unwind_backtrace == NULL) + 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); if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL) --arg.cnt; @@ -147,17 +115,3 @@ __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