From patchwork Mon Feb 17 13:59:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 1239253 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=209.132.180.131; helo=sourceware.org; envelope-from=libc-alpha-return-109855-incoming=patchwork.ozlabs.org@sourceware.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.a=rsa-sha1 header.s=default header.b=H+Yr1+Pm; dkim=pass (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256 header.s=google header.b=i9GFwaed; dkim-atps=neutral Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 48Llwx65Ltz9sNg for ; Tue, 18 Feb 2020 01:00:01 +1100 (AEDT) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id; q=dns; s= default; b=TLR/4BGQ/Es/DvHTWU0ExoXn/sSYSfXHV+vLIEkfw9NCKag8OuBYt SX/D+gh4r3TBkimySiqrpd2jTu9ZYJeExjEzvIxt74mEAbQC6CvsjBtvXcfBfWS0 VmyQETXiIg5BJ+LjEFzmpUdOf74Rk152CjPIAohIy/LOghsh2OKmjs= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id; s=default; bh=/6YVwAR34hUIb74jROTtV5hwZns=; b=H+Yr1+PmtqQtr0AO6PLZJfExyHEH lwDMGq1dZV6KanPKKY20udpPIkWilw1zbUT7EJ6VhG95+g7MfYvBB7efLqKDiPoV 6TJ9zbgInUCmsQjg3MeYpfeGP+mFBR4koFDs+dUU4JWPTRRs198qWCI5tP4z5J44 ov0FnFhhgopS53c= Received: (qmail 47492 invoked by alias); 17 Feb 2020 13:59:55 -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 47464 invoked by uid 89); 17 Feb 2020 13:59:54 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-22.0 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, SPF_PASS autolearn=ham version=3.3.1 spammy= X-HELO: mail-qk1-f195.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:subject:date:message-id; bh=aVFNYgH7JlhGirsD47xot7Vagw5CIxmVmItRyp/Z9GA=; b=i9GFwaedg41CC0FcnLY6nJhE+nbnXRgAbXv0HS365iJ7Rhx4ybwBfTCmJfroO9i4is ZvwfdmpwtxH8mpiv/6eo0EJWr2IZRB2eq7/MqkN6ZullY5uKCFt46+blMdGKf8tKsRUL r0meRoeOFDY2b0AFhL5p4GsHKtKB7GKIj/mxWcKxP1jeR1VYO/Op7Vl+ZfA2QFupeuW9 a004ra0+TKmh9bOO52/BtEzl2UDqJ2beeR9No3oo+E/GN5YCOtzmLY1PBLjMz2g7RW/u 5IDcFUixrvC8sVZp2uPLNqoXoLN3V4svDNtzS1iIH1dO3pUfoGdNuRNobkpyB9qyneqK Azjw== From: Adhemerval Zanella To: libc-alpha@sourceware.org Subject: [PATCH] mips: Fix bracktrace result for signal frames Date: Mon, 17 Feb 2020 10:59:44 -0300 Message-Id: <20200217135944.4688-1-adhemerval.zanella@linaro.org> MIPS fallback code handle a frame where its FDE can not be obtained (for instance a signal frame) by reading the kernel allocated signal frame and adding '2' to the value of 'sc_pc' [1]. The added value is used to recognize an end of an EH region on mips16 [2]. The fix adjust the obtained signal frame value and remove the libgcc added value by checking if the previous frame is a signal frame one. Checked with backtrace and tst-sigcontext-get_pc tests on mips-linux-gnu and mips64-linux-gnu. [1] libgcc/config/mips/linux-unwind.h from gcc code. [2] gcc/config/mips/mips.h from gcc code. */ --- debug/backtrace.c | 5 ++ sysdeps/generic/unwind-arch.h | 30 ++++++++++ sysdeps/unix/sysv/linux/mips/unwind-arch.h | 67 ++++++++++++++++++++++ 3 files changed, 102 insertions(+) create mode 100644 sysdeps/generic/unwind-arch.h create mode 100644 sysdeps/unix/sysv/linux/mips/unwind-arch.h diff --git a/debug/backtrace.c b/debug/backtrace.c index cc4b9a5c90..69cf4c23c8 100644 --- a/debug/backtrace.c +++ b/debug/backtrace.c @@ -23,6 +23,7 @@ #include #include #include +#include struct trace_arg { @@ -78,6 +79,10 @@ backtrace_helper (struct _Unwind_Context *ctx, void *a) if (arg->cnt != -1) { arg->array[arg->cnt] = (void *) 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); diff --git a/sysdeps/generic/unwind-arch.h b/sysdeps/generic/unwind-arch.h new file mode 100644 index 0000000000..d712e5e11d --- /dev/null +++ b/sysdeps/generic/unwind-arch.h @@ -0,0 +1,30 @@ +/* Return backtrace of current program state. Arch-specific bits. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef _UNWIND_ARCH_H +#define _UNWIND_ARCH_H + +#include + +static inline void * +unwind_arch_adjustment (void *prev, void *addr) +{ + return addr; +} + +#endif diff --git a/sysdeps/unix/sysv/linux/mips/unwind-arch.h b/sysdeps/unix/sysv/linux/mips/unwind-arch.h new file mode 100644 index 0000000000..a009899983 --- /dev/null +++ b/sysdeps/unix/sysv/linux/mips/unwind-arch.h @@ -0,0 +1,67 @@ +/* Return backtrace of current program state. Arch-specific bits. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef _UNWIND_ARCH_H +#define _UNWIND_ARCH_H + +#include + +/* MIPS fallback code handle a frame where its FDE can not be obtained + (for instance a signal frame) by reading the kernel allocated signal frame + and adding '2' to the value of 'sc_pc' [1]. The added value is used to + recognize an end of an EH region on mips16 [2]. + + The idea here is to adjust the obtained signal frame ADDR value and remove + the libgcc added value by checking if the previous frame is a signal frame + one. + + [1] libgcc/config/mips/linux-unwind.h from gcc code. + [2] gcc/config/mips/mips.h from gcc code. */ + +static inline void * +unwind_arch_adjustment (void *prev, void *addr) +{ + uint32_t *pc = (uint32_t *) prev; + + if (pc == NULL) + return addr; + + /* For MIPS16 or microMIPS frame libgcc makes no adjustment. */ + if ((uintptr_t) pc & 0x3) + return addr; + + /* The vDSO containes either + + 24021061 li v0, 0x1061 (rt_sigreturn) + 0000000c syscall + or + 24021017 li v0, 0x1017 (sigreturn) + 0000000c syscall */ + if (pc[1] != 0x0000000c) + return addr; +#if _MIPS_SIM == _ABIO32 + if (pc[0] == (0x24020000 | __NR_sigreturn)) + return (void *) ((uintptr_t) addr - 2); +#endif + if (pc[0] == (0x24020000 | __NR_rt_sigreturn)) + return (void *) ((uintptr_t) addr - 2); + + return addr; +} + +#endif