From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hall.aurel32.net (hall.aurel32.net [IPv6:2001:bc8:30d7:100::1]) by sourceware.org (Postfix) with ESMTPS id 4703E385DC00 for ; Mon, 30 Mar 2020 21:19:45 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 4703E385DC00 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=aurel32.net Authentication-Results: sourceware.org; spf=none smtp.mailfrom=aurelien@aurel32.net Received: from [2a01:e35:2fdd:a4e1:fe91:fc89:bc43:b814] (helo=ohm.rr44.fr) by hall.aurel32.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jJ1ot-0002h5-SO; Mon, 30 Mar 2020 23:19:43 +0200 Received: from aurel32 by ohm.rr44.fr with local (Exim 4.93) (envelope-from ) id 1jJ1ot-002jKW-8z; Mon, 30 Mar 2020 23:19:43 +0200 From: Aurelien Jarno To: libc-stable@sourceware.org Subject: [2.31 COMMITTED] mips: Fix bracktrace result for signal frames Date: Mon, 30 Mar 2020 23:19:32 +0200 Message-Id: <20200330211932.650846-1-aurelien@aurel32.net> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-28.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, KAM_SHORT, RCVD_IN_DNSWL_LOW, SPF_HELO_PASS, SPF_NONE, 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-stable@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-stable mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 Mar 2020 21:19:47 -0000 From: Adhemerval Zanella 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. */ (cherry picked from commit 6e05978f0c30e52420e086cc3156655471e6fb0a) --- 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 cc4b9a5c904..69cf4c23c85 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 00000000000..d712e5e11da --- /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 00000000000..a0098999835 --- /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 -- 2.25.1