From 01deabe193d420496913936927981de9e90cea57 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 6 Dec 2017 15:00:46 -0800 Subject: [PATCH] Linux/x86: Update cancel_jmp_buf to match __jmp_buf_tag [BZ #22563] On x86, padding in struct __jmp_buf_tag is used for shadow stack pointer to support shadow stack in Intel Control-flow Enforcemen Technology. Since the cancel_jmp_buf array is passed to setjmp and longjmp by casting it to pointer to struct __jmp_buf_tag, it should be as large as struct __jmp_buf_tag. Otherwise when shadow stack is enabled, setjmp and longjmp will write and read beyond cancel_jmp_buf when saving and restoring shadow stack pointer. This patch adds bits/types/__cancel_jmp_buf_tag.h to define struct __cancel_jmp_buf_tag so that Linux/x86 can add saved_mask to cancel_jmp_buf. [BZ #22563] * bits/types/__cancel_jmp_buf_tag.h: New file. * sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h * sysdeps/unix/sysv/linux/x86/pthreaddef.h: Likewise. * sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h: Likewise. * nptl/Makefile (headers): Add bits/types/__cancel_jmp_buf_tag.h. * nptl/descr.h [NEED_SAVED_MASK_IN_CANCEL_JMP_BUF] (pthread_unwind_buf): Add saved_mask to cancel_jmp_buf. * sysdeps/nptl/pthread.h: Include . (__pthread_unwind_buf_t): Use struct __cancel_jmp_buf_tag with __cancel_jmp_buf. --- bits/types/__cancel_jmp_buf_tag.h | 28 +++++++++++++++++ nptl/Makefile | 3 +- nptl/descr.h | 3 ++ sysdeps/nptl/pthread.h | 7 ++--- .../linux/x86/bits/types/__cancel_jmp_buf_tag.h | 31 +++++++++++++++++++ sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h | 36 ++++++++++++++++++++++ sysdeps/unix/sysv/linux/x86/pthreaddef.h | 22 +++++++++++++ 7 files changed, 124 insertions(+), 6 deletions(-) create mode 100644 bits/types/__cancel_jmp_buf_tag.h create mode 100644 sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h create mode 100644 sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h create mode 100644 sysdeps/unix/sysv/linux/x86/pthreaddef.h diff --git a/bits/types/__cancel_jmp_buf_tag.h b/bits/types/__cancel_jmp_buf_tag.h new file mode 100644 index 0000000000..c843f44239 --- /dev/null +++ b/bits/types/__cancel_jmp_buf_tag.h @@ -0,0 +1,28 @@ +/* Define struct __cancel_jmp_buf_tag. + Copyright (C) 2017 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 ____cancel_jmp_buf_tag_defined +#define ____cancel_jmp_buf_tag_defined 1 + +struct __cancel_jmp_buf_tag + { + __jmp_buf __cancel_jmp_buf; + int __mask_was_saved; + }; + +#endif diff --git a/nptl/Makefile b/nptl/Makefile index 570a42301c..60d036a1ea 100644 --- a/nptl/Makefile +++ b/nptl/Makefile @@ -22,7 +22,8 @@ subdir := nptl include ../Makeconfig -headers := pthread.h semaphore.h bits/semaphore.h +headers := pthread.h semaphore.h bits/semaphore.h \ + bits/types/__cancel_jmp_buf_tag.h extra-libs := libpthread extra-libs-others := $(extra-libs) diff --git a/nptl/descr.h b/nptl/descr.h index c83b17b674..fdeb397eab 100644 --- a/nptl/descr.h +++ b/nptl/descr.h @@ -65,6 +65,9 @@ struct pthread_unwind_buf { __jmp_buf jmp_buf; int mask_was_saved; +#ifdef NEED_SAVED_MASK_IN_CANCEL_JMP_BUF + __sigset_t saved_mask; +#endif } cancel_jmp_buf[1]; union diff --git a/sysdeps/nptl/pthread.h b/sysdeps/nptl/pthread.h index 2b2b386ab3..787ac6e4cd 100644 --- a/sysdeps/nptl/pthread.h +++ b/sysdeps/nptl/pthread.h @@ -27,6 +27,7 @@ #include #include #include +#include /* Detach state. */ @@ -523,11 +524,7 @@ extern void pthread_testcancel (void); typedef struct { - struct - { - __jmp_buf __cancel_jmp_buf; - int __mask_was_saved; - } __cancel_jmp_buf[1]; + struct __cancel_jmp_buf_tag __cancel_jmp_buf[1]; void *__pad[4]; } __pthread_unwind_buf_t __attribute__ ((__aligned__)); diff --git a/sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h b/sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h new file mode 100644 index 0000000000..830a6ec90c --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h @@ -0,0 +1,31 @@ +/* Define struct __cancel_jmp_buf_tag. + Copyright (C) 2017 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 ____cancel_jmp_buf_tag_defined +#define ____cancel_jmp_buf_tag_defined 1 + +#include + +struct __cancel_jmp_buf_tag + { + __jmp_buf __cancel_jmp_buf; + int __mask_was_saved; + __sigset_t __saved_mask; + }; + +#endif diff --git a/sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h b/sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h new file mode 100644 index 0000000000..8c36ba3a5d --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h @@ -0,0 +1,36 @@ +/* Internal pthread header. Linux/x86 version. + Copyright (C) 2017 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 + . */ + +#include_next + +#ifndef _PTHREADP_H_X86 +#define _PTHREADP_H_X86 1 + +extern struct pthread_unwind_buf ____pthread_unwind_buf_private; + +_Static_assert (sizeof (____pthread_unwind_buf_private.cancel_jmp_buf) + >= sizeof (struct __jmp_buf_tag), + "size of cancel_jmp_buf < sizeof __jmp_buf_tag"); + +extern __pthread_unwind_buf_t ____pthread_unwind_buf; + +_Static_assert (sizeof (____pthread_unwind_buf.__cancel_jmp_buf) + >= sizeof (struct __jmp_buf_tag), + "size of __cancel_jmp_buf < sizeof __jmp_buf_tag"); + +#endif diff --git a/sysdeps/unix/sysv/linux/x86/pthreaddef.h b/sysdeps/unix/sysv/linux/x86/pthreaddef.h new file mode 100644 index 0000000000..89d19d60a1 --- /dev/null +++ b/sysdeps/unix/sysv/linux/x86/pthreaddef.h @@ -0,0 +1,22 @@ +/* Pthread macros. Linux/x86 version. + Copyright (C) 2017 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 + . */ + +#include_next + +/* Need saved_mask in cancel_jmp_buf. */ +#define NEED_SAVED_MASK_IN_CANCEL_JMP_BUF 1 -- 2.14.3