1131 lines
38 KiB
Diff
1131 lines
38 KiB
Diff
commit 95e114a0919d844d8fe07839cb6538b7f5ee920e
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Author: Florian Weimer <fweimer@redhat.com>
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Date: Thu Dec 9 09:49:32 2021 +0100
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nptl: Add rseq registration
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The rseq area is placed directly into struct pthread. rseq
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registration failure is not treated as an error, so it is possible
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that threads run with inconsistent registration status.
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<sys/rseq.h> is not yet installed as a public header.
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Co-Authored-By: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
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Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
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diff --git a/nptl/descr.h b/nptl/descr.h
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index 57be5b4fef564b36..dabf980e29615db3 100644
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--- a/nptl/descr.h
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+++ b/nptl/descr.h
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@@ -35,6 +35,7 @@
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#include <bits/types/res_state.h>
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#include <kernel-features.h>
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#include <tls-internal-struct.h>
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+#include <sys/rseq.h>
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#ifndef TCB_ALIGNMENT
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# define TCB_ALIGNMENT 32
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@@ -407,6 +408,9 @@ struct pthread
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/* Used on strsignal. */
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struct tls_internal_t tls_state;
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+ /* rseq area registered with the kernel. */
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+ struct rseq rseq_area;
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+
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/* This member must be last. */
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char end_padding[];
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diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
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index 3db0c9fdf40ae2bf..d2b40924dafad316 100644
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--- a/nptl/pthread_create.c
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+++ b/nptl/pthread_create.c
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@@ -33,6 +33,7 @@
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#include <default-sched.h>
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#include <futex-internal.h>
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#include <tls-setup.h>
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+#include <rseq-internal.h>
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#include "libioP.h"
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#include <sys/single_threaded.h>
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#include <version.h>
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@@ -367,6 +368,9 @@ start_thread (void *arg)
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/* Initialize pointers to locale data. */
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__ctype_init ();
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+ /* Register rseq TLS to the kernel. */
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+ rseq_register_current_thread (pd);
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+
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#ifndef __ASSUME_SET_ROBUST_LIST
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if (__nptl_set_robust_list_avail)
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#endif
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@@ -572,6 +576,15 @@ out:
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process is really dead since 'clone' got passed the CLONE_CHILD_CLEARTID
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flag. The 'tid' field in the TCB will be set to zero.
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+ rseq TLS is still registered at this point. Rely on implicit
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+ unregistration performed by the kernel on thread teardown. This is not a
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+ problem because the rseq TLS lives on the stack, and the stack outlives
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+ the thread. If TCB allocation is ever changed, additional steps may be
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+ required, such as performing explicit rseq unregistration before
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+ reclaiming the rseq TLS area memory. It is NOT sufficient to block
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+ signals because the kernel may write to the rseq area even without
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+ signals.
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+
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The exit code is zero since in case all threads exit by calling
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'pthread_exit' the exit status must be 0 (zero). */
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while (1)
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diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c
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index ca494dd3a52c4ebf..fedb876fdb2642d2 100644
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--- a/sysdeps/nptl/dl-tls_init_tp.c
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+++ b/sysdeps/nptl/dl-tls_init_tp.c
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@@ -21,6 +21,7 @@
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#include <list.h>
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#include <pthreadP.h>
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#include <tls.h>
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+#include <rseq-internal.h>
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#ifndef __ASSUME_SET_ROBUST_LIST
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bool __nptl_set_robust_list_avail;
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@@ -57,11 +58,12 @@ __tls_pre_init_tp (void)
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void
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__tls_init_tp (void)
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{
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+ struct pthread *pd = THREAD_SELF;
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+
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/* Set up thread stack list management. */
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- list_add (&THREAD_SELF->list, &GL (dl_stack_user));
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+ list_add (&pd->list, &GL (dl_stack_user));
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/* Early initialization of the TCB. */
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- struct pthread *pd = THREAD_SELF;
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pd->tid = INTERNAL_SYSCALL_CALL (set_tid_address, &pd->tid);
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THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
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THREAD_SETMEM (pd, user_stack, true);
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@@ -90,6 +92,8 @@ __tls_init_tp (void)
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}
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}
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+ rseq_register_current_thread (pd);
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+
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/* Set initial thread's stack block from 0 up to __libc_stack_end.
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It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
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purposes this is good enough. */
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diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
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index 76ad06361c4323d7..f84ccd6bbb3b16ad 100644
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--- a/sysdeps/unix/sysv/linux/Makefile
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+++ b/sysdeps/unix/sysv/linux/Makefile
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@@ -130,7 +130,10 @@ ifeq ($(have-GLIBC_2.27)$(build-shared),yesyes)
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tests += tst-ofdlocks-compat
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endif
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-tests-internal += tst-sigcontext-get_pc
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+tests-internal += \
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+ tst-rseq \
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+ tst-sigcontext-get_pc \
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+ # tests-internal
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tests-time64 += \
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tst-adjtimex-time64 \
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@@ -356,4 +359,8 @@ endif
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ifeq ($(subdir),nptl)
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tests += tst-align-clone tst-getpid1
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+
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+# tst-rseq-nptl is an internal test because it requires a definition of
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+# __NR_rseq from the internal system call list.
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+tests-internal += tst-rseq-nptl
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endif
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diff --git a/sysdeps/unix/sysv/linux/aarch64/bits/rseq.h b/sysdeps/unix/sysv/linux/aarch64/bits/rseq.h
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new file mode 100644
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index 0000000000000000..9ba92725c76b9d4f
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--- /dev/null
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+++ b/sysdeps/unix/sysv/linux/aarch64/bits/rseq.h
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@@ -0,0 +1,43 @@
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+/* Restartable Sequences Linux aarch64 architecture header.
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+ Copyright (C) 2021 Free Software Foundation, Inc.
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+
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+ The GNU C Library is free software; you can redistribute it and/or
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+ modify it under the terms of the GNU Lesser General Public
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+ License as published by the Free Software Foundation; either
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+ version 2.1 of the License, or (at your option) any later version.
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+
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+ The GNU C Library is distributed in the hope that it will be useful,
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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+ Lesser General Public License for more details.
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+
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+ You should have received a copy of the GNU Lesser General Public
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+ License along with the GNU C Library; if not, see
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+ <https://www.gnu.org/licenses/>. */
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+
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+#ifndef _SYS_RSEQ_H
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+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
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+#endif
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+
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+/* RSEQ_SIG is a signature required before each abort handler code.
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+
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+ It is a 32-bit value that maps to actual architecture code compiled
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+ into applications and libraries. It needs to be defined for each
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+ architecture. When choosing this value, it needs to be taken into
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+ account that generating invalid instructions may have ill effects on
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+ tools like objdump, and may also have impact on the CPU speculative
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+ execution efficiency in some cases.
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+
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+ aarch64 -mbig-endian generates mixed endianness code vs data:
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+ little-endian code and big-endian data. Ensure the RSEQ_SIG signature
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+ matches code endianness. */
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+
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+#define RSEQ_SIG_CODE 0xd428bc00 /* BRK #0x45E0. */
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+
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+#ifdef __AARCH64EB__
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+# define RSEQ_SIG_DATA 0x00bc28d4 /* BRK #0x45E0. */
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+#else
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+# define RSEQ_SIG_DATA RSEQ_SIG_CODE
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+#endif
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+
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+#define RSEQ_SIG RSEQ_SIG_DATA
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diff --git a/sysdeps/unix/sysv/linux/arm/bits/rseq.h b/sysdeps/unix/sysv/linux/arm/bits/rseq.h
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new file mode 100644
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index 0000000000000000..0542b26f6a023dec
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--- /dev/null
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+++ b/sysdeps/unix/sysv/linux/arm/bits/rseq.h
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@@ -0,0 +1,83 @@
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+/* Restartable Sequences Linux arm architecture header.
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+ Copyright (C) 2021 Free Software Foundation, Inc.
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+
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+ The GNU C Library is free software; you can redistribute it and/or
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+ modify it under the terms of the GNU Lesser General Public
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+ License as published by the Free Software Foundation; either
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+ version 2.1 of the License, or (at your option) any later version.
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+
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+ The GNU C Library is distributed in the hope that it will be useful,
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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+ Lesser General Public License for more details.
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+
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+ You should have received a copy of the GNU Lesser General Public
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+ License along with the GNU C Library; if not, see
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+ <https://www.gnu.org/licenses/>. */
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+
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+#ifndef _SYS_RSEQ_H
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+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
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+#endif
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+
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+/*
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+ RSEQ_SIG is a signature required before each abort handler code.
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+
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+ It is a 32-bit value that maps to actual architecture code compiled
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+ into applications and libraries. It needs to be defined for each
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+ architecture. When choosing this value, it needs to be taken into
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+ account that generating invalid instructions may have ill effects on
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+ tools like objdump, and may also have impact on the CPU speculative
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+ execution efficiency in some cases.
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+
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+ - ARM little endian
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+
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+ RSEQ_SIG uses the udf A32 instruction with an uncommon immediate operand
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+ value 0x5de3. This traps if user-space reaches this instruction by mistake,
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+ and the uncommon operand ensures the kernel does not move the instruction
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+ pointer to attacker-controlled code on rseq abort.
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+
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+ The instruction pattern in the A32 instruction set is:
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+
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+ e7f5def3 udf #24035 ; 0x5de3
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+
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+ This translates to the following instruction pattern in the T16 instruction
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+ set:
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+
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+ little endian:
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+ def3 udf #243 ; 0xf3
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+ e7f5 b.n <7f5>
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+
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+ - ARMv6+ big endian (BE8):
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+
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+ ARMv6+ -mbig-endian generates mixed endianness code vs data: little-endian
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+ code and big-endian data. The data value of the signature needs to have its
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+ byte order reversed to generate the trap instruction:
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+
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+ Data: 0xf3def5e7
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+
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+ Translates to this A32 instruction pattern:
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+
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+ e7f5def3 udf #24035 ; 0x5de3
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+
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+ Translates to this T16 instruction pattern:
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+
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+ def3 udf #243 ; 0xf3
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+ e7f5 b.n <7f5>
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+
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+ - Prior to ARMv6 big endian (BE32):
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+
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+ Prior to ARMv6, -mbig-endian generates big-endian code and data
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+ (which match), so the endianness of the data representation of the
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+ signature should not be reversed. However, the choice between BE32
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+ and BE8 is done by the linker, so we cannot know whether code and
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+ data endianness will be mixed before the linker is invoked. So rather
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+ than try to play tricks with the linker, the rseq signature is simply
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+ data (not a trap instruction) prior to ARMv6 on big endian. This is
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+ why the signature is expressed as data (.word) rather than as
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+ instruction (.inst) in assembler. */
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+
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+#ifdef __ARMEB__
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+# define RSEQ_SIG 0xf3def5e7 /* udf #24035 ; 0x5de3 (ARMv6+) */
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+#else
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+# define RSEQ_SIG 0xe7f5def3 /* udf #24035 ; 0x5de3 */
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+#endif
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diff --git a/sysdeps/unix/sysv/linux/bits/rseq.h b/sysdeps/unix/sysv/linux/bits/rseq.h
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new file mode 100644
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index 0000000000000000..46cf5d1c743f25eb
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--- /dev/null
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+++ b/sysdeps/unix/sysv/linux/bits/rseq.h
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@@ -0,0 +1,29 @@
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+/* Restartable Sequences architecture header. Stub version.
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+ Copyright (C) 2021 Free Software Foundation, Inc.
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+
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+ The GNU C Library is free software; you can redistribute it and/or
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+ modify it under the terms of the GNU Lesser General Public
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+ License as published by the Free Software Foundation; either
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+ version 2.1 of the License, or (at your option) any later version.
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+
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+ The GNU C Library is distributed in the hope that it will be useful,
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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+ Lesser General Public License for more details.
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+
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+ You should have received a copy of the GNU Lesser General Public
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+ License along with the GNU C Library; if not, see
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+ <https://www.gnu.org/licenses/>. */
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+
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+#ifndef _SYS_RSEQ_H
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+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
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+#endif
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+
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+/* RSEQ_SIG is a signature required before each abort handler code.
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+
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+ It is a 32-bit value that maps to actual architecture code compiled
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+ into applications and libraries. It needs to be defined for each
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+ architecture. When choosing this value, it needs to be taken into
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+ account that generating invalid instructions may have ill effects on
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+ tools like objdump, and may also have impact on the CPU speculative
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+ execution efficiency in some cases. */
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diff --git a/sysdeps/unix/sysv/linux/mips/bits/rseq.h b/sysdeps/unix/sysv/linux/mips/bits/rseq.h
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new file mode 100644
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index 0000000000000000..a9defee568ae04a5
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--- /dev/null
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+++ b/sysdeps/unix/sysv/linux/mips/bits/rseq.h
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@@ -0,0 +1,62 @@
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+/* Restartable Sequences Linux mips architecture header.
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+ Copyright (C) 2021 Free Software Foundation, Inc.
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+
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+ The GNU C Library is free software; you can redistribute it and/or
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+ modify it under the terms of the GNU Lesser General Public
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+ License as published by the Free Software Foundation; either
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+ version 2.1 of the License, or (at your option) any later version.
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+
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+ The GNU C Library is distributed in the hope that it will be useful,
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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+ Lesser General Public License for more details.
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+
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+ You should have received a copy of the GNU Lesser General Public
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+ License along with the GNU C Library; if not, see
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+ <https://www.gnu.org/licenses/>. */
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+
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+#ifndef _SYS_RSEQ_H
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+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
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+#endif
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+
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+/* RSEQ_SIG is a signature required before each abort handler code.
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+
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+ It is a 32-bit value that maps to actual architecture code compiled
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+ into applications and libraries. It needs to be defined for each
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+ architecture. When choosing this value, it needs to be taken into
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+ account that generating invalid instructions may have ill effects on
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+ tools like objdump, and may also have impact on the CPU speculative
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+ execution efficiency in some cases.
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+
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+ RSEQ_SIG uses the break instruction. The instruction pattern is:
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+
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+ On MIPS:
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+ 0350000d break 0x350
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+
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+ On nanoMIPS:
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+ 00100350 break 0x350
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+
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+ On microMIPS:
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+ 0000d407 break 0x350
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+
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+ For nanoMIPS32 and microMIPS, the instruction stream is encoded as
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+ 16-bit halfwords, so the signature halfwords need to be swapped
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+ accordingly for little-endian. */
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+
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+#if defined (__nanomips__)
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+# ifdef __MIPSEL__
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+# define RSEQ_SIG 0x03500010
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+# else
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+# define RSEQ_SIG 0x00100350
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+# endif
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+#elif defined (__mips_micromips)
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+# ifdef __MIPSEL__
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+# define RSEQ_SIG 0xd4070000
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+# else
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+# define RSEQ_SIG 0x0000d407
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+# endif
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+#elif defined (__mips__)
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+# define RSEQ_SIG 0x0350000d
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+#else
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+/* Unknown MIPS architecture. */
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+#endif
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diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/rseq.h b/sysdeps/unix/sysv/linux/powerpc/bits/rseq.h
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new file mode 100644
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index 0000000000000000..05b3cf7b8fe75b92
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--- /dev/null
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+++ b/sysdeps/unix/sysv/linux/powerpc/bits/rseq.h
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@@ -0,0 +1,37 @@
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+/* Restartable Sequences Linux powerpc architecture header.
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+ Copyright (C) 2021 Free Software Foundation, Inc.
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+
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+ The GNU C Library is free software; you can redistribute it and/or
|
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+ 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.
|
|
+
|
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+ 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.
|
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+
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+ You should have received a copy of the GNU Lesser General Public
|
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+ License along with the GNU C Library; if not, see
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+ <https://www.gnu.org/licenses/>. */
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+
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+#ifndef _SYS_RSEQ_H
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+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
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+#endif
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+
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+/* RSEQ_SIG is a signature required before each abort handler code.
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+
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+ It is a 32-bit value that maps to actual architecture code compiled
|
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+ into applications and libraries. It needs to be defined for each
|
|
+ architecture. When choosing this value, it needs to be taken into
|
|
+ account that generating invalid instructions may have ill effects on
|
|
+ tools like objdump, and may also have impact on the CPU speculative
|
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+ execution efficiency in some cases.
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+
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+ RSEQ_SIG uses the following trap instruction:
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+
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+ powerpc-be: 0f e5 00 0b twui r5,11
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+ powerpc64-le: 0b 00 e5 0f twui r5,11
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+ powerpc64-be: 0f e5 00 0b twui r5,11 */
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+
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+#define RSEQ_SIG 0x0fe5000b
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diff --git a/sysdeps/unix/sysv/linux/rseq-internal.h b/sysdeps/unix/sysv/linux/rseq-internal.h
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new file mode 100644
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index 0000000000000000..909f5478251d3d13
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--- /dev/null
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+++ b/sysdeps/unix/sysv/linux/rseq-internal.h
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@@ -0,0 +1,45 @@
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+/* Restartable Sequences internal API. Linux implementation.
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+ Copyright (C) 2021 Free Software Foundation, Inc.
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+
|
|
+ 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
|
|
+ <https://www.gnu.org/licenses/>. */
|
|
+
|
|
+#ifndef RSEQ_INTERNAL_H
|
|
+#define RSEQ_INTERNAL_H
|
|
+
|
|
+#include <sysdep.h>
|
|
+#include <errno.h>
|
|
+#include <kernel-features.h>
|
|
+#include <stdio.h>
|
|
+#include <sys/rseq.h>
|
|
+
|
|
+#ifdef RSEQ_SIG
|
|
+static inline void
|
|
+rseq_register_current_thread (struct pthread *self)
|
|
+{
|
|
+ int ret = INTERNAL_SYSCALL_CALL (rseq,
|
|
+ &self->rseq_area, sizeof (self->rseq_area),
|
|
+ 0, RSEQ_SIG);
|
|
+ if (INTERNAL_SYSCALL_ERROR_P (ret))
|
|
+ THREAD_SETMEM (self, rseq_area.cpu_id, RSEQ_CPU_ID_REGISTRATION_FAILED);
|
|
+}
|
|
+#else /* RSEQ_SIG */
|
|
+static inline void
|
|
+rseq_register_current_thread (struct pthread *self)
|
|
+{
|
|
+ THREAD_SETMEM (self, rseq_area.cpu_id, RSEQ_CPU_ID_REGISTRATION_FAILED);
|
|
+}
|
|
+#endif /* RSEQ_SIG */
|
|
+
|
|
+#endif /* rseq-internal.h */
|
|
diff --git a/sysdeps/unix/sysv/linux/s390/bits/rseq.h b/sysdeps/unix/sysv/linux/s390/bits/rseq.h
|
|
new file mode 100644
|
|
index 0000000000000000..3030e38f403784b3
|
|
--- /dev/null
|
|
+++ b/sysdeps/unix/sysv/linux/s390/bits/rseq.h
|
|
@@ -0,0 +1,37 @@
|
|
+/* Restartable Sequences Linux s390 architecture header.
|
|
+ Copyright (C) 2021 Free Software Foundation, Inc.
|
|
+
|
|
+ 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
|
|
+ <https://www.gnu.org/licenses/>. */
|
|
+
|
|
+#ifndef _SYS_RSEQ_H
|
|
+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
|
|
+#endif
|
|
+
|
|
+/* RSEQ_SIG is a signature required before each abort handler code.
|
|
+
|
|
+ It is a 32-bit value that maps to actual architecture code compiled
|
|
+ into applications and libraries. It needs to be defined for each
|
|
+ architecture. When choosing this value, it needs to be taken into
|
|
+ account that generating invalid instructions may have ill effects on
|
|
+ tools like objdump, and may also have impact on the CPU speculative
|
|
+ execution efficiency in some cases.
|
|
+
|
|
+ RSEQ_SIG uses the trap4 instruction. As Linux does not make use of the
|
|
+ access-register mode nor the linkage stack this instruction will always
|
|
+ cause a special-operation exception (the trap-enabled bit in the DUCT
|
|
+ is and will stay 0). The instruction pattern is
|
|
+ b2 ff 0f ff trap4 4095(%r0) */
|
|
+
|
|
+#define RSEQ_SIG 0xB2FF0FFF
|
|
diff --git a/sysdeps/unix/sysv/linux/sys/rseq.h b/sysdeps/unix/sysv/linux/sys/rseq.h
|
|
new file mode 100644
|
|
index 0000000000000000..c8edff50d40e29b6
|
|
--- /dev/null
|
|
+++ b/sysdeps/unix/sysv/linux/sys/rseq.h
|
|
@@ -0,0 +1,174 @@
|
|
+/* Restartable Sequences exported symbols. Linux header.
|
|
+ Copyright (C) 2021 Free Software Foundation, Inc.
|
|
+
|
|
+ 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
|
|
+ <https://www.gnu.org/licenses/>. */
|
|
+
|
|
+#ifndef _SYS_RSEQ_H
|
|
+#define _SYS_RSEQ_H 1
|
|
+
|
|
+/* Architecture-specific rseq signature. */
|
|
+#include <bits/rseq.h>
|
|
+
|
|
+#include <stdint.h>
|
|
+#include <sys/cdefs.h>
|
|
+#include <bits/endian.h>
|
|
+
|
|
+#ifdef __has_include
|
|
+# if __has_include ("linux/rseq.h")
|
|
+# define __GLIBC_HAVE_KERNEL_RSEQ
|
|
+# endif
|
|
+#else
|
|
+# include <linux/version.h>
|
|
+# if LINUX_VERSION_CODE >= KERNEL_VERSION (4, 18, 0)
|
|
+# define __GLIBC_HAVE_KERNEL_RSEQ
|
|
+# endif
|
|
+#endif
|
|
+
|
|
+#ifdef __GLIBC_HAVE_KERNEL_RSEQ
|
|
+/* We use the structures declarations from the kernel headers. */
|
|
+# include <linux/rseq.h>
|
|
+#else /* __GLIBC_HAVE_KERNEL_RSEQ */
|
|
+/* We use a copy of the include/uapi/linux/rseq.h kernel header. */
|
|
+
|
|
+enum rseq_cpu_id_state
|
|
+ {
|
|
+ RSEQ_CPU_ID_UNINITIALIZED = -1,
|
|
+ RSEQ_CPU_ID_REGISTRATION_FAILED = -2,
|
|
+ };
|
|
+
|
|
+enum rseq_flags
|
|
+ {
|
|
+ RSEQ_FLAG_UNREGISTER = (1 << 0),
|
|
+ };
|
|
+
|
|
+enum rseq_cs_flags_bit
|
|
+ {
|
|
+ RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT = 0,
|
|
+ RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT = 1,
|
|
+ RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT = 2,
|
|
+ };
|
|
+
|
|
+enum rseq_cs_flags
|
|
+ {
|
|
+ RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT =
|
|
+ (1U << RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT),
|
|
+ RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL =
|
|
+ (1U << RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT),
|
|
+ RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE =
|
|
+ (1U << RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT),
|
|
+ };
|
|
+
|
|
+/* struct rseq_cs is aligned on 32 bytes to ensure it is always
|
|
+ contained within a single cache-line. It is usually declared as
|
|
+ link-time constant data. */
|
|
+struct rseq_cs
|
|
+ {
|
|
+ /* Version of this structure. */
|
|
+ uint32_t version;
|
|
+ /* enum rseq_cs_flags. */
|
|
+ uint32_t flags;
|
|
+ uint64_t start_ip;
|
|
+ /* Offset from start_ip. */
|
|
+ uint64_t post_commit_offset;
|
|
+ uint64_t abort_ip;
|
|
+ } __attribute__ ((__aligned__ (32)));
|
|
+
|
|
+/* struct rseq is aligned on 32 bytes to ensure it is always
|
|
+ contained within a single cache-line.
|
|
+
|
|
+ A single struct rseq per thread is allowed. */
|
|
+struct rseq
|
|
+ {
|
|
+ /* Restartable sequences cpu_id_start field. Updated by the
|
|
+ kernel. Read by user-space with single-copy atomicity
|
|
+ semantics. This field should only be read by the thread which
|
|
+ registered this data structure. Aligned on 32-bit. Always
|
|
+ contains a value in the range of possible CPUs, although the
|
|
+ value may not be the actual current CPU (e.g. if rseq is not
|
|
+ initialized). This CPU number value should always be compared
|
|
+ against the value of the cpu_id field before performing a rseq
|
|
+ commit or returning a value read from a data structure indexed
|
|
+ using the cpu_id_start value. */
|
|
+ uint32_t cpu_id_start;
|
|
+ /* Restartable sequences cpu_id field. Updated by the kernel.
|
|
+ Read by user-space with single-copy atomicity semantics. This
|
|
+ field should only be read by the thread which registered this
|
|
+ data structure. Aligned on 32-bit. Values
|
|
+ RSEQ_CPU_ID_UNINITIALIZED and RSEQ_CPU_ID_REGISTRATION_FAILED
|
|
+ have a special semantic: the former means "rseq uninitialized",
|
|
+ and latter means "rseq initialization failed". This value is
|
|
+ meant to be read within rseq critical sections and compared
|
|
+ with the cpu_id_start value previously read, before performing
|
|
+ the commit instruction, or read and compared with the
|
|
+ cpu_id_start value before returning a value loaded from a data
|
|
+ structure indexed using the cpu_id_start value. */
|
|
+ uint32_t cpu_id;
|
|
+ /* Restartable sequences rseq_cs field.
|
|
+
|
|
+ Contains NULL when no critical section is active for the current
|
|
+ thread, or holds a pointer to the currently active struct rseq_cs.
|
|
+
|
|
+ Updated by user-space, which sets the address of the currently
|
|
+ active rseq_cs at the beginning of assembly instruction sequence
|
|
+ block, and set to NULL by the kernel when it restarts an assembly
|
|
+ instruction sequence block, as well as when the kernel detects that
|
|
+ it is preempting or delivering a signal outside of the range
|
|
+ targeted by the rseq_cs. Also needs to be set to NULL by user-space
|
|
+ before reclaiming memory that contains the targeted struct rseq_cs.
|
|
+
|
|
+ Read and set by the kernel. Set by user-space with single-copy
|
|
+ atomicity semantics. This field should only be updated by the
|
|
+ thread which registered this data structure. Aligned on 64-bit. */
|
|
+ union
|
|
+ {
|
|
+ uint64_t ptr64;
|
|
+# ifdef __LP64__
|
|
+ uint64_t ptr;
|
|
+# else /* __LP64__ */
|
|
+ struct
|
|
+ {
|
|
+#if __BYTE_ORDER == __BIG_ENDIAN
|
|
+ uint32_t padding; /* Initialized to zero. */
|
|
+ uint32_t ptr32;
|
|
+# else /* LITTLE */
|
|
+ uint32_t ptr32;
|
|
+ uint32_t padding; /* Initialized to zero. */
|
|
+# endif /* ENDIAN */
|
|
+ } ptr;
|
|
+# endif /* __LP64__ */
|
|
+ } rseq_cs;
|
|
+
|
|
+ /* Restartable sequences flags field.
|
|
+
|
|
+ This field should only be updated by the thread which
|
|
+ registered this data structure. Read by the kernel.
|
|
+ Mainly used for single-stepping through rseq critical sections
|
|
+ with debuggers.
|
|
+
|
|
+ - RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT
|
|
+ Inhibit instruction sequence block restart on preemption
|
|
+ for this thread.
|
|
+ - RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL
|
|
+ Inhibit instruction sequence block restart on signal
|
|
+ delivery for this thread.
|
|
+ - RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE
|
|
+ Inhibit instruction sequence block restart on migration for
|
|
+ this thread. */
|
|
+ uint32_t flags;
|
|
+ } __attribute__ ((__aligned__ (32)));
|
|
+
|
|
+#endif /* __GLIBC_HAVE_KERNEL_RSEQ */
|
|
+
|
|
+#endif /* sys/rseq.h */
|
|
diff --git a/sysdeps/unix/sysv/linux/tst-rseq-nptl.c b/sysdeps/unix/sysv/linux/tst-rseq-nptl.c
|
|
new file mode 100644
|
|
index 0000000000000000..d31d94445caa9ee3
|
|
--- /dev/null
|
|
+++ b/sysdeps/unix/sysv/linux/tst-rseq-nptl.c
|
|
@@ -0,0 +1,260 @@
|
|
+/* Restartable Sequences NPTL test.
|
|
+ Copyright (C) 2021 Free Software Foundation, Inc.
|
|
+
|
|
+ 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
|
|
+ <https://www.gnu.org/licenses/>. */
|
|
+
|
|
+/* These tests validate that rseq is registered from various execution
|
|
+ contexts (main thread, destructor, other threads, other threads created
|
|
+ from destructor, forked process (without exec), pthread_atfork handlers,
|
|
+ pthread setspecific destructors, signal handlers, atexit handlers).
|
|
+
|
|
+ See the Linux kernel selftests for extensive rseq stress-tests. */
|
|
+
|
|
+#include <stdio.h>
|
|
+#include <support/check.h>
|
|
+#include <support/xthread.h>
|
|
+#include <sys/rseq.h>
|
|
+#include <unistd.h>
|
|
+
|
|
+#ifdef RSEQ_SIG
|
|
+# include <array_length.h>
|
|
+# include <errno.h>
|
|
+# include <error.h>
|
|
+# include <pthread.h>
|
|
+# include <signal.h>
|
|
+# include <stdlib.h>
|
|
+# include <string.h>
|
|
+# include <support/namespace.h>
|
|
+# include <support/xsignal.h>
|
|
+# include <syscall.h>
|
|
+# include <sys/types.h>
|
|
+# include <sys/wait.h>
|
|
+# include "tst-rseq.h"
|
|
+
|
|
+static pthread_key_t rseq_test_key;
|
|
+
|
|
+static void
|
|
+atfork_prepare (void)
|
|
+{
|
|
+ if (!rseq_thread_registered ())
|
|
+ {
|
|
+ printf ("error: rseq not registered in pthread atfork prepare\n");
|
|
+ support_record_failure ();
|
|
+ }
|
|
+}
|
|
+
|
|
+static void
|
|
+atfork_parent (void)
|
|
+{
|
|
+ if (!rseq_thread_registered ())
|
|
+ {
|
|
+ printf ("error: rseq not registered in pthread atfork parent\n");
|
|
+ support_record_failure ();
|
|
+ }
|
|
+}
|
|
+
|
|
+static void
|
|
+atfork_child (void)
|
|
+{
|
|
+ if (!rseq_thread_registered ())
|
|
+ {
|
|
+ printf ("error: rseq not registered in pthread atfork child\n");
|
|
+ support_record_failure ();
|
|
+ }
|
|
+}
|
|
+
|
|
+static void
|
|
+rseq_key_destructor (void *arg)
|
|
+{
|
|
+ /* Cannot use deferred failure reporting after main returns. */
|
|
+ if (!rseq_thread_registered ())
|
|
+ FAIL_EXIT1 ("rseq not registered in pthread key destructor");
|
|
+}
|
|
+
|
|
+static void
|
|
+atexit_handler (void)
|
|
+{
|
|
+ /* Cannot use deferred failure reporting after main returns. */
|
|
+ if (!rseq_thread_registered ())
|
|
+ FAIL_EXIT1 ("rseq not registered in atexit handler");
|
|
+}
|
|
+
|
|
+/* Used to avoid -Werror=stringop-overread warning with
|
|
+ pthread_setspecific and GCC 11. */
|
|
+static char one = 1;
|
|
+
|
|
+static void
|
|
+do_rseq_main_test (void)
|
|
+{
|
|
+ TEST_COMPARE (atexit (atexit_handler), 0);
|
|
+ rseq_test_key = xpthread_key_create (rseq_key_destructor);
|
|
+ TEST_COMPARE (pthread_atfork (atfork_prepare, atfork_parent, atfork_child), 0);
|
|
+ xraise (SIGUSR1);
|
|
+ TEST_COMPARE (pthread_setspecific (rseq_test_key, &one), 0);
|
|
+ TEST_VERIFY_EXIT (rseq_thread_registered ());
|
|
+}
|
|
+
|
|
+static void
|
|
+cancel_routine (void *arg)
|
|
+{
|
|
+ if (!rseq_thread_registered ())
|
|
+ {
|
|
+ printf ("error: rseq not registered in cancel routine\n");
|
|
+ support_record_failure ();
|
|
+ }
|
|
+}
|
|
+
|
|
+static pthread_barrier_t cancel_thread_barrier;
|
|
+static pthread_cond_t cancel_thread_cond = PTHREAD_COND_INITIALIZER;
|
|
+static pthread_mutex_t cancel_thread_mutex = PTHREAD_MUTEX_INITIALIZER;
|
|
+
|
|
+static void
|
|
+test_cancel_thread (void)
|
|
+{
|
|
+ pthread_cleanup_push (cancel_routine, NULL);
|
|
+ (void) xpthread_barrier_wait (&cancel_thread_barrier);
|
|
+ /* Wait forever until cancellation. */
|
|
+ xpthread_cond_wait (&cancel_thread_cond, &cancel_thread_mutex);
|
|
+ pthread_cleanup_pop (0);
|
|
+}
|
|
+
|
|
+static void *
|
|
+thread_function (void * arg)
|
|
+{
|
|
+ int i = (int) (intptr_t) arg;
|
|
+
|
|
+ xraise (SIGUSR1);
|
|
+ if (i == 0)
|
|
+ test_cancel_thread ();
|
|
+ TEST_COMPARE (pthread_setspecific (rseq_test_key, &one), 0);
|
|
+ return rseq_thread_registered () ? NULL : (void *) 1l;
|
|
+}
|
|
+
|
|
+static void
|
|
+sighandler (int sig)
|
|
+{
|
|
+ if (!rseq_thread_registered ())
|
|
+ {
|
|
+ printf ("error: rseq not registered in signal handler\n");
|
|
+ support_record_failure ();
|
|
+ }
|
|
+}
|
|
+
|
|
+static void
|
|
+setup_signals (void)
|
|
+{
|
|
+ struct sigaction sa;
|
|
+
|
|
+ sigemptyset (&sa.sa_mask);
|
|
+ sigaddset (&sa.sa_mask, SIGUSR1);
|
|
+ sa.sa_flags = 0;
|
|
+ sa.sa_handler = sighandler;
|
|
+ xsigaction (SIGUSR1, &sa, NULL);
|
|
+}
|
|
+
|
|
+static int
|
|
+do_rseq_threads_test (int nr_threads)
|
|
+{
|
|
+ pthread_t th[nr_threads];
|
|
+ int i;
|
|
+ int result = 0;
|
|
+
|
|
+ xpthread_barrier_init (&cancel_thread_barrier, NULL, 2);
|
|
+
|
|
+ for (i = 0; i < nr_threads; ++i)
|
|
+ th[i] = xpthread_create (NULL, thread_function,
|
|
+ (void *) (intptr_t) i);
|
|
+
|
|
+ (void) xpthread_barrier_wait (&cancel_thread_barrier);
|
|
+
|
|
+ xpthread_cancel (th[0]);
|
|
+
|
|
+ for (i = 0; i < nr_threads; ++i)
|
|
+ {
|
|
+ void *v;
|
|
+
|
|
+ v = xpthread_join (th[i]);
|
|
+ if (i != 0 && v != NULL)
|
|
+ {
|
|
+ printf ("error: join %d successful, but child failed\n", i);
|
|
+ result = 1;
|
|
+ }
|
|
+ else if (i == 0 && v == NULL)
|
|
+ {
|
|
+ printf ("error: join %d successful, child did not fail as expected\n", i);
|
|
+ result = 1;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ xpthread_barrier_destroy (&cancel_thread_barrier);
|
|
+
|
|
+ return result;
|
|
+}
|
|
+
|
|
+static void
|
|
+subprocess_callback (void *closure)
|
|
+{
|
|
+ do_rseq_main_test ();
|
|
+}
|
|
+
|
|
+static void
|
|
+do_rseq_fork_test (void)
|
|
+{
|
|
+ support_isolate_in_subprocess (subprocess_callback, NULL);
|
|
+}
|
|
+
|
|
+static int
|
|
+do_rseq_test (void)
|
|
+{
|
|
+ int t[] = { 1, 2, 6, 5, 4, 3, 50 };
|
|
+ int i, result = 0;
|
|
+
|
|
+ if (!rseq_available ())
|
|
+ FAIL_UNSUPPORTED ("kernel does not support rseq, skipping test");
|
|
+ setup_signals ();
|
|
+ xraise (SIGUSR1);
|
|
+ do_rseq_main_test ();
|
|
+ for (i = 0; i < array_length (t); i++)
|
|
+ if (do_rseq_threads_test (t[i]))
|
|
+ result = 1;
|
|
+ do_rseq_fork_test ();
|
|
+ return result;
|
|
+}
|
|
+
|
|
+static void __attribute__ ((destructor))
|
|
+do_rseq_destructor_test (void)
|
|
+{
|
|
+ /* Cannot use deferred failure reporting after main returns. */
|
|
+ if (do_rseq_test ())
|
|
+ FAIL_EXIT1 ("rseq not registered within destructor");
|
|
+ xpthread_key_delete (rseq_test_key);
|
|
+}
|
|
+
|
|
+#else /* RSEQ_SIG */
|
|
+static int
|
|
+do_rseq_test (void)
|
|
+{
|
|
+ FAIL_UNSUPPORTED ("glibc does not define RSEQ_SIG, skipping test");
|
|
+ return 0;
|
|
+}
|
|
+#endif /* RSEQ_SIG */
|
|
+
|
|
+static int
|
|
+do_test (void)
|
|
+{
|
|
+ return do_rseq_test ();
|
|
+}
|
|
+
|
|
+#include <support/test-driver.c>
|
|
diff --git a/sysdeps/unix/sysv/linux/tst-rseq.c b/sysdeps/unix/sysv/linux/tst-rseq.c
|
|
new file mode 100644
|
|
index 0000000000000000..926376b6a5446ece
|
|
--- /dev/null
|
|
+++ b/sysdeps/unix/sysv/linux/tst-rseq.c
|
|
@@ -0,0 +1,64 @@
|
|
+/* Restartable Sequences single-threaded tests.
|
|
+ Copyright (C) 2021 Free Software Foundation, Inc.
|
|
+
|
|
+ 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
|
|
+ <https://www.gnu.org/licenses/>. */
|
|
+
|
|
+/* These tests validate that rseq is registered from main in an executable
|
|
+ not linked against libpthread. */
|
|
+
|
|
+#include <support/check.h>
|
|
+#include <stdio.h>
|
|
+#include <sys/rseq.h>
|
|
+#include <unistd.h>
|
|
+
|
|
+#ifdef RSEQ_SIG
|
|
+# include <errno.h>
|
|
+# include <error.h>
|
|
+# include <stdlib.h>
|
|
+# include <string.h>
|
|
+# include <syscall.h>
|
|
+# include "tst-rseq.h"
|
|
+
|
|
+static void
|
|
+do_rseq_main_test (void)
|
|
+{
|
|
+ TEST_VERIFY_EXIT (rseq_thread_registered ());
|
|
+}
|
|
+
|
|
+static void
|
|
+do_rseq_test (void)
|
|
+{
|
|
+ if (!rseq_available ())
|
|
+ {
|
|
+ FAIL_UNSUPPORTED ("kernel does not support rseq, skipping test");
|
|
+ }
|
|
+ do_rseq_main_test ();
|
|
+}
|
|
+#else /* RSEQ_SIG */
|
|
+static void
|
|
+do_rseq_test (void)
|
|
+{
|
|
+ FAIL_UNSUPPORTED ("glibc does not define RSEQ_SIG, skipping test");
|
|
+}
|
|
+#endif /* RSEQ_SIG */
|
|
+
|
|
+static int
|
|
+do_test (void)
|
|
+{
|
|
+ do_rseq_test ();
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+#include <support/test-driver.c>
|
|
diff --git a/sysdeps/unix/sysv/linux/tst-rseq.h b/sysdeps/unix/sysv/linux/tst-rseq.h
|
|
new file mode 100644
|
|
index 0000000000000000..a476c316fc2671a0
|
|
--- /dev/null
|
|
+++ b/sysdeps/unix/sysv/linux/tst-rseq.h
|
|
@@ -0,0 +1,57 @@
|
|
+/* Restartable Sequences tests header.
|
|
+ Copyright (C) 2021 Free Software Foundation, Inc.
|
|
+
|
|
+ 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
|
|
+ <https://www.gnu.org/licenses/>. */
|
|
+
|
|
+#include <errno.h>
|
|
+#include <error.h>
|
|
+#include <stdbool.h>
|
|
+#include <stdint.h>
|
|
+#include <support/check.h>
|
|
+#include <syscall.h>
|
|
+#include <sys/rseq.h>
|
|
+#include <tls.h>
|
|
+
|
|
+static inline bool
|
|
+rseq_thread_registered (void)
|
|
+{
|
|
+ return THREAD_GETMEM_VOLATILE (THREAD_SELF, rseq_area.cpu_id) >= 0;
|
|
+}
|
|
+
|
|
+static inline int
|
|
+sys_rseq (struct rseq *rseq_abi, uint32_t rseq_len, int flags, uint32_t sig)
|
|
+{
|
|
+ return syscall (__NR_rseq, rseq_abi, rseq_len, flags, sig);
|
|
+}
|
|
+
|
|
+static inline bool
|
|
+rseq_available (void)
|
|
+{
|
|
+ int rc;
|
|
+
|
|
+ rc = sys_rseq (NULL, 0, 0, 0);
|
|
+ if (rc != -1)
|
|
+ FAIL_EXIT1 ("Unexpected rseq return value %d", rc);
|
|
+ switch (errno)
|
|
+ {
|
|
+ case ENOSYS:
|
|
+ return false;
|
|
+ case EINVAL:
|
|
+ /* rseq is implemented, but detected an invalid rseq_len parameter. */
|
|
+ return true;
|
|
+ default:
|
|
+ FAIL_EXIT1 ("Unexpected rseq error %s", strerror (errno));
|
|
+ }
|
|
+}
|
|
diff --git a/sysdeps/unix/sysv/linux/x86/bits/rseq.h b/sysdeps/unix/sysv/linux/x86/bits/rseq.h
|
|
new file mode 100644
|
|
index 0000000000000000..9fc909e7c8a25bbb
|
|
--- /dev/null
|
|
+++ b/sysdeps/unix/sysv/linux/x86/bits/rseq.h
|
|
@@ -0,0 +1,30 @@
|
|
+/* Restartable Sequences Linux x86 architecture header.
|
|
+ Copyright (C) 2021 Free Software Foundation, Inc.
|
|
+
|
|
+ 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
|
|
+ <https://www.gnu.org/licenses/>. */
|
|
+
|
|
+#ifndef _SYS_RSEQ_H
|
|
+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
|
|
+#endif
|
|
+
|
|
+/* RSEQ_SIG is a signature required before each abort handler code.
|
|
+
|
|
+ RSEQ_SIG is used with the following reserved undefined instructions, which
|
|
+ trap in user-space:
|
|
+
|
|
+ x86-32: 0f b9 3d 53 30 05 53 ud1 0x53053053,%edi
|
|
+ x86-64: 0f b9 3d 53 30 05 53 ud1 0x53053053(%rip),%edi */
|
|
+
|
|
+#define RSEQ_SIG 0x53053053
|