Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull restartable sequence support from Thomas Gleixner:
 "The restartable sequences syscall (finally):

  After a lot of back and forth discussion and massive delays caused by
  the speculative distraction of maintainers, the core set of
  restartable sequences has finally reached a consensus.

  It comes with the basic non disputed core implementation along with
  support for arm, powerpc and x86 and a full set of selftests

  It was exposed to linux-next earlier this week, so it does not fully
  comply with the merge window requirements, but there is really no
  point to drag it out for yet another cycle"

* 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq/selftests: Provide Makefile, scripts, gitignore
  rseq/selftests: Provide parametrized tests
  rseq/selftests: Provide basic percpu ops test
  rseq/selftests: Provide basic test
  rseq/selftests: Provide rseq library
  selftests/lib.mk: Introduce OVERRIDE_TARGETS
  powerpc: Wire up restartable sequences system call
  powerpc: Add syscall detection for restartable sequences
  powerpc: Add support for restartable sequences
  x86: Wire up restartable sequence system call
  x86: Add support for restartable sequences
  arm: Wire up restartable sequences system call
  arm: Add syscall detection for restartable sequences
  arm: Add restartable sequences support
  rseq: Introduce restartable sequences system call
  uapi/headers: Provide types_32_64.h
This commit is contained in:
Linus Torvalds 2018-06-10 10:17:09 -07:00
commit d82991a868
44 changed files with 5491 additions and 8 deletions

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@ -12134,6 +12134,18 @@ F: include/dt-bindings/reset/
F: include/linux/reset.h
F: include/linux/reset-controller.h
RESTARTABLE SEQUENCES SUPPORT
M: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
M: Peter Zijlstra <peterz@infradead.org>
M: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
M: Boqun Feng <boqun.feng@gmail.com>
L: linux-kernel@vger.kernel.org
S: Supported
F: kernel/rseq.c
F: include/uapi/linux/rseq.h
F: include/trace/events/rseq.h
F: tools/testing/selftests/rseq/
RFKILL
M: Johannes Berg <johannes@sipsolutions.net>
L: linux-wireless@vger.kernel.org

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@ -272,6 +272,13 @@ config HAVE_REGS_AND_STACK_ACCESS_API
declared in asm/ptrace.h
For example the kprobes-based event tracer needs this API.
config HAVE_RSEQ
bool
depends on HAVE_REGS_AND_STACK_ACCESS_API
help
This symbol should be selected by an architecture if it
supports an implementation of restartable sequences.
config HAVE_CLK
bool
help

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@ -91,6 +91,7 @@ config ARM
select HAVE_PERF_USER_STACK_DUMP
select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RSEQ
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UID16
select HAVE_VIRT_CPU_ACCOUNTING_GEN

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@ -39,12 +39,13 @@ saved_pc .req lr
.section .entry.text,"ax",%progbits
.align 5
#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING))
#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING) || \
IS_ENABLED(CONFIG_DEBUG_RSEQ))
/*
* This is the fast syscall return path. We do as little as possible here,
* such as avoiding writing r0 to the stack. We only use this path if we
* have tracing and context tracking disabled - the overheads from those
* features make this path too inefficient.
* have tracing, context tracking and rseq debug disabled - the overheads
* from those features make this path too inefficient.
*/
ret_fast_syscall:
UNWIND(.fnstart )
@ -71,14 +72,20 @@ fast_work_pending:
/* fall through to work_pending */
#else
/*
* The "replacement" ret_fast_syscall for when tracing or context tracking
* is enabled. As we will need to call out to some C functions, we save
* r0 first to avoid needing to save registers around each C function call.
* The "replacement" ret_fast_syscall for when tracing, context tracking,
* or rseq debug is enabled. As we will need to call out to some C functions,
* we save r0 first to avoid needing to save registers around each C function
* call.
*/
ret_fast_syscall:
UNWIND(.fnstart )
UNWIND(.cantunwind )
str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
#if IS_ENABLED(CONFIG_DEBUG_RSEQ)
/* do_rseq_syscall needs interrupts enabled. */
mov r0, sp @ 'regs'
bl do_rseq_syscall
#endif
disable_irq_notrace @ disable interrupts
ldr r2, [tsk, #TI_ADDR_LIMIT]
cmp r2, #TASK_SIZE
@ -113,6 +120,12 @@ ENDPROC(ret_fast_syscall)
*/
ENTRY(ret_to_user)
ret_slow_syscall:
#if IS_ENABLED(CONFIG_DEBUG_RSEQ)
/* do_rseq_syscall needs interrupts enabled. */
enable_irq_notrace @ enable interrupts
mov r0, sp @ 'regs'
bl do_rseq_syscall
#endif
disable_irq_notrace @ disable interrupts
ENTRY(ret_to_user_from_irq)
ldr r2, [tsk, #TI_ADDR_LIMIT]

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@ -540,6 +540,12 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
sigset_t *oldset = sigmask_to_save();
int ret;
/*
* Increment event counter and perform fixup for the pre-signal
* frame.
*/
rseq_signal_deliver(regs);
/*
* Set up the stack frame
*/
@ -660,6 +666,7 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
} else {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
rseq_handle_notify_resume(regs);
}
}
local_irq_disable();
@ -703,3 +710,10 @@ asmlinkage void addr_limit_check_failed(void)
{
addr_limit_user_check();
}
#ifdef CONFIG_DEBUG_RSEQ
asmlinkage void do_rseq_syscall(struct pt_regs *regs)
{
rseq_syscall(regs);
}
#endif

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@ -412,3 +412,4 @@
395 common pkey_alloc sys_pkey_alloc
396 common pkey_free sys_pkey_free
397 common statx sys_statx
398 common rseq sys_rseq

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@ -220,6 +220,7 @@ config PPC
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_VIRT_CPU_ACCOUNTING
select HAVE_IRQ_TIME_ACCOUNTING
select HAVE_RSEQ
select IOMMU_HELPER if PPC64
select IRQ_DOMAIN
select IRQ_FORCED_THREADING

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@ -392,3 +392,4 @@ SYSCALL(statx)
SYSCALL(pkey_alloc)
SYSCALL(pkey_free)
SYSCALL(pkey_mprotect)
SYSCALL(rseq)

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@ -12,7 +12,7 @@
#include <uapi/asm/unistd.h>
#define NR_syscalls 387
#define NR_syscalls 388
#define __NR__exit __NR_exit

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@ -398,5 +398,6 @@
#define __NR_pkey_alloc 384
#define __NR_pkey_free 385
#define __NR_pkey_mprotect 386
#define __NR_rseq 387
#endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */

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@ -365,6 +365,13 @@ syscall_dotrace_cont:
blrl /* Call handler */
.globl ret_from_syscall
ret_from_syscall:
#ifdef CONFIG_DEBUG_RSEQ
/* Check whether the syscall is issued inside a restartable sequence */
stw r3,GPR3(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
bl rseq_syscall
lwz r3,GPR3(r1)
#endif
mr r6,r3
CURRENT_THREAD_INFO(r12, r1)
/* disable interrupts so current_thread_info()->flags can't change */

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@ -194,6 +194,14 @@ system_call: /* label this so stack traces look sane */
.Lsyscall_exit:
std r3,RESULT(r1)
#ifdef CONFIG_DEBUG_RSEQ
/* Check whether the syscall is issued inside a restartable sequence */
addi r3,r1,STACK_FRAME_OVERHEAD
bl rseq_syscall
ld r3,RESULT(r1)
#endif
CURRENT_THREAD_INFO(r12, r1)
ld r8,_MSR(r1)

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@ -134,6 +134,8 @@ static void do_signal(struct task_struct *tsk)
/* Re-enable the breakpoints for the signal stack */
thread_change_pc(tsk, tsk->thread.regs);
rseq_signal_deliver(tsk->thread.regs);
if (is32) {
if (ksig.ka.sa.sa_flags & SA_SIGINFO)
ret = handle_rt_signal32(&ksig, oldset, tsk);
@ -168,6 +170,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
rseq_handle_notify_resume(regs);
}
user_enter();

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@ -183,6 +183,7 @@ config X86
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
select HAVE_STACK_VALIDATION if X86_64
select HAVE_RSEQ
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UNSTABLE_SCHED_CLOCK
select HAVE_USER_RETURN_NOTIFIER

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@ -164,6 +164,7 @@ static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags)
if (cached_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
rseq_handle_notify_resume(regs);
}
if (cached_flags & _TIF_USER_RETURN_NOTIFY)
@ -254,6 +255,8 @@ __visible inline void syscall_return_slowpath(struct pt_regs *regs)
WARN(irqs_disabled(), "syscall %ld left IRQs disabled", regs->orig_ax))
local_irq_enable();
rseq_syscall(regs);
/*
* First do one-time work. If these work items are enabled, we
* want to run them exactly once per syscall exit with IRQs on.

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@ -397,3 +397,4 @@
383 i386 statx sys_statx __ia32_sys_statx
384 i386 arch_prctl sys_arch_prctl __ia32_compat_sys_arch_prctl
385 i386 io_pgetevents sys_io_pgetevents __ia32_compat_sys_io_pgetevents
386 i386 rseq sys_rseq __ia32_sys_rseq

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@ -342,6 +342,7 @@
331 common pkey_free __x64_sys_pkey_free
332 common statx __x64_sys_statx
333 common io_pgetevents __x64_sys_io_pgetevents
334 common rseq __x64_sys_rseq
#
# x32-specific system call numbers start at 512 to avoid cache impact

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@ -688,6 +688,12 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
sigset_t *set = sigmask_to_save();
compat_sigset_t *cset = (compat_sigset_t *) set;
/*
* Increment event counter and perform fixup for the pre-signal
* frame.
*/
rseq_signal_deliver(regs);
/* Set up the stack frame */
if (is_ia32_frame(ksig)) {
if (ksig->ka.sa.sa_flags & SA_SIGINFO)

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@ -1824,6 +1824,7 @@ static int __do_execve_file(int fd, struct filename *filename,
current->fs->in_exec = 0;
current->in_execve = 0;
membarrier_execve(current);
rseq_execve(current);
acct_update_integrals(current);
task_numa_free(current);
free_bprm(bprm);

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@ -27,6 +27,7 @@
#include <linux/signal_types.h>
#include <linux/mm_types_task.h>
#include <linux/task_io_accounting.h>
#include <linux/rseq.h>
/* task_struct member predeclarations (sorted alphabetically): */
struct audit_context;
@ -1047,6 +1048,17 @@ struct task_struct {
unsigned long numa_pages_migrated;
#endif /* CONFIG_NUMA_BALANCING */
#ifdef CONFIG_RSEQ
struct rseq __user *rseq;
u32 rseq_len;
u32 rseq_sig;
/*
* RmW on rseq_event_mask must be performed atomically
* with respect to preemption.
*/
unsigned long rseq_event_mask;
#endif
struct tlbflush_unmap_batch tlb_ubc;
struct rcu_head rcu;
@ -1757,4 +1769,126 @@ extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
#define TASK_SIZE_OF(tsk) TASK_SIZE
#endif
#ifdef CONFIG_RSEQ
/*
* Map the event mask on the user-space ABI enum rseq_cs_flags
* for direct mask checks.
*/
enum rseq_event_mask_bits {
RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
};
enum rseq_event_mask {
RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT),
RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT),
RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT),
};
static inline void rseq_set_notify_resume(struct task_struct *t)
{
if (t->rseq)
set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
}
void __rseq_handle_notify_resume(struct pt_regs *regs);
static inline void rseq_handle_notify_resume(struct pt_regs *regs)
{
if (current->rseq)
__rseq_handle_notify_resume(regs);
}
static inline void rseq_signal_deliver(struct pt_regs *regs)
{
preempt_disable();
__set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
preempt_enable();
rseq_handle_notify_resume(regs);
}
/* rseq_preempt() requires preemption to be disabled. */
static inline void rseq_preempt(struct task_struct *t)
{
__set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
rseq_set_notify_resume(t);
}
/* rseq_migrate() requires preemption to be disabled. */
static inline void rseq_migrate(struct task_struct *t)
{
__set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
rseq_set_notify_resume(t);
}
/*
* If parent process has a registered restartable sequences area, the
* child inherits. Only applies when forking a process, not a thread. In
* case a parent fork() in the middle of a restartable sequence, set the
* resume notifier to force the child to retry.
*/
static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
{
if (clone_flags & CLONE_THREAD) {
t->rseq = NULL;
t->rseq_len = 0;
t->rseq_sig = 0;
t->rseq_event_mask = 0;
} else {
t->rseq = current->rseq;
t->rseq_len = current->rseq_len;
t->rseq_sig = current->rseq_sig;
t->rseq_event_mask = current->rseq_event_mask;
rseq_preempt(t);
}
}
static inline void rseq_execve(struct task_struct *t)
{
t->rseq = NULL;
t->rseq_len = 0;
t->rseq_sig = 0;
t->rseq_event_mask = 0;
}
#else
static inline void rseq_set_notify_resume(struct task_struct *t)
{
}
static inline void rseq_handle_notify_resume(struct pt_regs *regs)
{
}
static inline void rseq_signal_deliver(struct pt_regs *regs)
{
}
static inline void rseq_preempt(struct task_struct *t)
{
}
static inline void rseq_migrate(struct task_struct *t)
{
}
static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
{
}
static inline void rseq_execve(struct task_struct *t)
{
}
#endif
#ifdef CONFIG_DEBUG_RSEQ
void rseq_syscall(struct pt_regs *regs);
#else
static inline void rseq_syscall(struct pt_regs *regs)
{
}
#endif
#endif

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@ -66,6 +66,7 @@ struct old_linux_dirent;
struct perf_event_attr;
struct file_handle;
struct sigaltstack;
struct rseq;
union bpf_attr;
#include <linux/types.h>
@ -897,7 +898,8 @@ asmlinkage long sys_pkey_alloc(unsigned long flags, unsigned long init_val);
asmlinkage long sys_pkey_free(int pkey);
asmlinkage long sys_statx(int dfd, const char __user *path, unsigned flags,
unsigned mask, struct statx __user *buffer);
asmlinkage long sys_rseq(struct rseq __user *rseq, uint32_t rseq_len,
int flags, uint32_t sig);
/*
* Architecture-specific system calls

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@ -0,0 +1,57 @@
/* SPDX-License-Identifier: GPL-2.0+ */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM rseq
#if !defined(_TRACE_RSEQ_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_RSEQ_H
#include <linux/tracepoint.h>
#include <linux/types.h>
TRACE_EVENT(rseq_update,
TP_PROTO(struct task_struct *t),
TP_ARGS(t),
TP_STRUCT__entry(
__field(s32, cpu_id)
),
TP_fast_assign(
__entry->cpu_id = raw_smp_processor_id();
),
TP_printk("cpu_id=%d", __entry->cpu_id)
);
TRACE_EVENT(rseq_ip_fixup,
TP_PROTO(unsigned long regs_ip, unsigned long start_ip,
unsigned long post_commit_offset, unsigned long abort_ip),
TP_ARGS(regs_ip, start_ip, post_commit_offset, abort_ip),
TP_STRUCT__entry(
__field(unsigned long, regs_ip)
__field(unsigned long, start_ip)
__field(unsigned long, post_commit_offset)
__field(unsigned long, abort_ip)
),
TP_fast_assign(
__entry->regs_ip = regs_ip;
__entry->start_ip = start_ip;
__entry->post_commit_offset = post_commit_offset;
__entry->abort_ip = abort_ip;
),
TP_printk("regs_ip=0x%lx start_ip=0x%lx post_commit_offset=%lu abort_ip=0x%lx",
__entry->regs_ip, __entry->start_ip,
__entry->post_commit_offset, __entry->abort_ip)
);
#endif /* _TRACE_SOCK_H */
/* This part must be outside protection */
#include <trace/define_trace.h>

133
include/uapi/linux/rseq.h Normal file
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@ -0,0 +1,133 @@
/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
#ifndef _UAPI_LINUX_RSEQ_H
#define _UAPI_LINUX_RSEQ_H
/*
* linux/rseq.h
*
* Restartable sequences system call API
*
* Copyright (c) 2015-2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
#ifdef __KERNEL__
# include <linux/types.h>
#else
# include <stdint.h>
#endif
#include <linux/types_32_64.h>
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 4 * 8 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. */
__u32 version;
/* enum rseq_cs_flags */
__u32 flags;
LINUX_FIELD_u32_u64(start_ip);
/* Offset from start_ip. */
LINUX_FIELD_u32_u64(post_commit_offset);
LINUX_FIELD_u32_u64(abort_ip);
} __attribute__((aligned(4 * sizeof(__u64))));
/*
* struct rseq is aligned on 4 * 8 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, and read by user-space with single-copy atomicity
* semantics. 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.
*/
__u32 cpu_id_start;
/*
* Restartable sequences cpu_id field. Updated by the kernel,
* and read by user-space with single-copy atomicity semantics.
* 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.
*/
__u32 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 with single-copy atomicity semantics.
* Set by user-space with single-copy atomicity semantics. Aligned
* on 64-bit.
*/
LINUX_FIELD_u32_u64(rseq_cs);
/*
* - RSEQ_DISABLE flag:
*
* Fallback fast-track flag for single-stepping.
* Set by user-space if lack of progress is detected.
* Cleared by user-space after rseq finish.
* Read by the kernel.
* - RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT
* Inhibit instruction sequence block restart and event
* counter increment on preemption for this thread.
* - RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL
* Inhibit instruction sequence block restart and event
* counter increment on signal delivery for this thread.
* - RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE
* Inhibit instruction sequence block restart and event
* counter increment on migration for this thread.
*/
__u32 flags;
} __attribute__((aligned(4 * sizeof(__u64))));
#endif /* _UAPI_LINUX_RSEQ_H */

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@ -0,0 +1,50 @@
/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
#ifndef _UAPI_LINUX_TYPES_32_64_H
#define _UAPI_LINUX_TYPES_32_64_H
/*
* linux/types_32_64.h
*
* Integer type declaration for pointers across 32-bit and 64-bit systems.
*
* Copyright (c) 2015-2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
#ifdef __KERNEL__
# include <linux/types.h>
#else
# include <stdint.h>
#endif
#include <asm/byteorder.h>
#ifdef __BYTE_ORDER
# if (__BYTE_ORDER == __BIG_ENDIAN)
# define LINUX_BYTE_ORDER_BIG_ENDIAN
# else
# define LINUX_BYTE_ORDER_LITTLE_ENDIAN
# endif
#else
# ifdef __BIG_ENDIAN
# define LINUX_BYTE_ORDER_BIG_ENDIAN
# else
# define LINUX_BYTE_ORDER_LITTLE_ENDIAN
# endif
#endif
#ifdef __LP64__
# define LINUX_FIELD_u32_u64(field) __u64 field
# define LINUX_FIELD_u32_u64_INIT_ONSTACK(field, v) field = (intptr_t)v
#else
# ifdef LINUX_BYTE_ORDER_BIG_ENDIAN
# define LINUX_FIELD_u32_u64(field) __u32 field ## _padding, field
# define LINUX_FIELD_u32_u64_INIT_ONSTACK(field, v) \
field ## _padding = 0, field = (intptr_t)v
# else
# define LINUX_FIELD_u32_u64(field) __u32 field, field ## _padding
# define LINUX_FIELD_u32_u64_INIT_ONSTACK(field, v) \
field = (intptr_t)v, field ## _padding = 0
# endif
#endif
#endif /* _UAPI_LINUX_TYPES_32_64_H */

View File

@ -1428,6 +1428,29 @@ config ARCH_HAS_MEMBARRIER_CALLBACKS
config ARCH_HAS_MEMBARRIER_SYNC_CORE
bool
config RSEQ
bool "Enable rseq() system call" if EXPERT
default y
depends on HAVE_RSEQ
select MEMBARRIER
help
Enable the restartable sequences system call. It provides a
user-space cache for the current CPU number value, which
speeds up getting the current CPU number from user-space,
as well as an ABI to speed up user-space operations on
per-CPU data.
If unsure, say Y.
config DEBUG_RSEQ
default n
bool "Enabled debugging of rseq() system call" if EXPERT
depends on RSEQ && DEBUG_KERNEL
help
Enable extra debugging checks for the rseq system call.
If unsure, say N.
config EMBEDDED
bool "Embedded system"
option allnoconfig_y

View File

@ -114,6 +114,7 @@ obj-$(CONFIG_TORTURE_TEST) += torture.o
obj-$(CONFIG_HAS_IOMEM) += iomem.o
obj-$(CONFIG_ZONE_DEVICE) += memremap.o
obj-$(CONFIG_RSEQ) += rseq.o
$(obj)/configs.o: $(obj)/config_data.h

View File

@ -1900,6 +1900,8 @@ static __latent_entropy struct task_struct *copy_process(
*/
copy_seccomp(p);
rseq_fork(p, clone_flags);
/*
* Process group and session signals need to be delivered to just the
* parent before the fork or both the parent and the child after the

357
kernel/rseq.c Normal file
View File

@ -0,0 +1,357 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Restartable sequences system call
*
* Copyright (C) 2015, Google, Inc.,
* Paul Turner <pjt@google.com> and Andrew Hunter <ahh@google.com>
* Copyright (C) 2015-2018, EfficiOS Inc.,
* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/syscalls.h>
#include <linux/rseq.h>
#include <linux/types.h>
#include <asm/ptrace.h>
#define CREATE_TRACE_POINTS
#include <trace/events/rseq.h>
#define RSEQ_CS_PREEMPT_MIGRATE_FLAGS (RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE | \
RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT)
/*
*
* Restartable sequences are a lightweight interface that allows
* user-level code to be executed atomically relative to scheduler
* preemption and signal delivery. Typically used for implementing
* per-cpu operations.
*
* It allows user-space to perform update operations on per-cpu data
* without requiring heavy-weight atomic operations.
*
* Detailed algorithm of rseq user-space assembly sequences:
*
* init(rseq_cs)
* cpu = TLS->rseq::cpu_id_start
* [1] TLS->rseq::rseq_cs = rseq_cs
* [start_ip] ----------------------------
* [2] if (cpu != TLS->rseq::cpu_id)
* goto abort_ip;
* [3] <last_instruction_in_cs>
* [post_commit_ip] ----------------------------
*
* The address of jump target abort_ip must be outside the critical
* region, i.e.:
*
* [abort_ip] < [start_ip] || [abort_ip] >= [post_commit_ip]
*
* Steps [2]-[3] (inclusive) need to be a sequence of instructions in
* userspace that can handle being interrupted between any of those
* instructions, and then resumed to the abort_ip.
*
* 1. Userspace stores the address of the struct rseq_cs assembly
* block descriptor into the rseq_cs field of the registered
* struct rseq TLS area. This update is performed through a single
* store within the inline assembly instruction sequence.
* [start_ip]
*
* 2. Userspace tests to check whether the current cpu_id field match
* the cpu number loaded before start_ip, branching to abort_ip
* in case of a mismatch.
*
* If the sequence is preempted or interrupted by a signal
* at or after start_ip and before post_commit_ip, then the kernel
* clears TLS->__rseq_abi::rseq_cs, and sets the user-space return
* ip to abort_ip before returning to user-space, so the preempted
* execution resumes at abort_ip.
*
* 3. Userspace critical section final instruction before
* post_commit_ip is the commit. The critical section is
* self-terminating.
* [post_commit_ip]
*
* 4. <success>
*
* On failure at [2], or if interrupted by preempt or signal delivery
* between [1] and [3]:
*
* [abort_ip]
* F1. <failure>
*/
static int rseq_update_cpu_id(struct task_struct *t)
{
u32 cpu_id = raw_smp_processor_id();
if (__put_user(cpu_id, &t->rseq->cpu_id_start))
return -EFAULT;
if (__put_user(cpu_id, &t->rseq->cpu_id))
return -EFAULT;
trace_rseq_update(t);
return 0;
}
static int rseq_reset_rseq_cpu_id(struct task_struct *t)
{
u32 cpu_id_start = 0, cpu_id = RSEQ_CPU_ID_UNINITIALIZED;
/*
* Reset cpu_id_start to its initial state (0).
*/
if (__put_user(cpu_id_start, &t->rseq->cpu_id_start))
return -EFAULT;
/*
* Reset cpu_id to RSEQ_CPU_ID_UNINITIALIZED, so any user coming
* in after unregistration can figure out that rseq needs to be
* registered again.
*/
if (__put_user(cpu_id, &t->rseq->cpu_id))
return -EFAULT;
return 0;
}
static int rseq_get_rseq_cs(struct task_struct *t, struct rseq_cs *rseq_cs)
{
struct rseq_cs __user *urseq_cs;
unsigned long ptr;
u32 __user *usig;
u32 sig;
int ret;
ret = __get_user(ptr, &t->rseq->rseq_cs);
if (ret)
return ret;
if (!ptr) {
memset(rseq_cs, 0, sizeof(*rseq_cs));
return 0;
}
urseq_cs = (struct rseq_cs __user *)ptr;
if (copy_from_user(rseq_cs, urseq_cs, sizeof(*rseq_cs)))
return -EFAULT;
if (rseq_cs->version > 0)
return -EINVAL;
/* Ensure that abort_ip is not in the critical section. */
if (rseq_cs->abort_ip - rseq_cs->start_ip < rseq_cs->post_commit_offset)
return -EINVAL;
usig = (u32 __user *)(rseq_cs->abort_ip - sizeof(u32));
ret = get_user(sig, usig);
if (ret)
return ret;
if (current->rseq_sig != sig) {
printk_ratelimited(KERN_WARNING
"Possible attack attempt. Unexpected rseq signature 0x%x, expecting 0x%x (pid=%d, addr=%p).\n",
sig, current->rseq_sig, current->pid, usig);
return -EPERM;
}
return 0;
}
static int rseq_need_restart(struct task_struct *t, u32 cs_flags)
{
u32 flags, event_mask;
int ret;
/* Get thread flags. */
ret = __get_user(flags, &t->rseq->flags);
if (ret)
return ret;
/* Take critical section flags into account. */
flags |= cs_flags;
/*
* Restart on signal can only be inhibited when restart on
* preempt and restart on migrate are inhibited too. Otherwise,
* a preempted signal handler could fail to restart the prior
* execution context on sigreturn.
*/
if (unlikely((flags & RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL) &&
(flags & RSEQ_CS_PREEMPT_MIGRATE_FLAGS) !=
RSEQ_CS_PREEMPT_MIGRATE_FLAGS))
return -EINVAL;
/*
* Load and clear event mask atomically with respect to
* scheduler preemption.
*/
preempt_disable();
event_mask = t->rseq_event_mask;
t->rseq_event_mask = 0;
preempt_enable();
return !!(event_mask & ~flags);
}
static int clear_rseq_cs(struct task_struct *t)
{
/*
* The rseq_cs field is set to NULL on preemption or signal
* delivery on top of rseq assembly block, as well as on top
* of code outside of the rseq assembly block. This performs
* a lazy clear of the rseq_cs field.
*
* Set rseq_cs to NULL with single-copy atomicity.
*/
return __put_user(0UL, &t->rseq->rseq_cs);
}
/*
* Unsigned comparison will be true when ip >= start_ip, and when
* ip < start_ip + post_commit_offset.
*/
static bool in_rseq_cs(unsigned long ip, struct rseq_cs *rseq_cs)
{
return ip - rseq_cs->start_ip < rseq_cs->post_commit_offset;
}
static int rseq_ip_fixup(struct pt_regs *regs)
{
unsigned long ip = instruction_pointer(regs);
struct task_struct *t = current;
struct rseq_cs rseq_cs;
int ret;
ret = rseq_get_rseq_cs(t, &rseq_cs);
if (ret)
return ret;
/*
* Handle potentially not being within a critical section.
* If not nested over a rseq critical section, restart is useless.
* Clear the rseq_cs pointer and return.
*/
if (!in_rseq_cs(ip, &rseq_cs))
return clear_rseq_cs(t);
ret = rseq_need_restart(t, rseq_cs.flags);
if (ret <= 0)
return ret;
ret = clear_rseq_cs(t);
if (ret)
return ret;
trace_rseq_ip_fixup(ip, rseq_cs.start_ip, rseq_cs.post_commit_offset,
rseq_cs.abort_ip);
instruction_pointer_set(regs, (unsigned long)rseq_cs.abort_ip);
return 0;
}
/*
* This resume handler must always be executed between any of:
* - preemption,
* - signal delivery,
* and return to user-space.
*
* This is how we can ensure that the entire rseq critical section,
* consisting of both the C part and the assembly instruction sequence,
* will issue the commit instruction only if executed atomically with
* respect to other threads scheduled on the same CPU, and with respect
* to signal handlers.
*/
void __rseq_handle_notify_resume(struct pt_regs *regs)
{
struct task_struct *t = current;
int ret;
if (unlikely(t->flags & PF_EXITING))
return;
if (unlikely(!access_ok(VERIFY_WRITE, t->rseq, sizeof(*t->rseq))))
goto error;
ret = rseq_ip_fixup(regs);
if (unlikely(ret < 0))
goto error;
if (unlikely(rseq_update_cpu_id(t)))
goto error;
return;
error:
force_sig(SIGSEGV, t);
}
#ifdef CONFIG_DEBUG_RSEQ
/*
* Terminate the process if a syscall is issued within a restartable
* sequence.
*/
void rseq_syscall(struct pt_regs *regs)
{
unsigned long ip = instruction_pointer(regs);
struct task_struct *t = current;
struct rseq_cs rseq_cs;
if (!t->rseq)
return;
if (!access_ok(VERIFY_READ, t->rseq, sizeof(*t->rseq)) ||
rseq_get_rseq_cs(t, &rseq_cs) || in_rseq_cs(ip, &rseq_cs))
force_sig(SIGSEGV, t);
}
#endif
/*
* sys_rseq - setup restartable sequences for caller thread.
*/
SYSCALL_DEFINE4(rseq, struct rseq __user *, rseq, u32, rseq_len,
int, flags, u32, sig)
{
int ret;
if (flags & RSEQ_FLAG_UNREGISTER) {
/* Unregister rseq for current thread. */
if (current->rseq != rseq || !current->rseq)
return -EINVAL;
if (current->rseq_len != rseq_len)
return -EINVAL;
if (current->rseq_sig != sig)
return -EPERM;
ret = rseq_reset_rseq_cpu_id(current);
if (ret)
return ret;
current->rseq = NULL;
current->rseq_len = 0;
current->rseq_sig = 0;
return 0;
}
if (unlikely(flags))
return -EINVAL;
if (current->rseq) {
/*
* If rseq is already registered, check whether
* the provided address differs from the prior
* one.
*/
if (current->rseq != rseq || current->rseq_len != rseq_len)
return -EINVAL;
if (current->rseq_sig != sig)
return -EPERM;
/* Already registered. */
return -EBUSY;
}
/*
* If there was no rseq previously registered,
* ensure the provided rseq is properly aligned and valid.
*/
if (!IS_ALIGNED((unsigned long)rseq, __alignof__(*rseq)) ||
rseq_len != sizeof(*rseq))
return -EINVAL;
if (!access_ok(VERIFY_WRITE, rseq, rseq_len))
return -EFAULT;
current->rseq = rseq;
current->rseq_len = rseq_len;
current->rseq_sig = sig;
/*
* If rseq was previously inactive, and has just been
* registered, ensure the cpu_id_start and cpu_id fields
* are updated before returning to user-space.
*/
rseq_set_notify_resume(current);
return 0;
}

View File

@ -1191,6 +1191,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
if (p->sched_class->migrate_task_rq)
p->sched_class->migrate_task_rq(p);
p->se.nr_migrations++;
rseq_migrate(p);
perf_event_task_migrate(p);
}
@ -2634,6 +2635,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev,
{
sched_info_switch(rq, prev, next);
perf_event_task_sched_out(prev, next);
rseq_preempt(prev);
fire_sched_out_preempt_notifiers(prev, next);
prepare_task(next);
prepare_arch_switch(next);

View File

@ -432,3 +432,6 @@ COND_SYSCALL(setresgid16);
COND_SYSCALL(setresuid16);
COND_SYSCALL(setreuid16);
COND_SYSCALL(setuid16);
/* restartable sequence */
COND_SYSCALL(rseq);

View File

@ -29,6 +29,7 @@ TARGETS += powerpc
TARGETS += proc
TARGETS += pstore
TARGETS += ptrace
TARGETS += rseq
TARGETS += rtc
TARGETS += seccomp
TARGETS += sigaltstack

View File

@ -133,6 +133,9 @@ COMPILE.S = $(CC) $(ASFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c
LINK.S = $(CC) $(ASFLAGS) $(CPPFLAGS) $(LDFLAGS) $(TARGET_ARCH)
endif
# Selftest makefiles can override those targets by setting
# OVERRIDE_TARGETS = 1.
ifeq ($(OVERRIDE_TARGETS),)
$(OUTPUT)/%:%.c
$(LINK.c) $^ $(LDLIBS) -o $@
@ -141,5 +144,6 @@ $(OUTPUT)/%.o:%.S
$(OUTPUT)/%:%.S
$(LINK.S) $^ $(LDLIBS) -o $@
endif
.PHONY: run_tests all clean install emit_tests

View File

@ -0,0 +1,6 @@
basic_percpu_ops_test
basic_test
basic_rseq_op_test
param_test
param_test_benchmark
param_test_compare_twice

View File

@ -0,0 +1,30 @@
# SPDX-License-Identifier: GPL-2.0+ OR MIT
CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./
LDLIBS += -lpthread
# Own dependencies because we only want to build against 1st prerequisite, but
# still track changes to header files and depend on shared object.
OVERRIDE_TARGETS = 1
TEST_GEN_PROGS = basic_test basic_percpu_ops_test param_test \
param_test_benchmark param_test_compare_twice
TEST_GEN_PROGS_EXTENDED = librseq.so
TEST_PROGS = run_param_test.sh
include ../lib.mk
$(OUTPUT)/librseq.so: rseq.c rseq.h rseq-*.h
$(CC) $(CFLAGS) -shared -fPIC $< $(LDLIBS) -o $@
$(OUTPUT)/%: %.c $(TEST_GEN_PROGS_EXTENDED) rseq.h rseq-*.h
$(CC) $(CFLAGS) $< $(LDLIBS) -lrseq -o $@
$(OUTPUT)/param_test_benchmark: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
rseq.h rseq-*.h
$(CC) $(CFLAGS) -DBENCHMARK $< $(LDLIBS) -lrseq -o $@
$(OUTPUT)/param_test_compare_twice: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
rseq.h rseq-*.h
$(CC) $(CFLAGS) -DRSEQ_COMPARE_TWICE $< $(LDLIBS) -lrseq -o $@

View File

@ -0,0 +1,312 @@
// SPDX-License-Identifier: LGPL-2.1
#define _GNU_SOURCE
#include <assert.h>
#include <pthread.h>
#include <sched.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stddef.h>
#include "rseq.h"
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
struct percpu_lock_entry {
intptr_t v;
} __attribute__((aligned(128)));
struct percpu_lock {
struct percpu_lock_entry c[CPU_SETSIZE];
};
struct test_data_entry {
intptr_t count;
} __attribute__((aligned(128)));
struct spinlock_test_data {
struct percpu_lock lock;
struct test_data_entry c[CPU_SETSIZE];
int reps;
};
struct percpu_list_node {
intptr_t data;
struct percpu_list_node *next;
};
struct percpu_list_entry {
struct percpu_list_node *head;
} __attribute__((aligned(128)));
struct percpu_list {
struct percpu_list_entry c[CPU_SETSIZE];
};
/* A simple percpu spinlock. Returns the cpu lock was acquired on. */
int rseq_this_cpu_lock(struct percpu_lock *lock)
{
int cpu;
for (;;) {
int ret;
cpu = rseq_cpu_start();
ret = rseq_cmpeqv_storev(&lock->c[cpu].v,
0, 1, cpu);
if (rseq_likely(!ret))
break;
/* Retry if comparison fails or rseq aborts. */
}
/*
* Acquire semantic when taking lock after control dependency.
* Matches rseq_smp_store_release().
*/
rseq_smp_acquire__after_ctrl_dep();
return cpu;
}
void rseq_percpu_unlock(struct percpu_lock *lock, int cpu)
{
assert(lock->c[cpu].v == 1);
/*
* Release lock, with release semantic. Matches
* rseq_smp_acquire__after_ctrl_dep().
*/
rseq_smp_store_release(&lock->c[cpu].v, 0);
}
void *test_percpu_spinlock_thread(void *arg)
{
struct spinlock_test_data *data = arg;
int i, cpu;
if (rseq_register_current_thread()) {
fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
errno, strerror(errno));
abort();
}
for (i = 0; i < data->reps; i++) {
cpu = rseq_this_cpu_lock(&data->lock);
data->c[cpu].count++;
rseq_percpu_unlock(&data->lock, cpu);
}
if (rseq_unregister_current_thread()) {
fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
errno, strerror(errno));
abort();
}
return NULL;
}
/*
* A simple test which implements a sharded counter using a per-cpu
* lock. Obviously real applications might prefer to simply use a
* per-cpu increment; however, this is reasonable for a test and the
* lock can be extended to synchronize more complicated operations.
*/
void test_percpu_spinlock(void)
{
const int num_threads = 200;
int i;
uint64_t sum;
pthread_t test_threads[num_threads];
struct spinlock_test_data data;
memset(&data, 0, sizeof(data));
data.reps = 5000;
for (i = 0; i < num_threads; i++)
pthread_create(&test_threads[i], NULL,
test_percpu_spinlock_thread, &data);
for (i = 0; i < num_threads; i++)
pthread_join(test_threads[i], NULL);
sum = 0;
for (i = 0; i < CPU_SETSIZE; i++)
sum += data.c[i].count;
assert(sum == (uint64_t)data.reps * num_threads);
}
void this_cpu_list_push(struct percpu_list *list,
struct percpu_list_node *node,
int *_cpu)
{
int cpu;
for (;;) {
intptr_t *targetptr, newval, expect;
int ret;
cpu = rseq_cpu_start();
/* Load list->c[cpu].head with single-copy atomicity. */
expect = (intptr_t)RSEQ_READ_ONCE(list->c[cpu].head);
newval = (intptr_t)node;
targetptr = (intptr_t *)&list->c[cpu].head;
node->next = (struct percpu_list_node *)expect;
ret = rseq_cmpeqv_storev(targetptr, expect, newval, cpu);
if (rseq_likely(!ret))
break;
/* Retry if comparison fails or rseq aborts. */
}
if (_cpu)
*_cpu = cpu;
}
/*
* Unlike a traditional lock-less linked list; the availability of a
* rseq primitive allows us to implement pop without concerns over
* ABA-type races.
*/
struct percpu_list_node *this_cpu_list_pop(struct percpu_list *list,
int *_cpu)
{
for (;;) {
struct percpu_list_node *head;
intptr_t *targetptr, expectnot, *load;
off_t offset;
int ret, cpu;
cpu = rseq_cpu_start();
targetptr = (intptr_t *)&list->c[cpu].head;
expectnot = (intptr_t)NULL;
offset = offsetof(struct percpu_list_node, next);
load = (intptr_t *)&head;
ret = rseq_cmpnev_storeoffp_load(targetptr, expectnot,
offset, load, cpu);
if (rseq_likely(!ret)) {
if (_cpu)
*_cpu = cpu;
return head;
}
if (ret > 0)
return NULL;
/* Retry if rseq aborts. */
}
}
/*
* __percpu_list_pop is not safe against concurrent accesses. Should
* only be used on lists that are not concurrently modified.
*/
struct percpu_list_node *__percpu_list_pop(struct percpu_list *list, int cpu)
{
struct percpu_list_node *node;
node = list->c[cpu].head;
if (!node)
return NULL;
list->c[cpu].head = node->next;
return node;
}
void *test_percpu_list_thread(void *arg)
{
int i;
struct percpu_list *list = (struct percpu_list *)arg;
if (rseq_register_current_thread()) {
fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
errno, strerror(errno));
abort();
}
for (i = 0; i < 100000; i++) {
struct percpu_list_node *node;
node = this_cpu_list_pop(list, NULL);
sched_yield(); /* encourage shuffling */
if (node)
this_cpu_list_push(list, node, NULL);
}
if (rseq_unregister_current_thread()) {
fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
errno, strerror(errno));
abort();
}
return NULL;
}
/* Simultaneous modification to a per-cpu linked list from many threads. */
void test_percpu_list(void)
{
int i, j;
uint64_t sum = 0, expected_sum = 0;
struct percpu_list list;
pthread_t test_threads[200];
cpu_set_t allowed_cpus;
memset(&list, 0, sizeof(list));
/* Generate list entries for every usable cpu. */
sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
for (i = 0; i < CPU_SETSIZE; i++) {
if (!CPU_ISSET(i, &allowed_cpus))
continue;
for (j = 1; j <= 100; j++) {
struct percpu_list_node *node;
expected_sum += j;
node = malloc(sizeof(*node));
assert(node);
node->data = j;
node->next = list.c[i].head;
list.c[i].head = node;
}
}
for (i = 0; i < 200; i++)
pthread_create(&test_threads[i], NULL,
test_percpu_list_thread, &list);
for (i = 0; i < 200; i++)
pthread_join(test_threads[i], NULL);
for (i = 0; i < CPU_SETSIZE; i++) {
struct percpu_list_node *node;
if (!CPU_ISSET(i, &allowed_cpus))
continue;
while ((node = __percpu_list_pop(&list, i))) {
sum += node->data;
free(node);
}
}
/*
* All entries should now be accounted for (unless some external
* actor is interfering with our allowed affinity while this
* test is running).
*/
assert(sum == expected_sum);
}
int main(int argc, char **argv)
{
if (rseq_register_current_thread()) {
fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
errno, strerror(errno));
goto error;
}
printf("spinlock\n");
test_percpu_spinlock();
printf("percpu_list\n");
test_percpu_list();
if (rseq_unregister_current_thread()) {
fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
errno, strerror(errno));
goto error;
}
return 0;
error:
return -1;
}

View File

@ -0,0 +1,56 @@
// SPDX-License-Identifier: LGPL-2.1
/*
* Basic test coverage for critical regions and rseq_current_cpu().
*/
#define _GNU_SOURCE
#include <assert.h>
#include <sched.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <sys/time.h>
#include "rseq.h"
void test_cpu_pointer(void)
{
cpu_set_t affinity, test_affinity;
int i;
sched_getaffinity(0, sizeof(affinity), &affinity);
CPU_ZERO(&test_affinity);
for (i = 0; i < CPU_SETSIZE; i++) {
if (CPU_ISSET(i, &affinity)) {
CPU_SET(i, &test_affinity);
sched_setaffinity(0, sizeof(test_affinity),
&test_affinity);
assert(sched_getcpu() == i);
assert(rseq_current_cpu() == i);
assert(rseq_current_cpu_raw() == i);
assert(rseq_cpu_start() == i);
CPU_CLR(i, &test_affinity);
}
}
sched_setaffinity(0, sizeof(affinity), &affinity);
}
int main(int argc, char **argv)
{
if (rseq_register_current_thread()) {
fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
errno, strerror(errno));
goto init_thread_error;
}
printf("testing current cpu\n");
test_cpu_pointer();
if (rseq_unregister_current_thread()) {
fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
errno, strerror(errno));
goto init_thread_error;
}
return 0;
init_thread_error:
return -1;
}

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@ -0,0 +1,715 @@
/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* rseq-arm.h
*
* (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
#define RSEQ_SIG 0x53053053
#define rseq_smp_mb() __asm__ __volatile__ ("dmb" ::: "memory", "cc")
#define rseq_smp_rmb() __asm__ __volatile__ ("dmb" ::: "memory", "cc")
#define rseq_smp_wmb() __asm__ __volatile__ ("dmb" ::: "memory", "cc")
#define rseq_smp_load_acquire(p) \
__extension__ ({ \
__typeof(*p) ____p1 = RSEQ_READ_ONCE(*p); \
rseq_smp_mb(); \
____p1; \
})
#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb()
#define rseq_smp_store_release(p, v) \
do { \
rseq_smp_mb(); \
RSEQ_WRITE_ONCE(*p, v); \
} while (0)
#ifdef RSEQ_SKIP_FASTPATH
#include "rseq-skip.h"
#else /* !RSEQ_SKIP_FASTPATH */
#define __RSEQ_ASM_DEFINE_TABLE(version, flags, start_ip, \
post_commit_offset, abort_ip) \
".pushsection __rseq_table, \"aw\"\n\t" \
".balign 32\n\t" \
".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \
".popsection\n\t"
#define RSEQ_ASM_DEFINE_TABLE(start_ip, post_commit_ip, abort_ip) \
__RSEQ_ASM_DEFINE_TABLE(0x0, 0x0, start_ip, \
(post_commit_ip - start_ip), abort_ip)
#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
RSEQ_INJECT_ASM(1) \
"adr r0, " __rseq_str(cs_label) "\n\t" \
"str r0, %[" __rseq_str(rseq_cs) "]\n\t" \
__rseq_str(label) ":\n\t"
#define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \
RSEQ_INJECT_ASM(2) \
"ldr r0, %[" __rseq_str(current_cpu_id) "]\n\t" \
"cmp %[" __rseq_str(cpu_id) "], r0\n\t" \
"bne " __rseq_str(label) "\n\t"
#define __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \
abort_label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
__rseq_str(table_label) ":\n\t" \
".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \
".word " __rseq_str(RSEQ_SIG) "\n\t" \
__rseq_str(label) ":\n\t" \
teardown \
"b %l[" __rseq_str(abort_label) "]\n\t"
#define RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, abort_label, \
start_ip, post_commit_ip, abort_ip) \
__RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \
abort_label, 0x0, 0x0, start_ip, \
(post_commit_ip - start_ip), abort_ip)
#define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \
__rseq_str(label) ":\n\t" \
teardown \
"b %l[" __rseq_str(cmpfail_label) "]\n\t"
#define rseq_workaround_gcc_asm_size_guess() __asm__ __volatile__("")
static inline __attribute__((always_inline))
int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne %l[cmpfail]\n\t"
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne %l[error2]\n\t"
#endif
/* final store */
"str %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(5)
"b 5f\n\t"
RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
"5:\n\t"
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "r0", "memory", "cc"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
rseq_workaround_gcc_asm_size_guess();
return 0;
abort:
rseq_workaround_gcc_asm_size_guess();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_workaround_gcc_asm_size_guess();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
off_t voffp, intptr_t *load, int cpu)
{
RSEQ_INJECT_C(9)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
"ldr r0, %[v]\n\t"
"cmp %[expectnot], r0\n\t"
"beq %l[cmpfail]\n\t"
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
"ldr r0, %[v]\n\t"
"cmp %[expectnot], r0\n\t"
"beq %l[error2]\n\t"
#endif
"str r0, %[load]\n\t"
"add r0, %[voffp]\n\t"
"ldr r0, [r0]\n\t"
/* final store */
"str r0, %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(5)
"b 5f\n\t"
RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
"5:\n\t"
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* final store input */
[v] "m" (*v),
[expectnot] "r" (expectnot),
[voffp] "Ir" (voffp),
[load] "m" (*load)
RSEQ_INJECT_INPUT
: "r0", "memory", "cc"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
rseq_workaround_gcc_asm_size_guess();
return 0;
abort:
rseq_workaround_gcc_asm_size_guess();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_workaround_gcc_asm_size_guess();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_addv(intptr_t *v, intptr_t count, int cpu)
{
RSEQ_INJECT_C(9)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
#endif
"ldr r0, %[v]\n\t"
"add r0, %[count]\n\t"
/* final store */
"str r0, %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(4)
"b 5f\n\t"
RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
"5:\n\t"
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
[v] "m" (*v),
[count] "Ir" (count)
RSEQ_INJECT_INPUT
: "r0", "memory", "cc"
RSEQ_INJECT_CLOBBER
: abort
#ifdef RSEQ_COMPARE_TWICE
, error1
#endif
);
rseq_workaround_gcc_asm_size_guess();
return 0;
abort:
rseq_workaround_gcc_asm_size_guess();
RSEQ_INJECT_FAILED
return -1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t newv2,
intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne %l[cmpfail]\n\t"
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne %l[error2]\n\t"
#endif
/* try store */
"str %[newv2], %[v2]\n\t"
RSEQ_INJECT_ASM(5)
/* final store */
"str %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(6)
"b 5f\n\t"
RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
"5:\n\t"
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* try store input */
[v2] "m" (*v2),
[newv2] "r" (newv2),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "r0", "memory", "cc"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
rseq_workaround_gcc_asm_size_guess();
return 0;
abort:
rseq_workaround_gcc_asm_size_guess();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_workaround_gcc_asm_size_guess();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t newv2,
intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne %l[cmpfail]\n\t"
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne %l[error2]\n\t"
#endif
/* try store */
"str %[newv2], %[v2]\n\t"
RSEQ_INJECT_ASM(5)
"dmb\n\t" /* full mb provides store-release */
/* final store */
"str %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(6)
"b 5f\n\t"
RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
"5:\n\t"
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* try store input */
[v2] "m" (*v2),
[newv2] "r" (newv2),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "r0", "memory", "cc"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
rseq_workaround_gcc_asm_size_guess();
return 0;
abort:
rseq_workaround_gcc_asm_size_guess();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_workaround_gcc_asm_size_guess();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t expect2,
intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne %l[cmpfail]\n\t"
RSEQ_INJECT_ASM(4)
"ldr r0, %[v2]\n\t"
"cmp %[expect2], r0\n\t"
"bne %l[cmpfail]\n\t"
RSEQ_INJECT_ASM(5)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne %l[error2]\n\t"
"ldr r0, %[v2]\n\t"
"cmp %[expect2], r0\n\t"
"bne %l[error3]\n\t"
#endif
/* final store */
"str %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(6)
"b 5f\n\t"
RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
"5:\n\t"
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* cmp2 input */
[v2] "m" (*v2),
[expect2] "r" (expect2),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "r0", "memory", "cc"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2, error3
#endif
);
rseq_workaround_gcc_asm_size_guess();
return 0;
abort:
rseq_workaround_gcc_asm_size_guess();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_workaround_gcc_asm_size_guess();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("1st expected value comparison failed");
error3:
rseq_bug("2nd expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
void *dst, void *src, size_t len,
intptr_t newv, int cpu)
{
uint32_t rseq_scratch[3];
RSEQ_INJECT_C(9)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
"str %[src], %[rseq_scratch0]\n\t"
"str %[dst], %[rseq_scratch1]\n\t"
"str %[len], %[rseq_scratch2]\n\t"
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne 5f\n\t"
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f)
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne 7f\n\t"
#endif
/* try memcpy */
"cmp %[len], #0\n\t" \
"beq 333f\n\t" \
"222:\n\t" \
"ldrb %%r0, [%[src]]\n\t" \
"strb %%r0, [%[dst]]\n\t" \
"adds %[src], #1\n\t" \
"adds %[dst], #1\n\t" \
"subs %[len], #1\n\t" \
"bne 222b\n\t" \
"333:\n\t" \
RSEQ_INJECT_ASM(5)
/* final store */
"str %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(6)
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t"
"b 8f\n\t"
RSEQ_ASM_DEFINE_ABORT(3, 4,
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t",
abort, 1b, 2b, 4f)
RSEQ_ASM_DEFINE_CMPFAIL(5,
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t",
cmpfail)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_CMPFAIL(6,
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t",
error1)
RSEQ_ASM_DEFINE_CMPFAIL(7,
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t",
error2)
#endif
"8:\n\t"
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv),
/* try memcpy input */
[dst] "r" (dst),
[src] "r" (src),
[len] "r" (len),
[rseq_scratch0] "m" (rseq_scratch[0]),
[rseq_scratch1] "m" (rseq_scratch[1]),
[rseq_scratch2] "m" (rseq_scratch[2])
RSEQ_INJECT_INPUT
: "r0", "memory", "cc"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
rseq_workaround_gcc_asm_size_guess();
return 0;
abort:
rseq_workaround_gcc_asm_size_guess();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_workaround_gcc_asm_size_guess();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_workaround_gcc_asm_size_guess();
rseq_bug("cpu_id comparison failed");
error2:
rseq_workaround_gcc_asm_size_guess();
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
void *dst, void *src, size_t len,
intptr_t newv, int cpu)
{
uint32_t rseq_scratch[3];
RSEQ_INJECT_C(9)
rseq_workaround_gcc_asm_size_guess();
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */
"str %[src], %[rseq_scratch0]\n\t"
"str %[dst], %[rseq_scratch1]\n\t"
"str %[len], %[rseq_scratch2]\n\t"
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne 5f\n\t"
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f)
"ldr r0, %[v]\n\t"
"cmp %[expect], r0\n\t"
"bne 7f\n\t"
#endif
/* try memcpy */
"cmp %[len], #0\n\t" \
"beq 333f\n\t" \
"222:\n\t" \
"ldrb %%r0, [%[src]]\n\t" \
"strb %%r0, [%[dst]]\n\t" \
"adds %[src], #1\n\t" \
"adds %[dst], #1\n\t" \
"subs %[len], #1\n\t" \
"bne 222b\n\t" \
"333:\n\t" \
RSEQ_INJECT_ASM(5)
"dmb\n\t" /* full mb provides store-release */
/* final store */
"str %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(6)
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t"
"b 8f\n\t"
RSEQ_ASM_DEFINE_ABORT(3, 4,
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t",
abort, 1b, 2b, 4f)
RSEQ_ASM_DEFINE_CMPFAIL(5,
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t",
cmpfail)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_CMPFAIL(6,
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t",
error1)
RSEQ_ASM_DEFINE_CMPFAIL(7,
/* teardown */
"ldr %[len], %[rseq_scratch2]\n\t"
"ldr %[dst], %[rseq_scratch1]\n\t"
"ldr %[src], %[rseq_scratch0]\n\t",
error2)
#endif
"8:\n\t"
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv),
/* try memcpy input */
[dst] "r" (dst),
[src] "r" (src),
[len] "r" (len),
[rseq_scratch0] "m" (rseq_scratch[0]),
[rseq_scratch1] "m" (rseq_scratch[1]),
[rseq_scratch2] "m" (rseq_scratch[2])
RSEQ_INJECT_INPUT
: "r0", "memory", "cc"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
rseq_workaround_gcc_asm_size_guess();
return 0;
abort:
rseq_workaround_gcc_asm_size_guess();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_workaround_gcc_asm_size_guess();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_workaround_gcc_asm_size_guess();
rseq_bug("cpu_id comparison failed");
error2:
rseq_workaround_gcc_asm_size_guess();
rseq_bug("expected value comparison failed");
#endif
}
#endif /* !RSEQ_SKIP_FASTPATH */

View File

@ -0,0 +1,671 @@
/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* rseq-ppc.h
*
* (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
* (C) Copyright 2016-2018 - Boqun Feng <boqun.feng@gmail.com>
*/
#define RSEQ_SIG 0x53053053
#define rseq_smp_mb() __asm__ __volatile__ ("sync" ::: "memory", "cc")
#define rseq_smp_lwsync() __asm__ __volatile__ ("lwsync" ::: "memory", "cc")
#define rseq_smp_rmb() rseq_smp_lwsync()
#define rseq_smp_wmb() rseq_smp_lwsync()
#define rseq_smp_load_acquire(p) \
__extension__ ({ \
__typeof(*p) ____p1 = RSEQ_READ_ONCE(*p); \
rseq_smp_lwsync(); \
____p1; \
})
#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_lwsync()
#define rseq_smp_store_release(p, v) \
do { \
rseq_smp_lwsync(); \
RSEQ_WRITE_ONCE(*p, v); \
} while (0)
#ifdef RSEQ_SKIP_FASTPATH
#include "rseq-skip.h"
#else /* !RSEQ_SKIP_FASTPATH */
/*
* The __rseq_table section can be used by debuggers to better handle
* single-stepping through the restartable critical sections.
*/
#ifdef __PPC64__
#define STORE_WORD "std "
#define LOAD_WORD "ld "
#define LOADX_WORD "ldx "
#define CMP_WORD "cmpd "
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
".pushsection __rseq_table, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
".popsection\n\t"
#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
RSEQ_INJECT_ASM(1) \
"lis %%r17, (" __rseq_str(cs_label) ")@highest\n\t" \
"ori %%r17, %%r17, (" __rseq_str(cs_label) ")@higher\n\t" \
"rldicr %%r17, %%r17, 32, 31\n\t" \
"oris %%r17, %%r17, (" __rseq_str(cs_label) ")@high\n\t" \
"ori %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t" \
"std %%r17, %[" __rseq_str(rseq_cs) "]\n\t" \
__rseq_str(label) ":\n\t"
#else /* #ifdef __PPC64__ */
#define STORE_WORD "stw "
#define LOAD_WORD "lwz "
#define LOADX_WORD "lwzx "
#define CMP_WORD "cmpw "
#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
start_ip, post_commit_offset, abort_ip) \
".pushsection __rseq_table, \"aw\"\n\t" \
".balign 32\n\t" \
__rseq_str(label) ":\n\t" \
".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
/* 32-bit only supported on BE */ \
".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \
".popsection\n\t"
#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
RSEQ_INJECT_ASM(1) \
"lis %%r17, (" __rseq_str(cs_label) ")@ha\n\t" \
"addi %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t" \
"stw %%r17, %[" __rseq_str(rseq_cs) "]\n\t" \
__rseq_str(label) ":\n\t"
#endif /* #ifdef __PPC64__ */
#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
__RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
(post_commit_ip - start_ip), abort_ip)
#define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \
RSEQ_INJECT_ASM(2) \
"lwz %%r17, %[" __rseq_str(current_cpu_id) "]\n\t" \
"cmpw cr7, %[" __rseq_str(cpu_id) "], %%r17\n\t" \
"bne- cr7, " __rseq_str(label) "\n\t"
#define RSEQ_ASM_DEFINE_ABORT(label, abort_label) \
".pushsection __rseq_failure, \"ax\"\n\t" \
".long " __rseq_str(RSEQ_SIG) "\n\t" \
__rseq_str(label) ":\n\t" \
"b %l[" __rseq_str(abort_label) "]\n\t" \
".popsection\n\t"
/*
* RSEQ_ASM_OPs: asm operations for rseq
* RSEQ_ASM_OP_R_*: has hard-code registers in it
* RSEQ_ASM_OP_* (else): doesn't have hard-code registers(unless cr7)
*/
#define RSEQ_ASM_OP_CMPEQ(var, expect, label) \
LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t" \
CMP_WORD "cr7, %%r17, %[" __rseq_str(expect) "]\n\t" \
"bne- cr7, " __rseq_str(label) "\n\t"
#define RSEQ_ASM_OP_CMPNE(var, expectnot, label) \
LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t" \
CMP_WORD "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t" \
"beq- cr7, " __rseq_str(label) "\n\t"
#define RSEQ_ASM_OP_STORE(value, var) \
STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"
/* Load @var to r17 */
#define RSEQ_ASM_OP_R_LOAD(var) \
LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
/* Store r17 to @var */
#define RSEQ_ASM_OP_R_STORE(var) \
STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
/* Add @count to r17 */
#define RSEQ_ASM_OP_R_ADD(count) \
"add %%r17, %[" __rseq_str(count) "], %%r17\n\t"
/* Load (r17 + voffp) to r17 */
#define RSEQ_ASM_OP_R_LOADX(voffp) \
LOADX_WORD "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"
/* TODO: implement a faster memcpy. */
#define RSEQ_ASM_OP_R_MEMCPY() \
"cmpdi %%r19, 0\n\t" \
"beq 333f\n\t" \
"addi %%r20, %%r20, -1\n\t" \
"addi %%r21, %%r21, -1\n\t" \
"222:\n\t" \
"lbzu %%r18, 1(%%r20)\n\t" \
"stbu %%r18, 1(%%r21)\n\t" \
"addi %%r19, %%r19, -1\n\t" \
"cmpdi %%r19, 0\n\t" \
"bne 222b\n\t" \
"333:\n\t" \
#define RSEQ_ASM_OP_R_FINAL_STORE(var, post_commit_label) \
STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t" \
__rseq_str(post_commit_label) ":\n\t"
#define RSEQ_ASM_OP_FINAL_STORE(value, var, post_commit_label) \
STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
__rseq_str(post_commit_label) ":\n\t"
static inline __attribute__((always_inline))
int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail])
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2])
#endif
/* final store */
RSEQ_ASM_OP_FINAL_STORE(newv, v, 2)
RSEQ_INJECT_ASM(5)
RSEQ_ASM_DEFINE_ABORT(4, abort)
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "memory", "cc", "r17"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
off_t voffp, intptr_t *load, int cpu)
{
RSEQ_INJECT_C(9)
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
/* cmp @v not equal to @expectnot */
RSEQ_ASM_OP_CMPNE(v, expectnot, %l[cmpfail])
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
/* cmp @v not equal to @expectnot */
RSEQ_ASM_OP_CMPNE(v, expectnot, %l[error2])
#endif
/* load the value of @v */
RSEQ_ASM_OP_R_LOAD(v)
/* store it in @load */
RSEQ_ASM_OP_R_STORE(load)
/* dereference voffp(v) */
RSEQ_ASM_OP_R_LOADX(voffp)
/* final store the value at voffp(v) */
RSEQ_ASM_OP_R_FINAL_STORE(v, 2)
RSEQ_INJECT_ASM(5)
RSEQ_ASM_DEFINE_ABORT(4, abort)
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* final store input */
[v] "m" (*v),
[expectnot] "r" (expectnot),
[voffp] "b" (voffp),
[load] "m" (*load)
RSEQ_INJECT_INPUT
: "memory", "cc", "r17"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_addv(intptr_t *v, intptr_t count, int cpu)
{
RSEQ_INJECT_C(9)
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
#ifdef RSEQ_COMPARE_TWICE
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
#endif
/* load the value of @v */
RSEQ_ASM_OP_R_LOAD(v)
/* add @count to it */
RSEQ_ASM_OP_R_ADD(count)
/* final store */
RSEQ_ASM_OP_R_FINAL_STORE(v, 2)
RSEQ_INJECT_ASM(4)
RSEQ_ASM_DEFINE_ABORT(4, abort)
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* final store input */
[v] "m" (*v),
[count] "r" (count)
RSEQ_INJECT_INPUT
: "memory", "cc", "r17"
RSEQ_INJECT_CLOBBER
: abort
#ifdef RSEQ_COMPARE_TWICE
, error1
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t newv2,
intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail])
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2])
#endif
/* try store */
RSEQ_ASM_OP_STORE(newv2, v2)
RSEQ_INJECT_ASM(5)
/* final store */
RSEQ_ASM_OP_FINAL_STORE(newv, v, 2)
RSEQ_INJECT_ASM(6)
RSEQ_ASM_DEFINE_ABORT(4, abort)
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* try store input */
[v2] "m" (*v2),
[newv2] "r" (newv2),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "memory", "cc", "r17"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t newv2,
intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail])
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2])
#endif
/* try store */
RSEQ_ASM_OP_STORE(newv2, v2)
RSEQ_INJECT_ASM(5)
/* for 'release' */
"lwsync\n\t"
/* final store */
RSEQ_ASM_OP_FINAL_STORE(newv, v, 2)
RSEQ_INJECT_ASM(6)
RSEQ_ASM_DEFINE_ABORT(4, abort)
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* try store input */
[v2] "m" (*v2),
[newv2] "r" (newv2),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "memory", "cc", "r17"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t expect2,
intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail])
RSEQ_INJECT_ASM(4)
/* cmp @v2 equal to @expct2 */
RSEQ_ASM_OP_CMPEQ(v2, expect2, %l[cmpfail])
RSEQ_INJECT_ASM(5)
#ifdef RSEQ_COMPARE_TWICE
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2])
/* cmp @v2 equal to @expct2 */
RSEQ_ASM_OP_CMPEQ(v2, expect2, %l[error3])
#endif
/* final store */
RSEQ_ASM_OP_FINAL_STORE(newv, v, 2)
RSEQ_INJECT_ASM(6)
RSEQ_ASM_DEFINE_ABORT(4, abort)
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* cmp2 input */
[v2] "m" (*v2),
[expect2] "r" (expect2),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "memory", "cc", "r17"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2, error3
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("1st expected value comparison failed");
error3:
rseq_bug("2nd expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
void *dst, void *src, size_t len,
intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
/* setup for mempcy */
"mr %%r19, %[len]\n\t"
"mr %%r20, %[src]\n\t"
"mr %%r21, %[dst]\n\t"
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail])
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2])
#endif
/* try memcpy */
RSEQ_ASM_OP_R_MEMCPY()
RSEQ_INJECT_ASM(5)
/* final store */
RSEQ_ASM_OP_FINAL_STORE(newv, v, 2)
RSEQ_INJECT_ASM(6)
/* teardown */
RSEQ_ASM_DEFINE_ABORT(4, abort)
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv),
/* try memcpy input */
[dst] "r" (dst),
[src] "r" (src),
[len] "r" (len)
RSEQ_INJECT_INPUT
: "memory", "cc", "r17", "r18", "r19", "r20", "r21"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
void *dst, void *src, size_t len,
intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
/* setup for mempcy */
"mr %%r19, %[len]\n\t"
"mr %%r20, %[src]\n\t"
"mr %%r21, %[dst]\n\t"
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
RSEQ_INJECT_ASM(3)
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[cmpfail])
RSEQ_INJECT_ASM(4)
#ifdef RSEQ_COMPARE_TWICE
/* cmp cpuid */
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
/* cmp @v equal to @expect */
RSEQ_ASM_OP_CMPEQ(v, expect, %l[error2])
#endif
/* try memcpy */
RSEQ_ASM_OP_R_MEMCPY()
RSEQ_INJECT_ASM(5)
/* for 'release' */
"lwsync\n\t"
/* final store */
RSEQ_ASM_OP_FINAL_STORE(newv, v, 2)
RSEQ_INJECT_ASM(6)
/* teardown */
RSEQ_ASM_DEFINE_ABORT(4, abort)
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[current_cpu_id] "m" (__rseq_abi.cpu_id),
[rseq_cs] "m" (__rseq_abi.rseq_cs),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv),
/* try memcpy input */
[dst] "r" (dst),
[src] "r" (src),
[len] "r" (len)
RSEQ_INJECT_INPUT
: "memory", "cc", "r17", "r18", "r19", "r20", "r21"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
#undef STORE_WORD
#undef LOAD_WORD
#undef LOADX_WORD
#undef CMP_WORD
#endif /* !RSEQ_SKIP_FASTPATH */

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/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* rseq-skip.h
*
* (C) Copyright 2017-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
static inline __attribute__((always_inline))
int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
{
return -1;
}
static inline __attribute__((always_inline))
int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
off_t voffp, intptr_t *load, int cpu)
{
return -1;
}
static inline __attribute__((always_inline))
int rseq_addv(intptr_t *v, intptr_t count, int cpu)
{
return -1;
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t newv2,
intptr_t newv, int cpu)
{
return -1;
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t newv2,
intptr_t newv, int cpu)
{
return -1;
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t expect2,
intptr_t newv, int cpu)
{
return -1;
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
void *dst, void *src, size_t len,
intptr_t newv, int cpu)
{
return -1;
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
void *dst, void *src, size_t len,
intptr_t newv, int cpu)
{
return -1;
}

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// SPDX-License-Identifier: LGPL-2.1
/*
* rseq.c
*
* Copyright (C) 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This 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; only
* version 2.1 of the License.
*
* This 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.
*/
#define _GNU_SOURCE
#include <errno.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <syscall.h>
#include <assert.h>
#include <signal.h>
#include "rseq.h"
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
__attribute__((tls_model("initial-exec"))) __thread
volatile struct rseq __rseq_abi = {
.cpu_id = RSEQ_CPU_ID_UNINITIALIZED,
};
static __attribute__((tls_model("initial-exec"))) __thread
volatile int refcount;
static void signal_off_save(sigset_t *oldset)
{
sigset_t set;
int ret;
sigfillset(&set);
ret = pthread_sigmask(SIG_BLOCK, &set, oldset);
if (ret)
abort();
}
static void signal_restore(sigset_t oldset)
{
int ret;
ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
if (ret)
abort();
}
static int sys_rseq(volatile struct rseq *rseq_abi, uint32_t rseq_len,
int flags, uint32_t sig)
{
return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
}
int rseq_register_current_thread(void)
{
int rc, ret = 0;
sigset_t oldset;
signal_off_save(&oldset);
if (refcount++)
goto end;
rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), 0, RSEQ_SIG);
if (!rc) {
assert(rseq_current_cpu_raw() >= 0);
goto end;
}
if (errno != EBUSY)
__rseq_abi.cpu_id = -2;
ret = -1;
refcount--;
end:
signal_restore(oldset);
return ret;
}
int rseq_unregister_current_thread(void)
{
int rc, ret = 0;
sigset_t oldset;
signal_off_save(&oldset);
if (--refcount)
goto end;
rc = sys_rseq(&__rseq_abi, sizeof(struct rseq),
RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
if (!rc)
goto end;
ret = -1;
end:
signal_restore(oldset);
return ret;
}
int32_t rseq_fallback_current_cpu(void)
{
int32_t cpu;
cpu = sched_getcpu();
if (cpu < 0) {
perror("sched_getcpu()");
abort();
}
return cpu;
}

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/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* rseq.h
*
* (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
#ifndef RSEQ_H
#define RSEQ_H
#include <stdint.h>
#include <stdbool.h>
#include <pthread.h>
#include <signal.h>
#include <sched.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <sched.h>
#include <linux/rseq.h>
/*
* Empty code injection macros, override when testing.
* It is important to consider that the ASM injection macros need to be
* fully reentrant (e.g. do not modify the stack).
*/
#ifndef RSEQ_INJECT_ASM
#define RSEQ_INJECT_ASM(n)
#endif
#ifndef RSEQ_INJECT_C
#define RSEQ_INJECT_C(n)
#endif
#ifndef RSEQ_INJECT_INPUT
#define RSEQ_INJECT_INPUT
#endif
#ifndef RSEQ_INJECT_CLOBBER
#define RSEQ_INJECT_CLOBBER
#endif
#ifndef RSEQ_INJECT_FAILED
#define RSEQ_INJECT_FAILED
#endif
extern __thread volatile struct rseq __rseq_abi;
#define rseq_likely(x) __builtin_expect(!!(x), 1)
#define rseq_unlikely(x) __builtin_expect(!!(x), 0)
#define rseq_barrier() __asm__ __volatile__("" : : : "memory")
#define RSEQ_ACCESS_ONCE(x) (*(__volatile__ __typeof__(x) *)&(x))
#define RSEQ_WRITE_ONCE(x, v) __extension__ ({ RSEQ_ACCESS_ONCE(x) = (v); })
#define RSEQ_READ_ONCE(x) RSEQ_ACCESS_ONCE(x)
#define __rseq_str_1(x) #x
#define __rseq_str(x) __rseq_str_1(x)
#define rseq_log(fmt, args...) \
fprintf(stderr, fmt "(in %s() at " __FILE__ ":" __rseq_str(__LINE__)"\n", \
## args, __func__)
#define rseq_bug(fmt, args...) \
do { \
rseq_log(fmt, ##args); \
abort(); \
} while (0)
#if defined(__x86_64__) || defined(__i386__)
#include <rseq-x86.h>
#elif defined(__ARMEL__)
#include <rseq-arm.h>
#elif defined(__PPC__)
#include <rseq-ppc.h>
#else
#error unsupported target
#endif
/*
* Register rseq for the current thread. This needs to be called once
* by any thread which uses restartable sequences, before they start
* using restartable sequences, to ensure restartable sequences
* succeed. A restartable sequence executed from a non-registered
* thread will always fail.
*/
int rseq_register_current_thread(void);
/*
* Unregister rseq for current thread.
*/
int rseq_unregister_current_thread(void);
/*
* Restartable sequence fallback for reading the current CPU number.
*/
int32_t rseq_fallback_current_cpu(void);
/*
* Values returned can be either the current CPU number, -1 (rseq is
* uninitialized), or -2 (rseq initialization has failed).
*/
static inline int32_t rseq_current_cpu_raw(void)
{
return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id);
}
/*
* Returns a possible CPU number, which is typically the current CPU.
* The returned CPU number can be used to prepare for an rseq critical
* section, which will confirm whether the cpu number is indeed the
* current one, and whether rseq is initialized.
*
* The CPU number returned by rseq_cpu_start should always be validated
* by passing it to a rseq asm sequence, or by comparing it to the
* return value of rseq_current_cpu_raw() if the rseq asm sequence
* does not need to be invoked.
*/
static inline uint32_t rseq_cpu_start(void)
{
return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id_start);
}
static inline uint32_t rseq_current_cpu(void)
{
int32_t cpu;
cpu = rseq_current_cpu_raw();
if (rseq_unlikely(cpu < 0))
cpu = rseq_fallback_current_cpu();
return cpu;
}
/*
* rseq_prepare_unload() should be invoked by each thread using rseq_finish*()
* at least once between their last rseq_finish*() and library unload of the
* library defining the rseq critical section (struct rseq_cs). This also
* applies to use of rseq in code generated by JIT: rseq_prepare_unload()
* should be invoked at least once by each thread using rseq_finish*() before
* reclaim of the memory holding the struct rseq_cs.
*/
static inline void rseq_prepare_unload(void)
{
__rseq_abi.rseq_cs = 0;
}
#endif /* RSEQ_H_ */

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@ -0,0 +1,121 @@
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0+ or MIT
EXTRA_ARGS=${@}
OLDIFS="$IFS"
IFS=$'\n'
TEST_LIST=(
"-T s"
"-T l"
"-T b"
"-T b -M"
"-T m"
"-T m -M"
"-T i"
)
TEST_NAME=(
"spinlock"
"list"
"buffer"
"buffer with barrier"
"memcpy"
"memcpy with barrier"
"increment"
)
IFS="$OLDIFS"
REPS=1000
SLOW_REPS=100
function do_tests()
{
local i=0
while [ "$i" -lt "${#TEST_LIST[@]}" ]; do
echo "Running test ${TEST_NAME[$i]}"
./param_test ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit 1
echo "Running compare-twice test ${TEST_NAME[$i]}"
./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit 1
let "i++"
done
}
echo "Default parameters"
do_tests
echo "Loop injection: 10000 loops"
OLDIFS="$IFS"
IFS=$'\n'
INJECT_LIST=(
"1"
"2"
"3"
"4"
"5"
"6"
"7"
"8"
"9"
)
IFS="$OLDIFS"
NR_LOOPS=10000
i=0
while [ "$i" -lt "${#INJECT_LIST[@]}" ]; do
echo "Injecting at <${INJECT_LIST[$i]}>"
do_tests -${INJECT_LIST[i]} ${NR_LOOPS}
let "i++"
done
NR_LOOPS=
function inject_blocking()
{
OLDIFS="$IFS"
IFS=$'\n'
INJECT_LIST=(
"7"
"8"
"9"
)
IFS="$OLDIFS"
NR_LOOPS=-1
i=0
while [ "$i" -lt "${#INJECT_LIST[@]}" ]; do
echo "Injecting at <${INJECT_LIST[$i]}>"
do_tests -${INJECT_LIST[i]} -1 ${@}
let "i++"
done
NR_LOOPS=
}
echo "Yield injection (25%)"
inject_blocking -m 4 -y
echo "Yield injection (50%)"
inject_blocking -m 2 -y
echo "Yield injection (100%)"
inject_blocking -m 1 -y
echo "Kill injection (25%)"
inject_blocking -m 4 -k
echo "Kill injection (50%)"
inject_blocking -m 2 -k
echo "Kill injection (100%)"
inject_blocking -m 1 -k
echo "Sleep injection (1ms, 25%)"
inject_blocking -m 4 -s 1
echo "Sleep injection (1ms, 50%)"
inject_blocking -m 2 -s 1
echo "Sleep injection (1ms, 100%)"
inject_blocking -m 1 -s 1