mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-27 13:45:13 +07:00
5b0c308a05
In order to integrate rseq into user-space applications, expose a
__rseq_handled symbol so many rseq users can be linked into the same
application (e.g. librseq and glibc).
The __rseq_refcount TLS variable is static to the librseq library. It
ensures that rseq syscall registration/unregistration happens only for
the most early/late caller to rseq_{,un}register_current_thread for each
thread, thus ensuring that rseq is registered across the lifetime of all
rseq users for a given thread.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Carlos O'Donell <carlos@redhat.com>
CC: Florian Weimer <fweimer@redhat.com>
CC: Joseph Myers <joseph@codesourcery.com>
CC: Szabolcs Nagy <szabolcs.nagy@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ben Maurer <bmaurer@fb.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Paul Turner <pjt@google.com>
CC: linux-api@vger.kernel.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
164 lines
4.1 KiB
C
164 lines
4.1 KiB
C
/* 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 <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;
|
|
extern int __rseq_handled;
|
|
|
|
#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 (__AARCH64EL__)
|
|
#include <rseq-arm64.h>
|
|
#elif defined(__PPC__)
|
|
#include <rseq-ppc.h>
|
|
#elif defined(__mips__)
|
|
#include <rseq-mips.h>
|
|
#elif defined(__s390__)
|
|
#include <rseq-s390.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;
|
|
}
|
|
|
|
static inline void rseq_clear_rseq_cs(void)
|
|
{
|
|
#ifdef __LP64__
|
|
__rseq_abi.rseq_cs.ptr = 0;
|
|
#else
|
|
__rseq_abi.rseq_cs.ptr.ptr32 = 0;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* rseq_prepare_unload() should be invoked by each thread executing a rseq
|
|
* critical section at least once between their last critical section 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 executing a rseq critical section before reclaim of the memory
|
|
* holding the struct rseq_cs.
|
|
*/
|
|
static inline void rseq_prepare_unload(void)
|
|
{
|
|
rseq_clear_rseq_cs();
|
|
}
|
|
|
|
#endif /* RSEQ_H_ */
|