linux/tools/testing/selftests/rseq/rseq.h
Mathieu Desnoyers ae31573843 selftests/rseq: x86: Template memory ordering and percpu access mode
Introduce a rseq-x86-bits.h template header which is internally included
to generate the static inline functions covering:

- relaxed and release memory ordering,
- per-cpu-id and per-mm-cid per-cpu data access.

This introduces changes to the rseq.h selftests API which require to
update the rseq selftest programs. Similar API/templating changes need
to be done for other architectures.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-12-mathieu.desnoyers@efficios.com
2022-12-27 12:52:12 +01:00

385 lines
10 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 <stddef.h>
#include "rseq-abi.h"
#include "compiler.h"
#ifndef rseq_sizeof_field
#define rseq_sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
#endif
#ifndef rseq_offsetofend
#define rseq_offsetofend(TYPE, MEMBER) \
(offsetof(TYPE, MEMBER) + rseq_sizeof_field(TYPE, MEMBER))
#endif
/*
* 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
#include "rseq-thread-pointer.h"
/* Offset from the thread pointer to the rseq area. */
extern ptrdiff_t rseq_offset;
/*
* Size of the registered rseq area. 0 if the registration was
* unsuccessful.
*/
extern unsigned int rseq_size;
/* Flags used during rseq registration. */
extern unsigned int rseq_flags;
/*
* rseq feature size supported by the kernel. 0 if the registration was
* unsuccessful.
*/
extern unsigned int rseq_feature_size;
enum rseq_mo {
RSEQ_MO_RELAXED = 0,
RSEQ_MO_CONSUME = 1, /* Unused */
RSEQ_MO_ACQUIRE = 2, /* Unused */
RSEQ_MO_RELEASE = 3,
RSEQ_MO_ACQ_REL = 4, /* Unused */
RSEQ_MO_SEQ_CST = 5, /* Unused */
};
enum rseq_percpu_mode {
RSEQ_PERCPU_CPU_ID = 0,
RSEQ_PERCPU_MM_CID = 1,
};
static inline struct rseq_abi *rseq_get_abi(void)
{
return (struct rseq_abi *) ((uintptr_t) rseq_thread_pointer() + rseq_offset);
}
#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>
#elif defined(__riscv)
#include <rseq-riscv.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);
/*
* Restartable sequence fallback for reading the current node number.
*/
int32_t rseq_fallback_current_node(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_get_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_get_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 bool rseq_node_id_available(void)
{
return (int) rseq_feature_size >= rseq_offsetofend(struct rseq_abi, node_id);
}
/*
* Current NUMA node number.
*/
static inline uint32_t rseq_current_node_id(void)
{
assert(rseq_node_id_available());
return RSEQ_ACCESS_ONCE(rseq_get_abi()->node_id);
}
static inline bool rseq_mm_cid_available(void)
{
return (int) rseq_feature_size >= rseq_offsetofend(struct rseq_abi, mm_cid);
}
static inline uint32_t rseq_current_mm_cid(void)
{
return RSEQ_ACCESS_ONCE(rseq_get_abi()->mm_cid);
}
static inline void rseq_clear_rseq_cs(void)
{
RSEQ_WRITE_ONCE(rseq_get_abi()->rseq_cs.arch.ptr, 0);
}
/*
* 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) or the code referred to by the struct rseq_cs start_ip and
* post_commit_offset fields. 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 or reclaim of the code pointed to by struct
* rseq_cs start_ip and post_commit_offset fields.
*/
static inline void rseq_prepare_unload(void)
{
rseq_clear_rseq_cs();
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_storev(enum rseq_mo rseq_mo, enum rseq_percpu_mode percpu_mode,
intptr_t *v, intptr_t expect,
intptr_t newv, int cpu)
{
if (rseq_mo != RSEQ_MO_RELAXED)
return -1;
switch (percpu_mode) {
case RSEQ_PERCPU_CPU_ID:
return rseq_cmpeqv_storev_relaxed_cpu_id(v, expect, newv, cpu);
case RSEQ_PERCPU_MM_CID:
return rseq_cmpeqv_storev_relaxed_mm_cid(v, expect, newv, cpu);
}
return -1;
}
/*
* Compare @v against @expectnot. When it does _not_ match, load @v
* into @load, and store the content of *@v + voffp into @v.
*/
static inline __attribute__((always_inline))
int rseq_cmpnev_storeoffp_load(enum rseq_mo rseq_mo, enum rseq_percpu_mode percpu_mode,
intptr_t *v, intptr_t expectnot, long voffp, intptr_t *load,
int cpu)
{
if (rseq_mo != RSEQ_MO_RELAXED)
return -1;
switch (percpu_mode) {
case RSEQ_PERCPU_CPU_ID:
return rseq_cmpnev_storeoffp_load_relaxed_cpu_id(v, expectnot, voffp, load, cpu);
case RSEQ_PERCPU_MM_CID:
return rseq_cmpnev_storeoffp_load_relaxed_mm_cid(v, expectnot, voffp, load, cpu);
}
return -1;
}
static inline __attribute__((always_inline))
int rseq_addv(enum rseq_mo rseq_mo, enum rseq_percpu_mode percpu_mode,
intptr_t *v, intptr_t count, int cpu)
{
if (rseq_mo != RSEQ_MO_RELAXED)
return -1;
switch (percpu_mode) {
case RSEQ_PERCPU_CPU_ID:
return rseq_addv_relaxed_cpu_id(v, count, cpu);
case RSEQ_PERCPU_MM_CID:
return rseq_addv_relaxed_mm_cid(v, count, cpu);
}
return -1;
}
#ifdef RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV
/*
* pval = *(ptr+off)
* *pval += inc;
*/
static inline __attribute__((always_inline))
int rseq_offset_deref_addv(enum rseq_mo rseq_mo, enum rseq_percpu_mode percpu_mode,
intptr_t *ptr, long off, intptr_t inc, int cpu)
{
if (rseq_mo != RSEQ_MO_RELAXED)
return -1;
switch (percpu_mode) {
case RSEQ_PERCPU_CPU_ID:
return rseq_offset_deref_addv_relaxed_cpu_id(ptr, off, inc, cpu);
case RSEQ_PERCPU_MM_CID:
return rseq_offset_deref_addv_relaxed_mm_cid(ptr, off, inc, cpu);
}
return -1;
}
#endif
static inline __attribute__((always_inline))
int rseq_cmpeqv_trystorev_storev(enum rseq_mo rseq_mo, enum rseq_percpu_mode percpu_mode,
intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t newv2,
intptr_t newv, int cpu)
{
switch (rseq_mo) {
case RSEQ_MO_RELAXED:
switch (percpu_mode) {
case RSEQ_PERCPU_CPU_ID:
return rseq_cmpeqv_trystorev_storev_relaxed_cpu_id(v, expect, v2, newv2, newv, cpu);
case RSEQ_PERCPU_MM_CID:
return rseq_cmpeqv_trystorev_storev_relaxed_mm_cid(v, expect, v2, newv2, newv, cpu);
}
return -1;
case RSEQ_MO_RELEASE:
switch (percpu_mode) {
case RSEQ_PERCPU_CPU_ID:
return rseq_cmpeqv_trystorev_storev_release_cpu_id(v, expect, v2, newv2, newv, cpu);
case RSEQ_PERCPU_MM_CID:
return rseq_cmpeqv_trystorev_storev_release_mm_cid(v, expect, v2, newv2, newv, cpu);
}
return -1;
default:
return -1;
}
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_cmpeqv_storev(enum rseq_mo rseq_mo, enum rseq_percpu_mode percpu_mode,
intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t expect2,
intptr_t newv, int cpu)
{
if (rseq_mo != RSEQ_MO_RELAXED)
return -1;
switch (percpu_mode) {
case RSEQ_PERCPU_CPU_ID:
return rseq_cmpeqv_cmpeqv_storev_relaxed_cpu_id(v, expect, v2, expect2, newv, cpu);
case RSEQ_PERCPU_MM_CID:
return rseq_cmpeqv_cmpeqv_storev_relaxed_mm_cid(v, expect, v2, expect2, newv, cpu);
}
return -1;
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trymemcpy_storev(enum rseq_mo rseq_mo, enum rseq_percpu_mode percpu_mode,
intptr_t *v, intptr_t expect,
void *dst, void *src, size_t len,
intptr_t newv, int cpu)
{
switch (rseq_mo) {
case RSEQ_MO_RELAXED:
switch (percpu_mode) {
case RSEQ_PERCPU_CPU_ID:
return rseq_cmpeqv_trymemcpy_storev_relaxed_cpu_id(v, expect, dst, src, len, newv, cpu);
case RSEQ_PERCPU_MM_CID:
return rseq_cmpeqv_trymemcpy_storev_relaxed_mm_cid(v, expect, dst, src, len, newv, cpu);
}
return -1;
case RSEQ_MO_RELEASE:
switch (percpu_mode) {
case RSEQ_PERCPU_CPU_ID:
return rseq_cmpeqv_trymemcpy_storev_release_cpu_id(v, expect, dst, src, len, newv, cpu);
case RSEQ_PERCPU_MM_CID:
return rseq_cmpeqv_trymemcpy_storev_release_mm_cid(v, expect, dst, src, len, newv, cpu);
}
return -1;
default:
return -1;
}
}
#endif /* RSEQ_H_ */