summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/rseq/rseq.h
diff options
context:
space:
mode:
Diffstat (limited to 'tools/testing/selftests/rseq/rseq.h')
-rw-r--r--tools/testing/selftests/rseq/rseq.h175
1 files changed, 175 insertions, 0 deletions
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
new file mode 100644
index 000000000..9d850b290
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -0,0 +1,175 @@
+/* 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"
+
+/*
+ * 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;
+
+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>
+#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_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 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();
+}
+
+#endif /* RSEQ_H_ */