From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/tools/testing/selftests/rseq/rseq.c | 146 +++++++++++++++++++++++++++++-------------------
1 files changed, 89 insertions(+), 57 deletions(-)
diff --git a/kernel/tools/testing/selftests/rseq/rseq.c b/kernel/tools/testing/selftests/rseq/rseq.c
index 4847e97..986b945 100644
--- a/kernel/tools/testing/selftests/rseq/rseq.c
+++ b/kernel/tools/testing/selftests/rseq/rseq.c
@@ -25,83 +25,115 @@
#include <syscall.h>
#include <assert.h>
#include <signal.h>
+#include <limits.h>
+#include <dlfcn.h>
+#include <stddef.h>
+#include "../kselftest.h"
#include "rseq.h"
-#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+static const ptrdiff_t *libc_rseq_offset_p;
+static const unsigned int *libc_rseq_size_p;
+static const unsigned int *libc_rseq_flags_p;
-__attribute__((tls_model("initial-exec"))) __thread
-volatile struct rseq __rseq_abi = {
- .cpu_id = RSEQ_CPU_ID_UNINITIALIZED,
+/* Offset from the thread pointer to the rseq area. */
+ptrdiff_t rseq_offset;
+
+/* Size of the registered rseq area. 0 if the registration was
+ unsuccessful. */
+unsigned int rseq_size = -1U;
+
+/* Flags used during rseq registration. */
+unsigned int rseq_flags;
+
+static int rseq_ownership;
+
+static
+__thread struct rseq_abi __rseq_abi __attribute__((tls_model("initial-exec"))) = {
+ .cpu_id = RSEQ_ABI_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,
+static int sys_rseq(struct rseq_abi *rseq_abi, uint32_t rseq_len,
int flags, uint32_t sig)
{
return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
}
+int rseq_available(void)
+{
+ int rc;
+
+ rc = sys_rseq(NULL, 0, 0, 0);
+ if (rc != -1)
+ abort();
+ switch (errno) {
+ case ENOSYS:
+ return 0;
+ case EINVAL:
+ return 1;
+ default:
+ abort();
+ }
+}
+
int rseq_register_current_thread(void)
{
- int rc, ret = 0;
- sigset_t oldset;
+ int rc;
- 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 (!rseq_ownership) {
+ /* Treat libc's ownership as a successful registration. */
+ return 0;
}
- if (errno != EBUSY)
- __rseq_abi.cpu_id = -2;
- ret = -1;
- refcount--;
-end:
- signal_restore(oldset);
- return ret;
+ rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi), 0, RSEQ_SIG);
+ if (rc)
+ return -1;
+ assert(rseq_current_cpu_raw() >= 0);
+ return 0;
}
int rseq_unregister_current_thread(void)
{
- int rc, ret = 0;
- sigset_t oldset;
+ int rc;
- 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;
+ if (!rseq_ownership) {
+ /* Treat libc's ownership as a successful unregistration. */
+ return 0;
+ }
+ rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi), RSEQ_ABI_FLAG_UNREGISTER, RSEQ_SIG);
+ if (rc)
+ return -1;
+ return 0;
+}
+
+static __attribute__((constructor))
+void rseq_init(void)
+{
+ libc_rseq_offset_p = dlsym(RTLD_NEXT, "__rseq_offset");
+ libc_rseq_size_p = dlsym(RTLD_NEXT, "__rseq_size");
+ libc_rseq_flags_p = dlsym(RTLD_NEXT, "__rseq_flags");
+ if (libc_rseq_size_p && libc_rseq_offset_p && libc_rseq_flags_p) {
+ /* rseq registration owned by glibc */
+ rseq_offset = *libc_rseq_offset_p;
+ rseq_size = *libc_rseq_size_p;
+ rseq_flags = *libc_rseq_flags_p;
+ return;
+ }
+ if (!rseq_available())
+ return;
+ rseq_ownership = 1;
+ rseq_offset = (void *)&__rseq_abi - rseq_thread_pointer();
+ rseq_size = sizeof(struct rseq_abi);
+ rseq_flags = 0;
+}
+
+static __attribute__((destructor))
+void rseq_exit(void)
+{
+ if (!rseq_ownership)
+ return;
+ rseq_offset = 0;
+ rseq_size = -1U;
+ rseq_ownership = 0;
}
int32_t rseq_fallback_current_cpu(void)
--
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