#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
+#include <sys/types.h>
#include <sys/stat.h> /* For mode constants */
#include <fcntl.h> /* For O_* constants */
#include <assert.h>
#include <signal.h>
#include <dirent.h>
#include <lttng/align.h>
-#include <helper.h>
#include <limits.h>
#include <helper.h>
table = zmalloc(sizeof(struct shm_object_table) +
max_nb_obj * sizeof(table->objects[0]));
+ if (!table)
+ return NULL;
table->size = max_nb_obj;
return table;
}
static
struct shm_object *_shm_object_table_alloc_shm(struct shm_object_table *table,
- size_t memory_map_size)
+ size_t memory_map_size,
+ int stream_fd)
{
- int shmfd, waitfd[2], ret, i, sigblocked = 0;
+ int shmfd, waitfd[2], ret, i;
struct shm_object *obj;
char *memory_map;
- char tmp_name[NAME_MAX] = "/ust-shm-tmp-XXXXXX";
- sigset_t all_sigs, orig_sigs;
+ if (stream_fd < 0)
+ return NULL;
if (table->allocated_len >= table->size)
return NULL;
obj = &table->objects[table->allocated_len];
}
memcpy(obj->wait_fd, waitfd, sizeof(waitfd));
- /* shm_fd: create shm */
-
- /*
- * Theoretically, we could leak a shm if the application crashes
- * between open and unlink. Disable signals on this thread for
- * increased safety against this scenario.
- */
- sigfillset(&all_sigs);
- ret = pthread_sigmask(SIG_BLOCK, &all_sigs, &orig_sigs);
- if (ret == -1) {
- PERROR("pthread_sigmask");
- goto error_pthread_sigmask;
- }
- sigblocked = 1;
-
- /*
- * Allocate shm, and immediately unlink its shm oject, keeping
- * only the file descriptor as a reference to the object. If it
- * already exists (caused by short race window during which the
- * global object exists in a concurrent shm_open), simply retry.
- * We specifically do _not_ use the / at the beginning of the
- * pathname so that some OS implementations can keep it local to
- * the process (POSIX leaves this implementation-defined).
- */
- do {
- /*
- * Using mktemp filename with O_CREAT | O_EXCL open
- * flags.
- */
- mktemp(tmp_name);
- if (tmp_name[0] == '\0') {
- PERROR("mktemp");
- goto error_shm_open;
- }
- shmfd = shm_open(tmp_name,
- O_CREAT | O_EXCL | O_RDWR, 0700);
- } while (shmfd < 0 && (errno == EEXIST || errno == EACCES));
- if (shmfd < 0) {
- PERROR("shm_open");
- goto error_shm_open;
- }
- ret = shm_unlink(tmp_name);
- if (ret < 0 && errno != ENOENT) {
- PERROR("shm_unlink");
- goto error_shm_release;
- }
- sigblocked = 0;
- ret = pthread_sigmask(SIG_SETMASK, &orig_sigs, NULL);
- if (ret == -1) {
- PERROR("pthread_sigmask");
- goto error_sigmask_release;
- }
+ /* create shm */
+
+ shmfd = stream_fd;
ret = zero_file(shmfd, memory_map_size);
if (ret) {
PERROR("zero_file");
PERROR("ftruncate");
goto error_ftruncate;
}
+ obj->shm_fd_ownership = 0;
obj->shm_fd = shmfd;
/* memory_map: mmap */
error_mmap:
error_ftruncate:
-error_shm_release:
error_zero_file:
-error_sigmask_release:
- ret = close(shmfd);
- if (ret) {
- PERROR("close");
- assert(0);
- }
-error_shm_open:
- if (sigblocked) {
- ret = pthread_sigmask(SIG_SETMASK, &orig_sigs, NULL);
- if (ret == -1) {
- PERROR("pthread_sigmask");
- }
- }
-error_pthread_sigmask:
error_fcntl:
for (i = 0; i < 2; i++) {
ret = close(waitfd[i]);
/* no shm_fd */
obj->shm_fd = -1;
+ obj->shm_fd_ownership = 0;
obj->type = SHM_OBJECT_MEM;
obj->memory_map = memory_map;
struct shm_object *shm_object_table_alloc(struct shm_object_table *table,
size_t memory_map_size,
- enum shm_object_type type)
+ enum shm_object_type type,
+ int stream_fd)
{
switch (type) {
case SHM_OBJECT_SHM:
- return _shm_object_table_alloc_shm(table, memory_map_size);
+ return _shm_object_table_alloc_shm(table, memory_map_size,
+ stream_fd);
case SHM_OBJECT_MEM:
return _shm_object_table_alloc_mem(table, memory_map_size);
default:
obj->wait_fd[0] = -1; /* read end is unset */
obj->wait_fd[1] = wakeup_fd;
obj->shm_fd = shm_fd;
+ obj->shm_fd_ownership = 1;
ret = fcntl(obj->wait_fd[1], F_SETFD, FD_CLOEXEC);
if (ret < 0) {
obj->wait_fd[0] = -1; /* read end is unset */
obj->wait_fd[1] = wakeup_fd;
obj->shm_fd = -1;
+ obj->shm_fd_ownership = 0;
ret = fcntl(obj->wait_fd[1], F_SETFD, FD_CLOEXEC);
if (ret < 0) {
PERROR("umnmap");
assert(0);
}
- ret = close(obj->shm_fd);
- if (ret) {
- PERROR("close");
- assert(0);
+ if (obj->shm_fd_ownership) {
+ ret = close(obj->shm_fd);
+ if (ret) {
+ PERROR("close");
+ assert(0);
+ }
}
for (i = 0; i < 2; i++) {
if (obj->wait_fd[i] < 0)