#include <sys/mman.h>
#endif
+/* This is deprecated on glibc but is still used by FreeBSD */
+#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
+# define MAP_ANONYMOUS MAP_ANON
+#endif
+
#include <pulse/xmalloc.h>
#include <pulse/gccmacro.h>
#define MADV_REMOVE 9
#endif
-#define MAX_SHM_SIZE (PA_ALIGN(1024*1024*64))
+/* 1 GiB at max */
+#define MAX_SHM_SIZE (PA_ALIGN(1024*1024*1024))
#ifdef __linux__
/* On Linux we know that the shared memory blocks are files in
#define SHM_MARKER ((int) 0xbeefcafe)
/* We now put this SHM marker at the end of each segment. It's
- * optional, to not require a reboot when upgrading, though */
-struct shm_marker PA_GCC_PACKED {
+ * optional, to not require a reboot when upgrading, though. Note that
+ * on multiarch systems 32bit and 64bit processes might access this
+ * region simultaneously. The header fields need to be independant
+ * from the process' word with */
+struct shm_marker {
pa_atomic_t marker; /* 0xbeefcafe */
pa_atomic_t pid;
- uint64_t *_reserverd1;
- uint64_t *_reserverd2;
- uint64_t *_reserverd3;
- uint64_t *_reserverd4;
-};
+ uint64_t _reserved1;
+ uint64_t _reserved2;
+ uint64_t _reserved3;
+ uint64_t _reserved4;
+} PA_GCC_PACKED;
+
+#define SHM_MARKER_SIZE PA_ALIGN(sizeof(struct shm_marker))
+#ifdef HAVE_SHM_OPEN
static char *segment_name(char *fn, size_t l, unsigned id) {
pa_snprintf(fn, l, "/pulse-shm-%u", id);
return fn;
}
+#endif
int pa_shm_create_rw(pa_shm *m, size_t size, pa_bool_t shared, mode_t mode) {
+#ifdef HAVE_SHM_OPEN
char fn[32];
int fd = -1;
+#endif
pa_assert(m);
pa_assert(size > 0);
* ones */
pa_shm_cleanup();
- /* Round up to make it aligned */
- size = PA_ALIGN(size);
+ /* Round up to make it page aligned */
+ size = PA_PAGE_ALIGN(size);
if (!shared) {
m->id = 0;
m->size = size;
#ifdef MAP_ANONYMOUS
- if ((m->ptr = mmap(NULL, m->size, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+ if ((m->ptr = mmap(NULL, m->size, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, (off_t) 0)) == MAP_FAILED) {
pa_log("mmap() failed: %s", pa_cstrerror(errno));
goto fail;
}
goto fail;
}
- m->size = size + PA_ALIGN(sizeof(struct shm_marker));
+ m->size = size + SHM_MARKER_SIZE;
- if (ftruncate(fd, m->size) < 0) {
+ if (ftruncate(fd, (off_t) m->size) < 0) {
pa_log("ftruncate() failed: %s", pa_cstrerror(errno));
goto fail;
}
- if ((m->ptr = mmap(NULL, m->size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED) {
+#ifndef MAP_NORESERVE
+#define MAP_NORESERVE 0
+#endif
+
+ if ((m->ptr = mmap(NULL, PA_PAGE_ALIGN(m->size), PROT_READ|PROT_WRITE, MAP_SHARED|MAP_NORESERVE, fd, (off_t) 0)) == MAP_FAILED) {
pa_log("mmap() failed: %s", pa_cstrerror(errno));
goto fail;
}
/* We store our PID at the end of the shm block, so that we
* can check for dead shm segments later */
- marker = (struct shm_marker*) ((uint8_t*) m->ptr + m->size - PA_ALIGN(sizeof(struct shm_marker)));
+ marker = (struct shm_marker*) ((uint8_t*) m->ptr + m->size - SHM_MARKER_SIZE);
pa_atomic_store(&marker->pid, (int) getpid());
pa_atomic_store(&marker->marker, SHM_MARKER);
- pa_assert_se(close(fd) == 0);
+ pa_assert_se(pa_close(fd) == 0);
m->do_unlink = TRUE;
#else
return -1;
#endif
} else {
#ifdef HAVE_SHM_OPEN
- if (munmap(m->ptr, m->size) < 0)
+ if (munmap(m->ptr, PA_PAGE_ALIGN(m->size)) < 0)
pa_log("munmap() failed: %s", pa_cstrerror(errno));
if (m->do_unlink) {
#endif
}
- memset(m, 0, sizeof(*m));
+ pa_zero(*m);
}
void pa_shm_punch(pa_shm *m, size_t offset, size_t size) {
void *ptr;
- size_t o, ps;
+ size_t o;
pa_assert(m);
pa_assert(m->ptr);
/* You're welcome to implement this as NOOP on systems that don't
* support it */
- /* Align this to multiples of the page size */
+ /* Align the pointer up to multiples of the page size */
ptr = (uint8_t*) m->ptr + offset;
- o = (uint8_t*) ptr - (uint8_t*) PA_PAGE_ALIGN_PTR(ptr);
+ o = (size_t) ((uint8_t*) ptr - (uint8_t*) PA_PAGE_ALIGN_PTR(ptr));
if (o > 0) {
- ps = PA_PAGE_SIZE;
- ptr = (uint8_t*) ptr + (ps - o);
- size -= ps - o;
+ size_t delta = PA_PAGE_SIZE - o;
+ ptr = (uint8_t*) ptr + delta;
+ size -= delta;
}
+ /* Align the size down to multiples of page size */
+ size = (size / PA_PAGE_SIZE) * PA_PAGE_SIZE;
+
#ifdef MADV_REMOVE
if (madvise(ptr, size, MADV_REMOVE) >= 0)
return;
#endif
#ifdef MADV_DONTNEED
- pa_assert_se(madvise(ptr, size, MADV_DONTNEED) == 0);
+ madvise(ptr, size, MADV_DONTNEED);
#elif defined(POSIX_MADV_DONTNEED)
- pa_assert_se(posix_madvise(ptr, size, POSIX_MADV_DONTNEED) == 0);
+ posix_madvise(ptr, size, POSIX_MADV_DONTNEED);
#endif
}
segment_name(fn, sizeof(fn), m->id = id);
if ((fd = shm_open(fn, O_RDONLY, 0)) < 0) {
- if (errno != EACCES)
+ if (errno != EACCES && errno != ENOENT)
pa_log("shm_open() failed: %s", pa_cstrerror(errno));
goto fail;
}
}
if (st.st_size <= 0 ||
- st.st_size > (off_t) (MAX_SHM_SIZE+PA_ALIGN(sizeof(struct shm_marker))) ||
+ st.st_size > (off_t) (MAX_SHM_SIZE+SHM_MARKER_SIZE) ||
PA_ALIGN((size_t) st.st_size) != (size_t) st.st_size) {
pa_log("Invalid shared memory segment size");
goto fail;
}
- m->size = st.st_size;
+ m->size = (size_t) st.st_size;
- if ((m->ptr = mmap(NULL, m->size, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
+ if ((m->ptr = mmap(NULL, PA_PAGE_ALIGN(m->size), PROT_READ, MAP_SHARED, fd, (off_t) 0)) == MAP_FAILED) {
pa_log("mmap() failed: %s", pa_cstrerror(errno));
goto fail;
}
- m->do_unlink = 0;
- m->shared = 1;
+ m->do_unlink = FALSE;
+ m->shared = TRUE;
pa_assert_se(pa_close(fd) == 0);
if (pa_shm_attach_ro(&seg, id) < 0)
continue;
- if (seg.size < PA_ALIGN(sizeof(struct shm_marker))) {
+ if (seg.size < SHM_MARKER_SIZE) {
pa_shm_free(&seg);
continue;
}
- m = (struct shm_marker*) ((uint8_t*) seg.ptr + seg.size - PA_ALIGN(sizeof(struct shm_marker)));
+ m = (struct shm_marker*) ((uint8_t*) seg.ptr + seg.size - SHM_MARKER_SIZE);
if (pa_atomic_load(&m->marker) != SHM_MARKER) {
pa_shm_free(&seg);