-/* $Id$ */
-
/***
This file is part of PulseAudio.
#include <errno.h>
#include <string.h>
#include <sys/stat.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <signal.h>
#ifdef HAVE_SYS_MMAN_H
#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>
+
#include <pulsecore/core-error.h>
#include <pulsecore/log.h>
#include <pulsecore/random.h>
#include <pulsecore/core-util.h>
#include <pulsecore/macro.h>
-#include <pulse/xmalloc.h>
+#include <pulsecore/atomic.h>
#include "shm.h"
#define MADV_REMOVE 9
#endif
-#define MAX_SHM_SIZE (1024*1024*20)
+/* 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
+ * /dev/shm. We can use that information to list all blocks and
+ * cleanup unused ones */
+#define SHM_PATH "/dev/shm/"
+#define SHM_ID_LEN 10
+#elif defined(__sun)
+#define SHM_PATH "/tmp"
+#define SHM_ID_LEN 15
+#else
+#undef SHM_PATH
+#undef SHM_ID_LEN
+#endif
+
+#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. Note that
+ * on multiarch systems 32bit and 64bit processes might access this
+ * region simultaneously. The header fields need to be independent
+ * from the process' word with */
+struct shm_marker {
+ pa_atomic_t marker; /* 0xbeefcafe */
+ pa_atomic_t pid;
+ 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, int shared, mode_t mode) {
+int pa_shm_create_rw(pa_shm *m, size_t size, bool shared, mode_t mode) {
+#ifdef HAVE_SHM_OPEN
char fn[32];
int fd = -1;
+#endif
pa_assert(m);
pa_assert(size > 0);
- pa_assert(size < MAX_SHM_SIZE);
+ pa_assert(size <= MAX_SHM_SIZE);
+ pa_assert(!(mode & ~0777));
pa_assert(mode >= 0600);
+ /* Each time we create a new SHM area, let's first drop all stale
+ * ones */
+ pa_shm_cleanup();
+
+ /* 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;
}
m->ptr = pa_xmalloc(m->size);
#endif
- m->do_unlink = 0;
+ m->do_unlink = false;
} else {
#ifdef HAVE_SHM_OPEN
+ struct shm_marker *marker;
+
pa_random(&m->id, sizeof(m->id));
segment_name(fn, sizeof(fn), m->id);
- if ((fd = shm_open(fn, O_RDWR|O_CREAT|O_EXCL, mode & 0444)) < 0) {
+ if ((fd = shm_open(fn, O_RDWR|O_CREAT|O_EXCL, mode)) < 0) {
pa_log("shm_open() failed: %s", pa_cstrerror(errno));
goto fail;
}
- if (ftruncate(fd, m->size = size) < 0) {
+ m->size = size + SHM_MARKER_SIZE;
+
+ 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;
}
- close(fd);
- m->do_unlink = 1;
+ /* 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 - SHM_MARKER_SIZE);
+ pa_atomic_store(&marker->pid, (int) getpid());
+ pa_atomic_store(&marker->marker, SHM_MARKER);
+
+ pa_assert_se(pa_close(fd) == 0);
+ m->do_unlink = true;
#else
- return -1;
+ goto fail;
#endif
}
#ifdef HAVE_SHM_OPEN
if (fd >= 0) {
shm_unlink(fn);
- pa_assert_se(close(fd) >= 0);
+ pa_close(fd);
}
#endif
#ifdef MAP_FAILED
pa_assert(m->ptr != MAP_FAILED);
#endif
-
+
if (!m->shared) {
#ifdef MAP_ANONYMOUS
if (munmap(m->ptr, m->size) < 0)
#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) {
char fn[32];
-
+
segment_name(fn, sizeof(fn), m->id);
-
+
if (shm_unlink(fn) < 0)
pa_log(" shm_unlink(%s) failed: %s", fn, pa_cstrerror(errno));
}
#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) {
- pa_log("shm_open() failed: %s", pa_cstrerror(errno));
+ if (errno != EACCES && errno != ENOENT)
+ pa_log("shm_open() failed: %s", pa_cstrerror(errno));
goto fail;
}
goto fail;
}
- if (st.st_size <= 0 || st.st_size > MAX_SHM_SIZE) {
+ if (st.st_size <= 0 ||
+ 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(close(fd) >= 0);
+ pa_assert_se(pa_close(fd) == 0);
return 0;
fail:
if (fd >= 0)
- pa_assert_se(close(fd) >= 0);
+ pa_close(fd);
return -1;
}
}
#endif /* HAVE_SHM_OPEN */
+
+int pa_shm_cleanup(void) {
+
+#ifdef HAVE_SHM_OPEN
+#ifdef SHM_PATH
+ DIR *d;
+ struct dirent *de;
+
+ if (!(d = opendir(SHM_PATH))) {
+ pa_log_warn("Failed to read "SHM_PATH": %s", pa_cstrerror(errno));
+ return -1;
+ }
+
+ while ((de = readdir(d))) {
+ pa_shm seg;
+ unsigned id;
+ pid_t pid;
+ char fn[128];
+ struct shm_marker *m;
+
+#if defined(__sun)
+ if (strncmp(de->d_name, ".SHMDpulse-shm-", SHM_ID_LEN))
+#else
+ if (strncmp(de->d_name, "pulse-shm-", SHM_ID_LEN))
+#endif
+ continue;
+
+ if (pa_atou(de->d_name + SHM_ID_LEN, &id) < 0)
+ continue;
+
+ if (pa_shm_attach_ro(&seg, id) < 0)
+ continue;
+
+ if (seg.size < SHM_MARKER_SIZE) {
+ pa_shm_free(&seg);
+ continue;
+ }
+
+ 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);
+ continue;
+ }
+
+ if (!(pid = (pid_t) pa_atomic_load(&m->pid))) {
+ pa_shm_free(&seg);
+ continue;
+ }
+
+ if (kill(pid, 0) == 0 || errno != ESRCH) {
+ pa_shm_free(&seg);
+ continue;
+ }
+
+ pa_shm_free(&seg);
+
+ /* Ok, the owner of this shms segment is dead, so, let's remove the segment */
+ segment_name(fn, sizeof(fn), id);
+
+ if (shm_unlink(fn) < 0 && errno != EACCES && errno != ENOENT)
+ pa_log_warn("Failed to remove SHM segment %s: %s\n", fn, pa_cstrerror(errno));
+ }
+
+ closedir(d);
+#endif /* SHM_PATH */
+#endif /* HAVE_SHM_OPEN */
+
+ return 0;
+}