From 2abe070373048a47d66851e76593c11f95683059 Mon Sep 17 00:00:00 2001 From: Tim Deegan Date: Thu, 26 Jul 2007 12:00:32 +0100 Subject: [PATCH] [HVM] Save/restore: don't leak shared-memory segments after HVM live-migrate. Signed-off-by: Tim Deegan --- tools/xcutils/xc_save.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/tools/xcutils/xc_save.c b/tools/xcutils/xc_save.c index 188ea7b72e..3a97683a97 100644 --- a/tools/xcutils/xc_save.c +++ b/tools/xcutils/xc_save.c @@ -54,8 +54,18 @@ static int suspend(int domid) static char *qemu_active_path; static char *qemu_next_active_path; +static int qemu_shmid = -1; static struct xs_handle *xs; + +/* Mark the shared-memory segment for destruction */ +static void qemu_destroy_buffer(void) +{ + if (qemu_shmid != -1) + shmctl(qemu_shmid, IPC_RMID, NULL); + qemu_shmid = -1; +} + /* Get qemu to change buffers. */ static void qemu_flip_buffer(int domid, int next_active) { @@ -97,22 +107,23 @@ static void * init_qemu_maps(int domid, unsigned int bitmap_size) { key_t key; char key_ascii[17] = {0,}; - int shmid = -1; void *seg; char *path, *p; /* Make a shared-memory segment */ - while (shmid == -1) - { + do { key = rand(); /* No security, just a sequence of numbers */ - shmid = shmget(key, 2 * bitmap_size, + qemu_shmid = shmget(key, 2 * bitmap_size, IPC_CREAT|IPC_EXCL|S_IRUSR|S_IWUSR); - if (shmid == -1 && errno != EEXIST) + if (qemu_shmid == -1 && errno != EEXIST) errx(1, "can't get shmem to talk to qemu-dm"); - } + } while (qemu_shmid == -1); + + /* Remember to tidy up after ourselves */ + atexit(qemu_destroy_buffer); /* Map it into our address space */ - seg = shmat(shmid, NULL, 0); + seg = shmat(qemu_shmid, NULL, 0); if (seg == (void *) -1) errx(1, "can't map shmem to talk to qemu-dm"); memset(seg, 0, 2 * bitmap_size); -- 2.30.2