[dpdk-dev] [PATCH 1/3] vhost: fix error path when setting memory tables
Xia, Chenbo
chenbo.xia at intel.com
Fri Nov 6 03:53:00 CET 2020
Hi Maxime,
> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin at redhat.com>
> Sent: Thursday, November 5, 2020 7:46 PM
> To: dev at dpdk.org; Ding, Xuan <xuan.ding at intel.com>;
> stephen at networkplumber.org; Yigit, Ferruh <ferruh.yigit at intel.com>;
> thomas at monjalon.net; Xia, Chenbo <chenbo.xia at intel.com>
> Cc: stable at dpdk.org; Maxime Coquelin <maxime.coquelin at redhat.com>
> Subject: [PATCH 1/3] vhost: fix error path when setting memory tables
>
> If the an error is encountered before the memory regions
'the' should be deleted.
> are parsed, the file descriptors for these shared buffers
> is leaked.
s/is/are/
>
> This patch fixes this by closing the message file descriptors
> on error, taking care of avoiding double closing of the file
> descriptors. guest_pages is also freed, even though it was not
> leaked as its pointer was not overiden on subsequent function
s/overiden/overridden
With above changes:
Reviewed-by: Chenbo Xia <chenbo.xia at intel.com>
> calls.
>
> Fixes: 8f972312b8f4 ("vhost: support vhost-user")
> Cc: stable at dpdk.org
>
> Reported-by: Xuan Ding <xuan.ding at intel.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
> ---
> lib/librte_vhost/vhost_user.c | 65 +++++++++++++++++++++--------------
> 1 file changed, 39 insertions(+), 26 deletions(-)
>
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 8a8726f8b8..473fd778ca 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -99,8 +99,15 @@ close_msg_fds(struct VhostUserMsg *msg)
> {
> int i;
>
> - for (i = 0; i < msg->fd_num; i++)
> - close(msg->fds[i]);
> + for (i = 0; i < msg->fd_num; i++) {
> + int fd = msg->fds[i];
> +
> + if (fd == -1)
> + continue;
> +
> + msg->fds[i] = -1;
> + close(fd);
> + }
> }
>
> /*
> @@ -1004,7 +1011,6 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> uint64_t alignment;
> uint32_t i;
> int populate;
> - int fd;
>
> if (validate_msg_fds(msg, memory->nregions) != 0)
> return RTE_VHOST_MSG_RESULT_ERR;
> @@ -1012,16 +1018,13 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> if (memory->nregions > VHOST_MEMORY_MAX_NREGIONS) {
> VHOST_LOG_CONFIG(ERR,
> "too many memory regions (%u)\n", memory->nregions);
> - return RTE_VHOST_MSG_RESULT_ERR;
> + goto close_msg_fds;
> }
>
> if (dev->mem && !vhost_memory_changed(memory, dev->mem)) {
> VHOST_LOG_CONFIG(INFO,
> "(%d) memory regions not changed\n", dev->vid);
> -
> - close_msg_fds(msg);
> -
> - return RTE_VHOST_MSG_RESULT_OK;
> + goto close_msg_fds;
> }
>
> if (dev->mem) {
> @@ -1054,7 +1057,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> "(%d) failed to allocate memory "
> "for dev->guest_pages\n",
> dev->vid);
> - return RTE_VHOST_MSG_RESULT_ERR;
> + goto close_msg_fds;
> }
> }
>
> @@ -1064,18 +1067,23 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> VHOST_LOG_CONFIG(ERR,
> "(%d) failed to allocate memory for dev->mem\n",
> dev->vid);
> - return RTE_VHOST_MSG_RESULT_ERR;
> + goto free_guest_pages;
> }
> dev->mem->nregions = memory->nregions;
>
> for (i = 0; i < memory->nregions; i++) {
> - fd = msg->fds[i];
> reg = &dev->mem->regions[i];
>
> reg->guest_phys_addr = memory->regions[i].guest_phys_addr;
> reg->guest_user_addr = memory->regions[i].userspace_addr;
> reg->size = memory->regions[i].memory_size;
> - reg->fd = fd;
> + reg->fd = msg->fds[i];
> +
> + /*
> + * Assign invalid file descriptor value to avoid double
> + * closing on error path.
> + */
> + msg->fds[i] = -1;
>
> mmap_offset = memory->regions[i].mmap_offset;
>
> @@ -1085,7 +1093,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> "mmap_offset (%#"PRIx64") and memory_size "
> "(%#"PRIx64") overflow\n",
> mmap_offset, reg->size);
> - goto err_mmap;
> + goto free_mem_table;
> }
>
> mmap_size = reg->size + mmap_offset;
> @@ -1098,11 +1106,11 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> * to avoid failure, make sure in caller to keep length
> * aligned.
> */
> - alignment = get_blk_size(fd);
> + alignment = get_blk_size(reg->fd);
> if (alignment == (uint64_t)-1) {
> VHOST_LOG_CONFIG(ERR,
> "couldn't get hugepage size through fstat\n");
> - goto err_mmap;
> + goto free_mem_table;
> }
> mmap_size = RTE_ALIGN_CEIL(mmap_size, alignment);
> if (mmap_size == 0) {
> @@ -1118,17 +1126,17 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> VHOST_LOG_CONFIG(ERR, "mmap size (0x%" PRIx64 ") "
> "or alignment (0x%" PRIx64 ") is invalid\n",
> reg->size + mmap_offset, alignment);
> - goto err_mmap;
> + goto free_mem_table;
> }
>
> populate = dev->async_copy ? MAP_POPULATE : 0;
> mmap_addr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
> - MAP_SHARED | populate, fd, 0);
> + MAP_SHARED | populate, reg->fd, 0);
>
> if (mmap_addr == MAP_FAILED) {
> VHOST_LOG_CONFIG(ERR,
> "mmap region %u failed.\n", i);
> - goto err_mmap;
> + goto free_mem_table;
> }
>
> reg->mmap_addr = mmap_addr;
> @@ -1141,7 +1149,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> VHOST_LOG_CONFIG(ERR,
> "adding guest pages to region %u failed.\n",
> i);
> - goto err_mmap;
> + goto free_mem_table;
> }
>
> VHOST_LOG_CONFIG(INFO,
> @@ -1184,17 +1192,17 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> if (read_vhost_message(main_fd, &ack_msg) <= 0) {
> VHOST_LOG_CONFIG(ERR,
> "Failed to read qemu ack on postcopy set-mem-
> table\n");
> - goto err_mmap;
> + goto free_mem_table;
> }
>
> if (validate_msg_fds(&ack_msg, 0) != 0)
> - goto err_mmap;
> + goto free_mem_table;
>
> if (ack_msg.request.master != VHOST_USER_SET_MEM_TABLE) {
> VHOST_LOG_CONFIG(ERR,
> "Bad qemu ack on postcopy set-mem-table (%d)\n",
> ack_msg.request.master);
> - goto err_mmap;
> + goto free_mem_table;
> }
>
> /* Now userfault register and we can use the memory */
> @@ -1218,7 +1226,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> "Failed to register ufd for region %d: (ufd
> = %d) %s\n",
> i, dev->postcopy_ufd,
> strerror(errno));
> - goto err_mmap;
> + goto free_mem_table;
> }
> VHOST_LOG_CONFIG(INFO,
> "\t userfaultfd registered for range : "
> @@ -1227,7 +1235,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> (uint64_t)reg_struct.range.start +
> (uint64_t)reg_struct.range.len - 1);
> #else
> - goto err_mmap;
> + goto free_mem_table;
> #endif
> }
> }
> @@ -1249,7 +1257,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> dev = translate_ring_addresses(dev, i);
> if (!dev) {
> dev = *pdev;
> - goto err_mmap;
> + goto free_mem_table;
> }
>
> *pdev = dev;
> @@ -1260,10 +1268,15 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
>
> return RTE_VHOST_MSG_RESULT_OK;
>
> -err_mmap:
> +free_mem_table:
> free_mem_region(dev);
> rte_free(dev->mem);
> dev->mem = NULL;
> +free_guest_pages:
> + rte_free(dev->guest_pages);
> + dev->guest_pages = NULL;
> +close_msg_fds:
> + close_msg_fds(msg);
> return RTE_VHOST_MSG_RESULT_ERR;
> }
>
> --
> 2.26.2
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