| Message ID | 20190823135632.25010-1-stefanha@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | hostmem-file: fix pmem file size check | expand |
On Fri, Aug 23, 2019 at 02:56:32PM +0100, Stefan Hajnoczi wrote: > Commit 314aec4a6e06844937f1677f6cba21981005f389 ("hostmem-file: reject > invalid pmem file sizes") added a file size check that verifies the > hostmem object's size parameter against the actual devdax pmem file. > This is useful because getting the size wrong results in confusing > errors inside the guest. > > However, the code doesn't work properly for files where struct > stat::st_size is zero. Hostmem-file's ->alloc() function returns early > without setting an Error, causing the following assertion failure: > > qemu/memory.c:2215: memory_region_get_ram_ptr: Assertion `mr->ram_block' failed. > > This patch handles the case where qemu_get_pmem_size() returns 0 but > there is no error. > > Fixes: 314aec4a6e06844937f1677f6cba21981005f389 > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Queued, thanks.
diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c index 29e55c9195..ecc15e3eb0 100644 --- a/backends/hostmem-file.c +++ b/backends/hostmem-file.c @@ -67,12 +67,12 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) uint64_t size; size = qemu_get_pmem_size(fb->mem_path, &local_err); - if (!size) { + if (local_err) { error_propagate(errp, local_err); return; } - if (backend->size > size) { + if (size && backend->size > size) { error_setg(errp, "size property %" PRIu64 " is larger than " "pmem file \"%s\" size %" PRIu64, backend->size, fb->mem_path, size);
Commit 314aec4a6e06844937f1677f6cba21981005f389 ("hostmem-file: reject invalid pmem file sizes") added a file size check that verifies the hostmem object's size parameter against the actual devdax pmem file. This is useful because getting the size wrong results in confusing errors inside the guest. However, the code doesn't work properly for files where struct stat::st_size is zero. Hostmem-file's ->alloc() function returns early without setting an Error, causing the following assertion failure: qemu/memory.c:2215: memory_region_get_ram_ptr: Assertion `mr->ram_block' failed. This patch handles the case where qemu_get_pmem_size() returns 0 but there is no error. Fixes: 314aec4a6e06844937f1677f6cba21981005f389 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- backends/hostmem-file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)