[PATCH v2] util/memfd: allow allocating 0 bytes

[Elisha Hollander]

Signed-off-by: donno2048 <just4now666666@gmail.com>

---

 util/memfd.c | 10 ++++++----

 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/util/memfd.c b/util/memfd.c

index 8a2e906..e96e5af 100644

--- a/util/memfd.c

+++ b/util/memfd.c @@ -108,7 +108,7 @@ err:

 void *qemu_memfd_alloc(const char *name, size_t size, unsigned int seals,

                        int *fd, Error **errp)

 { - void *ptr;

+ void *ptr = NULL;

     int mfd = qemu_memfd_create(name, size, false, 0, seals, NULL);

     /* some systems have memfd without sealing */

@@ -131,9 +131,11 @@ void *qemu_memfd_alloc(const char *name, size_t size, unsigned int seals,

         }

     }

- ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, mfd, 0);

- if (ptr == MAP_FAILED) { - goto err;

+ if (size != 0) {

+ ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, mfd, 0); + if (ptr == MAP_FAILED) {

+ goto err;

+ }

     }

     *fd = mfd;

--

2.30.2