osdep: Make qemu_madvise() to set errno in all cases
The unspoken premise of qemu_madvise() is that errno is set on
error. And it is mostly the case except for posix_madvise() which
is documented to return either zero (on success) or a positive
error number. This means, we must set errno ourselves. And while
at it, make the function return a negative value on error, just
like other error paths do.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-ID: <af17113e7c1f2cc909ffd36d23f5a411b63b8764.1717584048.git.mprivozn@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/util/osdep.c b/util/osdep.c
index e996c47..e42f4e8 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -57,7 +57,12 @@
#if defined(CONFIG_MADVISE)
return madvise(addr, len, advice);
#elif defined(CONFIG_POSIX_MADVISE)
- return posix_madvise(addr, len, advice);
+ int rc = posix_madvise(addr, len, advice);
+ if (rc) {
+ errno = rc;
+ return -1;
+ }
+ return 0;
#else
errno = EINVAL;
return -1;
