Message ID | 1353425657-3237-1-git-send-email-stefanha@redhat.com |
---|---|
State | New |
Headers | show |
Am 20.11.2012 16:34, schrieb Stefan Hajnoczi: > It's poor symbol hygiene to provide a global symbols that collide with a > common library like libuuid. If QEMU links against a shared library > that depends on uuid_generate() it can end up calling our stub version > of the function. > > This exact scenario happened with GlusterFS libgfapi.so, which depends > on libglusterfs.so's uuid_generate(). > > Scope the uuid stubs for vdi.c only and avoid affecting other shared > objects. > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
On Tue, Nov 20, 2012 at 04:34:17PM +0100, Stefan Hajnoczi wrote: > It's poor symbol hygiene to provide a global symbols that collide with a > common library like libuuid. If QEMU links against a shared library > that depends on uuid_generate() it can end up calling our stub version > of the function. > > This exact scenario happened with GlusterFS libgfapi.so, which depends > on libglusterfs.so's uuid_generate(). > > Scope the uuid stubs for vdi.c only and avoid affecting other shared > objects. > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > block/vdi.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) Thanks, applied to the block tree: https://github.com/stefanha/qemu/commits/block Stefan
diff --git a/block/vdi.c b/block/vdi.c index f35b12e..c8330b7 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -60,9 +60,6 @@ /* TODO: move uuid emulation to some central place in QEMU. */ #include "sysemu.h" /* UUID_FMT */ typedef unsigned char uuid_t[16]; -void uuid_generate(uuid_t out); -int uuid_is_null(const uuid_t uu); -void uuid_unparse(const uuid_t uu, char *out); #endif /* Code configuration options. */ @@ -124,18 +121,18 @@ void uuid_unparse(const uuid_t uu, char *out); #define VDI_IS_ALLOCATED(X) ((X) < VDI_DISCARDED) #if !defined(CONFIG_UUID) -void uuid_generate(uuid_t out) +static inline void uuid_generate(uuid_t out) { memset(out, 0, sizeof(uuid_t)); } -int uuid_is_null(const uuid_t uu) +static inline int uuid_is_null(const uuid_t uu) { uuid_t null_uuid = { 0 }; return memcmp(uu, null_uuid, sizeof(uuid_t)) == 0; } -void uuid_unparse(const uuid_t uu, char *out) +static inline void uuid_unparse(const uuid_t uu, char *out) { snprintf(out, 37, UUID_FMT, uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7],
It's poor symbol hygiene to provide a global symbols that collide with a common library like libuuid. If QEMU links against a shared library that depends on uuid_generate() it can end up calling our stub version of the function. This exact scenario happened with GlusterFS libgfapi.so, which depends on libglusterfs.so's uuid_generate(). Scope the uuid stubs for vdi.c only and avoid affecting other shared objects. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- block/vdi.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)