summaryrefslogtreecommitdiff
path: root/src/loader/loader.c
diff options
context:
space:
mode:
authorChris Wilson <chris@chris-wilson.co.uk>2015-06-10 08:28:13 +0100
committerChris Wilson <chris@chris-wilson.co.uk>2015-07-08 11:04:02 +0100
commitf2413457937f8f4a92e11379569be69e508d7477 (patch)
tree9c1798e0cee26e2285c7c09163bc02fcab9936a9 /src/loader/loader.c
parentc8d3ebaffc0d7d915c1c19d54dba61fd1e57b338 (diff)
loader: Look for any version of currently linked libudev.so
Since there was an ABI break and linking twice against libudev.so.0 and libudev.so.1 causes the application to quickly crash, we first check if the application is currently linked against libudev before dlopening a local handle. However for backwards/forwards compatability, we need to inspect the application for current linkage against all known versions first. Not doing so causes a crash when both libraries are present and so mesa chooses libudev.so.1 but the application was linked against libudev.so.0. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Emil Velikov: I'm ever so slightly conserned that RTLD_NOLOAD is not part of the POSIX standard, thus it's missing on some platforms (*BSD seems ok, while Solaris, MacOS are not). Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> Cc: mesa-stable@lists.freedesktop.org
Diffstat (limited to 'src/loader/loader.c')
-rw-r--r--src/loader/loader.c46
1 files changed, 28 insertions, 18 deletions
diff --git a/src/loader/loader.c b/src/loader/loader.c
index 8452cd3560..8780587a72 100644
--- a/src/loader/loader.c
+++ b/src/loader/loader.c
@@ -128,26 +128,36 @@ static void *udev_handle = NULL;
static void *
udev_dlopen_handle(void)
{
- if (!udev_handle) {
- udev_handle = dlopen("libudev.so.1", RTLD_LOCAL | RTLD_LAZY);
-
- if (!udev_handle) {
- /* libudev.so.1 changed the return types of the two unref functions
- * from voids to pointers. We don't use those return values, and the
- * only ABI I've heard that cares about this kind of change (calling
- * a function with a void * return that actually only returns void)
- * might be ia64.
- */
- udev_handle = dlopen("libudev.so.0", RTLD_LOCAL | RTLD_LAZY);
-
- if (!udev_handle) {
- log_(_LOADER_WARNING, "Couldn't dlopen libudev.so.1 or "
- "libudev.so.0, driver detection may be broken.\n");
- }
+ char name[80];
+ unsigned flags = RTLD_NOLOAD | RTLD_LOCAL | RTLD_LAZY;
+ int version;
+
+ /* libudev.so.1 changed the return types of the two unref functions
+ * from voids to pointers. We don't use those return values, and the
+ * only ABI I've heard that cares about this kind of change (calling
+ * a function with a void * return that actually only returns void)
+ * might be ia64.
+ */
+
+ /* First try opening an already linked libudev, then try loading one */
+ do {
+ for (version = 1; version >= 0; version--) {
+ snprintf(name, sizeof(name), "libudev.so.%d", version);
+ udev_handle = dlopen(name, flags);
+ if (udev_handle)
+ return udev_handle;
}
- }
- return udev_handle;
+ if ((flags & RTLD_NOLOAD) == 0)
+ break;
+
+ flags &= ~RTLD_NOLOAD;
+ } while (1);
+
+ log_(_LOADER_WARNING,
+ "Couldn't dlopen libudev.so.1 or "
+ "libudev.so.0, driver detection may be broken.\n");
+ return NULL;
}
static int dlsym_failed = 0;