Caio Marcelo de Oliveira Filho
397d1a18ef
Inline the ring buffer and signal logic into lp_scene_queue instead of
using a u_ringbuffer. The code ends up simpler since there's no need
to handle serializing data from / to packets.
This fixes a crash when compiling Mesa with LTO, that happened because
of util_ringbuffer_dequeue() was writing data after the "header
packet", as shown below
struct scene_packet {
struct util_packet header;
struct lp_scene *scene;
};
/* Snippet of old lp_scene_deque(). */
packet.scene = NULL;
ret = util_ringbuffer_dequeue(queue->ring,
&packet.header,
sizeof packet / 4,
return packet.scene;
but due to the way aliasing analysis work the compiler didn't
considered the "&packet->header" to alias with "packet->scene". With
the aggressive inlining done by LTO, this would end up always
returning NULL instead of the content read by
util_ringbuffer_dequeue().
Issue found by Marco Simental and iThiago Macieira.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110884
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
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