From 9a80b7fd8f282d4b448f826ff88c8770c079fb72 Mon Sep 17 00:00:00 2001 From: Nathan Kidd Date: Fri, 15 Nov 2019 02:35:11 +0100 Subject: [PATCH] llvmpipe: Check thread creation errors In the case of glibc, pthread_t is internally a pointer. If lp_rast_destroy() passes a 0-value pthread_t to pthread_join(), the latter will SEGV dereferencing it. pthread_create() can fail if either the user's ulimit -u or Linux kernel's /proc/sys/kernel/threads-max is reached. Choosing to continue, rather than fail, on theory that it is better to run with the one main thread, than not run at all. Keeping as many threads as we got, since lack of threads severely degrades llvmpipe performance. Signed-off-by: Nathan Kidd Reviewed-by: Roland Scheidegger --- src/gallium/drivers/llvmpipe/lp_rast.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/gallium/drivers/llvmpipe/lp_rast.c b/src/gallium/drivers/llvmpipe/lp_rast.c index d50e92b2b61..ef783ea6fb1 100644 --- a/src/gallium/drivers/llvmpipe/lp_rast.c +++ b/src/gallium/drivers/llvmpipe/lp_rast.c @@ -867,6 +867,10 @@ create_rast_threads(struct lp_rasterizer *rast) pipe_semaphore_init(&rast->tasks[i].work_done, 0); rast->threads[i] = u_thread_create(thread_function, (void *) &rast->tasks[i]); + if (!rast->threads[i]) { + rast->num_threads = i; /* previous thread is max */ + break; + } } } -- 2.30.2