Module Name: src
Committed By: riastradh
Date: Sat Dec 24 15:46:50 UTC 2016
Modified Files:
src/sys/external/bsd/drm2/dist/drm/ttm: ttm_tt.c
Log Message:
Guarantee no zero-size uao/kmem allocations via ttm.
It may be that all callers guarantee no zero-size ttm objects, but I
can't prove that in five minutes of browsing callers. Rather than
add a KASSERT, lacking proof, we'll add a warning message so that if
it does happen then it happens noisily, but we'll also prevent the
bad consequences of passing zero into uao_create by rounding up to a
harmless nonzero allocation.
XXX pullup-7
To generate a diff of this commit:
cvs rdiff -u -r1.7 -r1.8 src/sys/external/bsd/drm2/dist/drm/ttm/ttm_tt.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/external/bsd/drm2/dist/drm/ttm/ttm_tt.c
diff -u src/sys/external/bsd/drm2/dist/drm/ttm/ttm_tt.c:1.7 src/sys/external/bsd/drm2/dist/drm/ttm/ttm_tt.c:1.8
--- src/sys/external/bsd/drm2/dist/drm/ttm/ttm_tt.c:1.7 Sun Apr 24 04:26:12 2016
+++ src/sys/external/bsd/drm2/dist/drm/ttm/ttm_tt.c Sat Dec 24 15:46:50 2016
@@ -203,6 +203,9 @@ int ttm_tt_init(struct ttm_tt *ttm, stru
ttm->dummy_read_page = dummy_read_page;
ttm->state = tt_unpopulated;
#ifdef __NetBSD__
+ WARN(size == 0, "zero-size allocation in %s, please file a NetBSD PR",
+ __func__); /* paranoia -- can't prove in five minutes */
+ size = MAX(size, 1);
ttm->swap_storage = uao_create(roundup2(size, PAGE_SIZE), 0);
uao_set_pgfl(ttm->swap_storage, bus_dmamem_pgfl(bdev->dmat));
#else
@@ -245,6 +248,9 @@ int ttm_dma_tt_init(struct ttm_dma_tt *t
ttm->dummy_read_page = dummy_read_page;
ttm->state = tt_unpopulated;
#ifdef __NetBSD__
+ WARN(size == 0, "zero-size allocation in %s, please file a NetBSD PR",
+ __func__); /* paranoia -- can't prove in five minutes */
+ size = MAX(size, 1);
ttm->swap_storage = uao_create(roundup2(size, PAGE_SIZE), 0);
uao_set_pgfl(ttm->swap_storage, bus_dmamem_pgfl(bdev->dmat));
#else
