If the application sends us a file descriptor pointing at a prime buffer that we've already got, we have to re-use the same bo_gem structure or chaos will result.
Track the set of all known prime objects and look to see if the kernel has returned one of those for a new file descriptor.
Also checks for prime buffers in the flink case.
Signed-off-by: Keith Packard keithp@keithp.com --- intel/intel_bufmgr_gem.c | 50 +++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 43 insertions(+), 7 deletions(-)
diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c index df6fcec..2b7fe07 100644 --- a/intel/intel_bufmgr_gem.c +++ b/intel/intel_bufmgr_gem.c @@ -149,6 +149,8 @@ struct _drm_intel_bo_gem {
/** * Kenel-assigned global name for this object + * + * List contains both flink named and prime fd'd objects */ unsigned int global_name; drmMMListHead name_list; @@ -862,10 +864,6 @@ drm_intel_bo_gem_create_from_name(drm_intel_bufmgr *bufmgr, } }
- bo_gem = calloc(1, sizeof(*bo_gem)); - if (!bo_gem) - return NULL; - VG_CLEAR(open_arg); open_arg.name = handle; ret = drmIoctl(bufmgr_gem->fd, @@ -874,9 +872,26 @@ drm_intel_bo_gem_create_from_name(drm_intel_bufmgr *bufmgr, if (ret != 0) { DBG("Couldn't reference %s handle 0x%08x: %s\n", name, handle, strerror(errno)); - free(bo_gem); return NULL; } + /* Now see if someone has used a prime handle to get this + * object from the kernel before by looking through the list + * again for a matching gem_handle + */ + for (list = bufmgr_gem->named.next; + list != &bufmgr_gem->named; + list = list->next) { + bo_gem = DRMLISTENTRY(drm_intel_bo_gem, list, name_list); + if (bo_gem->gem_handle == open_arg.handle) { + drm_intel_gem_bo_reference(&bo_gem->bo); + return &bo_gem->bo; + } + } + + bo_gem = calloc(1, sizeof(*bo_gem)); + if (!bo_gem) + return NULL; + bo_gem->bo.size = open_arg.size; bo_gem->bo.offset = 0; bo_gem->bo.virtual = NULL; @@ -2451,8 +2466,25 @@ drm_intel_bo_gem_create_from_prime(drm_intel_bufmgr *bufmgr, int prime_fd, int s uint32_t handle; drm_intel_bo_gem *bo_gem; struct drm_i915_gem_get_tiling get_tiling; + drmMMListHead *list;
ret = drmPrimeFDToHandle(bufmgr_gem->fd, prime_fd, &handle); + + /* + * See if the kernel has already returned this buffer to us. Just as + * for named buffers, we must not create two bo's pointing at the same + * kernel object + */ + for (list = bufmgr_gem->named.next; + list != &bufmgr_gem->named; + list = list->next) { + bo_gem = DRMLISTENTRY(drm_intel_bo_gem, list, name_list); + if (bo_gem->gem_handle == handle) { + drm_intel_gem_bo_reference(&bo_gem->bo); + return &bo_gem->bo; + } + } + if (ret) { fprintf(stderr,"ret is %d %d\n", ret, errno); return NULL; @@ -2487,8 +2519,8 @@ drm_intel_bo_gem_create_from_prime(drm_intel_bufmgr *bufmgr, int prime_fd, int s bo_gem->has_error = false; bo_gem->reusable = false;
- DRMINITLISTHEAD(&bo_gem->name_list); DRMINITLISTHEAD(&bo_gem->vma_list); + DRMLISTADDTAIL(&bo_gem->name_list, &bufmgr_gem->named);
VG_CLEAR(get_tiling); get_tiling.handle = bo_gem->gem_handle; @@ -2513,6 +2545,9 @@ drm_intel_bo_gem_export_to_prime(drm_intel_bo *bo, int *prime_fd) drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr; drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
+ if (DRMLISTEMPTY(&bo_gem->name_list)) + DRMLISTADDTAIL(&bo_gem->name_list, &bufmgr_gem->named); + if (drmPrimeHandleToFD(bufmgr_gem->fd, bo_gem->gem_handle, DRM_CLOEXEC, prime_fd) != 0) return -errno; @@ -2542,7 +2577,8 @@ drm_intel_gem_bo_flink(drm_intel_bo *bo, uint32_t * name) bo_gem->global_name = flink.name; bo_gem->reusable = false;
- DRMLISTADDTAIL(&bo_gem->name_list, &bufmgr_gem->named); + if (DRMLISTEMPTY(&bo_gem->name_list)) + DRMLISTADDTAIL(&bo_gem->name_list, &bufmgr_gem->named); }
*name = bo_gem->global_name;