We can't copy_*_user while holding reservations, that will (soon even for nouveau) lead to deadlocks. And it breaks the cross-driver contract around dma_resv.
Fix this by adding a slowpath for when we need relocations, and by pushing the writeback of the new presumed offsets to the very end.
Aside from "it compiles" entirely untested unfortunately.
Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Ben Skeggs bskeggs@redhat.com Cc: nouveau@lists.freedesktop.org --- drivers/gpu/drm/nouveau/nouveau_gem.c | 57 ++++++++++++++++++--------- 1 file changed, 38 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c index c77302f969e8..60309b997951 100644 --- a/drivers/gpu/drm/nouveau/nouveau_gem.c +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c @@ -482,12 +482,9 @@ validate_init(struct nouveau_channel *chan, struct drm_file *file_priv,
static int validate_list(struct nouveau_channel *chan, struct nouveau_cli *cli, - struct list_head *list, struct drm_nouveau_gem_pushbuf_bo *pbbo, - uint64_t user_pbbo_ptr) + struct list_head *list, struct drm_nouveau_gem_pushbuf_bo *pbbo) { struct nouveau_drm *drm = chan->drm; - struct drm_nouveau_gem_pushbuf_bo __user *upbbo = - (void __force __user *)(uintptr_t)user_pbbo_ptr; struct nouveau_bo *nvbo; int ret, relocs = 0;
@@ -531,10 +528,6 @@ validate_list(struct nouveau_channel *chan, struct nouveau_cli *cli, b->presumed.offset = nvbo->bo.offset; b->presumed.valid = 0; relocs++; - - if (copy_to_user(&upbbo[nvbo->pbbo_index].presumed, - &b->presumed, sizeof(b->presumed))) - return -EFAULT; } }
@@ -545,8 +538,8 @@ static int nouveau_gem_pushbuf_validate(struct nouveau_channel *chan, struct drm_file *file_priv, struct drm_nouveau_gem_pushbuf_bo *pbbo, - uint64_t user_buffers, int nr_buffers, - struct validate_op *op, int *apply_relocs) + int nr_buffers, + struct validate_op *op, bool *apply_relocs) { struct nouveau_cli *cli = nouveau_cli(file_priv); int ret; @@ -563,7 +556,7 @@ nouveau_gem_pushbuf_validate(struct nouveau_channel *chan, return ret; }
- ret = validate_list(chan, cli, &op->list, pbbo, user_buffers); + ret = validate_list(chan, cli, &op->list, pbbo); if (unlikely(ret < 0)) { if (ret != -ERESTARTSYS) NV_PRINTK(err, cli, "validating bo list\n"); @@ -603,16 +596,12 @@ u_memcpya(uint64_t user, unsigned nmemb, unsigned size) static int nouveau_gem_pushbuf_reloc_apply(struct nouveau_cli *cli, struct drm_nouveau_gem_pushbuf *req, + struct drm_nouveau_gem_pushbuf_reloc *reloc, struct drm_nouveau_gem_pushbuf_bo *bo) { - struct drm_nouveau_gem_pushbuf_reloc *reloc = NULL; int ret = 0; unsigned i;
- reloc = u_memcpya(req->relocs, req->nr_relocs, sizeof(*reloc)); - if (IS_ERR(reloc)) - return PTR_ERR(reloc); - for (i = 0; i < req->nr_relocs; i++) { struct drm_nouveau_gem_pushbuf_reloc *r = &reloc[i]; struct drm_nouveau_gem_pushbuf_bo *b; @@ -691,11 +680,13 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, void *data, struct nouveau_drm *drm = nouveau_drm(dev); struct drm_nouveau_gem_pushbuf *req = data; struct drm_nouveau_gem_pushbuf_push *push; + struct drm_nouveau_gem_pushbuf_reloc *reloc = NULL; struct drm_nouveau_gem_pushbuf_bo *bo; struct nouveau_channel *chan = NULL; struct validate_op op; struct nouveau_fence *fence = NULL; - int i, j, ret = 0, do_reloc = 0; + int i, j, ret = 0; + bool do_reloc = false;
if (unlikely(!abi16)) return -ENOMEM; @@ -753,7 +744,8 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, void *data, }
/* Validate buffer list */ - ret = nouveau_gem_pushbuf_validate(chan, file_priv, bo, req->buffers, +revalidate: + ret = nouveau_gem_pushbuf_validate(chan, file_priv, bo, req->nr_buffers, &op, &do_reloc); if (ret) { if (ret != -ERESTARTSYS) @@ -763,7 +755,18 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, void *data,
/* Apply any relocations that are required */ if (do_reloc) { - ret = nouveau_gem_pushbuf_reloc_apply(cli, req, bo); + if (!reloc) { + validate_fini(&op, chan, NULL, bo); + reloc = u_memcpya(req->relocs, req->nr_relocs, sizeof(*reloc)); + if (IS_ERR(reloc)) { + ret = PTR_ERR(reloc); + goto out_prevalid; + } + + goto revalidate; + } + + ret = nouveau_gem_pushbuf_reloc_apply(cli, req, reloc, bo); if (ret) { NV_PRINTK(err, cli, "reloc apply: %d\n", ret); goto out; @@ -849,6 +852,22 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, void *data, validate_fini(&op, chan, fence, bo); nouveau_fence_unref(&fence);
+ if (do_reloc) { + struct drm_nouveau_gem_pushbuf_bo __user *upbbo = + u64_to_user_ptr(req->buffers); + + for (i = 0; i < req->nr_buffers; i++) { + if (bo[i].presumed.valid) + continue; + + if (copy_to_user(&upbbo[i].presumed, &bo[i].presumed, + sizeof(bo[i].presumed))) { + ret = -EFAULT; + break; + } + } + u_free(reloc); + } out_prevalid: u_free(bo); u_free(push);