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@xxxxxxxxx>
Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
Cc: nouveau@xxxxxxxxxxxxxxxxxxxxx
---
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);
--
2.23.0.rc1
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