gpu: host1x: Do not leak BO's phys address to userspace

Perform gathers coping before patching them, so that original gathers are
left untouched. That's not as bad as leaking kernel addresses, but still
doesn't feel right.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/host1x/job.c

@@ -137,8 +137,9 @@ static void host1x_syncpt_patch_offset(struct host1x_syncpt *sp,
  * avoid a wrap condition in the HW).
  */
 static int do_waitchks(struct host1x_job *job, struct host1x *host,
-		       struct host1x_bo *patch)
+		       struct host1x_job_gather *g)
 {
+	struct host1x_bo *patch = g->bo;
 	int i;
 
 	/* compare syncpt vs wait threshold */
@@ -165,7 +166,8 @@ static int do_waitchks(struct host1x_job *job, struct host1x *host,
 				wait->syncpt_id, sp->name, wait->thresh,
 				host1x_syncpt_read_min(sp));
 
-			host1x_syncpt_patch_offset(sp, patch, wait->offset);
+			host1x_syncpt_patch_offset(sp, patch,
+						   g->offset + wait->offset);
 		}
 
 		wait->bo = NULL;
@@ -269,11 +271,12 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
 	return err;
 }
 
-static int do_relocs(struct host1x_job *job, struct host1x_bo *cmdbuf)
+static int do_relocs(struct host1x_job *job, struct host1x_job_gather *g)
 {
 	int i = 0;
 	u32 last_page = ~0;
 	void *cmdbuf_page_addr = NULL;
+	struct host1x_bo *cmdbuf = g->bo;
 
 	/* pin & patch the relocs for one gather */
 	for (i = 0; i < job->num_relocs; i++) {
@@ -286,6 +289,13 @@ static int do_relocs(struct host1x_job *job, struct host1x_bo *cmdbuf)
 		if (cmdbuf != reloc->cmdbuf.bo)
 			continue;
 
+		if (IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL)) {
+			target = (u32 *)job->gather_copy_mapped +
+					reloc->cmdbuf.offset / sizeof(u32) +
+						g->offset / sizeof(u32);
+			goto patch_reloc;
+		}
+
 		if (last_page != reloc->cmdbuf.offset >> PAGE_SHIFT) {
 			if (cmdbuf_page_addr)
 				host1x_bo_kunmap(cmdbuf, last_page,
@@ -302,6 +312,7 @@ static int do_relocs(struct host1x_job *job, struct host1x_bo *cmdbuf)
 		}
 
 		target = cmdbuf_page_addr + (reloc->cmdbuf.offset & ~PAGE_MASK);
+patch_reloc:
 		*target = reloc_addr;
 	}
 
@@ -573,6 +584,12 @@ int host1x_job_pin(struct host1x_job *job, struct device *dev)
 	if (err)
 		goto out;
 
+	if (IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL)) {
+		err = copy_gathers(job, dev);
+		if (err)
+			goto out;
+	}
+
 	/* patch gathers */
 	for (i = 0; i < job->num_gathers; i++) {
 		struct host1x_job_gather *g = &job->gathers[i];
@@ -581,6 +598,8 @@ int host1x_job_pin(struct host1x_job *job, struct device *dev)
 		if (g->handled)
 			continue;
 
+		/* copy_gathers() sets gathers base if firewall is enabled */
+		if (!IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL))
 			g->base = job->gather_addr_phys[i];
 
 		for (j = i + 1; j < job->num_gathers; j++) {
@@ -590,19 +609,15 @@ int host1x_job_pin(struct host1x_job *job, struct device *dev)
 			}
 		}
 
-		err = do_relocs(job, g->bo);
+		err = do_relocs(job, g);
 		if (err)
-			goto out;
+			break;
 
-		err = do_waitchks(job, host, g->bo);
+		err = do_waitchks(job, host, g);
 		if (err)
-			goto out;
+			break;
 	}
 
-	if (!IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL))
-		goto out;
-
-	err = copy_gathers(job, dev);
 out:
 	if (err)
 		host1x_job_unpin(job);