gpu: nvgpu: mm: use constants for string lengths

For VM and allocator names, hardcoded constants were used which
can be a weakness. This patch uses proper defines in headers
instead.

JIRA NVGPU-4946

Change-Id: I1cc100a558d0c44c208a7e579cc36b71a0d4eeec
Signed-off-by: Nicolas Benech <nbenech@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2291069
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-mobile-cert <svc-mobile-cert@nvidia.com>
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/common/mm/as.c

@@ -56,7 +56,7 @@ static int gk20a_vm_alloc_share(struct gk20a_as_share *as_share,
 	struct gk20a *g = gk20a_from_as(as);
 	struct mm_gk20a *mm = &g->mm;
 	struct vm_gk20a *vm;
-	char name[32];
+	char name[NVGPU_VM_NAME_LEN];
 	char *p;
 	const bool userspace_managed =
 		(flags & NVGPU_AS_ALLOC_USERSPACE_MANAGED) != 0U;

drivers/gpu/nvgpu/common/mm/vm.c

@@ -398,7 +398,15 @@ static int nvgpu_vm_init_user_vma(struct gk20a *g, struct vm_gk20a *vm,
 			const char *name)
 {
 	int err = 0;
-	char alloc_name[32];
+	char alloc_name[NVGPU_ALLOC_NAME_LEN];
+	size_t name_len;
+
+	name_len  = strlen("gk20a_") + strlen(name);
+	if (name_len >= NVGPU_ALLOC_NAME_LEN) {
+		nvgpu_err(g, "Invalid MAX_NAME_SIZE %lu %u", name_len,
+			NVGPU_ALLOC_NAME_LEN);
+		return -EINVAL;
+	}
 
 	/*
 	 * User VMA.

drivers/gpu/nvgpu/include/nvgpu/allocator.h

@@ -57,6 +57,8 @@ struct nvgpu_alloc_carveout;
 struct vm_gk20a;
 struct gk20a;
 
+#define NVGPU_ALLOC_NAME_LEN	32U
+
 /**
  * Structure containing operations for an allocator to implement.
  */
@@ -217,7 +219,7 @@ struct nvgpu_allocator {
 	/**
 	 * Name of allocator.
 	 */
-	char name[32];
+	char name[NVGPU_ALLOC_NAME_LEN];
 	/**
 	 * Synchronization mutex.
 	 */

drivers/gpu/nvgpu/include/nvgpu/vm.h

@@ -97,6 +97,8 @@ struct nvgpu_os_buffer;
 #include <nvgpu_rmos/include/vm.h>
 #endif
 
+#define NVGPU_VM_NAME_LEN	20U
+
 /**
  * This structure describes the properties of batch mapping/unmapping.
  */
@@ -222,7 +224,7 @@ struct vm_gk20a {
 	 */
 	struct gk20a_as_share *as_share;
 	/** Name of the Virtual Memory context. */
-	char name[20];
+	char name[NVGPU_VM_NAME_LEN];
 
 	/** Start GPU address of the context. */
 	u64 va_start;