[Mesa-dev] [PATCH] radv: Use build ID if available for cache UUID.

[Bas Nieuwenhuizen]

To get an useful UUID for systems that have a non-useful mtime
for the binaries.

I started using using SHA1 to ensure we get reasonable mixing
in the various possibilities and the various build id lengths.

CC: <mesa-stable at lists.freedesktop.org>
---
 src/amd/vulkan/radv_device.c | 43 +++++++++++++++++++++++++++++-------
 1 file changed, 35 insertions(+), 8 deletions(-)

diff --git a/src/amd/vulkan/radv_device.c b/src/amd/vulkan/radv_device.c
index 8989ec3553f..a2a73089f27 100644
--- a/src/amd/vulkan/radv_device.c
+++ b/src/amd/vulkan/radv_device.c
@@ -45,22 +45,49 @@
 #include "sid.h"
 #include "gfx9d.h"
 #include "addrlib/gfx9/chip/gfx9_enum.h"
+#include "util/build_id.h"
 #include "util/debug.h"
+#include "util/mesa-sha1.h"
+
+static bool
+radv_get_build_id(void *ptr, struct mesa_sha1 *ctx)
+{
+	uint32_t timestamp;
+
+#ifdef HAVE_DL_ITERATE_PHDR
+	const struct build_id_note *note = NULL;
+	if ((note = build_id_find_nhdr_for_addr(ptr))) {
+		_mesa_sha1_update(ctx, build_id_data(note), build_id_length(note));
+	} else
+#endif
+	if (disk_cache_get_function_timestamp(ptr, &timestamp)) {
+		if (!timestamp) {
+			fprintf(stderr, "radv: The provided filesystem timestamp for the cache is bogus!\n");
+		}
+
+		_mesa_sha1_update(ctx, &timestamp, sizeof(timestamp));
+	} else
+		return false;
+	return true;
+}
 
 static int
 radv_device_get_cache_uuid(enum radeon_family family, void *uuid)
 {
-	uint32_t mesa_timestamp, llvm_timestamp;
-	uint16_t f = family;
+	struct mesa_sha1 ctx;
+	unsigned char sha1[20];
+	unsigned ptr_size = sizeof(void*);
 	memset(uuid, 0, VK_UUID_SIZE);
-	if (!disk_cache_get_function_timestamp(radv_device_get_cache_uuid, &mesa_timestamp) ||
-	    !disk_cache_get_function_timestamp(LLVMInitializeAMDGPUTargetInfo, &llvm_timestamp))
+
+	if (!radv_get_build_id(radv_device_get_cache_uuid, &ctx) ||
+	    !radv_get_build_id(LLVMInitializeAMDGPUTargetInfo, &ctx))
 		return -1;
 
-	memcpy(uuid, &mesa_timestamp, 4);
-	memcpy((char*)uuid + 4, &llvm_timestamp, 4);
-	memcpy((char*)uuid + 8, &f, 2);
-	snprintf((char*)uuid + 10, VK_UUID_SIZE - 10, "radv%zd", sizeof(void *));
+	_mesa_sha1_update(&ctx, &family, sizeof(family));
+	_mesa_sha1_update(&ctx, &ptr_size, sizeof(ptr_size));
+	_mesa_sha1_final(&ctx, sha1);
+
+	memcpy(uuid, sha1, VK_UUID_SIZE);
 	return 0;
 }
 
-- 
2.19.0