diff mbox series

[2/2] ring-buffer/selftest: Handle meta-page bigger than the system

Message ID 20240828154040.2803428-2-vdonnefort@google.com (mailing list archive)
State Superseded
Commit 75d7ff9aa0ae1a8d1b3f9c8c87dde3a4fbe9a2cf
Headers show
Series [1/2] ring-buffer/selftest: Verify the entire meta-page padding | expand

Commit Message

Vincent Donnefort Aug. 28, 2024, 3:40 p.m. UTC 
Handle the case where the meta-page content is bigger than the system
page-size. This prepares the ground for extending features covered by
the meta-page.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
diff mbox series

Patch

diff --git a/tools/testing/selftests/ring-buffer/map_test.c b/tools/testing/selftests/ring-buffer/map_test.c
index ba12fd31de87..d10a847130fb 100644
--- a/tools/testing/selftests/ring-buffer/map_test.c
+++ b/tools/testing/selftests/ring-buffer/map_test.c
@@ -92,12 +92,22 @@  int tracefs_cpu_map(struct tracefs_cpu_map_desc *desc, int cpu)
 	if (desc->cpu_fd < 0)
 		return -ENODEV;
 
+again:
 	map = mmap(NULL, page_size, PROT_READ, MAP_SHARED, desc->cpu_fd, 0);
 	if (map == MAP_FAILED)
 		return -errno;
 
 	desc->meta = (struct trace_buffer_meta *)map;
 
+	/* the meta-page is bigger than the original mapping */
+	if (page_size < desc->meta->meta_struct_len) {
+		int meta_page_size = desc->meta->meta_page_size;
+
+		munmap(desc->meta, page_size);
+		page_size = meta_page_size;
+		goto again;
+	}
+
 	return 0;
 }