From: Vincent Donnefort vdonnefort@google.com

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.

Cc: Shuah Khan skhan@linuxfoundation.org Cc: linux-kselftest@vger.kernel.org Link: https://lore.kernel.org/20240910162335.2993310-3-vdonnefort@google.com Acked-by: Shuah Khan skhan@linuxfoundation.org Signed-off-by: Vincent Donnefort vdonnefort@google.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org --- tools/testing/selftests/ring-buffer/map_test.c | 10 ++++++++++ 1 file changed, 10 insertions(+)

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; }