From: Vincent Donnefort Date: Tue, 10 Sep 2024 16:23:35 +0000 (+0100) Subject: selftests/ring-buffer: Handle meta-page bigger than the system X-Git-Tag: dma-mapping-6.12-2024-10-20~198^2 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=75d7ff9aa0ae1a8d1b3f9c8c87dde3a4fbe9a2cf;p=users%2Fhch%2Fdma-mapping.git selftests/ring-buffer: Handle meta-page bigger than the system 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 Cc: linux-kselftest@vger.kernel.org Link: https://lore.kernel.org/20240910162335.2993310-3-vdonnefort@google.com Acked-by: Shuah Khan Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt (Google) --- 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; }