summaryrefslogtreecommitdiff
path: root/kernel/trace
diff options
context:
space:
mode:
authorSteven Rostedt <rostedt@goodmis.org>2024-08-15 11:50:32 -0400
committerSteven Rostedt (Google) <rostedt@goodmis.org>2024-08-26 13:34:22 -0400
commitd0f2d6e9512ecf4306c4432761f04bd35cf9e3a6 (patch)
tree384ff8e3b59b174a4d3c6add233074608eb2ff93 /kernel/trace
parentbca704f62db2e2bb644fa845e98b08cf1e22f814 (diff)
ring-buffer: Add magic and struct size to boot up meta data
Add a magic number as well as save the struct size of the ring_buffer_meta structure in the meta data to also use as validation. Updating the magic number could be used to force a invalidation between kernel versions, and saving the structure size is also a good method to make sure the content is what is expected. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Vincent Donnefort <vdonnefort@google.com> Link: https://lore.kernel.org/20240815115032.0c197b32@rorschach.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/ring_buffer.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index b16f301b8a93..c3a5e6cbb940 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -44,7 +44,11 @@
static void update_pages_handler(struct work_struct *work);
+#define RING_BUFFER_META_MAGIC 0xBADFEED
+
struct ring_buffer_meta {
+ int magic;
+ int struct_size;
unsigned long text_addr;
unsigned long data_addr;
unsigned long first_buffer;
@@ -1627,6 +1631,13 @@ static bool rb_meta_valid(struct ring_buffer_meta *meta, int cpu,
unsigned long buffers_end;
int i;
+ /* Check the meta magic and meta struct size */
+ if (meta->magic != RING_BUFFER_META_MAGIC ||
+ meta->struct_size != sizeof(*meta)) {
+ pr_info("Ring buffer boot meta[%d] mismatch of magic or struct size\n", cpu);
+ return false;
+ }
+
/* The subbuffer's size and number of subbuffers must match */
if (meta->subbuf_size != subbuf_size ||
meta->nr_subbufs != nr_pages + 1) {
@@ -1858,6 +1869,9 @@ static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages)
memset(meta, 0, next_meta - (void *)meta);
+ meta->magic = RING_BUFFER_META_MAGIC;
+ meta->struct_size = sizeof(*meta);
+
meta->nr_subbufs = nr_pages + 1;
meta->subbuf_size = PAGE_SIZE;