tmakin/ack-tegra
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ring-buffer: Add magic and struct size to boot up meta data

Browse Source 
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>
This commit is contained in:
Steven Rostedt
2024-08-15 11:50:32 -04:00
committed by Steven Rostedt (Google)
parent bca704f62d
commit d0f2d6e951
1 changed files with 14 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/trace/ring_buffer.c
+14
View File
@@ -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;