mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-16 14:30:06 -04:00
Code Issues Packages Projects Releases Wiki Activity

tracing/remotes: Fix struct_len in trace_remote_alloc_buffer()

Browse Source 
Pre-calculate desc->struct_len up-front in trace_remote_alloc_buffer()
with trace_buffer_desc_size() to fix double-counting.

While at it, use the accessor __first_ring_buffer_desc().

Link: https://patch.msgid.link/20260709160017.1729517-3-vdonnefort@google.com
Fixes: 96e43537af ("tracing: Introduce trace remotes")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Vincent Donnefort
2026-07-09 17:00:16 +01:00
committed by Steven Rostedt
parent ec082d0b97
commit d471d4f86e
1 changed files with 4 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
kernel/trace/trace_remote.c
View File

@@ -979,27 +979,22 @@ EXPORT_SYMBOL_GPL(trace_remote_free_buffer);
int trace_remote_alloc_buffer(struct trace_buffer_desc *desc, size_t desc_size, size_t buffer_size,
const struct cpumask *cpumask)
{
size_t min_desc_size = trace_buffer_desc_size(buffer_size, cpumask_weight(cpumask));
unsigned int nr_pages = max(DIV_ROUND_UP(buffer_size, PAGE_SIZE), 2UL) + 1;
void *desc_end = desc + desc_size;
struct ring_buffer_desc *rb_desc;
int cpu, ret = -ENOMEM;
if (desc_size < struct_size(desc, __data, 0))
if (desc_size < min_desc_size)
return -EINVAL;
desc->nr_cpus = 0;
desc->struct_len = struct_size(desc, __data, 0);
desc->struct_len = min_desc_size;
rb_desc = (struct ring_buffer_desc *)&desc->__data[0];
rb_desc = __first_ring_buffer_desc(desc);
for_each_cpu(cpu, cpumask) {
unsigned int id;
if ((void *)rb_desc + struct_size(rb_desc, page_va, nr_pages) > desc_end) {
ret = -EINVAL;
goto err;
}
rb_desc->cpu = cpu;
rb_desc->nr_page_va = 0;
rb_desc->meta_va = (unsigned long)__get_free_page(GFP_KERNEL);
@@ -1015,8 +1010,6 @@ int trace_remote_alloc_buffer(struct trace_buffer_desc *desc, size_t desc_size,
rb_desc->nr_page_va++;
}
desc->struct_len += offsetof(struct ring_buffer_desc, page_va);
desc->struct_len += struct_size(rb_desc, page_va, rb_desc->nr_page_va);
rb_desc = __next_ring_buffer_desc(rb_desc);
}