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authorAlexei Starovoitov <ast@kernel.org>2025-02-20 18:10:24 -0800
committerAlexei Starovoitov <ast@kernel.org>2025-02-20 18:13:57 -0800
commitbd4319b6c2b36aa5c6534aec1dbe16921ec960ef (patch)
treeaec6748a7c59ea9a3ebb2c543b2e7f0ce2806b91 /kernel/trace/ring_buffer.c
parent7042882abc04c720ea798198981943502f4221fe (diff)
parent319fc77f8f45a1b3dba15b0cc1a869778fd222f7 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf bpf-6.14-rc4
Cross-merge bpf fixes after downstream PR (bpf-6.14-rc4). Minor conflict: kernel/bpf/btf.c Adjacent changes: kernel/bpf/arena.c kernel/bpf/btf.c kernel/bpf/syscall.c kernel/bpf/verifier.c mm/memory.c Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c28
1 files changed, 26 insertions, 2 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index b8e0ae15ca5b..bb6089c2951e 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1672,7 +1672,8 @@ static void *rb_range_buffer(struct ring_buffer_per_cpu *cpu_buffer, int idx)
* must be the same.
*/
static bool rb_meta_valid(struct ring_buffer_meta *meta, int cpu,
- struct trace_buffer *buffer, int nr_pages)
+ struct trace_buffer *buffer, int nr_pages,
+ unsigned long *subbuf_mask)
{
int subbuf_size = PAGE_SIZE;
struct buffer_data_page *subbuf;
@@ -1680,6 +1681,9 @@ static bool rb_meta_valid(struct ring_buffer_meta *meta, int cpu,
unsigned long buffers_end;
int i;
+ if (!subbuf_mask)
+ return false;
+
/* Check the meta magic and meta struct size */
if (meta->magic != RING_BUFFER_META_MAGIC ||
meta->struct_size != sizeof(*meta)) {
@@ -1712,6 +1716,8 @@ static bool rb_meta_valid(struct ring_buffer_meta *meta, int cpu,
subbuf = rb_subbufs_from_meta(meta);
+ bitmap_clear(subbuf_mask, 0, meta->nr_subbufs);
+
/* Is the meta buffers and the subbufs themselves have correct data? */
for (i = 0; i < meta->nr_subbufs; i++) {
if (meta->buffers[i] < 0 ||
@@ -1725,6 +1731,12 @@ static bool rb_meta_valid(struct ring_buffer_meta *meta, int cpu,
return false;
}
+ if (test_bit(meta->buffers[i], subbuf_mask)) {
+ pr_info("Ring buffer boot meta [%d] array has duplicates\n", cpu);
+ return false;
+ }
+
+ set_bit(meta->buffers[i], subbuf_mask);
subbuf = (void *)subbuf + subbuf_size;
}
@@ -1838,6 +1850,11 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer)
cpu_buffer->cpu);
goto invalid;
}
+
+ /* If the buffer has content, update pages_touched */
+ if (ret)
+ local_inc(&cpu_buffer->pages_touched);
+
entries += ret;
entry_bytes += local_read(&head_page->page->commit);
local_set(&cpu_buffer->head_page->entries, ret);
@@ -1889,17 +1906,22 @@ static void rb_meta_init_text_addr(struct ring_buffer_meta *meta)
static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages)
{
struct ring_buffer_meta *meta;
+ unsigned long *subbuf_mask;
unsigned long delta;
void *subbuf;
int cpu;
int i;
+ /* Create a mask to test the subbuf array */
+ subbuf_mask = bitmap_alloc(nr_pages + 1, GFP_KERNEL);
+ /* If subbuf_mask fails to allocate, then rb_meta_valid() will return false */
+
for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
void *next_meta;
meta = rb_range_meta(buffer, nr_pages, cpu);
- if (rb_meta_valid(meta, cpu, buffer, nr_pages)) {
+ if (rb_meta_valid(meta, cpu, buffer, nr_pages, subbuf_mask)) {
/* Make the mappings match the current address */
subbuf = rb_subbufs_from_meta(meta);
delta = (unsigned long)subbuf - meta->first_buffer;
@@ -1943,6 +1965,7 @@ static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages)
subbuf += meta->subbuf_size;
}
}
+ bitmap_free(subbuf_mask);
}
static void *rbm_start(struct seq_file *m, loff_t *pos)
@@ -7126,6 +7149,7 @@ int ring_buffer_map(struct trace_buffer *buffer, int cpu,
kfree(cpu_buffer->subbuf_ids);
cpu_buffer->subbuf_ids = NULL;
rb_free_meta_page(cpu_buffer);
+ atomic_dec(&cpu_buffer->resize_disabled);
}
unlock: