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| author | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2026-03-22 12:20:42 +0000 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2026-03-22 12:20:42 +0000 |
| commit | 9e4e86a604dfd06402933467578c4b79f5412b2c (patch) | |
| tree | 5cf2d962b699987c8a785e35a5f5c5f450532c0a /kernel/trace/ring_buffer.c | |
| parent | e8b83499b4cbc8b989f7cd6aaa893b669326e93c (diff) | |
| parent | f338e77383789c0cae23ca3d48adcc5e9e137e3c (diff) | |
Merge tag 'v7.0-rc4' into togreg
Linux 7.0-rc4
Required for the ds4422 series which is build upon;
5187e03b817c ("iio: dac: ds4424: reject -128 RAW value")
Diffstat (limited to 'kernel/trace/ring_buffer.c')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index f16f053ef77d..17d0ea0cc3e6 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -7310,6 +7310,27 @@ int ring_buffer_map(struct trace_buffer *buffer, int cpu, return err; } +/* + * This is called when a VMA is duplicated (e.g., on fork()) to increment + * the user_mapped counter without remapping pages. + */ +void ring_buffer_map_dup(struct trace_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (WARN_ON(!cpumask_test_cpu(cpu, buffer->cpumask))) + return; + + cpu_buffer = buffer->buffers[cpu]; + + guard(mutex)(&cpu_buffer->mapping_lock); + + if (cpu_buffer->user_mapped) + __rb_inc_dec_mapped(cpu_buffer, true); + else + WARN(1, "Unexpected buffer stat, it should be mapped"); +} + int ring_buffer_unmap(struct trace_buffer *buffer, int cpu) { struct ring_buffer_per_cpu *cpu_buffer; |
