Re: [PATCH v17 2/6] ring-buffer: Introducing ring-buffer mapping functions
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2024-02-13 20:51:40
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On Tue, 13 Feb 2024 11:49:41 +0000 Vincent Donnefort [off-list ref] wrote: Did you test with lockdep?
quoted hunk ↗ jump to hunk
+static int __rb_inc_dec_mapped(struct trace_buffer *buffer, + struct ring_buffer_per_cpu *cpu_buffer, + bool inc) +{ + unsigned long flags; + + lockdep_assert_held(cpu_buffer->mapping_lock);
/work/git/linux-trace.git/kernel/trace/ring_buffer.c: In function ‘__rb_inc_dec_mapped’:
/work/git/linux-trace.git/include/linux/lockdep.h:234:61: error: invalid type argument of ‘->’ (have ‘struct mutex’)
234 | #define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map)
| ^~
/work/git/linux-trace.git/include/asm-generic/bug.h:123:32: note: in definition of macro ‘WARN_ON’
123 | int __ret_warn_on = !!(condition); \
| ^~~~~~~~~
/work/git/linux-trace.git/include/linux/lockdep.h:267:9: note: in expansion of macro ‘lockdep_assert’
267 | lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
| ^~~~~~~~~~~~~~
/work/git/linux-trace.git/include/linux/lockdep.h:267:24: note: in expansion of macro ‘lockdep_is_held’
267 | lockdep_assert(lockdep_is_held(l) != LOCK_STATE_NOT_HELD)
| ^~~~~~~~~~~~~~~
/work/git/linux-trace.git/kernel/trace/ring_buffer.c:6167:9: note: in expansion of macro ‘lockdep_assert_held’
6167 | lockdep_assert_held(cpu_buffer->mapping_lock);
| ^~~~~~~~~~~~~~~~~~~
I believe that is supposed to be:
lockdep_assert_held(&cpu_buffer->mapping_lock);
-- Steve
quoted hunk ↗ jump to hunk
+ + if (inc && cpu_buffer->mapped == UINT_MAX) + return -EBUSY; + + if (WARN_ON(!inc && cpu_buffer->mapped == 0)) + return -EINVAL; + + mutex_lock(&buffer->mutex); + raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags); + + if (inc) + cpu_buffer->mapped++; + else + cpu_buffer->mapped--; + + raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags); + mutex_unlock(&buffer->mutex); + + return 0; +}