Revision 5e98e916f95bdc50e90f3199d7f3d74b94fa5976 authored by Linus Torvalds on 12 February 2023, 21:52:17 UTC, committed by Linus Torvalds on 12 February 2023, 21:52:17 UTC
Pull tracing fix from Steven Rostedt:
 "Fix showing of TASK_COMM_LEN instead of its value

  The TASK_COMM_LEN was converted from a macro into an enum so that BTF
  would have access to it. But this unfortunately caused TASK_COMM_LEN
  to display in the format fields of trace events, as they are created
  by the TRACE_EVENT() macro and such, macros convert to their values,
  where as enums do not.

  To handle this, instead of using the field itself to be display, save
  the value of the array size as another field in the trace_event_fields
  structure, and use that instead.

  Not only does this fix the issue, but also converts the other trace
  events that have this same problem (but were not breaking tooling).

  With this change, the original work around b3bc8547d3be6 ("tracing:
  Have TRACE_DEFINE_ENUM affect trace event types as well") could be
  reverted (but that should be done in the merge window)"

* tag 'trace-v6.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Fix TASK_COMM_LEN in trace event format file
2 parent s 711e9a4 + b6c7abd
Raw File
memweight.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/export.h>
#include <linux/bug.h>
#include <linux/bitmap.h>

/**
 * memweight - count the total number of bits set in memory area
 * @ptr: pointer to the start of the area
 * @bytes: the size of the area
 */
size_t memweight(const void *ptr, size_t bytes)
{
	size_t ret = 0;
	size_t longs;
	const unsigned char *bitmap = ptr;

	for (; bytes > 0 && ((unsigned long)bitmap) % sizeof(long);
			bytes--, bitmap++)
		ret += hweight8(*bitmap);

	longs = bytes / sizeof(long);
	if (longs) {
		BUG_ON(longs >= INT_MAX / BITS_PER_LONG);
		ret += bitmap_weight((unsigned long *)bitmap,
				longs * BITS_PER_LONG);
		bytes -= longs * sizeof(long);
		bitmap += longs * sizeof(long);
	}
	/*
	 * The reason that this last loop is distinct from the preceding
	 * bitmap_weight() call is to compute 1-bits in the last region smaller
	 * than sizeof(long) properly on big-endian systems.
	 */
	for (; bytes > 0; bytes--, bitmap++)
		ret += hweight8(*bitmap);

	return ret;
}
EXPORT_SYMBOL(memweight);
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