Commit 10d34700 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf tools: Add reallocarray_as_needed() 



Add helper reallocarray_as_needed() to reallocate an array to a larger
size and initialize the extra entries to an arbitrary value.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20220711093218.10967-24-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent a5367ecb

tools/perf/util/util.c

+33 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/kernel.h>

#include <linux/log2.h>

#include <linux/time64.h>

#include <linux/overflow.h>

#include <unistd.h>

#include "cap.h"

#include "strlist.h"
@@ -500,3 +501,35 @@ char *filename_with_chroot(int pid, const char *filename) 


	return new_name;

}



/*

 * Reallocate an array *arr of size *arr_sz so that it is big enough to contain

 * x elements of size msz, initializing new entries to *init_val or zero if

 * init_val is NULL

 */

int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x, size_t msz, const void *init_val)

{

	size_t new_sz = *arr_sz;

	void *new_arr;

	size_t i;



	if (!new_sz)

		new_sz = msz >= 64 ? 1 : roundup(64, msz); /* Start with at least 64 bytes */

	while (x >= new_sz) {

		if (check_mul_overflow(new_sz, (size_t)2, &new_sz))

			return -ENOMEM;

	}

	if (new_sz == *arr_sz)

		return 0;

	new_arr = calloc(new_sz, msz);

	if (!new_arr)

		return -ENOMEM;

	memcpy(new_arr, *arr, *arr_sz * msz);

	if (init_val) {

		for (i = *arr_sz; i < new_sz; i++)

			memcpy(new_arr + (i * msz), init_val, msz);

	}

	*arr = new_arr;

	*arr_sz = new_sz;

	return 0;

}

tools/perf/util/util.h

+15 −0
Original line number Diff line number Diff line
@@ -79,4 +79,19 @@ struct perf_debuginfod { 
void perf_debuginfod_setup(struct perf_debuginfod *di);



char *filename_with_chroot(int pid, const char *filename);



int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x,

			       size_t msz, const void *init_val);



#define realloc_array_as_needed(a, n, x, v) ({			\

	typeof(x) __x = (x);					\

	__x >= (n) ?						\

		do_realloc_array_as_needed((void **)&(a),	\

					   &(n),		\

					   __x,			\

					   sizeof(*(a)),	\

					   (const void *)(v)) :	\

		0;						\

	})



#endif /* GIT_COMPAT_UTIL_H */