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| author | Adrian Hunter <adrian.hunter@intel.com> | 2022-07-11 11:32:06 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-07-20 16:08:37 +0200 |
| commit | 10d34700223b14ed94a6399cf026142956f87965 (patch) | |
| tree | fbb9e3142583266b2d1622cb861df04d23e9b8b2 | |
| parent | perf tools: Automatically use guest kcore_dir if present (diff) | |
| download | linux-10d34700223b14ed94a6399cf026142956f87965.tar.xz linux-10d34700223b14ed94a6399cf026142956f87965.zip | |
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: Adrian 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: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/util.c | 33 | ||||
| -rw-r--r-- | tools/perf/util/util.h | 15 |
2 files changed, 48 insertions, 0 deletions
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c index 9b02edf9311d..391c1e928bd7 100644 --- a/tools/perf/util/util.c +++ b/tools/perf/util/util.c @@ -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; +} diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h index 0f78f1e7782d..c1f2d423a9ec 100644 --- a/tools/perf/util/util.h +++ b/tools/perf/util/util.h @@ -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 */ |