The implementation of strjoin is a bit suboptimal. The destination string is traversed from the beginning due to strcat and we have a left-over separator at the end, while it should only be in-between.
Fix this. Signed-off-by: Ahmad Fatoum <a.fat...@pengutronix.de> --- Originally posted at: https://lore.barebox.org/barebox/20221027073334.gs6...@pengutronix.de/ Changes: - remove if statemnt in loop (Sascha) Signed-off-by: Ahmad Fatoum <a.fat...@pengutronix.de> --- lib/string.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/lib/string.c b/lib/string.c index d8e5edd40648..695e50bc8fc1 100644 --- a/lib/string.c +++ b/lib/string.c @@ -1005,7 +1005,7 @@ char *strjoin(const char *separator, char **arr, size_t arrlen) { size_t separatorlen; int len = 1; /* '\0' */ - char *buf; + char *buf, *p; int i; separatorlen = strlen(separator); @@ -1013,13 +1013,18 @@ char *strjoin(const char *separator, char **arr, size_t arrlen) for (i = 0; i < arrlen; i++) len += strlen(arr[i]) + separatorlen; - buf = xzalloc(len); + if (!arrlen) + return xzalloc(1); - for (i = 0; i < arrlen; i++) { - strcat(buf, arr[i]); - strcat(buf, separator); + p = buf = xmalloc(len); + + for (i = 0; i < arrlen - 1; i++) { + p = stpcpy(p, arr[i]); + p = mempcpy(p, separator, separatorlen); } + stpcpy(p, arr[i]); + return buf; } EXPORT_SYMBOL(strjoin); -- 2.39.2
