From: Jiri Olsa <[email protected]> Added a 'left' variable to make the flow clearer, and added a debug check for the return value - returning 'n' is more obvious.
Added small comment for readn. Signed-off-by: Jiri Olsa <[email protected]> Original-patch-by: Ingo Molnar <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: David Ahern <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/util/util.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c index 9440481e9092..6ea0b4ae9569 100644 --- a/tools/perf/util/util.c +++ b/tools/perf/util/util.c @@ -6,6 +6,7 @@ #endif #include <stdio.h> #include <stdlib.h> +#include <linux/kernel.h> /* * XXX We need to find a better place for these things... @@ -151,21 +152,26 @@ unsigned long convert_unit(unsigned long value, char *unit) return value; } +/* + * Read exactly 'n' bytes or return an error. + */ ssize_t readn(int fd, void *buf, size_t n) { void *buf_start = buf; + size_t left = n; - while (n) { - ssize_t ret = read(fd, buf, n); + while (left) { + ssize_t ret = read(fd, buf, left); if (ret <= 0) return ret; - n -= ret; - buf += ret; + left -= ret; + buf += ret; } - return buf - buf_start; + BUG_ON((size_t)(buf - buf_start) != n); + return n; } size_t hex_width(u64 v) -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
