Commit-ID: 7c72440506e2108494bab3b68a4118fa61a9dbf4 Gitweb: http://git.kernel.org/tip/7c72440506e2108494bab3b68a4118fa61a9dbf4 Author: David Carrillo-Cisneros <[email protected]> AuthorDate: Mon, 17 Jul 2017 21:25:37 -0700 Committer: Arnaldo Carvalho de Melo <[email protected]> CommitDate: Tue, 18 Jul 2017 23:14:29 -0300
perf util: Add const modifier to buf in "writen" function Make buf in helper function "writen" constant to simplify the life of its callers. This requires to hack a cast of buf prior to passing it to "ion" which is simpler than the alternative of reworking the "ion" function to provide a read and a write paths, the latter with constant buf argument. Signed-off-by: David Carrillo-Cisneros <[email protected]> Acked-by: David Ahern <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: He Kuang <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Turner <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Simon Que <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/util/util.c | 6 ++++-- tools/perf/util/util.h | 2 +- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c index 9e4ea85..4c360da 100644 --- a/tools/perf/util/util.c +++ b/tools/perf/util/util.c @@ -281,6 +281,7 @@ static ssize_t ion(bool is_read, int fd, void *buf, size_t n) size_t left = n; while (left) { + /* buf must be treated as const if !is_read. */ ssize_t ret = is_read ? read(fd, buf, left) : write(fd, buf, left); @@ -308,9 +309,10 @@ ssize_t readn(int fd, void *buf, size_t n) /* * Write exactly 'n' bytes or return an error. */ -ssize_t writen(int fd, void *buf, size_t n) +ssize_t writen(int fd, const void *buf, size_t n) { - return ion(false, fd, buf, n); + /* ion does not modify buf. */ + return ion(false, fd, (void *)buf, n); } size_t hex_width(u64 v) diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h index 062dd20..b136c27 100644 --- a/tools/perf/util/util.h +++ b/tools/perf/util/util.h @@ -38,7 +38,7 @@ int copyfile_ns(const char *from, const char *to, struct nsinfo *nsi); int copyfile_offset(int fromfd, loff_t from_ofs, int tofd, loff_t to_ofs, u64 size); ssize_t readn(int fd, void *buf, size_t n); -ssize_t writen(int fd, void *buf, size_t n); +ssize_t writen(int fd, const void *buf, size_t n); size_t hex_width(u64 v); int hex2u64(const char *ptr, u64 *val);
