Commit 7c724405 authored by David Carrillo-Cisneros's avatar David Carrillo-Cisneros Committed by Arnaldo Carvalho de Melo

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: default avatarDavid Carrillo-Cisneros <davidcc@google.com>
Acked-by: default avatarDavid Ahern <dsahern@gmail.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170718042549.145161-5-davidcc@google.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 2ff5365d
......@@ -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)
......
......@@ -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);
......
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