forked from Minki/linux
c03538b1f1
Move the readn()/writen() functions into libperf. Keep those non-namespaced names because they will be shared only between perf and libperf. Again, these are not exported functions. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexey Budankov <alexey.budankov@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20190721112506.12306-61-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
47 lines
877 B
C
47 lines
877 B
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <unistd.h>
|
|
#include <stdbool.h>
|
|
#include <errno.h>
|
|
#include <linux/kernel.h>
|
|
#include <internal/lib.h>
|
|
|
|
static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
|
|
{
|
|
void *buf_start = buf;
|
|
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);
|
|
|
|
if (ret < 0 && errno == EINTR)
|
|
continue;
|
|
if (ret <= 0)
|
|
return ret;
|
|
|
|
left -= ret;
|
|
buf += ret;
|
|
}
|
|
|
|
BUG_ON((size_t)(buf - buf_start) != n);
|
|
return n;
|
|
}
|
|
|
|
/*
|
|
* Read exactly 'n' bytes or return an error.
|
|
*/
|
|
ssize_t readn(int fd, void *buf, size_t n)
|
|
{
|
|
return ion(true, fd, buf, n);
|
|
}
|
|
|
|
/*
|
|
* Write exactly 'n' bytes or return an error.
|
|
*/
|
|
ssize_t writen(int fd, const void *buf, size_t n)
|
|
{
|
|
/* ion does not modify buf. */
|
|
return ion(false, fd, (void *)buf, n);
|
|
}
|