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https://github.com/torvalds/linux
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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>
46 lines
877 B
C
46 lines
877 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <unistd.h>
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#include <stdbool.h>
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#include <errno.h>
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#include <linux/kernel.h>
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#include <internal/lib.h>
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static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
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{
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void *buf_start = buf;
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size_t left = n;
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while (left) {
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/* buf must be treated as const if !is_read. */
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ssize_t ret = is_read ? read(fd, buf, left) :
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write(fd, buf, left);
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if (ret < 0 && errno == EINTR)
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continue;
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if (ret <= 0)
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return ret;
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left -= ret;
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buf += ret;
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}
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BUG_ON((size_t)(buf - buf_start) != n);
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return n;
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}
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/*
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* Read exactly 'n' bytes or return an error.
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*/
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ssize_t readn(int fd, void *buf, size_t n)
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{
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return ion(true, fd, buf, n);
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}
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/*
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* Write exactly 'n' bytes or return an error.
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*/
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ssize_t writen(int fd, const void *buf, size_t n)
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{
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/* ion does not modify buf. */
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return ion(false, fd, (void *)buf, n);
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}
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