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// SPDX-License-Identifier: LGPL-2.1+
/* Copyright (C) 2022 Kent Overstreet */
#ifdef __KERNEL__
#include <linux/export.h>
#include <linux/kernel.h>
#else
#define EXPORT_SYMBOL(x)
#endif
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/printbuf.h>
int printbuf_make_room(struct printbuf *out, unsigned extra)
{
unsigned new_size;
char *buf;
if (!out->heap_allocated)
return 0;
/* Reserved space for terminating nul: */
extra += 1;
if (out->pos + extra < out->size)
return 0;
new_size = roundup_pow_of_two(out->size + extra);
buf = krealloc(out->buf, new_size, !out->atomic ? GFP_KERNEL : GFP_NOWAIT);
if (!buf) {
out->allocation_failure = true;
return -ENOMEM;
}
out->buf = buf;
out->size = new_size;
return 0;
}
EXPORT_SYMBOL(printbuf_make_room);
/**
* printbuf_str - returns printbuf's buf as a C string, guaranteed to be null
* terminated
*/
const char *printbuf_str(const struct printbuf *buf)
{
/*
* If we've written to a printbuf then it's guaranteed to be a null
* terminated string - but if we haven't, then we might not have
* allocated a buffer at all:
*/
return buf->pos
? buf->buf
: "";
}
EXPORT_SYMBOL(printbuf_str);
/**
* printbuf_exit - exit a printbuf, freeing memory it owns and poisoning it
* against accidental use.
*/
void printbuf_exit(struct printbuf *buf)
{
if (buf->heap_allocated) {
kfree(buf->buf);
buf->buf = ERR_PTR(-EINTR); /* poison value */
}
}
EXPORT_SYMBOL(printbuf_exit);
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