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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
* Copyright (c) 2016 Facebook
* Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
*/
#include <uapi/linux/btf.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bpf.h>
#include <linux/bpf_verifier.h>
bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log)
{
return log->len_total >= 128 && log->len_total <= UINT_MAX >> 2 &&
log->level && log->ubuf && !(log->level & ~BPF_LOG_MASK);
}
void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
va_list args)
{
unsigned int n;
n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args);
WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1,
"verifier log line truncated - local buffer too short\n");
if (log->level == BPF_LOG_KERNEL) {
bool newline = n > 0 && log->kbuf[n - 1] == '\n';
pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n");
return;
}
n = min(log->len_total - log->len_used - 1, n);
log->kbuf[n] = '\0';
if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1))
log->len_used += n;
else
log->ubuf = NULL;
}
void bpf_vlog_reset(struct bpf_verifier_log *log, u32 new_pos)
{
char zero = 0;
if (!bpf_verifier_log_needed(log))
return;
log->len_used = new_pos;
if (put_user(zero, log->ubuf + new_pos))
log->ubuf = NULL;
}
/* log_level controls verbosity level of eBPF verifier.
* bpf_verifier_log_write() is used to dump the verification trace to the log,
* so the user can figure out what's wrong with the program
*/
__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
const char *fmt, ...)
{
va_list args;
if (!bpf_verifier_log_needed(&env->log))
return;
va_start(args, fmt);
bpf_verifier_vlog(&env->log, fmt, args);
va_end(args);
}
EXPORT_SYMBOL_GPL(bpf_verifier_log_write);
__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
const char *fmt, ...)
{
va_list args;
if (!bpf_verifier_log_needed(log))
return;
va_start(args, fmt);
bpf_verifier_vlog(log, fmt, args);
va_end(args);
}
EXPORT_SYMBOL_GPL(bpf_log);
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