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4294a0a7ab
kernel/bpf/verifier.c file is large and growing larger all the time. So it's good to start splitting off more or less self-contained parts into separate files to keep source code size (somewhat) somewhat under control. This patch is a one step in this direction, moving some of BPF verifier log routines into a separate kernel/bpf/log.c. Right now it's most low-level and isolated routines to append data to log, reset log to previous position, etc. Eventually we could probably move verifier state printing logic here as well, but this patch doesn't attempt to do that yet. Subsequent patches will add more logic to verifier log management, so having basics in a separate file will make sure verifier.c doesn't grow more with new changes. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-2-andrii@kernel.org
85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
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* Copyright (c) 2016 Facebook
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* Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
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*/
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#include <uapi/linux/btf.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/bpf.h>
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#include <linux/bpf_verifier.h>
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bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log)
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{
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return log->len_total >= 128 && log->len_total <= UINT_MAX >> 2 &&
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log->level && log->ubuf && !(log->level & ~BPF_LOG_MASK);
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}
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void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
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va_list args)
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{
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unsigned int n;
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n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args);
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WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1,
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"verifier log line truncated - local buffer too short\n");
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if (log->level == BPF_LOG_KERNEL) {
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bool newline = n > 0 && log->kbuf[n - 1] == '\n';
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pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n");
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return;
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}
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n = min(log->len_total - log->len_used - 1, n);
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log->kbuf[n] = '\0';
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if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1))
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log->len_used += n;
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else
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log->ubuf = NULL;
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}
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void bpf_vlog_reset(struct bpf_verifier_log *log, u32 new_pos)
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{
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char zero = 0;
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if (!bpf_verifier_log_needed(log))
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return;
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log->len_used = new_pos;
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if (put_user(zero, log->ubuf + new_pos))
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log->ubuf = NULL;
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}
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/* log_level controls verbosity level of eBPF verifier.
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* bpf_verifier_log_write() is used to dump the verification trace to the log,
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* so the user can figure out what's wrong with the program
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*/
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__printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
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const char *fmt, ...)
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{
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va_list args;
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if (!bpf_verifier_log_needed(&env->log))
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return;
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va_start(args, fmt);
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bpf_verifier_vlog(&env->log, fmt, args);
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va_end(args);
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}
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EXPORT_SYMBOL_GPL(bpf_verifier_log_write);
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__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
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const char *fmt, ...)
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{
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va_list args;
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if (!bpf_verifier_log_needed(log))
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return;
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va_start(args, fmt);
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bpf_verifier_vlog(log, fmt, args);
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va_end(args);
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}
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EXPORT_SYMBOL_GPL(bpf_log);
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