Differential D19258 Diff 54099 sys/compat/linuxkpi/common/src/linux_seq_file.c

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sys/compat/linuxkpi/common/src/linux_seq_file.c

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				/*-
				* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
				*
				* Copyright (c) 2016-2018, Matthew Macy <mmacy@freebsd.org>
				*
				* Redistribution and use in source and binary forms, with or without
				* modification, are permitted provided that the following conditions
				* are met:
				* 1. Redistributions of source code must retain the above copyright
				* notice, this list of conditions and the following disclaimer.
				* 2. Redistributions in binary form must reproduce the above copyright
				* notice, this list of conditions and the following disclaimer in the
				* documentation and/or other materials provided with the distribution.
				*
				* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
				* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
				* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
				* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
				* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
				* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
				* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
				* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
				* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
				* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
				* SUCH DAMAGE.
				*
				*/

				#include <sys/cdefs.h>
				__FBSDID("$FreeBSD$");

				#include <sys/types.h>
				#include <sys/systm.h>
				#include <sys/param.h>
				#include <sys/sbuf.h>
				#include <sys/syslog.h>
				#include <sys/vnode.h>

				#include <linux/seq_file.h>
				#include <linux/file.h>

				#undef file
				MALLOC_DEFINE(M_LSEQ, "seq_file", "seq_file");

				ssize_t
				seq_read(struct linux_file f, char ubuf, size_t size, off_t *ppos)
				{
				struct seq_file *m = f->private_data;
				void *p;
				int rc;
				off_t pos = 0;

				p = m->op->start(m, &pos);
				rc = m->op->show(m, p);
				if (rc)
				return (rc);
				return (size);
				}

				int
				seq_write(struct seq_file seq, const void data, size_t len)
				{

				return (sbuf_bcpy(seq->buf, data, len));
				}

				/*
				* This only needs to be a valid address for lkpi
				* drivers it should never actually be called
				*/
				off_t
				seq_lseek(struct linux_file *file, off_t offset, int whence)
				{

				panic("%s not supported\n", __FUNCTION__);
				return (0);
				}

				static void *
				single_start(struct seq_file p, off_t pos)
				{

				return ((void )(uintptr_t)(pos == 0));
				}

				static void *
				single_next(struct seq_file p, void v, off_t *pos)
				{

				++*pos;
				return (NULL);
				}

				static void
				single_stop(struct seq_file p, void v)
				{
				}

				int
				seq_open(struct linux_file f, const struct seq_operations op)
				{
				struct seq_file *p;

				if (f->private_data != NULL)
				log(LOG_WARNING, "%s private_data not NULL", __func__);

				if ((p = malloc(sizeof(*p), M_LSEQ, M_NOWAIT\|M_ZERO)) == NULL)
				return (-ENOMEM);

				f->private_data = p;
				p->op = op;
				p->file = f;
				return (0);
				}

				int
				single_open(struct linux_file f, int (show)(struct seq_file , void ), void *d)
				{
				struct seq_operations *op;
				int rc = -ENOMEM;

				op = malloc(sizeof(*op), M_LSEQ, M_NOWAIT);
				if (op) {
				op->start = single_start;
				op->next = single_next;
				op->stop = single_stop;
				op->show = show;
				rc = seq_open(f, op);
				if (rc)
				free(op, M_LSEQ);
				else
				((struct seq_file *)f->private_data)->private = d;

				}
				return (rc);
				}

				int
				seq_release(struct inode inode __unused, struct linux_file file)
				{
				struct seq_file *m;

				m = file->private_data;
				free(m, M_LSEQ);
				return (0);
				}

				int
				single_release(struct vnode v, struct linux_file f)
				{
				const struct seq_operations op = ((struct seq_file )f->private_data)->op;
				int rc;

				rc = seq_release(v, f);
				free(__DECONST(void *, op), M_LSEQ);
				return (rc);
				}