1810bcca4b
On i386 and amd64, add a vm_phys segment for physical memory used to store the kernel binary and other preloaded data. This makes it possible to free such memory back to the system once it is no longer needed, e.g., when a preloaded kernel module is unloaded. Previously, it would have remained unused. Reviewed by: kib, royger MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D16330
312 lines
6.9 KiB
C
312 lines
6.9 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 1998 Michael Smith
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/linker.h>
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#include <vm/vm.h>
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#include <vm/vm_extern.h>
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/*
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* Preloaded module support
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*/
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vm_offset_t preload_addr_relocate = 0;
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caddr_t preload_metadata;
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/*
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* Search for the preloaded module (name)
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*/
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caddr_t
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preload_search_by_name(const char *name)
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{
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caddr_t curp;
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uint32_t *hdr;
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int next;
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if (preload_metadata != NULL) {
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curp = preload_metadata;
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for (;;) {
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hdr = (uint32_t *)curp;
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if (hdr[0] == 0 && hdr[1] == 0)
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break;
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/* Search for a MODINFO_NAME field */
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if ((hdr[0] == MODINFO_NAME) &&
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!strcmp(name, curp + sizeof(uint32_t) * 2))
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return(curp);
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/* skip to next field */
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next = sizeof(uint32_t) * 2 + hdr[1];
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next = roundup(next, sizeof(u_long));
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curp += next;
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}
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}
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return(NULL);
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}
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/*
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* Search for the first preloaded module of (type)
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*/
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caddr_t
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preload_search_by_type(const char *type)
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{
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caddr_t curp, lname;
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uint32_t *hdr;
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int next;
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if (preload_metadata != NULL) {
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curp = preload_metadata;
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lname = NULL;
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for (;;) {
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hdr = (uint32_t *)curp;
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if (hdr[0] == 0 && hdr[1] == 0)
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break;
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/* remember the start of each record */
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if (hdr[0] == MODINFO_NAME)
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lname = curp;
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/* Search for a MODINFO_TYPE field */
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if ((hdr[0] == MODINFO_TYPE) &&
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!strcmp(type, curp + sizeof(uint32_t) * 2))
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return(lname);
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/* skip to next field */
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next = sizeof(uint32_t) * 2 + hdr[1];
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next = roundup(next, sizeof(u_long));
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curp += next;
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}
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}
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return(NULL);
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}
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/*
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* Walk through the preloaded module list
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*/
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caddr_t
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preload_search_next_name(caddr_t base)
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{
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caddr_t curp;
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uint32_t *hdr;
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int next;
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if (preload_metadata != NULL) {
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/* Pick up where we left off last time */
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if (base) {
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/* skip to next field */
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curp = base;
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hdr = (uint32_t *)curp;
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next = sizeof(uint32_t) * 2 + hdr[1];
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next = roundup(next, sizeof(u_long));
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curp += next;
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} else
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curp = preload_metadata;
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for (;;) {
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hdr = (uint32_t *)curp;
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if (hdr[0] == 0 && hdr[1] == 0)
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break;
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/* Found a new record? */
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if (hdr[0] == MODINFO_NAME)
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return curp;
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/* skip to next field */
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next = sizeof(uint32_t) * 2 + hdr[1];
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next = roundup(next, sizeof(u_long));
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curp += next;
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}
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}
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return(NULL);
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}
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/*
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* Given a preloaded module handle (mod), return a pointer
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* to the data for the attribute (inf).
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*/
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caddr_t
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preload_search_info(caddr_t mod, int inf)
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{
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caddr_t curp;
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uint32_t *hdr;
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uint32_t type = 0;
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int next;
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if (mod == NULL)
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return (NULL);
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curp = mod;
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for (;;) {
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hdr = (uint32_t *)curp;
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/* end of module data? */
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if (hdr[0] == 0 && hdr[1] == 0)
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break;
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/*
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* We give up once we've looped back to what we were looking at
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* first - this should normally be a MODINFO_NAME field.
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*/
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if (type == 0) {
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type = hdr[0];
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} else {
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if (hdr[0] == type)
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break;
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}
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/*
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* Attribute match? Return pointer to data.
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* Consumer may safely assume that size value precedes
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* data.
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*/
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if (hdr[0] == inf)
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return(curp + (sizeof(uint32_t) * 2));
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/* skip to next field */
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next = sizeof(uint32_t) * 2 + hdr[1];
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next = roundup(next, sizeof(u_long));
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curp += next;
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}
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return(NULL);
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}
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/*
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* Delete a preload record by name.
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*/
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void
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preload_delete_name(const char *name)
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{
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caddr_t addr, curp;
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uint32_t *hdr, sz;
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int next;
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int clearing;
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addr = 0;
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sz = 0;
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if (preload_metadata != NULL) {
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clearing = 0;
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curp = preload_metadata;
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for (;;) {
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hdr = (uint32_t *)curp;
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if (hdr[0] == MODINFO_NAME || (hdr[0] == 0 && hdr[1] == 0)) {
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/* Free memory used to store the file. */
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if (addr != 0 && sz != 0)
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kmem_bootstrap_free((vm_offset_t)addr, sz);
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addr = 0;
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sz = 0;
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if (hdr[0] == 0)
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break;
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if (!strcmp(name, curp + sizeof(uint32_t) * 2))
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clearing = 1; /* got it, start clearing */
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else if (clearing) {
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clearing = 0; /* at next one now.. better stop */
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}
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}
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if (clearing) {
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if (hdr[0] == MODINFO_ADDR)
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addr = *(caddr_t *)(curp + sizeof(uint32_t) * 2);
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else if (hdr[0] == MODINFO_SIZE)
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sz = *(uint32_t *)(curp + sizeof(uint32_t) * 2);
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hdr[0] = MODINFO_EMPTY;
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}
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/* skip to next field */
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next = sizeof(uint32_t) * 2 + hdr[1];
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next = roundup(next, sizeof(u_long));
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curp += next;
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}
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}
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}
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void *
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preload_fetch_addr(caddr_t mod)
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{
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caddr_t *mdp;
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mdp = (caddr_t *)preload_search_info(mod, MODINFO_ADDR);
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if (mdp == NULL)
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return (NULL);
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return (*mdp + preload_addr_relocate);
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}
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size_t
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preload_fetch_size(caddr_t mod)
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{
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size_t *mdp;
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mdp = (size_t *)preload_search_info(mod, MODINFO_SIZE);
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if (mdp == NULL)
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return (0);
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return (*mdp);
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}
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/* Called from locore. Convert physical pointers to kvm. Sigh. */
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void
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preload_bootstrap_relocate(vm_offset_t offset)
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{
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caddr_t curp;
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uint32_t *hdr;
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vm_offset_t *ptr;
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int next;
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if (preload_metadata != NULL) {
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curp = preload_metadata;
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for (;;) {
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hdr = (uint32_t *)curp;
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if (hdr[0] == 0 && hdr[1] == 0)
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break;
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/* Deal with the ones that we know we have to fix */
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switch (hdr[0]) {
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case MODINFO_ADDR:
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case MODINFO_METADATA|MODINFOMD_SSYM:
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case MODINFO_METADATA|MODINFOMD_ESYM:
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ptr = (vm_offset_t *)(curp + (sizeof(uint32_t) * 2));
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*ptr += offset;
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break;
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}
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/* The rest is beyond us for now */
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/* skip to next field */
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next = sizeof(uint32_t) * 2 + hdr[1];
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next = roundup(next, sizeof(u_long));
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curp += next;
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}
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}
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}
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