33bd6b5ac5
When using grub_malloc(), grub_zalloc() or grub_calloc(), these functions can fail if we are out of memory. After allocating memory we should check if these functions returned NULL and handle this error if they did. On the occasion make a NULL check in ATA code more obvious. Signed-off-by: Alec Brown <alec.r.brown@oracle.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
124 lines
3.4 KiB
C
124 lines
3.4 KiB
C
/* memdisk.c - Access embedded memory disk. */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2007,2008 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <grub/disk.h>
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#include <grub/dl.h>
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#include <grub/kernel.h>
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#include <grub/misc.h>
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#include <grub/mm.h>
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#include <grub/types.h>
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#include <grub/safemath.h>
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GRUB_MOD_LICENSE ("GPLv3+");
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static char *memdisk_addr;
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static grub_off_t memdisk_size = 0;
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static int
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grub_memdisk_iterate (grub_disk_dev_iterate_hook_t hook, void *hook_data,
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grub_disk_pull_t pull)
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{
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if (pull != GRUB_DISK_PULL_NONE)
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return 0;
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return hook ("memdisk", hook_data);
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}
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static grub_err_t
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grub_memdisk_open (const char *name, grub_disk_t disk)
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{
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if (grub_strcmp (name, "memdisk"))
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return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "not a memdisk");
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disk->total_sectors = memdisk_size / GRUB_DISK_SECTOR_SIZE;
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disk->max_agglomerate = GRUB_DISK_MAX_MAX_AGGLOMERATE;
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disk->id = 0;
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return GRUB_ERR_NONE;
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}
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static void
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grub_memdisk_close (grub_disk_t disk __attribute((unused)))
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{
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}
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static grub_err_t
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grub_memdisk_read (grub_disk_t disk __attribute((unused)), grub_disk_addr_t sector,
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grub_size_t size, char *buf)
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{
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grub_memcpy (buf, memdisk_addr + (sector << GRUB_DISK_SECTOR_BITS), size << GRUB_DISK_SECTOR_BITS);
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return 0;
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}
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static grub_err_t
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grub_memdisk_write (grub_disk_t disk __attribute((unused)), grub_disk_addr_t sector,
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grub_size_t size, const char *buf)
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{
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grub_memcpy (memdisk_addr + (sector << GRUB_DISK_SECTOR_BITS), buf, size << GRUB_DISK_SECTOR_BITS);
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return 0;
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}
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static struct grub_disk_dev grub_memdisk_dev =
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{
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.name = "memdisk",
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.id = GRUB_DISK_DEVICE_MEMDISK_ID,
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.disk_iterate = grub_memdisk_iterate,
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.disk_open = grub_memdisk_open,
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.disk_close = grub_memdisk_close,
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.disk_read = grub_memdisk_read,
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.disk_write = grub_memdisk_write,
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.next = 0
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};
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GRUB_MOD_INIT(memdisk)
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{
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struct grub_module_header *header;
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FOR_MODULES (header)
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if (header->type == OBJ_TYPE_MEMDISK)
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{
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char *memdisk_orig_addr;
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memdisk_orig_addr = (char *) header + sizeof (struct grub_module_header);
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grub_dprintf ("memdisk", "Found memdisk image at %p\n", memdisk_orig_addr);
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if (grub_sub (header->size, sizeof (struct grub_module_header), &memdisk_size))
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{
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grub_error (GRUB_ERR_OUT_OF_RANGE, "underflow detected while obtaining memdisk size");
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return;
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}
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memdisk_addr = grub_malloc (memdisk_size);
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if (memdisk_addr == NULL)
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return;
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grub_dprintf ("memdisk", "Copying memdisk image to dynamic memory\n");
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grub_memmove (memdisk_addr, memdisk_orig_addr, memdisk_size);
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grub_disk_dev_register (&grub_memdisk_dev);
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break;
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}
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}
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GRUB_MOD_FINI(memdisk)
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{
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if (! memdisk_size)
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return;
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grub_free (memdisk_addr);
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grub_disk_dev_unregister (&grub_memdisk_dev);
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}
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