From 6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:29:51 +0200 Subject: Adding upstream version 2.06. Signed-off-by: Daniel Baumann --- grub-core/kern/disk_common.c | 66 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 grub-core/kern/disk_common.c (limited to 'grub-core/kern/disk_common.c') diff --git a/grub-core/kern/disk_common.c b/grub-core/kern/disk_common.c new file mode 100644 index 0000000..e09fba8 --- /dev/null +++ b/grub-core/kern/disk_common.c @@ -0,0 +1,66 @@ +/* This function performs three tasks: + - Make sectors disk relative from partition relative. + - Normalize offset to be less than the sector size. + - Verify that the range is inside the partition. */ +static grub_err_t +grub_disk_adjust_range (grub_disk_t disk, grub_disk_addr_t *sector, + grub_off_t *offset, grub_size_t size) +{ + grub_partition_t part; + grub_disk_addr_t total_sectors; + + *sector += *offset >> GRUB_DISK_SECTOR_BITS; + *offset &= GRUB_DISK_SECTOR_SIZE - 1; + + for (part = disk->partition; part; part = part->parent) + { + grub_disk_addr_t start; + grub_uint64_t len; + + start = part->start; + len = part->len; + + if (*sector >= len + || len - *sector < ((*offset + size + GRUB_DISK_SECTOR_SIZE - 1) + >> GRUB_DISK_SECTOR_BITS)) + return grub_error (GRUB_ERR_OUT_OF_RANGE, + N_("attempt to read or write outside of partition")); + + *sector += start; + } + + /* Transform total_sectors to number of 512B blocks. */ + total_sectors = disk->total_sectors << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS); + + /* + * Some drivers have problems with disks above reasonable sizes. + * Clamp the size to GRUB_DISK_MAX_SECTORS. Just one condition is enough + * since GRUB_DISK_SIZE_UNKNOWN is always above GRUB_DISK_MAX_SECTORS, + * assuming a maximum 4 KiB sector size. + */ + if (total_sectors > GRUB_DISK_MAX_SECTORS) + total_sectors = GRUB_DISK_MAX_SECTORS; + + if ((total_sectors <= *sector + || ((*offset + size + GRUB_DISK_SECTOR_SIZE - 1) + >> GRUB_DISK_SECTOR_BITS) > total_sectors - *sector)) + return grub_error (GRUB_ERR_OUT_OF_RANGE, + N_("attempt to read or write outside of disk `%s'"), disk->name); + + return GRUB_ERR_NONE; +} + +static inline grub_disk_addr_t +transform_sector (grub_disk_t disk, grub_disk_addr_t sector) +{ + return sector >> (disk->log_sector_size - GRUB_DISK_SECTOR_BITS); +} + +static unsigned +grub_disk_cache_get_index (unsigned long dev_id, unsigned long disk_id, + grub_disk_addr_t sector) +{ + return ((dev_id * 524287UL + disk_id * 2606459UL + + ((unsigned) (sector >> GRUB_DISK_CACHE_BITS))) + % GRUB_DISK_CACHE_NUM); +} -- cgit v1.2.3