On Mon, 30 Nov 2020 15:42:14 +0100 Daniel Kiper <dki...@net-space.pl> wrote:
> On Fri, Nov 27, 2020 at 02:36:23AM -0600, Glenn Washburn wrote: > > There is a hardcoded maximum disk size that can be read or written > > from, currently set at 1EiB in grub_disk_adjust_range. Move the > > literal into a macro in disk.h, so our assumptions are more > > visible. This hard coded limit does not prevent using larger disks, > > just grub won't read/write past the limit. The comment accompanying > > this restriction didn't quite make sense to me, so its been > > modified. > > > > Signed-off-by: Glenn Washburn <developm...@efficientek.com> > > --- > > grub-core/kern/disk_common.c | 13 +++++++------ > > include/grub/disk.h | 6 ++++++ > > 2 files changed, 13 insertions(+), 6 deletions(-) > > > > diff --git a/grub-core/kern/disk_common.c > > b/grub-core/kern/disk_common.c index 5b92f670b..d20ed20d2 100644 > > --- a/grub-core/kern/disk_common.c > > +++ b/grub-core/kern/disk_common.c > > @@ -32,13 +32,14 @@ grub_disk_adjust_range (grub_disk_t disk, > > grub_disk_addr_t *sector, /* Transform total_sectors to number of > > 512B blocks. */ total_sectors = grub_disk_from_native_sector > > (disk, disk->total_sectors); > > > > - /* Some drivers have problems with disks above reasonable. > > - Treat unknown as 1EiB disk. While on it, clamp the size to > > 1EiB. > > - Just one condition is enough since GRUB_DISK_UNKNOWN_SIZE << > > ls is always > > - above 9EiB. > > + /* > > + 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_UNKNOWN_SIZE is always above > > GRUB_DISK_MAX_SECTORS, > > + assuming a maximum 4KiB sector size. > > */ > > - if (total_sectors > (1ULL << 51)) > > - total_sectors = (1ULL << 51); > > + if (total_sectors > GRUB_DISK_MAX_SECTORS) > > + total_sectors = GRUB_DISK_MAX_SECTORS; > > > > if ((total_sectors <= *sector > > || ((*offset + size + GRUB_DISK_SECTOR_SIZE - 1) > > diff --git a/include/grub/disk.h b/include/grub/disk.h > > index 1a9e8fcf4..0bf08091f 100644 > > --- a/include/grub/disk.h > > +++ b/include/grub/disk.h > > @@ -157,6 +157,12 @@ struct grub_disk_memberlist > > typedef struct grub_disk_memberlist *grub_disk_memberlist_t; > > #endif > > > > +/* > > + Some drivers have problems with disks above reasonable sizes. > > + Set max disk size at 1EiB. > > The comment is formatted incorrectly [1]. Yep, copy/paste from the comment changed in previous diff which had an incorrectly formatted comment and didn't catch it. Good catch. I'll fix the comment in the previous diff as well. > > +*/ > > +#define GRUB_DISK_MAX_SECTORS (1ULL << (60 - 9)) > > + > > /* The sector size. */ > > #define GRUB_DISK_SECTOR_SIZE 0x200 > > #define GRUB_DISK_SECTOR_BITS 9 > > Please move the constant below these definitions and do this: > #define GRUB_DISK_MAX_SECTORS (1ULL << (60 - > GRUB_DISK_SECTOR_BITS)) Great idea. > [1] > https://www.gnu.org/software/grub/manual/grub-dev/grub-dev.html#Comments _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
