From c06aa36fd08d398a4ee2c05f0a8da8ee85f70e56 Mon Sep 17 00:00:00 2001 From: Leif Lindholm Date: Sat, 27 Feb 2016 13:44:59 +0100 Subject: [PATCH 232/261] efidisk: Respect block_io_protocol buffer alignment Returned from the OpenProtocol operation, the grub_efi_block_io_media structure contains the io_align field, specifying the minimum alignment required for buffers used in any data transfers with the device. Make grub_efidisk_readwrite() allocate a temporary buffer, aligned to this boundary, if the buffer passed to it does not already meet the requirements. Also sanity check the io_align field in grub_efidisk_open() for power-of-two-ness and bail if invalid. Cherry-picked-from: 51f375d688529b7c1819ba40188ee52b9333887c Resolves: rhbz#1300009 --- grub-core/disk/efi/efidisk.c | 48 +++++++++++++++++++++++++++++++++++++------- 1 file changed, 41 insertions(+), 7 deletions(-) diff --git a/grub-core/disk/efi/efidisk.c b/grub-core/disk/efi/efidisk.c index 845c66fa9..f04f20b84 100644 --- a/grub-core/disk/efi/efidisk.c +++ b/grub-core/disk/efi/efidisk.c @@ -487,8 +487,15 @@ grub_efidisk_open (const char *name, struct grub_disk *disk) m = d->block_io->media; /* FIXME: Probably it is better to store the block size in the disk, and total sectors should be replaced with total blocks. */ - grub_dprintf ("efidisk", "m = %p, last block = %llx, block size = %x\n", - m, (unsigned long long) m->last_block, m->block_size); + grub_dprintf ("efidisk", + "m = %p, last block = %llx, block size = %x, io align = %x\n", + m, (unsigned long long) m->last_block, m->block_size, + m->io_align); + + /* Ensure required buffer alignment is a power of two (or is zero). */ + if (m->io_align & (m->io_align - 1)) + return grub_error (GRUB_ERR_IO, "invalid buffer alignment %d", m->io_align); + disk->total_sectors = m->last_block + 1; /* Don't increase this value due to bug in some EFI. */ disk->max_agglomerate = 0xa0000 >> (GRUB_DISK_CACHE_BITS + GRUB_DISK_SECTOR_BITS); @@ -518,15 +525,42 @@ grub_efidisk_readwrite (struct grub_disk *disk, grub_disk_addr_t sector, { struct grub_efidisk_data *d; grub_efi_block_io_t *bio; + grub_efi_status_t status; + grub_size_t io_align, num_bytes; + char *aligned_buf; d = disk->data; bio = d->block_io; - return efi_call_5 ((wr ? bio->write_blocks : bio->read_blocks), bio, - bio->media->media_id, - (grub_efi_uint64_t) sector, - (grub_efi_uintn_t) size << disk->log_sector_size, - buf); + /* Set alignment to 1 if 0 specified */ + io_align = bio->media->io_align ? bio->media->io_align : 1; + num_bytes = size << disk->log_sector_size; + + if ((grub_addr_t) buf & (io_align - 1)) + { + aligned_buf = grub_memalign (io_align, num_bytes); + if (! aligned_buf) + return GRUB_EFI_OUT_OF_RESOURCES; + if (wr) + grub_memcpy (aligned_buf, buf, num_bytes); + } + else + { + aligned_buf = buf; + } + + status = efi_call_5 ((wr ? bio->write_blocks : bio->read_blocks), bio, + bio->media->media_id, (grub_efi_uint64_t) sector, + (grub_efi_uintn_t) num_bytes, aligned_buf); + + if ((grub_addr_t) buf & (io_align - 1)) + { + if (!wr) + grub_memcpy (buf, aligned_buf, num_bytes); + grub_free (aligned_buf); + } + + return status; } static grub_err_t -- 2.13.5