[U-Boot] [PATCH] disk: efi: correct the allocation size for mbr header in stack

[Patrick Delaunay]

use ALLOC_CACHE_ALIGN_BUFFER_PAD for mbr header allocation
in stack to fix alloc issue in is_gpt_valid()

this patch fix also issue for GPT partition handling
with blocksize != 512 in set_protective_mbr()

Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
---

in is_gpt_valid(), the line before the patch:

ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr, dev_desc->blksz)

cause to an over-sized allocation in stack :
   size = sizeof(legacy_mbr) * dev_desc->blksz + alignment

that crash with v2017.11 in my board SPL configuration
   size > 512 * 512 = 256 kB

it is a regression introduced by commit
  ff98cb90514d9b787ddc097c203ac8db2941efe1
  part: extract MBR signature from partitions

 disk/part_efi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/disk/part_efi.c b/disk/part_efi.c
index f6f5bee..bea8b20 100644
--- a/disk/part_efi.c
+++ b/disk/part_efi.c
@@ -350,7 +350,7 @@ static int part_test_efi(struct blk_desc *dev_desc)
 static int set_protective_mbr(struct blk_desc *dev_desc)
 {
 	/* Setup the Protective MBR */
-	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, p_mbr, 1);
+	ALLOC_CACHE_ALIGN_BUFFER_PAD(legacy_mbr, p_mbr, 1, dev_desc->blksz);
 	memset(p_mbr, 0, sizeof(*p_mbr));
 
 	if (p_mbr == NULL) {
@@ -931,7 +931,7 @@ static int is_gpt_valid(struct blk_desc *dev_desc, u64 lba,
 		return 0;
 	}
 
-	ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr, dev_desc->blksz);
+	ALLOC_CACHE_ALIGN_BUFFER_PAD(legacy_mbr, mbr, 1, dev_desc->blksz);
 
 	/* Read MBR Header from device */
 	if (blk_dread(dev_desc, 0, 1, (ulong *)mbr) != 1) {
-- 
2.7.4