[PATCH v2] lib/relocator: always enforce the requested alignment in malloc_in_range()

[Roger Pau Monne]

On failure to allocate from grub_relocator_firmware_alloc_region() in
malloc_in_range() the function would stop enforcing the alignment, and
the following was returned:

lib/relocator.c:431: trying to allocate in 0x200000-0xffbf9fff aligned 0x200000 
size 0x406000
lib/relocator.c:1197: allocated: 0x74de2000+0x406000
lib/relocator.c:1407: allocated 0x74de2000/0x74de2000

Fix this by making sure that target always contains a suitably aligned
address.  After the change the return from the function is:

lib/relocator.c:431: trying to allocate in 0x200000-0xffb87fff aligned 0x200000 
size 0x478000
lib/relocator.c:1204: allocated: 0x74c00000+0x478000
lib/relocator.c:1414: allocated 0x74c00000/0x74c00000

Fixes: 3a5768645c05 ('First version of allocation from firmware')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Changes since v1:
 - Fix one instance to use ALIGN_DOWN().
---
 grub-core/lib/relocator.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/grub-core/lib/relocator.c b/grub-core/lib/relocator.c
index bfcc70dac3cc..725bca7c3c10 100644
--- a/grub-core/lib/relocator.c
+++ b/grub-core/lib/relocator.c
@@ -744,7 +744,7 @@ malloc_in_range (struct grub_relocator *rel,
            {
              target = starta;
              if (target < start)
-               target = start;
+               target = ALIGN_UP (start, align);
              if (target + size <= end && target + size <= events[j].pos)
                /* Found an usable address.  */
                goto found;
@@ -761,7 +761,7 @@ malloc_in_range (struct grub_relocator *rel,
            {
              target = starta - size;
              if (target > end - size)
-               target = end - size;
+               target = ALIGN_DOWN (end - size, align);
              if (target >= start && target >= events[j].pos)
                goto found;
            }
-- 
2.40.0