When calling locate_hole() with "hole_size" equal to the size of an
available memory block, it fails to use that memory block.
"end" and "hole_max" point to the last byte within the range, hence
- "size = end - start" is one less than "hole_size",
- "hole_base + hole_size" is one more than "hole_max".
Subtract one from "hole_size" when doing the comparison (adding 1 to "size"
could overflow in case of one big range covering the whole address space).
Signed-off-by: Geert Uytterhoeven <geert at linux-m68k.org>
---
Question:
The code no longer handles the case where "hole_size" is zero.
Should this be rejected (like is done for a zero "hole_end" at the top
of the function), or accepted?
kexec/kexec.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kexec/kexec.c b/kexec/kexec.c
index 2b98ef0..eafd6c2 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -270,7 +270,7 @@ unsigned long locate_hole(struct kexec_info *info,
}
/* Is there enough space left so we can use it? */
size = end - start;
- if (size >= hole_size) {
+ if (size >= hole_size - 1) {
if (hole_end > 0) {
hole_base = start;
break;
@@ -286,7 +286,7 @@ unsigned long locate_hole(struct kexec_info *info,
"0x%lx bytes...\n", hole_size);
return ULONG_MAX;
}
- if ((hole_base + hole_size) > hole_max) {
+ if ((hole_base + hole_size - 1) > hole_max) {
fprintf(stderr, "Could not find a free area of memory below: "
"0x%lx...\n", hole_max);
return ULONG_MAX;
--
1.7.9.5
