[PATCH v5 12/19] x86, kaslr: Fix a bug that relocation can not be handled when kernel is loaded above 2G

Yinghai Lu
2015-03-18T07:28:19Z

From: Baoquan He <bhe@redhat.com>

When process 32 bit relocation tables a local variable extended is
defined to calculate the physical address of relocs entry. However
it's type is int which is enough for i386, for x86_64 not enough.
That's why relocation can only be handled when kernel is loaded
below 2G, otherwise a overflow will happen and cause system hang.

Here change it to long as 32 bit inverse relocation processing does,
and this change is safe for i386 relocation handling too.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
arch/x86/boot/compressed/misc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 94e283c..d6b4d91 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -273,7 +273,7 @@ static void handle_relocations(void *output, unsigned long output_len)
* So we work backwards from the end of the decompressed image.
*/
for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
- int extended = *reloc;
+ long extended = *reloc;
extended += map;

ptr = (unsigned long)extended;
--
1.8.4.5