From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 25 Apr 2008 15:07:03 +0000 (+0200)
Subject: x86: harden kernel code patching
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=00c6b2d5d7b2414bd46c620d6a8c37fa7a716f29;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git

x86: harden kernel code patching

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 60299f61843f..65c7857a90dd 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -519,6 +519,7 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len)
 		pages[1] = vmalloc_to_page(addr + PAGE_SIZE);
 	} else {
 		pages[0] = virt_to_page(addr);
+		WARN_ON(!PageReserved(pages[0]));
 		pages[1] = virt_to_page(addr + PAGE_SIZE);
 	}
 	BUG_ON(!pages[0]);