File linux-2.6-x86_64-page-align-e820-area.patch of Package kernel
Date: Mon, 16 Oct 2006 14:28:36 -0400
From: Vivek Goyal <vgoyal@redhat.com>
Subject: [PATCH][RHEL5] BZ#210499: Avoid bss stomping by bootmem allocator
initialization code
This patch was discussed on LKML sometime back regarding one of the
x86_64 boot problems. It solves the issue for BZ#210499. Posting it for
inclusion in RHEL5.
http://marc.theaimsgroup.com/?l=linux-netdev&m=116016517332266&w=2
I have forwarded the patch again to Andrew for inclusion in -mm.
Thanks
Vivek
o Currently some code pieces assume that address returned by find_e820_area()
are page aligned. But looks like find_e820_area() had no such intention
and hence one might end up stomping over some of the data. One such
case is bootmem allocator initialization code stomped over bss.
o This patch modified find_e820_area() to return page aligned address. This
might be little wasteful of memory but at the same time probably it is
easier to handle page aligned memory.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
---
arch/x86_64/kernel/e820.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff -puN arch/x86_64/kernel/e820.c~x86_64-return-page-aligned-phy-addr-from-find-e820-area arch/x86_64/kernel/e820.c
--- linux-2.6.19-rc1-1M/arch/x86_64/kernel/e820.c~x86_64-return-page-aligned-phy-addr-from-find-e820-area 2006-10-06 15:28:13.000000000 -0400
+++ linux-2.6.19-rc1-1M-root/arch/x86_64/kernel/e820.c 2006-10-06 15:44:45.000000000 -0400
@@ -54,13 +54,13 @@ static inline int bad_addr(unsigned long
/* various gunk below that needed for SMP startup */
if (addr < 0x8000) {
- *addrp = 0x8000;
+ *addrp = PAGE_ALIGN(0x8000);
return 1;
}
/* direct mapping tables of the kernel */
if (last >= table_start<<PAGE_SHIFT && addr < table_end<<PAGE_SHIFT) {
- *addrp = table_end << PAGE_SHIFT;
+ *addrp = PAGE_ALIGN(table_end << PAGE_SHIFT);
return 1;
}
@@ -65,7 +65,7 @@ static inline int bad_addr(unsigned long
#ifdef CONFIG_BLK_DEV_INITRD
if (LOADER_TYPE && INITRD_START && last >= INITRD_START &&
addr < INITRD_START+INITRD_SIZE) {
- *addrp = INITRD_START + INITRD_SIZE;
+ *addrp = PAGE_ALIGN(INITRD_START + INITRD_SIZE);
return 1;
}
#endif
@@ -75,13 +75,13 @@ static inline int bad_addr(unsigned long
*addrp = 1024*1024;
return 1;
}
- if (last >= __pa_symbol(&_text) && last < __pa_symbol(&_end)) {
- *addrp = __pa_symbol(&_end);
+ if (last >= __pa_symbol(&_text) && addr < __pa_symbol(&_end)) {
+ *addrp = PAGE_ALIGN(__pa_symbol(&_end));
return 1;
}
if (last >= ebda_addr && addr < ebda_addr + ebda_size) {
- *addrp = ebda_addr + ebda_size;
+ *addrp = PAGE_ALIGN(ebda_addr + ebda_size);
return 1;
}
@@ -152,7 +152,7 @@ unsigned long __init find_e820_area(unsi
continue;
while (bad_addr(&addr, size) && addr+size <= ei->addr+ei->size)
;
- last = addr + size;
+ last = PAGE_ALIGN(addr) + size;
if (last > ei->addr + ei->size)
continue;
if (last > end)
_