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Message-ID: <20100328233502.GC10304@cmpxchg.org>
Date: Mon, 29 Mar 2010 01:35:02 +0200
From: Johannes Weiner <hannes@...xchg.org>
To: Yinghai Lu <yinghai@...nel.org>
Cc: Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
"H. Peter Anvin" <hpa@...or.com>,
Andrew Morton <akpm@...ux-foundation.org>,
David Miller <davem@...emloft.net>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Linus Torvalds <torvalds@...ux-foundation.org>,
linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org
Subject: [patch v5] x86: page-alin initrd area size
Initrd memory is freed late and page-wise, so allocate full pages and
not share the last one with somebody else.
Also add a warning and a fixup in free_init_pages() to catch unaligned
ranges more explicitely in the future.
Signed-off-by: Yinghai Lu <yinghai@...nel.org>
Signed-off-by: Johannes Weiner <hannes@...xchg.org>
---
arch/x86/kernel/head32.c | 8 +++++++-
arch/x86/kernel/head64.c | 8 +++++++-
arch/x86/kernel/setup.c | 14 ++++++++++----
arch/x86/mm/init.c | 12 ++++++++----
4 files changed, 32 insertions(+), 10 deletions(-)
On Sat, Mar 27, 2010 at 06:58:38PM -0700, Yinghai Lu wrote:
> please check.
I am really fed up with you replying to one point of an email and
skipping over five others. So here is my version of the patch,
the maintainers can choose.
Differences:
o only align the allocation area size, no need to also copy
alignment bits in relocate_initrd()
o keep the alignment fixup in free_init_pages() out of line and
self-contained
diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index adedeef..086392a 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -46,7 +46,13 @@ void __init i386_start_kernel(void)
if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
u64 ramdisk_image = boot_params.hdr.ramdisk_image;
u64 ramdisk_size = boot_params.hdr.ramdisk_size;
- u64 ramdisk_end = ramdisk_image + ramdisk_size;
+ u64 ramdisk_end;
+ /*
+ * Initrd memory is freed late and page-wise, so make
+ * sure not to share a page with other users. Assume
+ * start is aligned.
+ */
+ ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size);
reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
}
#endif
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index b5a9896..b2c2321 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -105,7 +105,13 @@ void __init x86_64_start_reservations(char *real_mode_data)
if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
- unsigned long ramdisk_end = ramdisk_image + ramdisk_size;
+ unsigned long ramdisk_end;
+ /*
+ * Initrd memory is freed late and page-wise, so make
+ * sure not to share a page with other users. Assume
+ * start is aligned.
+ */
+ ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size);
reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
}
#endif
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 5d7ba1a..f5bde5f 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -318,12 +318,18 @@ static void __init relocate_initrd(void)
u64 ramdisk_image = boot_params.hdr.ramdisk_image;
u64 ramdisk_size = boot_params.hdr.ramdisk_size;
u64 end_of_lowmem = max_low_pfn_mapped << PAGE_SHIFT;
- u64 ramdisk_here;
+ u64 ramdisk_here, area_size;
unsigned long slop, clen, mapaddr;
char *p, *q;
+ /*
+ * Initrd memory is freed late and page-wise, so make sure not
+ * to share a page with other users. Assume start is aligned.
+ */
+ area_size = PAGE_ALIGN(ramdisk_size);
+
/* We need to move the initrd down into lowmem */
- ramdisk_here = find_e820_area(0, end_of_lowmem, ramdisk_size,
+ ramdisk_here = find_e820_area(0, end_of_lowmem, area_size,
PAGE_SIZE);
if (ramdisk_here == -1ULL)
@@ -332,7 +338,7 @@ static void __init relocate_initrd(void)
/* Note: this includes all the lowmem currently occupied by
the initrd, we rely on that fact to keep the data intact. */
- reserve_early(ramdisk_here, ramdisk_here + ramdisk_size,
+ reserve_early(ramdisk_here, ramdisk_here + area_size,
"NEW RAMDISK");
initrd_start = ramdisk_here + PAGE_OFFSET;
initrd_end = initrd_start + ramdisk_size;
@@ -378,7 +384,7 @@ static void __init reserve_initrd(void)
{
u64 ramdisk_image = boot_params.hdr.ramdisk_image;
u64 ramdisk_size = boot_params.hdr.ramdisk_size;
- u64 ramdisk_end = ramdisk_image + ramdisk_size;
+ u64 ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size);
u64 end_of_lowmem = max_low_pfn_mapped << PAGE_SHIFT;
if (!boot_params.hdr.type_of_loader ||
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index e71c5cb..4b28d5e 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -333,6 +333,11 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
unsigned long addr = begin;
+ if (WARN_ON(addr & ~PAGE_MASK || end & ~PAGE_MASK)) {
+ addr = PAGE_ALIGN(addr);
+ end &= PAGE_MASK;
+ }
+
if (addr >= end)
return;
@@ -355,11 +360,10 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
- for (; addr < end; addr += PAGE_SIZE) {
+ for (; addr != end; addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
- memset((void *)(addr & ~(PAGE_SIZE-1)),
- POISON_FREE_INITMEM, PAGE_SIZE);
+ memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
free_page(addr);
totalram_pages++;
}
@@ -376,6 +380,6 @@ void free_initmem(void)
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
- free_init_pages("initrd memory", start, end);
+ free_init_pages("initrd memory", start, PAGE_ALIGN(end));
}
#endif
--
1.7.0.2
--
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