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author | Dave Young <hidave.darkstar@gmail.com> | 2008-08-21 03:43:03 +0400 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-08-21 12:13:21 +0400 |
commit | e621bd18958ef5dbace3129ebe17a0a475e127d9 (patch) | |
tree | 214b768e7791b60db3e06676d76e01e77e54c791 | |
parent | 6a55617ed5d1aa62b850de2cf66f5ede2eef4825 (diff) | |
download | linux-e621bd18958ef5dbace3129ebe17a0a475e127d9.tar.xz |
i386: vmalloc size fix
Booting kernel with vmalloc=[any size<=16m] will oops on my pc (i386/1G memory).
BUG_ON in arch/x86/mm/init_32.c triggered:
BUG_ON((unsigned long)high_memory > VMALLOC_START);
It's due to the vm area hole.
In include/asm-x86/pgtable_32.h:
#define VMALLOC_OFFSET (8 * 1024 * 1024)
#define VMALLOC_START (((unsigned long)high_memory + 2 * VMALLOC_OFFSET - 1) \
& ~(VMALLOC_OFFSET - 1))
There's several related point:
1. MAXMEM :
(-__PAGE_OFFSET - __VMALLOC_RESERVE).
The space after VMALLOC_END is included as well, I set it to
(VMALLOC_END - PAGE_OFFSET - __VMALLOC_RESERVE)
2. VMALLOC_OFFSET is not considered in __VMALLOC_RESERVE
fixed by adding VMALLOC_OFFSET to it.
3. VMALLOC_START :
(((unsigned long)high_memory + 2 * VMALLOC_OFFSET - 1) & ~(VMALLOC_OFFSET - 1))
So it's not always 8M, bigger than 8M possible.
I set it to ((unsigned long)high_memory + VMALLOC_OFFSET)
4. the VMALLOC_RESERVE is an unused macro, so remove it here.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: akpm@linux-foundation.org
Cc: hidave.darkstar@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r-- | arch/x86/mm/pgtable_32.c | 3 | ||||
-rw-r--r-- | include/asm-x86/page_32.h | 3 | ||||
-rw-r--r-- | include/asm-x86/pgtable_32.h | 5 |
3 files changed, 5 insertions, 6 deletions
diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c index cab0abbd1ebe..0951db9ee519 100644 --- a/arch/x86/mm/pgtable_32.c +++ b/arch/x86/mm/pgtable_32.c @@ -123,7 +123,8 @@ static int __init parse_vmalloc(char *arg) if (!arg) return -EINVAL; - __VMALLOC_RESERVE = memparse(arg, &arg); + /* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/ + __VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET; return 0; } early_param("vmalloc", parse_vmalloc); diff --git a/include/asm-x86/page_32.h b/include/asm-x86/page_32.h index ab8528793f08..632feb156cc2 100644 --- a/include/asm-x86/page_32.h +++ b/include/asm-x86/page_32.h @@ -89,9 +89,6 @@ extern int nx_enabled; extern unsigned int __VMALLOC_RESERVE; extern int sysctl_legacy_va_layout; -#define VMALLOC_RESERVE ((unsigned long)__VMALLOC_RESERVE) -#define MAXMEM (-__PAGE_OFFSET - __VMALLOC_RESERVE) - extern void find_low_pfn_range(void); extern unsigned long init_memory_mapping(unsigned long start, unsigned long end); diff --git a/include/asm-x86/pgtable_32.h b/include/asm-x86/pgtable_32.h index 5c3b26567a95..9bb5269475cc 100644 --- a/include/asm-x86/pgtable_32.h +++ b/include/asm-x86/pgtable_32.h @@ -56,8 +56,7 @@ void paging_init(void); * area for the same reason. ;) */ #define VMALLOC_OFFSET (8 * 1024 * 1024) -#define VMALLOC_START (((unsigned long)high_memory + 2 * VMALLOC_OFFSET - 1) \ - & ~(VMALLOC_OFFSET - 1)) +#define VMALLOC_START ((unsigned long)high_memory + VMALLOC_OFFSET) #ifdef CONFIG_X86_PAE #define LAST_PKMAP 512 #else @@ -73,6 +72,8 @@ void paging_init(void); # define VMALLOC_END (FIXADDR_START - 2 * PAGE_SIZE) #endif +#define MAXMEM (VMALLOC_END - PAGE_OFFSET - __VMALLOC_RESERVE) + /* * Define this if things work differently on an i386 and an i486: * it will (on an i486) warn about kernel memory accesses that are |