diff options
Diffstat (limited to 'include/asm-s390/pgtable.h')
| -rw-r--r-- | include/asm-s390/pgtable.h | 46 |
1 files changed, 16 insertions, 30 deletions
diff --git a/include/asm-s390/pgtable.h b/include/asm-s390/pgtable.h index 1f530f8a628..79b9eab1a0c 100644 --- a/include/asm-s390/pgtable.h +++ b/include/asm-s390/pgtable.h @@ -104,41 +104,27 @@ extern char empty_zero_page[PAGE_SIZE]; #ifndef __ASSEMBLY__ /* - * Just any arbitrary offset to the start of the vmalloc VM area: the - * current 8MB value just means that there will be a 8MB "hole" after the - * physical memory until the kernel virtual memory starts. That means that - * any out-of-bounds memory accesses will hopefully be caught. - * The vmalloc() routines leaves a hole of 4kB between each vmalloced - * area for the same reason. ;) - * vmalloc area starts at 4GB to prevent syscall table entry exchanging - * from modules. - */ -extern unsigned long vmalloc_end; - -#ifdef CONFIG_64BIT -#define VMALLOC_ADDR (max(0x100000000UL, (unsigned long) high_memory)) -#else -#define VMALLOC_ADDR ((unsigned long) high_memory) -#endif -#define VMALLOC_OFFSET (8*1024*1024) -#define VMALLOC_START ((VMALLOC_ADDR + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)) -#define VMALLOC_END vmalloc_end - -/* - * We need some free virtual space to be able to do vmalloc. - * VMALLOC_MIN_SIZE defines the minimum size of the vmalloc - * area. On a machine with 2GB memory we make sure that we - * have at least 128MB free space for vmalloc. On a machine - * with 4TB we make sure we have at least 128GB. + * The vmalloc area will always be on the topmost area of the kernel + * mapping. We reserve 96MB (31bit) / 1GB (64bit) for vmalloc, + * which should be enough for any sane case. + * By putting vmalloc at the top, we maximise the gap between physical + * memory and vmalloc to catch misplaced memory accesses. As a side + * effect, this also makes sure that 64 bit module code cannot be used + * as system call address. */ #ifndef __s390x__ -#define VMALLOC_MIN_SIZE 0x8000000UL -#define VMALLOC_END_INIT 0x80000000UL +#define VMALLOC_START 0x78000000UL +#define VMALLOC_END 0x7e000000UL +#define VMEM_MAP_MAX 0x80000000UL #else /* __s390x__ */ -#define VMALLOC_MIN_SIZE 0x2000000000UL -#define VMALLOC_END_INIT 0x40000000000UL +#define VMALLOC_START 0x3e000000000UL +#define VMALLOC_END 0x3e040000000UL +#define VMEM_MAP_MAX 0x40000000000UL #endif /* __s390x__ */ +#define VMEM_MAP ((struct page *) VMALLOC_END) +#define VMEM_MAP_SIZE ((VMALLOC_START / PAGE_SIZE) * sizeof(struct page)) + /* * A 31 bit pagetable entry of S390 has following format: * | PFRA | | OS | |