diff options
| author | Vasily Gorbik <gor@linux.ibm.com> | 2020-10-05 13:53:36 +0200 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2020-11-09 11:20:59 +0100 |
| commit | 0c4ec024a481774df98910c79a4b3a105d1bb996 (patch) | |
| tree | fee5cfbcb8c2558986b7a5408a649f5de27a8cb8 /arch/s390/boot | |
| parent | e385b550faf356db47234083c53e9841e8ec05c5 (diff) | |
s390/kasan: move memory needs estimation into a function
Also correct rounding downs in estimation calculations.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/boot')
| -rw-r--r-- | arch/s390/boot/kaslr.c | 30 |
1 files changed, 8 insertions, 22 deletions
diff --git a/arch/s390/boot/kaslr.c b/arch/s390/boot/kaslr.c index d844a5ef9089..987a9eaf228a 100644 --- a/arch/s390/boot/kaslr.c +++ b/arch/s390/boot/kaslr.c @@ -7,6 +7,7 @@ #include <asm/cpacf.h> #include <asm/timex.h> #include <asm/sclp.h> +#include <asm/kasan.h> #include "compressed/decompressor.h" #include "boot.h" @@ -179,34 +180,19 @@ unsigned long get_random_base(unsigned long safe_addr) if (memory_end_set) memory_limit = min(memory_limit, memory_end); + /* + * Avoid putting kernel in the end of physical memory + * which kasan will use for shadow memory and early pgtable + * mapping allocations. + */ + memory_limit -= kasan_estimate_memory_needs(memory_limit); + if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && INITRD_START && INITRD_SIZE) { if (safe_addr < INITRD_START + INITRD_SIZE) safe_addr = INITRD_START + INITRD_SIZE; } safe_addr = ALIGN(safe_addr, THREAD_SIZE); - if ((IS_ENABLED(CONFIG_KASAN))) { - /* - * Estimate kasan memory requirements, which it will reserve - * at the very end of available physical memory. To estimate - * that, we take into account that kasan would require - * 1/8 of available physical memory (for shadow memory) + - * creating page tables for the whole memory + shadow memory - * region (1 + 1/8). To keep page tables estimates simple take - * the double of combined ptes size. - */ - memory_limit = get_mem_detect_end(); - if (memory_end_set && memory_limit > memory_end) - memory_limit = memory_end; - - /* for shadow memory */ - kasan_needs = memory_limit / 8; - /* for paging structures */ - kasan_needs += (memory_limit + kasan_needs) / PAGE_SIZE / - _PAGE_ENTRIES * _PAGE_TABLE_SIZE * 2; - memory_limit -= kasan_needs; - } - kernel_size = vmlinux.image_size + vmlinux.bss_size; if (safe_addr + kernel_size > memory_limit) return 0; |