diff options
| author |   Nick Desaulniers <ndesaulniers@google.com> | 2017-08-03 11:03:58 -0700 |
|---|---|---|
| committer |   Will Deacon <will.deacon@arm.com> | 2017-08-04 15:06:35 +0100 |
| commit | 82cd588052815eb4146f9f7c5347ca5e32c56360 (patch) | |
| tree | 074b02c750f56f8d41f0f48eba80c031c6adf8bd /arch/arm64/include/asm/memory.h | |
| parent | arm64: Fix potential race with hardware DBM in ptep_set_access_flags() (diff) | |
| download | linux-dev-82cd588052815eb4146f9f7c5347ca5e32c56360.tar.xz linux-dev-82cd588052815eb4146f9f7c5347ca5e32c56360.zip | |
arm64: avoid overflow in VA_START and PAGE_OFFSET
The bitmask used to define these values produces overflow, as seen by
this compiler warning:
arch/arm64/kernel/head.S:47:8: warning:
integer overflow in preprocessor expression
#elif (PAGE_OFFSET & 0x1fffff) != 0
^~~~~~~~~~~
arch/arm64/include/asm/memory.h:52:46: note:
expanded from macro 'PAGE_OFFSET'
#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS -
1))
~~~~~~~~~~~~~~~~~~ ^
It would be preferrable to use GENMASK_ULL() instead, but it's not set
up to be used from assembly (the UL() macro token pastes UL suffixes
when not included in assembly sources).
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Suggested-by: Yury Norov <ynorov@caviumnetworks.com>
Suggested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to '')
| -rw-r--r-- | arch/arm64/include/asm/memory.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 32f82723338a..ef39dcb9ca6a 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -64,8 +64,10 @@ * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area. */ #define VA_BITS (CONFIG_ARM64_VA_BITS) -#define VA_START (UL(0xffffffffffffffff) << VA_BITS) -#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1)) +#define VA_START (UL(0xffffffffffffffff) - \ + (UL(1) << VA_BITS) + 1) +#define PAGE_OFFSET (UL(0xffffffffffffffff) - \ + (UL(1) << (VA_BITS - 1)) + 1) #define KIMAGE_VADDR (MODULES_END) #define MODULES_END (MODULES_VADDR + MODULES_VSIZE) #define MODULES_VADDR (VA_START + KASAN_SHADOW_SIZE) |