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authorNick Desaulniers <ndesaulniers@google.com>2017-08-03 11:03:58 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-08 11:51:58 +0200
commit28dae08f1e1d7d913c1b67ea20578c02150c9515 (patch)
tree3a655990bee7a9e3674e7ef41f7d79b0da65217f
parenteca9e0aff522167860b8ef1aee4cc416d7b13dbd (diff)
arm64: avoid overflow in VA_START and PAGE_OFFSET
commit 82cd588052815eb4146f9f7c5347ca5e32c56360 upstream. 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> [natechancellor: KIMAGE_VADDR doesn't exist] Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/arm64/include/asm/memory.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 853953cd1f08..b42b930cc19a 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -49,8 +49,10 @@
* and PAGE_OFFSET - it must be within 128MB of the kernel text.
*/
#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 MODULES_END (PAGE_OFFSET)
#define MODULES_VADDR (MODULES_END - SZ_64M)
#define PCI_IO_END (MODULES_VADDR - SZ_2M)