diff options
| author | Thomas Weißschuh <thomas.weissschuh@linutronix.de> | 2025-08-21 09:56:44 +0200 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2025-09-03 12:07:23 +0100 |
| commit | 9a6d3ff10f7f538835cae4799562004ee46922c5 (patch) | |
| tree | 0c5d7895dfe33e4f99c9b4b4cad3f622bf2bd53a | |
| parent | d82aa5d3501b25bfb7bc2a24a68ad0a83b2ad10b (diff) | |
arm64: uapi: Provide correct __BITS_PER_LONG for the compat vDSO
The generic vDSO library uses the UAPI headers. On arm64 __BITS_PER_LONG is
always '64' even when used from the compat vDSO. In that case __GENMASK()
does an illegal bitshift, invoking undefined behaviour.
Change __BITS_PER_LONG to also work when used from the comapt vDSO.
To not confuse real userspace, only do this when building the kernel.
Reported-by: John Stultz <jstultz@google.com>
Closes: https://lore.kernel.org/lkml/CANDhNCqvKOc9JgphQwr0eDyJiyG4oLFS9R8rSFvU0fpurrJFDg@mail.gmail.com/
Fixes: cd3557a7618b ("vdso/gettimeofday: Add support for auxiliary clocks")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/r/20250821-vdso-arm64-compat-bitsperlong-v1-1-700bcabe7732@linutronix.de
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/include/uapi/asm/bitsperlong.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm64/include/uapi/asm/bitsperlong.h b/arch/arm64/include/uapi/asm/bitsperlong.h index 485d60bee26c..d59730975f30 100644 --- a/arch/arm64/include/uapi/asm/bitsperlong.h +++ b/arch/arm64/include/uapi/asm/bitsperlong.h @@ -17,7 +17,12 @@ #ifndef __ASM_BITSPERLONG_H #define __ASM_BITSPERLONG_H +#if defined(__KERNEL__) && !defined(__aarch64__) +/* Used by the compat vDSO */ +#define __BITS_PER_LONG 32 +#else #define __BITS_PER_LONG 64 +#endif #include <asm-generic/bitsperlong.h> |