From 016ff72bd2090903715c0f9422a44afbb966f4ee Mon Sep 17 00:00:00 2001 From: Rohan McLure Date: Wed, 21 Sep 2022 16:55:48 +1000 Subject: powerpc: Fix fallocate and fadvise64_64 compat parameter combination As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate compatibility handlers assume parameters are passed with 32-bit big-endian ABI. This affects the assignment of odd-even parameter pairs to the high or low words of a 64-bit syscall parameter. Fix fadvise64_64 fallocate compat handlers to correctly swap upper/lower 32 bits conditioned on endianness. A future patch will replace the arch-specific compat fallocate with an asm-generic implementation. This patch is intended for ease of back-port. [1]: https://lore.kernel.org/all/be29926f-226e-48dc-871a-e29a54e80583@www.fastmail.com/ Fixes: 57f48b4b74e7 ("powerpc/compat_sys: swap hi/lo parts of 64-bit syscall args in LE mode") Reported-by: Arnd Bergmann Signed-off-by: Rohan McLure Reviewed-by: Arnd Bergmann Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220921065605.1051927-9-rmclure@linux.ibm.com --- arch/powerpc/include/asm/syscalls.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'arch/powerpc/include/asm/syscalls.h') diff --git a/arch/powerpc/include/asm/syscalls.h b/arch/powerpc/include/asm/syscalls.h index 21c2faaa2957..ae7ca59f6267 100644 --- a/arch/powerpc/include/asm/syscalls.h +++ b/arch/powerpc/include/asm/syscalls.h @@ -8,6 +8,18 @@ #include #include +/* + * long long munging: + * The 32 bit ABI passes long longs in an odd even register pair. + * High and low parts are swapped depending on endian mode, + * so define a macro (similar to mips linux32) to handle that. + */ +#ifdef __LITTLE_ENDIAN__ +#define merge_64(low, high) (((u64)high << 32) | low) +#else +#define merge_64(high, low) (((u64)high << 32) | low) +#endif + struct rtas_args; long sys_mmap(unsigned long addr, size_t len, -- cgit