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| author |   Rohan McLure <rmclure@linux.ibm.com> | 2022-09-21 16:55:48 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-09-26 23:00:15 +1000 |
| commit | 016ff72bd2090903715c0f9422a44afbb966f4ee (patch) | |
| tree | d0cb41079d4fc1b109957920bd3e6fcedd559a49 /arch/powerpc/include/asm/syscalls.h | |
| parent | powerpc/64s: Fix comment on interrupt handler prologue (diff) | |
| download | linux-dev-016ff72bd2090903715c0f9422a44afbb966f4ee.tar.xz linux-dev-016ff72bd2090903715c0f9422a44afbb966f4ee.zip | |
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 <arnd@arndb.de>
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-9-rmclure@linux.ibm.com
Diffstat (limited to 'arch/powerpc/include/asm/syscalls.h')
| -rw-r--r-- | arch/powerpc/include/asm/syscalls.h | 12 |
1 files changed, 12 insertions, 0 deletions
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 <linux/types.h> #include <linux/compat.h> +/* + * 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, |