[PATCH] arm64: fix off-by-one in compat syscall table for syscalls over 382

[Will Deacon]

Greg, Sasha,

Is there anything else I need to do to get this queued in the 3.17.y
and 3.18.y stable trees? There's no corresponding upstream commit since
the issue was fixed by accident in 3.19+ as a result of something else.

Will

On Tue, Dec 22, 2015 at 05:16:12PM +0000, Will Deacon wrote:
> [fix targetting -stable only, no upstream commit required]
> 
> In the bad old days, our compat syscall table was a linear array
> defined in assembly code using a series of .quad directives generated
> from a preprocessed header file.
> 
> When I added compat support for memfd_create and getrandom in commit
> a97a42c47608 ("arm64: compat: wire up memfd_create and getrandom
> syscalls for aarch32"), I forgot to pad the gap where seccomp was due
> to go, and so the new syscalls actually ended up being off-by-one in the
> table for v3.17 and v3.18 (in 3.19 seccomp was added and in v4.0 we
> moved the table construction into C).
> 
> This patch is intended for -stable trees based on v3.17 or v3.18.
> 
> Cc: <stable at vger.kernel.org> # 3.17 and 3.18 only
> Fixes: a97a42c47608 ("arm64: compat: wire up memfd_create and getrandom syscalls for aarch32")
> Reported-by: Edmund Grimley-Evans <Edmund.Grimley-Evans at arm.com>
> Signed-off-by: Will Deacon <will.deacon at arm.com>
> ---
>  arch/arm64/include/asm/unistd32.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
> index 9dfdac4a74a1..fbe1ab059bbb 100644
> --- a/arch/arm64/include/asm/unistd32.h
> +++ b/arch/arm64/include/asm/unistd32.h
> @@ -788,6 +788,7 @@ __SYSCALL(__NR_sched_getattr, sys_sched_getattr)
>  #define __NR_renameat2 382
>  __SYSCALL(__NR_renameat2, sys_renameat2)
>  			/* 383 for seccomp */
> +__SYSCALL(383, sys_ni_syscall)
>  #define __NR_getrandom 384
>  __SYSCALL(__NR_getrandom, sys_getrandom)
>  #define __NR_memfd_create 385
> -- 
> 2.1.4
>