[PATCH] arm64: uid16: fix __kernel_old_{gid,uid}_t definitions

Hi Arnd,

On Mon, Jun 02, 2014 at 12:45:39PM +0100, Arnd Bergmann wrote:

On Monday 02 June 2014 11:47:29 Will Deacon wrote:

quoted

Whilst native arm64 applications don't have the 16-bit UID/GID syscalls
wired up, compat tasks can still access them. The 16-bit wrappers for
these syscalls use __kernel_old_uid_t and __kernel_old_gid_t, which must
be 16-bit data types to maintain compatibility with the 16-bit UIDs used
by compat applications.

This patch defines 16-bit __kernel_old_{gid,uid}_t types for arm64
instead of using the 32-bit types provided by asm-generic.

Signed-off-by: Will Deacon <redacted>

Acked-by: Arnd Bergmann <arnd@arndb.de>

Cheers!

Is this a theoretical problem, or did you actually encounter binaries
with old uid syscalls?

I hit it during an AArch32 LTP run which passes '-1' for some parameters
to the 16-bit flavours of setreuid etc. So I suppose it's theoretical in
the sense that I've only observed the issue within a testsuite as opposed
to a real application.

Will