Hi Arnd,
On Thu, Jan 10, 2019 at 05:24:31PM +0100, Arnd Bergmann wrote:
> While reading through the sysvipc implementation, I noticed that the n32
> semctl/shmctl/msgctl system calls behave differently based on whether
> o32 support is enabled or not: Without o32, the IPC_64 flag passed by
> user space is rejected but calls without that flag get IPC_64 behavior.
>
> As far as I can tell, this was inadvertently changed by a cleanup patch
> but never noticed by anyone, possibly nobody has tried using sysvipc
> on n32 after linux-3.19.
>
> Change it back to the old behavior now.
>
> Fixes: 78aaf956ba3a ("MIPS: Compat: Fix build error if CONFIG_MIPS32_COMPAT
> but no compat ABI.")
> Cc: sta...@vger.kernel.org
> Signed-off-by: Arnd Bergmann <a...@arndb.de>
> ---
> As stated above, this was only found by inspection, the patch is not
> tested. Please review accordingly.
Nice catch! Would you prefer to merge this yourself, or that I take it
through the mips tree?
If the former then:
Acked-by: Paul Burton <paul.bur...@mips.com>
I suspect kernels configured with n32 support but no o32 support are
probably not very common - for internal testing we currently always
enable both.
Thanks,
Paul
> ---
> arch/mips/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index 787290781b8c..0d14f51d0002 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -3155,6 +3155,7 @@ config MIPS32_O32
> config MIPS32_N32
> bool "Kernel support for n32 binaries"
> depends on 64BIT
> + select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
> select COMPAT
> select MIPS32_COMPAT
> select SYSVIPC_COMPAT if SYSVIPC
> --
> 2.20.0
>
