[RFC-resend 0/2] compat: in_compat_syscall() differs on x86

From: Dmitry Safonov
Date: Fri Oct 12 2018 - 09:43:00 EST


Reading xfrm (ipsec) code I've found such code:

: #ifdef CONFIG_COMPAT
: if (in_compat_syscall())
: return -EOPNOTSUPP;
: #endif

While I can read that it's false on native i386, it's a bit misleading
and in result it's better to introduce a helper for that.
Grepping other code, I've found that there are already such helpers.
And the uniq behavior of in_compat_syscall() on x86 is disturbing.

Adjusting it to generic with the following..

(on the first non-resend RFC I managed to forget Cc'ing Andy..
sorry about that, was sure I did add him).

Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Andy Lutomirsky <luto@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Cc: Stephen Boyd <sboyd@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Cc: Dmitry Safonov <0x7f454c46@xxxxxxxxx>

Dmitry Safonov (2):
x86/compat: Adjust in_compat_syscall() to generic code under !COMPAT
compat: Cleanup in_compat_syscall() callers

arch/x86/include/asm/compat.h | 9 ++++++++-
arch/x86/include/asm/ftrace.h | 4 +---
arch/x86/kernel/process_64.c | 4 ++--
arch/x86/kernel/sys_x86_64.c | 11 ++++++-----
arch/x86/mm/hugetlbpage.c | 4 ++--
arch/x86/mm/mmap.c | 2 +-
drivers/firmware/efi/efivars.c | 16 ++++------------
include/linux/compat.h | 4 ++--
kernel/time/time.c | 2 +-
net/xfrm/xfrm_state.c | 2 --
net/xfrm/xfrm_user.c | 2 --
11 files changed, 27 insertions(+), 33 deletions(-)

--
2.13.6