• Dominik Brodowski's avatar
    syscalls/core: Prepare CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y for compat syscalls · 7303e30e
    Dominik Brodowski authored
    It may be useful for an architecture to override the definitions of the
    <linux/compat.h>, in particular to use a different calling convention
    for syscalls. This patch provides a mechanism to do so, based on the
    previously introduced CONFIG_ARCH_HAS_SYSCALL_WRAPPER. If it is enabled,
    <asm/sycall_wrapper.h> is included in <linux/compat.h> and may be used
    to define the macros mentioned above. Moreover, as the syscall calling
    convention may be different if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is set,
    the compat syscall function prototypes in <linux/compat.h> are #ifndef'd
    out in that case.
    As some of the syscalls and/or compat syscalls may not be present,
    the COND_SYSCALL() and COND_SYSCALL_COMPAT() macros in kernel/sys_ni.c
    as well as the SYS_NI() and COMPAT_SYS_NI() macros in
    kernel/time/posix-stubs.c can be re-defined in <asm/syscall_wrapper.h> iff
    Signed-off-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
    Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    Cc: Al Viro <viro@zeniv.linux.org.uk>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Brian Gerst <brgerst@gmail.com>
    Cc: Denys Vlasenko <dvlasenk@redhat.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Josh Poimboeuf <jpoimboe@redhat.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Link: http://lkml.kernel.org/r/20180405095307.3730-5-linux@dominikbrodowski.netSigned-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
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