lkml.org 
[lkml]   [2018]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v5 13/25] m68k: add asm/syscall.h
    Hi Geert,

    On Mon, Dec 10, 2018 at 09:45:42AM +0100, Geert Uytterhoeven wrote:
    > Hi Dmitry,
    >
    > On Mon, Dec 10, 2018 at 5:30 AM Dmitry V. Levin <ldv@altlinux.org> wrote:
    > > syscall_get_* functions are required to be implemented on all
    > > architectures in order to extend the generic ptrace API with
    > > PTRACE_GET_SYSCALL_INFO request.
    > >
    > > This introduces asm/syscall.h on m68k implementing all 5 syscall_get_*
    > > functions as documented in asm-generic/syscall.h: syscall_get_nr,
    > > syscall_get_arguments, syscall_get_error, syscall_get_return_value,
    > > and syscall_get_arch.
    > >
    > > Cc: Geert Uytterhoeven <geert@linux-m68k.org>
    > > Cc: Oleg Nesterov <oleg@redhat.com>
    > > Cc: Andy Lutomirski <luto@kernel.org>
    > > Cc: Elvira Khabirova <lineprinter@altlinux.org>
    > > Cc: Eugene Syromyatnikov <esyr@redhat.com>
    > > Cc: linux-m68k@lists.linux-m68k.org
    > > Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
    > > ---
    > >
    > > Notes:
    > > v5: added syscall_get_nr, syscall_get_arguments, syscall_get_error,
    > > and syscall_get_return_value
    > > v1: added syscall_get_arch
    >
    > > --- /dev/null
    > > +++ b/arch/m68k/include/asm/syscall.h
    > > @@ -0,0 +1,39 @@
    >
    > > +static inline void
    > > +syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
    > > + unsigned int i, unsigned int n, unsigned long *args)
    > > +{
    > > + BUG_ON(i + n > 6);
    >
    > Does this have to crash the kernel?

    This is what most of other architectures do, but we could choose
    a softer approach, e.g. use WARN_ON_ONCE instead.

    > Perhaps you can return an error code instead?

    That would be problematic given the signature of this function
    and the nature of the potential bug which would most likely be a usage error.


    --
    ldv
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2018-12-10 13:41    [W:2.055 / U:0.028 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site