Re: [PATCH v2 00/44] Meta Linux Kernel Port
On 05/12/12 18:39, Al Viro wrote:
> On Wed, Dec 05, 2012 at 05:11:32PM +, Al Viro wrote:
>> On Wed, Dec 05, 2012 at 04:08:18PM +, James Hogan wrote:
>>
>>> other work not included:
>>> * switch to generic kernel_{thread,execve} (will be posted separately to
>>> aid review)
>>
>>> other changes:
>> ...
>>> * switch to generic sys_execve
>>
>> ... which should've broken your kernel_execve().
>
> BTW, one general note: lose the magical 7th argument. In the few syscalls
> that do need pt_regs, you can bloody well use current_pt_regs() instead;
> it's what, (register & constant) + constant? Passing it as explicit
> argument is saving at most two arithmetical insns on those syscalls.
> Moreover, for fork/clone/vfork we really don't need it until copy_thread();
> one of the changes in -next kills passing pt_regs * to do_fork() and through
> all that call chain (furthermore, if you make that
> childregs->ctx.AX[0].U0 = ALIGN(usp, 8);
> in copy_thread() conditional on usp != 0, you can go with generic
> variants from kernel/fork.c; again, see linux-next for examples of that).
> What's left? sigreturn and sigaltstack?
>
> Seriously, drop that struct pt_regs *; it makes things uglier, (slightly)
> hurts the syscall overhead and doesn't help the few syscalls that even
> look at that argument.
>
Done (with generic clone), thanks for pointing out the linux-next
changes. I'll base the next patchset on -next.
Thanks for all the review comments so far, they're much appreciated.
Cheers
James
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Re: [PATCH v2 00/44] Meta Linux Kernel Port
On 05/12/12 18:39, Al Viro wrote:
On Wed, Dec 05, 2012 at 05:11:32PM +, Al Viro wrote:
On Wed, Dec 05, 2012 at 04:08:18PM +, James Hogan wrote:
other work not included:
* switch to generic kernel_{thread,execve} (will be posted separately to
aid review)
other changes:
...
* switch to generic sys_execve
... which should've broken your kernel_execve().
BTW, one general note: lose the magical 7th argument. In the few syscalls
that do need pt_regs, you can bloody well use current_pt_regs() instead;
it's what, (register constant) + constant? Passing it as explicit
argument is saving at most two arithmetical insns on those syscalls.
Moreover, for fork/clone/vfork we really don't need it until copy_thread();
one of the changes in -next kills passing pt_regs * to do_fork() and through
all that call chain (furthermore, if you make that
childregs-ctx.AX[0].U0 = ALIGN(usp, 8);
in copy_thread() conditional on usp != 0, you can go with generic
variants from kernel/fork.c; again, see linux-next for examples of that).
What's left? sigreturn and sigaltstack?
Seriously, drop that struct pt_regs *; it makes things uglier, (slightly)
hurts the syscall overhead and doesn't help the few syscalls that even
look at that argument.
Done (with generic clone), thanks for pointing out the linux-next
changes. I'll base the next patchset on -next.
Thanks for all the review comments so far, they're much appreciated.
Cheers
James
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 00/44] Meta Linux Kernel Port
On 05/12/12 17:11, Al Viro wrote:
> On Wed, Dec 05, 2012 at 04:08:18PM +, James Hogan wrote:
>
>> other work not included:
>> * switch to generic kernel_{thread,execve} (will be posted separately to
>> aid review)
>
>> other changes:
> ...
>> * switch to generic sys_execve
>
> ... which should've broken your kernel_execve().
>
Hi Al,
Yes, you're right. I should have taken more care separating that patch
out. Sorry about that.
Cheers
James
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 00/44] Meta Linux Kernel Port
On 05/12/12 17:11, Al Viro wrote:
On Wed, Dec 05, 2012 at 04:08:18PM +, James Hogan wrote:
other work not included:
* switch to generic kernel_{thread,execve} (will be posted separately to
aid review)
other changes:
...
* switch to generic sys_execve
... which should've broken your kernel_execve().
Hi Al,
Yes, you're right. I should have taken more care separating that patch
out. Sorry about that.
Cheers
James
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 00/44] Meta Linux Kernel Port
On Wed, Dec 05, 2012 at 05:11:32PM +, Al Viro wrote:
> On Wed, Dec 05, 2012 at 04:08:18PM +, James Hogan wrote:
>
> > other work not included:
> > * switch to generic kernel_{thread,execve} (will be posted separately to
> > aid review)
>
> > other changes:
> ...
> > * switch to generic sys_execve
>
> ... which should've broken your kernel_execve().
BTW, one general note: lose the magical 7th argument. In the few syscalls
that do need pt_regs, you can bloody well use current_pt_regs() instead;
it's what, (register & constant) + constant? Passing it as explicit
argument is saving at most two arithmetical insns on those syscalls.
Moreover, for fork/clone/vfork we really don't need it until copy_thread();
one of the changes in -next kills passing pt_regs * to do_fork() and through
all that call chain (furthermore, if you make that
childregs->ctx.AX[0].U0 = ALIGN(usp, 8);
in copy_thread() conditional on usp != 0, you can go with generic
variants from kernel/fork.c; again, see linux-next for examples of that).
What's left? sigreturn and sigaltstack?
Seriously, drop that struct pt_regs *; it makes things uglier, (slightly)
hurts the syscall overhead and doesn't help the few syscalls that even
look at that argument.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 00/44] Meta Linux Kernel Port
On Wed, Dec 05, 2012 at 04:08:18PM +, James Hogan wrote:
> other work not included:
> * switch to generic kernel_{thread,execve} (will be posted separately to
> aid review)
> other changes:
...
> * switch to generic sys_execve
... which should've broken your kernel_execve().
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 00/44] Meta Linux Kernel Port
On Wed, Dec 05, 2012 at 04:08:18PM +, James Hogan wrote:
other work not included:
* switch to generic kernel_{thread,execve} (will be posted separately to
aid review)
other changes:
...
* switch to generic sys_execve
... which should've broken your kernel_execve().
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 00/44] Meta Linux Kernel Port
On Wed, Dec 05, 2012 at 05:11:32PM +, Al Viro wrote:
On Wed, Dec 05, 2012 at 04:08:18PM +, James Hogan wrote:
other work not included:
* switch to generic kernel_{thread,execve} (will be posted separately to
aid review)
other changes:
...
* switch to generic sys_execve
... which should've broken your kernel_execve().
BTW, one general note: lose the magical 7th argument. In the few syscalls
that do need pt_regs, you can bloody well use current_pt_regs() instead;
it's what, (register constant) + constant? Passing it as explicit
argument is saving at most two arithmetical insns on those syscalls.
Moreover, for fork/clone/vfork we really don't need it until copy_thread();
one of the changes in -next kills passing pt_regs * to do_fork() and through
all that call chain (furthermore, if you make that
childregs-ctx.AX[0].U0 = ALIGN(usp, 8);
in copy_thread() conditional on usp != 0, you can go with generic
variants from kernel/fork.c; again, see linux-next for examples of that).
What's left? sigreturn and sigaltstack?
Seriously, drop that struct pt_regs *; it makes things uglier, (slightly)
hurts the syscall overhead and doesn't help the few syscalls that even
look at that argument.
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
