Re: futex: Switch to USER_DS for futex test (was: Re: linux-next: manual merge of the akpm-current tree with the tip tree)
On Tue, Jan 14, 2014 at 5:32 PM, Geert Uytterhoeven
wrote:
> https://lkml.org/lkml/2013/12/11/141
>
> On Tue, Jan 14, 2014 at 5:19 PM, H. Peter Anvin wrote:
>> On 01/14/2014 05:17 AM, Geert Uytterhoeven wrote:
This seems terribly broken, the *futex_value*() ops should not need
that; they are supposed to access userspace without any of that.
>>>
>>> Why don't they need set_fs(USER_DS)?
>>
>> Because USER_DS is the normal operating state? It would appear m68k is
>
> Is it?
>
>> the only(?) arch that calls initcalls with get_fs() == KERNEL_DS...
>
> On ARM:
>
> fs = 0x0, USER_DS = 0xbf00, KERNEL_DS = 0x0
>
> Presumably also on s390, as the fix for m68k broke s390. That's why it's still
> in -mm and not yet in mainline.
On uml/amd64:
fs = 0x, USER_DS = 0x7fc000, KERNEL_DS = 0x
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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Re: futex: Switch to USER_DS for futex test (was: Re: linux-next: manual merge of the akpm-current tree with the tip tree)
On Tue, Jan 14, 2014 at 5:32 PM, Geert Uytterhoeven
ge...@linux-m68k.org wrote:
https://lkml.org/lkml/2013/12/11/141
On Tue, Jan 14, 2014 at 5:19 PM, H. Peter Anvin h...@zytor.com wrote:
On 01/14/2014 05:17 AM, Geert Uytterhoeven wrote:
This seems terribly broken, the *futex_value*() ops should not need
that; they are supposed to access userspace without any of that.
Why don't they need set_fs(USER_DS)?
Because USER_DS is the normal operating state? It would appear m68k is
Is it?
the only(?) arch that calls initcalls with get_fs() == KERNEL_DS...
On ARM:
fs = 0x0, USER_DS = 0xbf00, KERNEL_DS = 0x0
Presumably also on s390, as the fix for m68k broke s390. That's why it's still
in -mm and not yet in mainline.
On uml/amd64:
fs = 0x, USER_DS = 0x7fc000, KERNEL_DS = 0x
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say programmer or something like that.
-- Linus Torvalds
--
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: futex: Switch to USER_DS for futex test (was: Re: linux-next: manual merge of the akpm-current tree with the tip tree)
CC linux-arch
https://lkml.org/lkml/2013/12/11/141
On Tue, Jan 14, 2014 at 5:19 PM, H. Peter Anvin wrote:
> On 01/14/2014 05:17 AM, Geert Uytterhoeven wrote:
>>>
>>> This seems terribly broken, the *futex_value*() ops should not need
>>> that; they are supposed to access userspace without any of that.
>>
>> Why don't they need set_fs(USER_DS)?
>
> Because USER_DS is the normal operating state? It would appear m68k is
Is it?
> the only(?) arch that calls initcalls with get_fs() == KERNEL_DS...
On ARM:
fs = 0x0, USER_DS = 0xbf00, KERNEL_DS = 0x0
Presumably also on s390, as the fix for m68k broke s390. That's why it's still
in -mm and not yet in mainline.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
--
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: futex: Switch to USER_DS for futex test (was: Re: linux-next: manual merge of the akpm-current tree with the tip tree)
CC linux-arch
https://lkml.org/lkml/2013/12/11/141
On Tue, Jan 14, 2014 at 5:19 PM, H. Peter Anvin h...@zytor.com wrote:
On 01/14/2014 05:17 AM, Geert Uytterhoeven wrote:
This seems terribly broken, the *futex_value*() ops should not need
that; they are supposed to access userspace without any of that.
Why don't they need set_fs(USER_DS)?
Because USER_DS is the normal operating state? It would appear m68k is
Is it?
the only(?) arch that calls initcalls with get_fs() == KERNEL_DS...
On ARM:
fs = 0x0, USER_DS = 0xbf00, KERNEL_DS = 0x0
Presumably also on s390, as the fix for m68k broke s390. That's why it's still
in -mm and not yet in mainline.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say programmer or something like that.
-- Linus Torvalds
--
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/
