* [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again
@ 2020-05-27 12:28 Petr Mladek
2020-05-28 1:03 ` Michael Ellerman
0 siblings, 1 reply; 6+ messages in thread
From: Petr Mladek @ 2020-05-27 12:28 UTC (permalink / raw)
To: Michael Ellerman
Cc: Miroslav Benes, Petr Mladek, Benjamin Herrenschmidt,
Paul Mackerras, linuxppc-dev, linux-kernel, Daniel Borkmann,
Alexei Starovoitov, Masami Hiramatsu, Brendan Gregg,
Christoph Hellwig
The commit 0ebeea8ca8a4d1d453a ("bpf: Restrict bpf_probe_read{, str}() only
to archs where they work") caused that bpf_probe_read{, str}() functions
were not longer available on architectures where the same logical address
might have different content in kernel and user memory mapping. These
architectures should use probe_read_{user,kernel}_str helpers.
For backward compatibility, the problematic functions are still available
on architectures where the user and kernel address spaces are not
overlapping. This is defined CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.
At the moment, these backward compatible functions are enabled only
on x86_64, arm, and arm64. Let's do it also on powerpc that has
the non overlapping address space as well.
Signed-off-by: Petr Mladek <pmladek@suse.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
---
arch/powerpc/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d13b5328ca10..b29d7cb38368 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -126,6 +126,7 @@ config PPC
select ARCH_HAS_MMIOWB if PPC64
select ARCH_HAS_PHYS_TO_DMA
select ARCH_HAS_PMEM_API
+ select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
select ARCH_HAS_PTE_DEVMAP if PPC_BOOK3S_64
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_MEMBARRIER_CALLBACKS
--
2.26.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again
2020-05-27 12:28 [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again Petr Mladek
@ 2020-05-28 1:03 ` Michael Ellerman
2020-05-28 9:13 ` Petr Mladek
0 siblings, 1 reply; 6+ messages in thread
From: Michael Ellerman @ 2020-05-28 1:03 UTC (permalink / raw)
To: Petr Mladek
Cc: Miroslav Benes, Petr Mladek, Benjamin Herrenschmidt,
Paul Mackerras, linuxppc-dev, linux-kernel, Daniel Borkmann,
Alexei Starovoitov, Masami Hiramatsu, Brendan Gregg,
Christoph Hellwig
Petr Mladek <pmladek@suse.com> writes:
> The commit 0ebeea8ca8a4d1d453a ("bpf: Restrict bpf_probe_read{, str}() only
> to archs where they work") caused that bpf_probe_read{, str}() functions
> were not longer available on architectures where the same logical address
> might have different content in kernel and user memory mapping. These
> architectures should use probe_read_{user,kernel}_str helpers.
>
> For backward compatibility, the problematic functions are still available
> on architectures where the user and kernel address spaces are not
> overlapping. This is defined CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.
>
> At the moment, these backward compatible functions are enabled only
> on x86_64, arm, and arm64. Let's do it also on powerpc that has
> the non overlapping address space as well.
>
> Signed-off-by: Petr Mladek <pmladek@suse.com>
This seems like it should have a Fixes: tag and go into v5.7?
cheers
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index d13b5328ca10..b29d7cb38368 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -126,6 +126,7 @@ config PPC
> select ARCH_HAS_MMIOWB if PPC64
> select ARCH_HAS_PHYS_TO_DMA
> select ARCH_HAS_PMEM_API
> + select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
> select ARCH_HAS_PTE_DEVMAP if PPC_BOOK3S_64
> select ARCH_HAS_PTE_SPECIAL
> select ARCH_HAS_MEMBARRIER_CALLBACKS
> --
> 2.26.2
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again
2020-05-28 1:03 ` Michael Ellerman
@ 2020-05-28 9:13 ` Petr Mladek
2020-05-28 12:23 ` Michael Ellerman
0 siblings, 1 reply; 6+ messages in thread
From: Petr Mladek @ 2020-05-28 9:13 UTC (permalink / raw)
To: Michael Ellerman
Cc: Miroslav Benes, Benjamin Herrenschmidt, Paul Mackerras,
linuxppc-dev, linux-kernel, Daniel Borkmann, Alexei Starovoitov,
Masami Hiramatsu, Brendan Gregg, Christoph Hellwig
On Thu 2020-05-28 11:03:43, Michael Ellerman wrote:
> Petr Mladek <pmladek@suse.com> writes:
> > The commit 0ebeea8ca8a4d1d453a ("bpf: Restrict bpf_probe_read{, str}() only
> > to archs where they work") caused that bpf_probe_read{, str}() functions
> > were not longer available on architectures where the same logical address
> > might have different content in kernel and user memory mapping. These
> > architectures should use probe_read_{user,kernel}_str helpers.
> >
> > For backward compatibility, the problematic functions are still available
> > on architectures where the user and kernel address spaces are not
> > overlapping. This is defined CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.
> >
> > At the moment, these backward compatible functions are enabled only
> > on x86_64, arm, and arm64. Let's do it also on powerpc that has
> > the non overlapping address space as well.
> >
> > Signed-off-by: Petr Mladek <pmladek@suse.com>
>
> This seems like it should have a Fixes: tag and go into v5.7?
Good point:
Fixes: commit 0ebeea8ca8a4d1d4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work")
And yes, it should ideally go into v5.7 either directly or via stable.
Should I resend the patch with Fixes and
Cc: stable@vger.kernel.org #v45.7 lines, please?
Best Regards,
Petr
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again
2020-05-28 9:13 ` Petr Mladek
@ 2020-05-28 12:23 ` Michael Ellerman
2020-05-28 15:06 ` Daniel Borkmann
0 siblings, 1 reply; 6+ messages in thread
From: Michael Ellerman @ 2020-05-28 12:23 UTC (permalink / raw)
To: Petr Mladek
Cc: Miroslav Benes, Benjamin Herrenschmidt, Paul Mackerras,
linuxppc-dev, linux-kernel, Daniel Borkmann, Alexei Starovoitov,
Masami Hiramatsu, Brendan Gregg, Christoph Hellwig
Petr Mladek <pmladek@suse.com> writes:
> On Thu 2020-05-28 11:03:43, Michael Ellerman wrote:
>> Petr Mladek <pmladek@suse.com> writes:
>> > The commit 0ebeea8ca8a4d1d453a ("bpf: Restrict bpf_probe_read{, str}() only
>> > to archs where they work") caused that bpf_probe_read{, str}() functions
>> > were not longer available on architectures where the same logical address
>> > might have different content in kernel and user memory mapping. These
>> > architectures should use probe_read_{user,kernel}_str helpers.
>> >
>> > For backward compatibility, the problematic functions are still available
>> > on architectures where the user and kernel address spaces are not
>> > overlapping. This is defined CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.
>> >
>> > At the moment, these backward compatible functions are enabled only
>> > on x86_64, arm, and arm64. Let's do it also on powerpc that has
>> > the non overlapping address space as well.
>> >
>> > Signed-off-by: Petr Mladek <pmladek@suse.com>
>>
>> This seems like it should have a Fixes: tag and go into v5.7?
>
> Good point:
>
> Fixes: commit 0ebeea8ca8a4d1d4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work")
>
> And yes, it should ideally go into v5.7 either directly or via stable.
>
> Should I resend the patch with Fixes and
> Cc: stable@vger.kernel.org #v45.7 lines, please?
If it goes into v5.7 then it doesn't need a Cc: stable, and I guess a
Fixes: tag is nice to have but not so important as it already mentions
the commit that caused the problem. So a resend probably isn't
necessary.
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Daniel can you pick this up, or should I?
cheers
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again
2020-05-28 12:23 ` Michael Ellerman
@ 2020-05-28 15:06 ` Daniel Borkmann
2020-05-29 0:05 ` Michael Ellerman
0 siblings, 1 reply; 6+ messages in thread
From: Daniel Borkmann @ 2020-05-28 15:06 UTC (permalink / raw)
To: Michael Ellerman, Petr Mladek
Cc: Miroslav Benes, Benjamin Herrenschmidt, Paul Mackerras,
linuxppc-dev, linux-kernel, Alexei Starovoitov, Masami Hiramatsu,
Brendan Gregg, Christoph Hellwig, bpf
On 5/28/20 2:23 PM, Michael Ellerman wrote:
> Petr Mladek <pmladek@suse.com> writes:
>> On Thu 2020-05-28 11:03:43, Michael Ellerman wrote:
>>> Petr Mladek <pmladek@suse.com> writes:
>>>> The commit 0ebeea8ca8a4d1d453a ("bpf: Restrict bpf_probe_read{, str}() only
>>>> to archs where they work") caused that bpf_probe_read{, str}() functions
>>>> were not longer available on architectures where the same logical address
>>>> might have different content in kernel and user memory mapping. These
>>>> architectures should use probe_read_{user,kernel}_str helpers.
>>>>
>>>> For backward compatibility, the problematic functions are still available
>>>> on architectures where the user and kernel address spaces are not
>>>> overlapping. This is defined CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.
>>>>
>>>> At the moment, these backward compatible functions are enabled only
>>>> on x86_64, arm, and arm64. Let's do it also on powerpc that has
>>>> the non overlapping address space as well.
>>>>
>>>> Signed-off-by: Petr Mladek <pmladek@suse.com>
>>>
>>> This seems like it should have a Fixes: tag and go into v5.7?
>>
>> Good point:
>>
>> Fixes: commit 0ebeea8ca8a4d1d4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work")
>>
>> And yes, it should ideally go into v5.7 either directly or via stable.
>>
>> Should I resend the patch with Fixes and
>> Cc: stable@vger.kernel.org #v45.7 lines, please?
>
> If it goes into v5.7 then it doesn't need a Cc: stable, and I guess a
> Fixes: tag is nice to have but not so important as it already mentions
> the commit that caused the problem. So a resend probably isn't
> necessary.
>
> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
>
> Daniel can you pick this up, or should I?
Yeah I'll take it into bpf tree for v5.7.
Thanks everyone,
Daniel
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again
2020-05-28 15:06 ` Daniel Borkmann
@ 2020-05-29 0:05 ` Michael Ellerman
0 siblings, 0 replies; 6+ messages in thread
From: Michael Ellerman @ 2020-05-29 0:05 UTC (permalink / raw)
To: Daniel Borkmann, Petr Mladek
Cc: Miroslav Benes, Benjamin Herrenschmidt, Paul Mackerras,
linuxppc-dev, linux-kernel, Alexei Starovoitov, Masami Hiramatsu,
Brendan Gregg, Christoph Hellwig, bpf
Daniel Borkmann <daniel@iogearbox.net> writes:
> On 5/28/20 2:23 PM, Michael Ellerman wrote:
>> Petr Mladek <pmladek@suse.com> writes:
>>> On Thu 2020-05-28 11:03:43, Michael Ellerman wrote:
>>>> Petr Mladek <pmladek@suse.com> writes:
>>>>> The commit 0ebeea8ca8a4d1d453a ("bpf: Restrict bpf_probe_read{, str}() only
>>>>> to archs where they work") caused that bpf_probe_read{, str}() functions
>>>>> were not longer available on architectures where the same logical address
>>>>> might have different content in kernel and user memory mapping. These
>>>>> architectures should use probe_read_{user,kernel}_str helpers.
>>>>>
>>>>> For backward compatibility, the problematic functions are still available
>>>>> on architectures where the user and kernel address spaces are not
>>>>> overlapping. This is defined CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.
>>>>>
>>>>> At the moment, these backward compatible functions are enabled only
>>>>> on x86_64, arm, and arm64. Let's do it also on powerpc that has
>>>>> the non overlapping address space as well.
>>>>>
>>>>> Signed-off-by: Petr Mladek <pmladek@suse.com>
>>>>
>>>> This seems like it should have a Fixes: tag and go into v5.7?
>>>
>>> Good point:
>>>
>>> Fixes: commit 0ebeea8ca8a4d1d4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work")
>>>
>>> And yes, it should ideally go into v5.7 either directly or via stable.
>>>
>>> Should I resend the patch with Fixes and
>>> Cc: stable@vger.kernel.org #v45.7 lines, please?
>>
>> If it goes into v5.7 then it doesn't need a Cc: stable, and I guess a
>> Fixes: tag is nice to have but not so important as it already mentions
>> the commit that caused the problem. So a resend probably isn't
>> necessary.
>>
>> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
>>
>> Daniel can you pick this up, or should I?
>
> Yeah I'll take it into bpf tree for v5.7.
Thanks.
cheers
^ permalink raw reply [flat|nested] 6+ messages in thread
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2020-05-27 12:28 [PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again Petr Mladek
2020-05-28 1:03 ` Michael Ellerman
2020-05-28 9:13 ` Petr Mladek
2020-05-28 12:23 ` Michael Ellerman
2020-05-28 15:06 ` Daniel Borkmann
2020-05-29 0:05 ` Michael Ellerman
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