* [PATCH v6 00/10] Introduce CAP_PERFMON to secure system performance monitoring and observability
From: Alexey Budankov @ 2020-01-28 5:52 UTC (permalink / raw)
To: Peter Zijlstra, Arnaldo Carvalho de Melo, Ingo Molnar,
benh@kernel.crashing.org, Paul Mackerras, Michael Ellerman,
james.bottomley@hansenpartnership.com, Serge Hallyn, Will Deacon,
Robert Richter, Alexei Starovoitov
Cc: Song Liu, Andi Kleen, linux-parisc@vger.kernel.org,
Alexander Shishkin, linuxppc-dev@lists.ozlabs.org,
intel-gfx@lists.freedesktop.org, Igor Lubashev, linux-kernel,
Stephane Eranian, linux-perf-users@vger.kernel.org,
selinux@vger.kernel.org, linux-security-module@vger.kernel.org,
oprofile-list, Lionel Landwerlin, Namhyung Kim, Jiri Olsa,
linux-arm-kernel
Currently access to perf_events, i915_perf and other performance monitoring and
observability subsystems of the kernel is open only for a privileged process [1]
with CAP_SYS_ADMIN capability enabled in the process effective set [2].
This patch set introduces CAP_PERFMON capability designed to secure system
performance monitoring and observability operations so that CAP_PERFMON would
assist CAP_SYS_ADMIN capability in its governing role for performance monitoring
and observability subsystems of the kernel.
CAP_PERFMON intends to harden system security and integrity during system
performance monitoring and observability operations by decreasing attack surface
that is available to a CAP_SYS_ADMIN privileged process [2]. Providing the access
to system performance monitoring and observability operations under CAP_PERFMON
capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes chances
to misuse the credentials and makes the operation more secure. Thus, CAP_PERFMON
implements the principal of least privilege for performance monitoring and
observability operations (POSIX IEEE 1003.1e: 2.2.2.39 principle of least
privilege: A security design principle that states that a process or program be
granted only those privileges (e.g., capabilities) necessary to accomplish its
legitimate function, and only for the time that such privileges are actually
required)
CAP_PERFMON intends to meet the demand to secure system performance monitoring
and observability operations for adoption in security sensitive, restricted,
multiuser production environments (e.g. HPC clusters, cloud and virtual compute
environments), where root or CAP_SYS_ADMIN credentials are not available to mass
users of a system, and securely unblock applicability and scalability of system
performance monitoring and observability operations beyond root or CAP_SYS_ADMIN
process use cases.
CAP_PERFMON intends to take over CAP_SYS_ADMIN credentials related to system
performance monitoring and observability operations and balance amount of
CAP_SYS_ADMIN credentials following the recommendations in the capabilities man
page [2] for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to
kernel developers, below." For backward compatibility reasons access to system
performance monitoring and observability subsystems of the kernel remains open
for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN capability usage for
secure system performance monitoring and observability operations is discouraged
with respect to the designed CAP_PERFMON capability.
Possible alternative solution to this system security hardening, capabilities
balancing task of making performance monitoring and observability operations
more accessible could be to use the existing CAP_SYS_PTRACE capability to govern
system performance monitoring and observability subsystems. However CAP_SYS_PTRACE
capability still provides users with more credentials than are required for secure
performance monitoring and observability operations and this excess is avoided by
the designed CAP_PERFMON capability.
Although software running under CAP_PERFMON can not ensure avoidance of related
hardware issues, the software can still mitigate those issues following the official
embargoed hardware issues mitigation procedure [3]. The bugs in the software itself
can be fixed following the standard kernel development process [4] to maintain and
harden security of system performance monitoring and observability operations.
Finally, the patch set is shaped in the way that simplifies backtracking procedure
of possible induced issues [5] as much as possible.
The patch set is for tip perf/core repository:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip perf/core
sha1: 56ee04aa63285d6bc8a995a26e2441ae3d419bcd
---
Changes in v6:
- avoided noaudit checks in perfmon_capable() to explicitly advertise CAP_PERFMON
usage thru audit logs to secure system performance monitoring and observability
Changes in v5:
- renamed CAP_SYS_PERFMON to CAP_PERFMON
- extended perfmon_capable() with noaudit checks
Changes in v4:
- converted perfmon_capable() into an inline function
- made perf_events kprobes, uprobes, hw breakpoints and namespaces data available
to CAP_SYS_PERFMON privileged processes
- applied perfmon_capable() to drivers/perf and drivers/oprofile
- extended __cmd_ftrace() with support of CAP_SYS_PERFMON
Changes in v3:
- implemented perfmon_capable() macros aggregating required capabilities checks
Changes in v2:
- made perf_events trace points available to CAP_SYS_PERFMON privileged processes
- made perf_event_paranoid_check() treat CAP_SYS_PERFMON equally to CAP_SYS_ADMIN
- applied CAP_SYS_PERFMON to i915_perf, bpf_trace, powerpc and parisc system
performance monitoring and observability related subsystems
---
Alexey Budankov (10):
capabilities: introduce CAP_PERFMON to kernel and user space
perf/core: open access to the core for CAP_PERFMON privileged process
perf/core: open access to probes for CAP_PERFMON privileged process
perf tool: extend Perf tool with CAP_PERFMON capability support
drm/i915/perf: open access for CAP_PERFMON privileged process
trace/bpf_trace: open access for CAP_PERFMON privileged process
powerpc/perf: open access for CAP_PERFMON privileged process
parisc/perf: open access for CAP_PERFMON privileged process
drivers/perf: open access for CAP_PERFMON privileged process
drivers/oprofile: open access for CAP_PERFMON privileged process
arch/parisc/kernel/perf.c | 2 +-
arch/powerpc/perf/imc-pmu.c | 4 ++--
drivers/gpu/drm/i915/i915_perf.c | 13 ++++++-------
drivers/oprofile/event_buffer.c | 2 +-
drivers/perf/arm_spe_pmu.c | 4 ++--
include/linux/capability.h | 4 ++++
include/linux/perf_event.h | 6 +++---
include/uapi/linux/capability.h | 8 +++++++-
kernel/events/core.c | 6 +++---
kernel/trace/bpf_trace.c | 2 +-
security/selinux/include/classmap.h | 4 ++--
tools/perf/builtin-ftrace.c | 5 +++--
tools/perf/design.txt | 3 ++-
tools/perf/util/cap.h | 4 ++++
tools/perf/util/evsel.c | 10 +++++-----
tools/perf/util/util.c | 1 +
16 files changed, 47 insertions(+), 31 deletions(-)
---
Testing and validation (Intel Skylake, 8 cores, Fedora 29, 5.5.0-rc3+, x86_64):
libcap library [6], [7], [8] and Perf tool can be used to apply CAP_PERFMON
capability for secure system performance monitoring and observability beyond the
scope permitted by the system wide perf_event_paranoid kernel setting [9] and
below are the steps for evaluation:
- patch, build and boot the kernel
- patch, build Perf tool e.g. to /home/user/perf
...
# git clone git://git.kernel.org/pub/scm/libs/libcap/libcap.git libcap
# pushd libcap
# patch libcap/include/uapi/linux/capabilities.h with [PATCH 1]
# make
# pushd progs
# ./setcap "cap_perfmon,cap_sys_ptrace,cap_syslog=ep" /home/user/perf
# ./setcap -v "cap_perfmon,cap_sys_ptrace,cap_syslog=ep" /home/user/perf
/home/user/perf: OK
# ./getcap /home/user/perf
/home/user/perf = cap_sys_ptrace,cap_syslog,cap_perfmon+ep
# echo 2 > /proc/sys/kernel/perf_event_paranoid
# cat /proc/sys/kernel/perf_event_paranoid
2
...
$ /home/user/perf top
... works as expected ...
$ cat /proc/`pidof perf`/status
Name: perf
Umask: 0002
State: S (sleeping)
Tgid: 2958
Ngid: 0
Pid: 2958
PPid: 9847
TracerPid: 0
Uid: 500 500 500 500
Gid: 500 500 500 500
FDSize: 256
...
CapInh: 0000000000000000
CapPrm: 0000004400080000
CapEff: 0000004400080000 => 01000100 00000000 00001000 00000000 00000000
cap_perfmon,cap_sys_ptrace,cap_syslog
CapBnd: 0000007fffffffff
CapAmb: 0000000000000000
NoNewPrivs: 0
Seccomp: 0
Speculation_Store_Bypass: thread vulnerable
Cpus_allowed: ff
Cpus_allowed_list: 0-7
...
Usage of cap_perfmon effectively avoids unused credentials excess:
- with cap_sys_admin:
CapEff: 0000007fffffffff => 01111111 11111111 11111111 11111111 11111111
- with cap_perfmon:
CapEff: 0000004400080000 => 01000100 00000000 00001000 00000000 00000000
38 34 19
perfmon syslog sys_ptrace
---
[1] https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html
[2] http://man7.org/linux/man-pages/man7/capabilities.7.html
[3] https://www.kernel.org/doc/html/latest/process/embargoed-hardware-issues.html
[4] https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html
[5] https://www.kernel.org/doc/html/latest/process/management-style.html#decisions
[6] http://man7.org/linux/man-pages/man8/setcap.8.html
[7] https://git.kernel.org/pub/scm/libs/libcap/libcap.git
[8] https://sites.google.com/site/fullycapable/, posix_1003.1e-990310.pdf
[9] http://man7.org/linux/man-pages/man2/perf_event_open.2.html
--
2.20.1
^ permalink raw reply
* Re: [PATCH V12] mm/debug: Add tests validating architecture page table helpers
From: Qian Cai @ 2020-01-28 5:48 UTC (permalink / raw)
To: Anshuman Khandual
Cc: Mark Rutland, linux-ia64, linux-sh, Peter Zijlstra, James Hogan,
Tetsuo Handa, Heiko Carstens, Michal Hocko, Linux-MM, Dave Hansen,
Paul Mackerras, sparclinux, Thomas Gleixner, linux-s390, x86,
Russell King - ARM Linux, Matthew Wilcox, Steven Price,
Jason Gunthorpe, Gerald Schaefer, linux-snps-arc,
linux-arm-kernel, Ingo Molnar, Kees Cook, Masahiro Yamada,
Mark Brown, Kirill A . Shutemov, Dan Williams, Vlastimil Babka,
Sri Krishna chowdary, Ard Biesheuvel, Greg Kroah-Hartman,
linux-mips, Ralf Baechle, linux-kernel, Paul Burton,
Mike Rapoport, Vineet Gupta, Martin Schwidefsky, Andrew Morton,
linuxppc-dev, David S. Miller
In-Reply-To: <012158b7-a40e-050f-cd1b-d6ce7faf042f@arm.com>
> On Jan 27, 2020, at 11:58 PM, Anshuman Khandual <Anshuman.Khandual@arm.com> wrote:
>
> As I had mentioned before, the test attempts to formalize page table helper semantics
> as expected from generic MM code paths and intend to catch deviations when enabled on
> a given platform. How else should we test semantics errors otherwise ? There are past
> examples of usefulness for this procedure on arm64 and on s390. I am wondering how
> else to prove the usefulness of a debug feature if these references are not enough.
Not saying it will not be useful. As you mentioned it actually found a bug or two in the past. The problem is that there is always a cost to maintain something like this, and nobody knew how things could be broken even for the isolated code you mentioned in the future given how complicated the kernel code base is. I am not so positive that many developers would enable this debug feature and use it on a regular basis from the information you gave so far.
On the other hand, it might just be good at maintaining this thing out of tree by yourself anyway, because if there isn’t going to be used by many developers, few people is going to contribute to this and even noticed when it is broken. What’s the point of getting this merged apart from being getting some meaningless credits?
^ permalink raw reply
* Re: [PATCH V12] mm/debug: Add tests validating architecture page table helpers
From: Anshuman Khandual @ 2020-01-28 4:57 UTC (permalink / raw)
To: Qian Cai
Cc: Mark Rutland, linux-ia64, linux-sh, Peter Zijlstra, James Hogan,
Tetsuo Handa, Heiko Carstens, Michal Hocko, Linux-MM, Dave Hansen,
Paul Mackerras, sparclinux, Thomas Gleixner, linux-s390, x86,
Russell King - ARM Linux, Matthew Wilcox, Steven Price,
Jason Gunthorpe, Gerald Schaefer, linux-snps-arc,
linux-arm-kernel, Ingo Molnar, Kees Cook, Masahiro Yamada,
Mark Brown, Kirill A . Shutemov, Dan Williams, Vlastimil Babka,
Sri Krishna chowdary, Ard Biesheuvel, Greg Kroah-Hartman,
linux-mips, Ralf Baechle, linux-kernel, Paul Burton,
Mike Rapoport, Vineet Gupta, Martin Schwidefsky, Andrew Morton,
linuxppc-dev, David S. Miller
In-Reply-To: <016A776F-EFD9-4D2B-A3A9-788008617D95@lca.pw>
On 01/28/2020 09:03 AM, Qian Cai wrote:
>
>
>> On Jan 27, 2020, at 10:06 PM, Anshuman Khandual <anshuman.khandual@arm.com> wrote:
>>
>>
>>
>> On 01/28/2020 07:41 AM, Qian Cai wrote:
>>>
>>>
>>>> On Jan 27, 2020, at 8:28 PM, Anshuman Khandual <Anshuman.Khandual@arm.com> wrote:
>>>>
>>>> This adds tests which will validate architecture page table helpers and
>>>> other accessors in their compliance with expected generic MM semantics.
>>>> This will help various architectures in validating changes to existing
>>>> page table helpers or addition of new ones.
>>>>
>>>> This test covers basic page table entry transformations including but not
>>>> limited to old, young, dirty, clean, write, write protect etc at various
>>>> level along with populating intermediate entries with next page table page
>>>> and validating them.
>>>>
>>>> Test page table pages are allocated from system memory with required size
>>>> and alignments. The mapped pfns at page table levels are derived from a
>>>> real pfn representing a valid kernel text symbol. This test gets called
>>>> right after page_alloc_init_late().
>>>>
>>>> This gets build and run when CONFIG_DEBUG_VM_PGTABLE is selected along with
>>>> CONFIG_VM_DEBUG. Architectures willing to subscribe this test also need to
>>>> select CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE which for now is limited to x86 and
>>>> arm64. Going forward, other architectures too can enable this after fixing
>>>> build or runtime problems (if any) with their page table helpers.
>>
>> Hello Qian,
>>
>>>
>>> What’s the value of this block of new code? It only supports x86 and arm64
>>> which are supposed to be good now.
>>
>> We have been over the usefulness of this code many times before as the patch is
>> already in it's V12. Currently it is enabled on arm64, x86 (except PAE), arc and
>> ppc32. There are build time or runtime problems with other archs which prevent
>
> I am not sure if I care too much about arc and ppc32 which are pretty much legacy
> platforms.
Okay but FWIW the maintainers for all these enabled platforms cared for this test
at the least and really helped in shaping the test to it's current state. Besides
I am still failing to understand your point here about evaluating particular feature's
usefulness based on it's support on relative and perceived importance of some platforms
compared to others. Again the idea is to integrate all platforms eventually but we had
discovered build and runtime issues which needs to be resolved at platform level first.
Unless I am mistaken, debug feature like this which is putting down a framework while
also benefiting some initial platforms to start with, will be a potential candidate for
eventual inclusion in the mainline. Otherwise, please point to any other agreed upon
community criteria for debug feature's mainline inclusion which I will try to adhere.
I wonder if all other similar debug features from the past ever met 'the all inclusive
at the beginning' criteria which you are trying to propose here. This test also adds a
feature file, enlisting all supported archs as suggested by Ingo for the exact same
reason. This is not the first time, a feature is listing out archs which are supported
and archs which are not.
>
>> enablement of this test (for the moment) but then the goal is to integrate all
>> of them going forward. The test not only validates platform's adherence to the
>> expected semantics from generic MM but also helps in keeping it that way during
>> code changes in future as well.
>
> Another option maybe to get some decent arches on board first before merging this
> thing, so it have more changes to catch regressions for developers who might run this.
>
>>
>>> Did those tests ever find any regression or this is almost only useful for new
>>
>> The test has already found problems with s390 page table helpers.
>
> Hmm, that is pretty weak where s390 is not even official supported with this version.
And there were valid reasons why s390 could not be enabled just yet as explained by s390
folks during our previous discussions. I just pointed out an example where this test was
useful as you had asked previously. Not being official supported in this version does
not take away the fact the it was indeed useful for that platform in discovering a bug.
>
>>
>>> architectures which only happened once in a few years?
>>
>> Again, not only it validates what exist today but its also a tool to make
>> sure that all platforms continue adhere to a common agreed upon semantics
>> as reflected through the tests here.
>>
>>> The worry if not many people will use this config and code those that much in
>>
>> Debug features or tests in the kernel are used when required. These are never or
>> should not be enabled by default. AFAICT this is true even for entire DEBUG_VM
>> packaged tests. Do you have any particular data or precedence to substantiate
>> the fact that this test will be used any less often than the other similar ones
>> in the tree ? I can only speak for arm64 platform but the very idea for this
>> test came from Catalin when we were trying to understand the semantics for THP
>> helpers while enabling THP migration without split. Apart from going over the
>> commit messages from the past, there were no other way to figure out how any
>> particular page table helper is suppose to change given page table entry. This
>> test tries to formalize those semantics.
>
> I am thinking about how we made so many mistakes before by merging too many of
> those debugging options that many of them have been broken for many releases
> proving that nobody actually used them regularly. We don’t need to repeat the same
Again will ask for some data to substantiate these claims. Though I am not really
sure but believe that there are integration test frameworks out there which regularly
validates each of these code path on multiple platforms. One such automation found
that V11 of the test was broken on X86 PAE platform which I fixed. Nonetheless, I can
speak only for arm64 platform and we intend to use this test to validate arm64 exported
page table helpers. Citing unsubstantiated past examples should not really block these
enabled platforms (arm64 at the very least) from getting this debug feature which has
already demonstrated it's usefulness during arm64 THP migration development and on s390
platforms as well.
> mistake again. I am actually thinking about to remove things like page_poisoning often
> which is almost are never found any bug recently and only cause pains when interacting
> with other new features that almost nobody will test them together to begin with.
> We even have some SLUB debugging code sit there for almost 15 years that almost
> nobody used it and maintainers refused to remove it.
Unlike those, the proposed test here is isolated as a stand alone test and stays clear
off from any other code path. I have not been involved in or aware of the usefulness of
existing MM debug features and hence will just leave them upto the judgment of the
maintainers whether to keep or discard them.
>
>>
>>> the future because it is inefficient to find bugs, it will simply be rotten
>> Could you be more specific here ? What parts of the test are inefficient ? I
>> am happy to improve upon the test. Do let me know you if you have suggestions.
>>
>>> like a few other debugging options out there we have in the mainline that
>> will be a pain to remove later on.
>>>
>>
>> Even though I am not agreeing to your assessment about the usefulness of the
>> test without any substantial data backing up the claims, the test case in
>> itself is very much compartmentalized, staying clear from generic MM and
>> debug_vm_pgtable() is only function executing the test which is getting
>> called from kernel_init_freeable() path.
>
> I am thinking exactly the other way around. You are proposing to merge this tests
> without proving how useful it will be able to find regressions for future developers
> to make sure it will actually get used.
As I had mentioned before, the test attempts to formalize page table helper semantics
as expected from generic MM code paths and intend to catch deviations when enabled on
a given platform. How else should we test semantics errors otherwise ? There are past
examples of usefulness for this procedure on arm64 and on s390. I am wondering how
else to prove the usefulness of a debug feature if these references are not enough.
>
^ permalink raw reply
* Re: [PATCH V12] mm/debug: Add tests validating architecture page table helpers
From: Qian Cai @ 2020-01-28 3:33 UTC (permalink / raw)
To: Anshuman Khandual
Cc: Mark Rutland, linux-ia64, linux-sh, Peter Zijlstra, James Hogan,
Tetsuo Handa, Heiko Carstens, Michal Hocko, Linux-MM, Dave Hansen,
Paul Mackerras, sparclinux, Thomas Gleixner, linux-s390, x86,
Russell King - ARM Linux, Matthew Wilcox, Steven Price,
Jason Gunthorpe, Gerald Schaefer, linux-snps-arc,
linux-arm-kernel, Ingo Molnar, Kees Cook, Masahiro Yamada,
Mark Brown, Kirill A . Shutemov, Dan Williams, Vlastimil Babka,
Sri Krishna chowdary, Ard Biesheuvel, Greg Kroah-Hartman,
linux-mips, Ralf Baechle, linux-kernel, Paul Burton,
Mike Rapoport, Vineet Gupta, Martin Schwidefsky, Andrew Morton,
linuxppc-dev, David S. Miller
In-Reply-To: <214c0d53-eb34-9b0c-2e4e-1aa005146331@arm.com>
> On Jan 27, 2020, at 10:06 PM, Anshuman Khandual <anshuman.khandual@arm.com> wrote:
>
>
>
> On 01/28/2020 07:41 AM, Qian Cai wrote:
>>
>>
>>> On Jan 27, 2020, at 8:28 PM, Anshuman Khandual <Anshuman.Khandual@arm.com> wrote:
>>>
>>> This adds tests which will validate architecture page table helpers and
>>> other accessors in their compliance with expected generic MM semantics.
>>> This will help various architectures in validating changes to existing
>>> page table helpers or addition of new ones.
>>>
>>> This test covers basic page table entry transformations including but not
>>> limited to old, young, dirty, clean, write, write protect etc at various
>>> level along with populating intermediate entries with next page table page
>>> and validating them.
>>>
>>> Test page table pages are allocated from system memory with required size
>>> and alignments. The mapped pfns at page table levels are derived from a
>>> real pfn representing a valid kernel text symbol. This test gets called
>>> right after page_alloc_init_late().
>>>
>>> This gets build and run when CONFIG_DEBUG_VM_PGTABLE is selected along with
>>> CONFIG_VM_DEBUG. Architectures willing to subscribe this test also need to
>>> select CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE which for now is limited to x86 and
>>> arm64. Going forward, other architectures too can enable this after fixing
>>> build or runtime problems (if any) with their page table helpers.
>
> Hello Qian,
>
>>
>> What’s the value of this block of new code? It only supports x86 and arm64
>> which are supposed to be good now.
>
> We have been over the usefulness of this code many times before as the patch is
> already in it's V12. Currently it is enabled on arm64, x86 (except PAE), arc and
> ppc32. There are build time or runtime problems with other archs which prevent
I am not sure if I care too much about arc and ppc32 which are pretty much legacy
platforms.
> enablement of this test (for the moment) but then the goal is to integrate all
> of them going forward. The test not only validates platform's adherence to the
> expected semantics from generic MM but also helps in keeping it that way during
> code changes in future as well.
Another option maybe to get some decent arches on board first before merging this
thing, so it have more changes to catch regressions for developers who might run this.
>
>> Did those tests ever find any regression or this is almost only useful for new
>
> The test has already found problems with s390 page table helpers.
Hmm, that is pretty weak where s390 is not even official supported with this version.
>
>> architectures which only happened once in a few years?
>
> Again, not only it validates what exist today but its also a tool to make
> sure that all platforms continue adhere to a common agreed upon semantics
> as reflected through the tests here.
>
>> The worry if not many people will use this config and code those that much in
>
> Debug features or tests in the kernel are used when required. These are never or
> should not be enabled by default. AFAICT this is true even for entire DEBUG_VM
> packaged tests. Do you have any particular data or precedence to substantiate
> the fact that this test will be used any less often than the other similar ones
> in the tree ? I can only speak for arm64 platform but the very idea for this
> test came from Catalin when we were trying to understand the semantics for THP
> helpers while enabling THP migration without split. Apart from going over the
> commit messages from the past, there were no other way to figure out how any
> particular page table helper is suppose to change given page table entry. This
> test tries to formalize those semantics.
I am thinking about how we made so many mistakes before by merging too many of
those debugging options that many of them have been broken for many releases
proving that nobody actually used them regularly. We don’t need to repeat the same
mistake again. I am actually thinking about to remove things like page_poisoning often
which is almost are never found any bug recently and only cause pains when interacting
with other new features that almost nobody will test them together to begin with.
We even have some SLUB debugging code sit there for almost 15 years that almost
nobody used it and maintainers refused to remove it.
>
>> the future because it is inefficient to find bugs, it will simply be rotten
> Could you be more specific here ? What parts of the test are inefficient ? I
> am happy to improve upon the test. Do let me know you if you have suggestions.
>
>> like a few other debugging options out there we have in the mainline that
> will be a pain to remove later on.
>>
>
> Even though I am not agreeing to your assessment about the usefulness of the
> test without any substantial data backing up the claims, the test case in
> itself is very much compartmentalized, staying clear from generic MM and
> debug_vm_pgtable() is only function executing the test which is getting
> called from kernel_init_freeable() path.
I am thinking exactly the other way around. You are proposing to merge this tests
without proving how useful it will be able to find regressions for future developers
to make sure it will actually get used.
^ permalink raw reply
* Re: [PATCH V12] mm/debug: Add tests validating architecture page table helpers
From: Anshuman Khandual @ 2020-01-28 3:06 UTC (permalink / raw)
To: Qian Cai
Cc: Mark Rutland, linux-ia64, linux-sh, Peter Zijlstra, James Hogan,
Tetsuo Handa, Heiko Carstens, Michal Hocko, linux-mm, Dave Hansen,
Paul Mackerras, sparclinux, Thomas Gleixner, linux-s390, x86,
Russell King - ARM Linux, Matthew Wilcox, Steven Price,
Jason Gunthorpe, Gerald Schaefer, linux-snps-arc,
linux-arm-kernel, Ingo Molnar, Kees Cook, Masahiro Yamada,
Mark Brown, Kirill A . Shutemov, Dan Williams, Vlastimil Babka,
Sri Krishna chowdary, Ard Biesheuvel, Greg Kroah-Hartman,
linux-mips, Ralf Baechle, linux-kernel, Paul Burton,
Mike Rapoport, Vineet Gupta, Martin Schwidefsky, Andrew Morton,
linuxppc-dev, David S. Miller
In-Reply-To: <14882A91-17DE-4ABD-ABF2-08E7CCEDF660@lca.pw>
On 01/28/2020 07:41 AM, Qian Cai wrote:
>
>
>> On Jan 27, 2020, at 8:28 PM, Anshuman Khandual <Anshuman.Khandual@arm.com> wrote:
>>
>> This adds tests which will validate architecture page table helpers and
>> other accessors in their compliance with expected generic MM semantics.
>> This will help various architectures in validating changes to existing
>> page table helpers or addition of new ones.
>>
>> This test covers basic page table entry transformations including but not
>> limited to old, young, dirty, clean, write, write protect etc at various
>> level along with populating intermediate entries with next page table page
>> and validating them.
>>
>> Test page table pages are allocated from system memory with required size
>> and alignments. The mapped pfns at page table levels are derived from a
>> real pfn representing a valid kernel text symbol. This test gets called
>> right after page_alloc_init_late().
>>
>> This gets build and run when CONFIG_DEBUG_VM_PGTABLE is selected along with
>> CONFIG_VM_DEBUG. Architectures willing to subscribe this test also need to
>> select CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE which for now is limited to x86 and
>> arm64. Going forward, other architectures too can enable this after fixing
>> build or runtime problems (if any) with their page table helpers.
Hello Qian,
>
> What’s the value of this block of new code? It only supports x86 and arm64
> which are supposed to be good now.
We have been over the usefulness of this code many times before as the patch is
already in it's V12. Currently it is enabled on arm64, x86 (except PAE), arc and
ppc32. There are build time or runtime problems with other archs which prevent
enablement of this test (for the moment) but then the goal is to integrate all
of them going forward. The test not only validates platform's adherence to the
expected semantics from generic MM but also helps in keeping it that way during
code changes in future as well.
> Did those tests ever find any regression or this is almost only useful for new
The test has already found problems with s390 page table helpers.
> architectures which only happened once in a few years?
Again, not only it validates what exist today but its also a tool to make
sure that all platforms continue adhere to a common agreed upon semantics
as reflected through the tests here.
> The worry if not many people will use this config and code those that much in
Debug features or tests in the kernel are used when required. These are never or
should not be enabled by default. AFAICT this is true even for entire DEBUG_VM
packaged tests. Do you have any particular data or precedence to substantiate
the fact that this test will be used any less often than the other similar ones
in the tree ? I can only speak for arm64 platform but the very idea for this
test came from Catalin when we were trying to understand the semantics for THP
helpers while enabling THP migration without split. Apart from going over the
commit messages from the past, there were no other way to figure out how any
particular page table helper is suppose to change given page table entry. This
test tries to formalize those semantics.
> the future because it is inefficient to find bugs, it will simply be rotten
Could you be more specific here ? What parts of the test are inefficient ? I
am happy to improve upon the test. Do let me know you if you have suggestions.
> like a few other debugging options out there we have in the mainline that
will be a pain to remove later on.
>
Even though I am not agreeing to your assessment about the usefulness of the
test without any substantial data backing up the claims, the test case in
itself is very much compartmentalized, staying clear from generic MM and
debug_vm_pgtable() is only function executing the test which is getting
called from kernel_init_freeable() path.
- Anshuman
^ permalink raw reply
* Re: [PATCH V12] mm/debug: Add tests validating architecture page table helpers
From: Qian Cai @ 2020-01-28 2:11 UTC (permalink / raw)
To: Anshuman Khandual
Cc: Mark Rutland, linux-ia64, linux-sh, Peter Zijlstra, James Hogan,
Tetsuo Handa, Heiko Carstens, Michal Hocko, linux-mm, Dave Hansen,
Paul Mackerras, sparclinux, Thomas Gleixner, linux-s390, x86,
Russell King - ARM Linux, Matthew Wilcox, Steven Price,
Jason Gunthorpe, Gerald Schaefer, linux-snps-arc,
linux-arm-kernel, Ingo Molnar, Kees Cook, Masahiro Yamada,
Mark Brown, Kirill A . Shutemov, Dan Williams, Vlastimil Babka,
Sri Krishna chowdary, Ard Biesheuvel, Greg Kroah-Hartman,
linux-mips, Ralf Baechle, linux-kernel, Paul Burton,
Mike Rapoport, Vineet Gupta, Martin Schwidefsky, Andrew Morton,
linuxppc-dev, David S. Miller
In-Reply-To: <1580174873-18117-1-git-send-email-anshuman.khandual@arm.com>
> On Jan 27, 2020, at 8:28 PM, Anshuman Khandual <Anshuman.Khandual@arm.com> wrote:
>
> This adds tests which will validate architecture page table helpers and
> other accessors in their compliance with expected generic MM semantics.
> This will help various architectures in validating changes to existing
> page table helpers or addition of new ones.
>
> This test covers basic page table entry transformations including but not
> limited to old, young, dirty, clean, write, write protect etc at various
> level along with populating intermediate entries with next page table page
> and validating them.
>
> Test page table pages are allocated from system memory with required size
> and alignments. The mapped pfns at page table levels are derived from a
> real pfn representing a valid kernel text symbol. This test gets called
> right after page_alloc_init_late().
>
> This gets build and run when CONFIG_DEBUG_VM_PGTABLE is selected along with
> CONFIG_VM_DEBUG. Architectures willing to subscribe this test also need to
> select CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE which for now is limited to x86 and
> arm64. Going forward, other architectures too can enable this after fixing
> build or runtime problems (if any) with their page table helpers.
What’s the value of this block of new code? It only supports x86 and arm64 which are supposed to be good now. Did those tests ever find any regression or this is almost only useful for new architectures which only happened once in a few years? The worry if not many people will use this config and code those that much in the future because it is inefficient to find bugs, it will simply be rotten like a few other debugging options out there we have in the mainline that will be a pain to remove later on.
^ permalink raw reply
* [PATCH V12] mm/debug: Add tests validating architecture page table helpers
From: Anshuman Khandual @ 2020-01-28 1:27 UTC (permalink / raw)
To: linux-mm
Cc: Mark Rutland, linux-ia64, linux-sh, Peter Zijlstra, James Hogan,
Tetsuo Handa, Heiko Carstens, Michal Hocko, Dave Hansen,
Paul Mackerras, sparclinux, Thomas Gleixner, linux-s390, x86,
Russell King - ARM Linux, Matthew Wilcox, Steven Price,
Jason Gunthorpe, Gerald Schaefer, linux-snps-arc,
linux-arm-kernel, Ingo Molnar, Kees Cook, Anshuman Khandual,
Masahiro Yamada, Mark Brown, Kirill A . Shutemov, Dan Williams,
Vlastimil Babka, Sri Krishna chowdary, Ard Biesheuvel,
Greg Kroah-Hartman, linux-mips, Ralf Baechle, linux-kernel,
Paul Burton, Mike Rapoport, Vineet Gupta, Martin Schwidefsky,
Andrew Morton, linuxppc-dev, David S. Miller
This adds tests which will validate architecture page table helpers and
other accessors in their compliance with expected generic MM semantics.
This will help various architectures in validating changes to existing
page table helpers or addition of new ones.
This test covers basic page table entry transformations including but not
limited to old, young, dirty, clean, write, write protect etc at various
level along with populating intermediate entries with next page table page
and validating them.
Test page table pages are allocated from system memory with required size
and alignments. The mapped pfns at page table levels are derived from a
real pfn representing a valid kernel text symbol. This test gets called
right after page_alloc_init_late().
This gets build and run when CONFIG_DEBUG_VM_PGTABLE is selected along with
CONFIG_VM_DEBUG. Architectures willing to subscribe this test also need to
select CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE which for now is limited to x86 and
arm64. Going forward, other architectures too can enable this after fixing
build or runtime problems (if any) with their page table helpers.
Folks interested in making sure that a given platform's page table helpers
conform to expected generic MM semantics should enable the above config
which will just trigger this test during boot. Any non conformity here will
be reported as an warning which would need to be fixed. This test will help
catch any changes to the agreed upon semantics expected from generic MM and
enable platforms to accommodate it thereafter.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Steven Price <Steven.Price@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sri Krishna chowdary <schowdary@nvidia.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Russell King - ARM Linux <linux@armlinux.org.uk>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-mips@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> #PPC32
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
This adds a test validation for architecture exported page table helpers.
Patch adds basic transformation tests at various levels of the page table.
This test was originally suggested by Catalin during arm64 THP migration
RFC discussion earlier. Going forward it can include more specific tests
with respect to various generic MM functions like THP, HugeTLB etc and
platform specific tests.
https://lore.kernel.org/linux-mm/20190628102003.GA56463@arrakis.emea.arm.com/
Needs to be applied on linux V5.5-rc7
Changes in V12:
- Replaced __mmdrop() with mmdrop()
- Enable ARCH_HAS_DEBUG_VM_PGTABLE on X86 for non CONFIG_X86_PAE platforms as the
test procedure interfere with pre-allocated PMDs attached to the PGD resulting
in runtime failures with VM_BUG_ON()
Changes in V11: (https://patchwork.kernel.org/project/linux-mm/list/?series=221135)
- Rebased the patch on V5.4
Changes in V10: (https://patchwork.kernel.org/project/linux-mm/list/?series=205529)
- Always enable DEBUG_VM_PGTABLE when DEBUG_VM is enabled per Ingo
- Added tags from Ingo
Changes in V9: (https://patchwork.kernel.org/project/linux-mm/list/?series=201429)
- Changed feature support enumeration for powerpc platforms per Christophe
- Changed config wrapper for basic_[pmd|pud]_tests() to enable ARC platform
- Enabled the test on ARC platform
Changes in V8: (https://patchwork.kernel.org/project/linux-mm/list/?series=194297)
- Enabled ARCH_HAS_DEBUG_VM_PGTABLE on PPC32 platform per Christophe
- Updated feature documentation as DEBUG_VM_PGTABLE is now enabled on PPC32 platform
- Moved ARCH_HAS_DEBUG_VM_PGTABLE earlier to indent it with DEBUG_VM per Christophe
- Added an information message in debug_vm_pgtable() per Christophe
- Dropped random_vaddr boundary condition checks per Christophe and Qian
- Replaced virt_addr_valid() check with pfn_valid() check in debug_vm_pgtable()
- Slightly changed pr_fmt(fmt) information
Changes in V7: (https://patchwork.kernel.org/project/linux-mm/list/?series=193051)
- Memory allocation and free routines for mapped pages have been droped
- Mapped pfns are derived from standard kernel text symbol per Matthew
- Moved debug_vm_pgtaable() after page_alloc_init_late() per Michal and Qian
- Updated the commit message per Michal
- Updated W=1 GCC warning problem on x86 per Qian Cai
- Addition of new alloc_contig_pages() helper has been submitted separately
Changes in V6: (https://patchwork.kernel.org/project/linux-mm/list/?series=187589)
- Moved alloc_gigantic_page_order() into mm/page_alloc.c per Michal
- Moved alloc_gigantic_page_order() within CONFIG_CONTIG_ALLOC in the test
- Folded Andrew's include/asm-generic/pgtable.h fix into the test patch 2/2
Changes in V5: (https://patchwork.kernel.org/project/linux-mm/list/?series=185991)
- Redefined and moved X86 mm_p4d_folded() into a different header per Kirill/Ingo
- Updated the config option comment per Ingo and dropped 'kernel module' reference
- Updated the commit message and dropped 'kernel module' reference
- Changed DEBUG_ARCH_PGTABLE_TEST into DEBUG_VM_PGTABLE per Ingo
- Moved config option from mm/Kconfig.debug into lib/Kconfig.debug
- Renamed core test function arch_pgtable_tests() as debug_vm_pgtable()
- Renamed mm/arch_pgtable_test.c as mm/debug_vm_pgtable.c
- debug_vm_pgtable() gets called from kernel_init_freeable() after init_mm_internals()
- Added an entry in Documentation/features/debug/ per Ingo
- Enabled the test on arm64 and x86 platforms for now
Changes in V4: (https://patchwork.kernel.org/project/linux-mm/list/?series=183465)
- Disable DEBUG_ARCH_PGTABLE_TEST for ARM and IA64 platforms
Changes in V3: (https://lore.kernel.org/patchwork/project/lkml/list/?series=411216)
- Changed test trigger from module format into late_initcall()
- Marked all functions with __init to be freed after completion
- Changed all __PGTABLE_PXX_FOLDED checks as mm_pxx_folded()
- Folded in PPC32 fixes from Christophe
Changes in V2:
https://lore.kernel.org/linux-mm/1568268173-31302-1-git-send-email-anshuman.khandual@arm.com/T/#t
- Fixed small typo error in MODULE_DESCRIPTION()
- Fixed m64k build problems for lvalue concerns in pmd_xxx_tests()
- Fixed dynamic page table level folding problems on x86 as per Kirril
- Fixed second pointers during pxx_populate_tests() per Kirill and Gerald
- Allocate and free pte table with pte_alloc_one/pte_free per Kirill
- Modified pxx_clear_tests() to accommodate s390 lower 12 bits situation
- Changed RANDOM_NZVALUE value from 0xbe to 0xff
- Changed allocation, usage, free sequence for saved_ptep
- Renamed VMA_FLAGS as VMFLAGS
- Implemented a new method for random vaddr generation
- Implemented some other cleanups
- Dropped extern reference to mm_alloc()
- Created and exported new alloc_gigantic_page_order()
- Dropped the custom allocator and used new alloc_gigantic_page_order()
Changes in V1:
https://lore.kernel.org/linux-mm/1567497706-8649-1-git-send-email-anshuman.khandual@arm.com/
- Added fallback mechanism for PMD aligned memory allocation failure
Changes in RFC V2:
https://lore.kernel.org/linux-mm/1565335998-22553-1-git-send-email-anshuman.khandual@arm.com/T/#u
- Moved test module and it's config from lib/ to mm/
- Renamed config TEST_ARCH_PGTABLE as DEBUG_ARCH_PGTABLE_TEST
- Renamed file from test_arch_pgtable.c to arch_pgtable_test.c
- Added relevant MODULE_DESCRIPTION() and MODULE_AUTHOR() details
- Dropped loadable module config option
- Basic tests now use memory blocks with required size and alignment
- PUD aligned memory block gets allocated with alloc_contig_range()
- If PUD aligned memory could not be allocated it falls back on PMD aligned
memory block from page allocator and pud_* tests are skipped
- Clear and populate tests now operate on real in memory page table entries
- Dummy mm_struct gets allocated with mm_alloc()
- Dummy page table entries get allocated with [pud|pmd|pte]_alloc_[map]()
- Simplified [p4d|pgd]_basic_tests(), now has random values in the entries
Original RFC V1:
https://lore.kernel.org/linux-mm/1564037723-26676-1-git-send-email-anshuman.khandual@arm.com/
.../debug/debug-vm-pgtable/arch-support.txt | 35 ++
arch/arc/Kconfig | 1 +
arch/arm64/Kconfig | 1 +
arch/powerpc/Kconfig | 1 +
arch/x86/Kconfig | 1 +
arch/x86/include/asm/pgtable_64.h | 6 +
include/asm-generic/pgtable.h | 6 +
init/main.c | 1 +
lib/Kconfig.debug | 22 +
mm/Makefile | 1 +
mm/debug_vm_pgtable.c | 388 ++++++++++++++++++
11 files changed, 463 insertions(+)
create mode 100644 Documentation/features/debug/debug-vm-pgtable/arch-support.txt
create mode 100644 mm/debug_vm_pgtable.c
diff --git a/Documentation/features/debug/debug-vm-pgtable/arch-support.txt b/Documentation/features/debug/debug-vm-pgtable/arch-support.txt
new file mode 100644
index 000000000000..f3f8111edbe3
--- /dev/null
+++ b/Documentation/features/debug/debug-vm-pgtable/arch-support.txt
@@ -0,0 +1,35 @@
+#
+# Feature name: debug-vm-pgtable
+# Kconfig: ARCH_HAS_DEBUG_VM_PGTABLE
+# description: arch supports pgtable tests for semantics compliance
+#
+ -----------------------
+ | arch |status|
+ -----------------------
+ | alpha: | TODO |
+ | arc: | ok |
+ | arm: | TODO |
+ | arm64: | ok |
+ | c6x: | TODO |
+ | csky: | TODO |
+ | h8300: | TODO |
+ | hexagon: | TODO |
+ | ia64: | TODO |
+ | m68k: | TODO |
+ | microblaze: | TODO |
+ | mips: | TODO |
+ | nds32: | TODO |
+ | nios2: | TODO |
+ | openrisc: | TODO |
+ | parisc: | TODO |
+ | powerpc/32: | ok |
+ | powerpc/64: | TODO |
+ | riscv: | TODO |
+ | s390: | TODO |
+ | sh: | TODO |
+ | sparc: | TODO |
+ | um: | TODO |
+ | unicore32: | TODO |
+ | x86: | ok |
+ | xtensa: | TODO |
+ -----------------------
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 26108ea785c2..6a76f3b609b2 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -6,6 +6,7 @@
config ARC
def_bool y
select ARC_TIMERS
+ select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_SETUP_DMA_OPS
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e688dfad0b72..876c9a672db1 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -11,6 +11,7 @@ config ARM64
select ACPI_PPTT if ACPI
select ARCH_CLOCKSOURCE_DATA
select ARCH_HAS_DEBUG_VIRTUAL
+ select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1ec34e16ed65..253dcab0bebc 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -120,6 +120,7 @@ config PPC
#
select ARCH_32BIT_OFF_T if PPC32
select ARCH_HAS_DEBUG_VIRTUAL
+ select ARCH_HAS_DEBUG_VM_PGTABLE if PPC32
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FORTIFY_SOURCE
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5e8949953660..218536a4581d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -61,6 +61,7 @@ config X86
select ARCH_CLOCKSOURCE_INIT
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_DEBUG_VIRTUAL
+ select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FAST_MULTIPLIER
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 0b6c4042942a..fb0e76d254b3 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -53,6 +53,12 @@ static inline void sync_initial_page_table(void) { }
struct mm_struct;
+#define mm_p4d_folded mm_p4d_folded
+static inline bool mm_p4d_folded(struct mm_struct *mm)
+{
+ return !pgtable_l5_enabled();
+}
+
void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte);
void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte);
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 798ea36a0549..e0b04787e789 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -1208,6 +1208,12 @@ static inline bool arch_has_pfn_modify_check(void)
# define PAGE_KERNEL_EXEC PAGE_KERNEL
#endif
+#ifdef CONFIG_DEBUG_VM_PGTABLE
+extern void debug_vm_pgtable(void);
+#else
+static inline void debug_vm_pgtable(void) { }
+#endif
+
#endif /* !__ASSEMBLY__ */
#ifndef io_remap_pfn_range
diff --git a/init/main.c b/init/main.c
index da1bc0b60a7d..5e59e6ac0780 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1197,6 +1197,7 @@ static noinline void __init kernel_init_freeable(void)
sched_init_smp();
page_alloc_init_late();
+ debug_vm_pgtable();
/* Initialize page ext after all struct pages are initialized. */
page_ext_init();
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5ffe144c9794..7cceae923c05 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -653,6 +653,12 @@ config SCHED_STACK_END_CHECK
data corruption or a sporadic crash at a later stage once the region
is examined. The runtime overhead introduced is minimal.
+config ARCH_HAS_DEBUG_VM_PGTABLE
+ bool
+ help
+ An architecture should select this when it can successfully
+ build and run DEBUG_VM_PGTABLE.
+
config DEBUG_VM
bool "Debug VM"
depends on DEBUG_KERNEL
@@ -688,6 +694,22 @@ config DEBUG_VM_PGFLAGS
If unsure, say N.
+config DEBUG_VM_PGTABLE
+ bool "Debug arch page table for semantics compliance"
+ depends on MMU
+ depends on DEBUG_VM
+ depends on ARCH_HAS_DEBUG_VM_PGTABLE
+ default y
+ help
+ This option provides a debug method which can be used to test
+ architecture page table helper functions on various platforms in
+ verifying if they comply with expected generic MM semantics. This
+ will help architecture code in making sure that any changes or
+ new additions of these helpers still conform to expected
+ semantics of the generic MM.
+
+ If unsure, say N.
+
config ARCH_HAS_DEBUG_VIRTUAL
bool
diff --git a/mm/Makefile b/mm/Makefile
index 1937cc251883..eba423a26b19 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
obj-$(CONFIG_DEBUG_RODATA_TEST) += rodata_test.o
+obj-$(CONFIG_DEBUG_VM_PGTABLE) += debug_vm_pgtable.o
obj-$(CONFIG_PAGE_OWNER) += page_owner.o
obj-$(CONFIG_CLEANCACHE) += cleancache.o
obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
new file mode 100644
index 000000000000..0f37f32d15f1
--- /dev/null
+++ b/mm/debug_vm_pgtable.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This kernel test validates architecture page table helpers and
+ * accessors and helps in verifying their continued compliance with
+ * expected generic MM semantics.
+ *
+ * Copyright (C) 2019 ARM Ltd.
+ *
+ * Author: Anshuman Khandual <anshuman.khandual@arm.com>
+ */
+#define pr_fmt(fmt) "debug_vm_pgtable: %s: " fmt, __func__
+
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/hugetlb.h>
+#include <linux/kernel.h>
+#include <linux/kconfig.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/mm_types.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include <linux/printk.h>
+#include <linux/random.h>
+#include <linux/spinlock.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/start_kernel.h>
+#include <linux/sched/mm.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+/*
+ * Basic operations
+ *
+ * mkold(entry) = An old and not a young entry
+ * mkyoung(entry) = A young and not an old entry
+ * mkdirty(entry) = A dirty and not a clean entry
+ * mkclean(entry) = A clean and not a dirty entry
+ * mkwrite(entry) = A write and not a write protected entry
+ * wrprotect(entry) = A write protected and not a write entry
+ * pxx_bad(entry) = A mapped and non-table entry
+ * pxx_same(entry1, entry2) = Both entries hold the exact same value
+ */
+#define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
+
+/*
+ * On s390 platform, the lower 12 bits are used to identify given page table
+ * entry type and for other arch specific requirements. But these bits might
+ * affect the ability to clear entries with pxx_clear(). So while loading up
+ * the entries skip all lower 12 bits in order to accommodate s390 platform.
+ * It does not have affect any other platform.
+ */
+#define RANDOM_ORVALUE (0xfffffffffffff000UL)
+#define RANDOM_NZVALUE (0xff)
+
+static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ WARN_ON(!pte_same(pte, pte));
+ WARN_ON(!pte_young(pte_mkyoung(pte)));
+ WARN_ON(!pte_dirty(pte_mkdirty(pte)));
+ WARN_ON(!pte_write(pte_mkwrite(pte)));
+ WARN_ON(pte_young(pte_mkold(pte)));
+ WARN_ON(pte_dirty(pte_mkclean(pte)));
+ WARN_ON(pte_write(pte_wrprotect(pte)));
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ WARN_ON(!pmd_same(pmd, pmd));
+ WARN_ON(!pmd_young(pmd_mkyoung(pmd)));
+ WARN_ON(!pmd_dirty(pmd_mkdirty(pmd)));
+ WARN_ON(!pmd_write(pmd_mkwrite(pmd)));
+ WARN_ON(pmd_young(pmd_mkold(pmd)));
+ WARN_ON(pmd_dirty(pmd_mkclean(pmd)));
+ WARN_ON(pmd_write(pmd_wrprotect(pmd)));
+ /*
+ * A huge page does not point to next level page table
+ * entry. Hence this must qualify as pmd_bad().
+ */
+ WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ pud_t pud = pfn_pud(pfn, prot);
+
+ WARN_ON(!pud_same(pud, pud));
+ WARN_ON(!pud_young(pud_mkyoung(pud)));
+ WARN_ON(!pud_write(pud_mkwrite(pud)));
+ WARN_ON(pud_write(pud_wrprotect(pud)));
+ WARN_ON(pud_young(pud_mkold(pud)));
+
+ if (mm_pmd_folded(mm) || __is_defined(ARCH_HAS_4LEVEL_HACK))
+ return;
+
+ /*
+ * A huge page does not point to next level page table
+ * entry. Hence this must qualify as pud_bad().
+ */
+ WARN_ON(!pud_bad(pud_mkhuge(pud)));
+}
+#else
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+#endif
+#else
+static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+#endif
+
+static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ p4d_t p4d;
+
+ memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
+ WARN_ON(!p4d_same(p4d, p4d));
+}
+
+static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+ pgd_t pgd;
+
+ memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
+ WARN_ON(!pgd_same(pgd, pgd));
+}
+
+#ifndef __ARCH_HAS_4LEVEL_HACK
+static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
+{
+ pud_t pud = READ_ONCE(*pudp);
+
+ if (mm_pmd_folded(mm))
+ return;
+
+ pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
+ WRITE_ONCE(*pudp, pud);
+ pud_clear(pudp);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(!pud_none(pud));
+}
+
+static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
+ pmd_t *pmdp)
+{
+ pud_t pud;
+
+ if (mm_pmd_folded(mm))
+ return;
+ /*
+ * This entry points to next level page table page.
+ * Hence this must not qualify as pud_bad().
+ */
+ pmd_clear(pmdp);
+ pud_clear(pudp);
+ pud_populate(mm, pudp, pmdp);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(pud_bad(pud));
+}
+#else
+static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
+static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
+ pmd_t *pmdp)
+{
+}
+#endif
+
+#ifndef __ARCH_HAS_5LEVEL_HACK
+static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
+{
+ p4d_t p4d = READ_ONCE(*p4dp);
+
+ if (mm_pud_folded(mm))
+ return;
+
+ p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
+ WRITE_ONCE(*p4dp, p4d);
+ p4d_clear(p4dp);
+ p4d = READ_ONCE(*p4dp);
+ WARN_ON(!p4d_none(p4d));
+}
+
+static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
+ pud_t *pudp)
+{
+ p4d_t p4d;
+
+ if (mm_pud_folded(mm))
+ return;
+
+ /*
+ * This entry points to next level page table page.
+ * Hence this must not qualify as p4d_bad().
+ */
+ pud_clear(pudp);
+ p4d_clear(p4dp);
+ p4d_populate(mm, p4dp, pudp);
+ p4d = READ_ONCE(*p4dp);
+ WARN_ON(p4d_bad(p4d));
+}
+
+static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
+{
+ pgd_t pgd = READ_ONCE(*pgdp);
+
+ if (mm_p4d_folded(mm))
+ return;
+
+ pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
+ WRITE_ONCE(*pgdp, pgd);
+ pgd_clear(pgdp);
+ pgd = READ_ONCE(*pgdp);
+ WARN_ON(!pgd_none(pgd));
+}
+
+static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
+ p4d_t *p4dp)
+{
+ pgd_t pgd;
+
+ if (mm_p4d_folded(mm))
+ return;
+
+ /*
+ * This entry points to next level page table page.
+ * Hence this must not qualify as pgd_bad().
+ */
+ p4d_clear(p4dp);
+ pgd_clear(pgdp);
+ pgd_populate(mm, pgdp, p4dp);
+ pgd = READ_ONCE(*pgdp);
+ WARN_ON(pgd_bad(pgd));
+}
+#else
+static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
+static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
+static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
+ pud_t *pudp)
+{
+}
+static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
+ p4d_t *p4dp)
+{
+}
+#endif
+
+static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep)
+{
+ pte_t pte = READ_ONCE(*ptep);
+
+ pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
+ WRITE_ONCE(*ptep, pte);
+ pte_clear(mm, 0, ptep);
+ pte = READ_ONCE(*ptep);
+ WARN_ON(!pte_none(pte));
+}
+
+static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
+{
+ pmd_t pmd = READ_ONCE(*pmdp);
+
+ pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
+ WRITE_ONCE(*pmdp, pmd);
+ pmd_clear(pmdp);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(!pmd_none(pmd));
+}
+
+static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
+ pgtable_t pgtable)
+{
+ pmd_t pmd;
+
+ /*
+ * This entry points to next level page table page.
+ * Hence this must not qualify as pmd_bad().
+ */
+ pmd_clear(pmdp);
+ pmd_populate(mm, pmdp, pgtable);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(pmd_bad(pmd));
+}
+
+static unsigned long __init get_random_vaddr(void)
+{
+ unsigned long random_vaddr, random_pages, total_user_pages;
+
+ total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
+
+ random_pages = get_random_long() % total_user_pages;
+ random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
+
+ return random_vaddr;
+}
+
+void __init debug_vm_pgtable(void)
+{
+ struct mm_struct *mm;
+ pgd_t *pgdp;
+ p4d_t *p4dp, *saved_p4dp;
+ pud_t *pudp, *saved_pudp;
+ pmd_t *pmdp, *saved_pmdp, pmd;
+ pte_t *ptep;
+ pgtable_t saved_ptep;
+ pgprot_t prot;
+ phys_addr_t paddr;
+ unsigned long vaddr, pte_aligned, pmd_aligned;
+ unsigned long pud_aligned, p4d_aligned, pgd_aligned;
+
+ pr_info("Validating architecture page table helpers\n");
+ prot = vm_get_page_prot(VMFLAGS);
+ vaddr = get_random_vaddr();
+ mm = mm_alloc();
+ if (!mm) {
+ pr_err("mm_struct allocation failed\n");
+ return;
+ }
+
+ /*
+ * PFN for mapping at PTE level is determined from a standard kernel
+ * text symbol. But pfns for higher page table levels are derived by
+ * masking lower bits of this real pfn. These derived pfns might not
+ * exist on the platform but that does not really matter as pfn_pxx()
+ * helpers will still create appropriate entries for the test. This
+ * helps avoid large memory block allocations to be used for mapping
+ * at higher page table levels.
+ */
+ paddr = __pa(&start_kernel);
+
+ pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
+ pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
+ pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
+ p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
+ pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
+ WARN_ON(!pfn_valid(pte_aligned));
+
+ pgdp = pgd_offset(mm, vaddr);
+ p4dp = p4d_alloc(mm, pgdp, vaddr);
+ pudp = pud_alloc(mm, p4dp, vaddr);
+ pmdp = pmd_alloc(mm, pudp, vaddr);
+ ptep = pte_alloc_map(mm, pmdp, vaddr);
+
+ /*
+ * Save all the page table page addresses as the page table
+ * entries will be used for testing with random or garbage
+ * values. These saved addresses will be used for freeing
+ * page table pages.
+ */
+ pmd = READ_ONCE(*pmdp);
+ saved_p4dp = p4d_offset(pgdp, 0UL);
+ saved_pudp = pud_offset(p4dp, 0UL);
+ saved_pmdp = pmd_offset(pudp, 0UL);
+ saved_ptep = pmd_pgtable(pmd);
+
+ pte_basic_tests(pte_aligned, prot);
+ pmd_basic_tests(pmd_aligned, prot);
+ pud_basic_tests(pud_aligned, prot);
+ p4d_basic_tests(p4d_aligned, prot);
+ pgd_basic_tests(pgd_aligned, prot);
+
+ pte_clear_tests(mm, ptep);
+ pmd_clear_tests(mm, pmdp);
+ pud_clear_tests(mm, pudp);
+ p4d_clear_tests(mm, p4dp);
+ pgd_clear_tests(mm, pgdp);
+
+ pte_unmap(ptep);
+
+ pmd_populate_tests(mm, pmdp, saved_ptep);
+ pud_populate_tests(mm, pudp, saved_pmdp);
+ p4d_populate_tests(mm, p4dp, saved_pudp);
+ pgd_populate_tests(mm, pgdp, saved_p4dp);
+
+ p4d_free(mm, saved_p4dp);
+ pud_free(mm, saved_pudp);
+ pmd_free(mm, saved_pmdp);
+ pte_free(mm, saved_ptep);
+
+ mm_dec_nr_puds(mm);
+ mm_dec_nr_pmds(mm);
+ mm_dec_nr_ptes(mm);
+ mmdrop(mm);
+}
--
2.20.1
^ permalink raw reply related
* Re: [PATCH] powerpc/64: system call implement the bulk of the logic in C fix
From: Nicholas Piggin @ 2020-01-28 0:41 UTC (permalink / raw)
To: Michal Suchánek; +Cc: linuxppc-dev
In-Reply-To: <20200127180832.GX4113@kitsune.suse.cz>
Michal Suchánek's on January 28, 2020 4:08 am:
> On Tue, Jan 28, 2020 at 12:17:12AM +1000, Nicholas Piggin wrote:
>> This incremental patch fixes several soft-mask debug and unsafe
>> smp_processor_id messages due to tracing and false positives in
>> "unreconciled" code.
>>
>> It also fixes a bug with syscall tracing functions that set registers
>> (e.g., PTRACE_SETREG) not setting GPRs properly.
>>
>> There was a bug reported with the TM selftests, I haven't been able
>> to reproduce that one.
>>
>> I can squash this into the main patch and resend the series if it
>> helps but the incremental helps to see the bug fixes.
>
> There are some whitespace differences between this and the series I have
> applied locally. What does it apply to?
>
> Is there some revision of the patchset I missed?
No I may have just missed some of your whitespace cleanups, or maybe I got
some that Michael made which you don't have in his next-test branch.
Thanks,
Nick
^ permalink raw reply
* [PATCH] powerpc/64: system call implement the bulk of the logic in C fix 2 (tabort_syscall)
From: Nicholas Piggin @ 2020-01-28 0:18 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Michal Suchanek, Nicholas Piggin
Another incremental patch which fixes silly tabort_syscall bug that
causes kernel crashes when making system calls in transactional state.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/entry_64.S | 9 +++------
arch/powerpc/kernel/syscall_64.c | 4 ++--
2 files changed, 5 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index d0bb238805e6..94b3db203ec3 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -165,16 +165,13 @@ syscall_restore_regs:
b .Lsyscall_restore_regs_cont
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-_GLOBAL(tabort_syscall)
+_GLOBAL(tabort_syscall) /* (unsigned long nip, unsigned long msr) */
/* Firstly we need to enable TM in the kernel */
mfmsr r10
li r9, 1
rldimi r10, r9, MSR_TM_LG, 63-MSR_TM_LG
mtmsrd r10, 0
- ld r11,_NIP(r13)
- ld r12,_MSR(r13)
-
/* tabort, this dooms the transaction, nothing else */
li r9, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT)
TABORT(R9)
@@ -188,8 +185,8 @@ _GLOBAL(tabort_syscall)
li r9, MSR_RI
andc r10, r10, r9
mtmsrd r10, 1
- mtspr SPRN_SRR0, r11
- mtspr SPRN_SRR1, r12
+ mtspr SPRN_SRR0, r3
+ mtspr SPRN_SRR1, r4
RFI_TO_USER
b . /* prevent speculative execution */
#endif
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index cfe458adde07..69a4ef13973b 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -15,7 +15,7 @@
#include <asm/time.h>
#include <asm/unistd.h>
-extern void __noreturn tabort_syscall(void);
+extern void __noreturn tabort_syscall(unsigned long nip, unsigned long msr);
typedef long (*syscall_fn)(long, long, long, long, long, long);
@@ -30,7 +30,7 @@ notrace long system_call_exception(long r3, long r4, long r5, long r6, long r7,
if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
unlikely(regs->msr & MSR_TS_T))
- tabort_syscall();
+ tabort_syscall(regs->nip, regs->msr);
account_cpu_user_entry();
--
2.23.0
^ permalink raw reply related
* [PATCH v2] powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits.
From: Christophe Leroy @ 2020-01-27 23:54 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linuxppc-dev, linux-kernel
Reorder Linux PTE bits to (almost) match Hash PTE bits.
RW Kernel : PP = 00
RO Kernel : PP = 00
RW User : PP = 01
RO User : PP = 11
So naturally, we should have
_PAGE_USER = 0x001
_PAGE_RW = 0x002
Today 0x001 and 0x002 and _PAGE_PRESENT and _PAGE_HASHPTE which
both are software only bits.
Switch _PAGE_USER and _PAGE_PRESET
Switch _PAGE_RW and _PAGE_HASHPTE
This allows to remove a few insns.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
v2: rebased on today's powerpc/merge
---
arch/powerpc/include/asm/book3s/32/hash.h | 8 ++++----
arch/powerpc/kernel/head_32.S | 9 +++------
arch/powerpc/mm/book3s32/hash_low.S | 14 ++++++--------
3 files changed, 13 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/32/hash.h b/arch/powerpc/include/asm/book3s/32/hash.h
index 2a0a467d2985..34a7215ae81e 100644
--- a/arch/powerpc/include/asm/book3s/32/hash.h
+++ b/arch/powerpc/include/asm/book3s/32/hash.h
@@ -17,9 +17,9 @@
* updating the accessed and modified bits in the page table tree.
*/
-#define _PAGE_PRESENT 0x001 /* software: pte contains a translation */
-#define _PAGE_HASHPTE 0x002 /* hash_page has made an HPTE for this pte */
-#define _PAGE_USER 0x004 /* usermode access allowed */
+#define _PAGE_USER 0x001 /* usermode access allowed */
+#define _PAGE_RW 0x002 /* software: user write access allowed */
+#define _PAGE_PRESENT 0x004 /* software: pte contains a translation */
#define _PAGE_GUARDED 0x008 /* G: prohibit speculative access */
#define _PAGE_COHERENT 0x010 /* M: enforce memory coherence (SMP systems) */
#define _PAGE_NO_CACHE 0x020 /* I: cache inhibit */
@@ -27,7 +27,7 @@
#define _PAGE_DIRTY 0x080 /* C: page changed */
#define _PAGE_ACCESSED 0x100 /* R: page referenced */
#define _PAGE_EXEC 0x200 /* software: exec allowed */
-#define _PAGE_RW 0x400 /* software: user write access allowed */
+#define _PAGE_HASHPTE 0x400 /* hash_page has made an HPTE for this pte */
#define _PAGE_SPECIAL 0x800 /* software: Special page */
#ifdef CONFIG_PTE_64BIT
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 0493fcac6409..1587a754f061 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -310,7 +310,7 @@ BEGIN_MMU_FTR_SECTION
andis. r0, r5, (DSISR_BAD_FAULT_32S | DSISR_DABRMATCH)@h
#endif
bne handle_page_fault_tramp_2 /* if not, try to put a PTE */
- rlwinm r3, r5, 32 - 15, 21, 21 /* DSISR_STORE -> _PAGE_RW */
+ rlwinm r3, r5, 32 - 24, 30, 30 /* DSISR_STORE -> _PAGE_RW */
bl hash_page
b handle_page_fault_tramp_1
FTR_SECTION_ELSE
@@ -437,7 +437,6 @@ InstructionTLBMiss:
andc. r1,r1,r0 /* check access & ~permission */
bne- InstructionAddressInvalid /* return if access not permitted */
/* Convert linux-style PTE to low word of PPC-style PTE */
- rlwimi r0,r0,32-2,31,31 /* _PAGE_USER -> PP lsb */
ori r1, r1, 0xe06 /* clear out reserved bits */
andc r1, r0, r1 /* PP = user? 1 : 0 */
BEGIN_FTR_SECTION
@@ -505,9 +504,8 @@ DataLoadTLBMiss:
* we would need to update the pte atomically with lwarx/stwcx.
*/
/* Convert linux-style PTE to low word of PPC-style PTE */
- rlwinm r1,r0,32-9,30,30 /* _PAGE_RW -> PP msb */
- rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
- rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */
+ rlwinm r1,r0,0,30,30 /* _PAGE_RW -> PP msb */
+ rlwimi r0,r0,1,30,30 /* _PAGE_USER -> PP msb */
ori r1,r1,0xe04 /* clear out reserved bits */
andc r1,r0,r1 /* PP = user? rw? 1: 3: 0 */
BEGIN_FTR_SECTION
@@ -585,7 +583,6 @@ DataStoreTLBMiss:
* we would need to update the pte atomically with lwarx/stwcx.
*/
/* Convert linux-style PTE to low word of PPC-style PTE */
- rlwimi r0,r0,32-2,31,31 /* _PAGE_USER -> PP lsb */
li r1,0xe06 /* clear out reserved bits & PP msb */
andc r1,r0,r1 /* PP = user? 1: 0 */
BEGIN_FTR_SECTION
diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S
index c11b0a005196..18fdabde5007 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -41,7 +41,7 @@ mmu_hash_lock:
/*
* Load a PTE into the hash table, if possible.
* The address is in r4, and r3 contains an access flag:
- * _PAGE_RW (0x400) if a write.
+ * _PAGE_RW (0x002) if a write.
* r9 contains the SRR1 value, from which we use the MSR_PR bit.
* SPRG_THREAD contains the physical address of the current task's thread.
*
@@ -78,7 +78,7 @@ _GLOBAL(hash_page)
blt+ 112f /* assume user more likely */
lis r5, (swapper_pg_dir - ADDR_OFFSET)@ha /* if kernel address, use */
addi r5 ,r5 ,(swapper_pg_dir - ADDR_OFFSET)@l /* kernel page table */
- rlwimi r3,r9,32-12,29,29 /* MSR_PR -> _PAGE_USER */
+ rlwimi r3,r9,32-14,31,31 /* MSR_PR -> _PAGE_USER */
112:
#ifndef CONFIG_PTE_64BIT
rlwimi r5,r4,12,20,29 /* insert top 10 bits of address */
@@ -106,7 +106,7 @@ _GLOBAL(hash_page)
#else
rlwimi r8,r4,23,20,28 /* compute pte address */
#endif
- rlwinm r0,r3,32-3,24,24 /* _PAGE_RW access -> _PAGE_DIRTY */
+ rlwinm r0,r3,6,24,24 /* _PAGE_RW access -> _PAGE_DIRTY */
ori r0,r0,_PAGE_ACCESSED|_PAGE_HASHPTE
/*
@@ -316,11 +316,9 @@ Hash_msk = (((1 << Hash_bits) - 1) * 64)
_GLOBAL(create_hpte)
/* Convert linux-style PTE (r5) to low word of PPC-style PTE (r8) */
- rlwinm r8,r5,32-9,30,30 /* _PAGE_RW -> PP msb */
rlwinm r0,r5,32-6,30,30 /* _PAGE_DIRTY -> PP msb */
- and r8,r8,r0 /* writable if _RW & _DIRTY */
- rlwimi r5,r5,32-1,30,30 /* _PAGE_USER -> PP msb */
- rlwimi r5,r5,32-2,31,31 /* _PAGE_USER -> PP lsb */
+ and r8,r5,r0 /* writable if _RW & _DIRTY */
+ rlwimi r5,r5,1,30,30 /* _PAGE_USER -> PP msb */
ori r8,r8,0xe04 /* clear out reserved bits */
andc r8,r5,r8 /* PP = user? (rw&dirty? 1: 3): 0 */
BEGIN_FTR_SECTION
@@ -572,7 +570,7 @@ _GLOBAL(flush_hash_pages)
33: lwarx r8,0,r5 /* fetch the pte flags word */
andi. r0,r8,_PAGE_HASHPTE
beq 8f /* done if HASHPTE is already clear */
- rlwinm r8,r8,0,31,29 /* clear HASHPTE bit */
+ rlwinm r8,r8,0,~_PAGE_HASHPTE /* clear HASHPTE bit */
stwcx. r8,0,r5 /* update the pte */
bne- 33b
--
2.25.0
^ permalink raw reply related
* Re: [PATCH] powerpc/64: system call implement the bulk of the logic in C fix
From: Michal Suchánek @ 2020-01-27 18:08 UTC (permalink / raw)
To: Nicholas Piggin; +Cc: linuxppc-dev
In-Reply-To: <20200127141712.96738-1-npiggin@gmail.com>
On Tue, Jan 28, 2020 at 12:17:12AM +1000, Nicholas Piggin wrote:
> This incremental patch fixes several soft-mask debug and unsafe
> smp_processor_id messages due to tracing and false positives in
> "unreconciled" code.
>
> It also fixes a bug with syscall tracing functions that set registers
> (e.g., PTRACE_SETREG) not setting GPRs properly.
>
> There was a bug reported with the TM selftests, I haven't been able
> to reproduce that one.
>
> I can squash this into the main patch and resend the series if it
> helps but the incremental helps to see the bug fixes.
There are some whitespace differences between this and the series I have
applied locally. What does it apply to?
Is there some revision of the patchset I missed?
Thanks
Michal
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> arch/powerpc/include/asm/cputime.h | 39 +++++++++++++++++-------------
> arch/powerpc/kernel/syscall_64.c | 26 ++++++++++++++------
> 2 files changed, 41 insertions(+), 24 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h
> index c43614cffaac..6639a6847cc0 100644
> --- a/arch/powerpc/include/asm/cputime.h
> +++ b/arch/powerpc/include/asm/cputime.h
> @@ -44,6 +44,28 @@ static inline unsigned long cputime_to_usecs(const cputime_t ct)
> #ifdef CONFIG_PPC64
> #define get_accounting(tsk) (&get_paca()->accounting)
> static inline void arch_vtime_task_switch(struct task_struct *tsk) { }
> +
> +/*
> + * account_cpu_user_entry/exit runs "unreconciled", so can't trace,
> + * can't use use get_paca()
> + */
> +static notrace inline void account_cpu_user_entry(void)
> +{
> + unsigned long tb = mftb();
> + struct cpu_accounting_data *acct = &local_paca->accounting;
> +
> + acct->utime += (tb - acct->starttime_user);
> + acct->starttime = tb;
> +}
> +static notrace inline void account_cpu_user_exit(void)
> +{
> + unsigned long tb = mftb();
> + struct cpu_accounting_data *acct = &local_paca->accounting;
> +
> + acct->stime += (tb - acct->starttime);
> + acct->starttime_user = tb;
> +}
> +
> #else
> #define get_accounting(tsk) (&task_thread_info(tsk)->accounting)
> /*
> @@ -60,23 +82,6 @@ static inline void arch_vtime_task_switch(struct task_struct *prev)
> }
> #endif
>
> -static inline void account_cpu_user_entry(void)
> -{
> - unsigned long tb = mftb();
> - struct cpu_accounting_data *acct = get_accounting(current);
> -
> - acct->utime += (tb - acct->starttime_user);
> - acct->starttime = tb;
> -}
> -static inline void account_cpu_user_exit(void)
> -{
> - unsigned long tb = mftb();
> - struct cpu_accounting_data *acct = get_accounting(current);
> -
> - acct->stime += (tb - acct->starttime);
> - acct->starttime_user = tb;
> -}
> -
> #endif /* __KERNEL__ */
> #else /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
> static inline void account_cpu_user_entry(void)
> diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
> index 529393a1ff1e..cfe458adde07 100644
> --- a/arch/powerpc/kernel/syscall_64.c
> +++ b/arch/powerpc/kernel/syscall_64.c
> @@ -19,7 +19,8 @@ extern void __noreturn tabort_syscall(void);
>
> typedef long (*syscall_fn)(long, long, long, long, long, long);
>
> -long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
> +/* Has to run notrace because it is entered "unreconciled" */
> +notrace long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
> unsigned long r0, struct pt_regs *regs)
> {
> unsigned long ti_flags;
> @@ -36,7 +37,7 @@ long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
> #ifdef CONFIG_PPC_SPLPAR
> if (IS_ENABLED(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) &&
> firmware_has_feature(FW_FEATURE_SPLPAR)) {
> - struct lppaca *lp = get_lppaca();
> + struct lppaca *lp = local_paca->lppaca_ptr;
>
> if (unlikely(local_paca->dtl_ridx != be64_to_cpu(lp->dtl_idx)))
> accumulate_stolen_time();
> @@ -71,13 +72,22 @@ long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
> * We use the return value of do_syscall_trace_enter() as the
> * syscall number. If the syscall was rejected for any reason
> * do_syscall_trace_enter() returns an invalid syscall number
> - * and the test below against NR_syscalls will fail.
> + * and the test against NR_syscalls will fail and the return
> + * value to be used is in regs->gpr[3].
> */
> r0 = do_syscall_trace_enter(regs);
> - }
> -
> - if (unlikely(r0 >= NR_syscalls))
> + if (unlikely(r0 >= NR_syscalls))
> + return regs->gpr[3];
> + r3 = regs->gpr[3];
> + r4 = regs->gpr[4];
> + r5 = regs->gpr[5];
> + r6 = regs->gpr[6];
> + r7 = regs->gpr[7];
> + r8 = regs->gpr[8];
> +
> + } else if (unlikely(r0 >= NR_syscalls)) {
> return -ENOSYS;
> + }
>
> /* May be faster to do array_index_nospec? */
> barrier_nospec();
> @@ -139,8 +149,10 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
> regs->gpr[3] = r3;
> }
>
> - if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE))
> + if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE)) {
> do_syscall_trace_leave(regs);
> + ret |= _TIF_RESTOREALL;
> + }
>
> again:
> local_irq_disable();
> --
> 2.23.0
>
^ permalink raw reply
* Re: [PATCH] of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc
From: Frank Rowand @ 2020-01-27 17:30 UTC (permalink / raw)
To: Michael Ellerman, robh+dt
Cc: devicetree, ulf.hansson, linux-kernel, linuxppc-dev, chzigotzky,
hch
In-Reply-To: <20200126115247.13402-1-mpe@ellerman.id.au>
+ Frank (me)
On 1/26/20 5:52 AM, Michael Ellerman wrote:
> There's an OF helper called of_dma_is_coherent(), which checks if a
> device has a "dma-coherent" property to see if the device is coherent
> for DMA.
>
> But on some platforms devices are coherent by default, and on some
> platforms it's not possible to update existing device trees to add the
> "dma-coherent" property.
>
> So add a Kconfig symbol to allow arch code to tell
> of_dma_is_coherent() that devices are coherent by default, regardless
> of the presence of the property.
>
> Select that symbol on powerpc when NOT_COHERENT_CACHE is not set, ie.
> when the system has a coherent cache.
>
> Fixes: 92ea637edea3 ("of: introduce of_dma_is_coherent() helper")
> Cc: stable@vger.kernel.org # v3.16+
> Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> ---
> arch/powerpc/Kconfig | 1 +
> drivers/of/Kconfig | 4 ++++
> drivers/of/address.c | 6 +++++-
> 3 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 1ec34e16ed65..19f5aa8ac9a3 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -238,6 +238,7 @@ config PPC
> select NEED_DMA_MAP_STATE if PPC64 || NOT_COHERENT_CACHE
> select NEED_SG_DMA_LENGTH
> select OF
> + select OF_DMA_DEFAULT_COHERENT if !NOT_COHERENT_CACHE
> select OF_EARLY_FLATTREE
> select OLD_SIGACTION if PPC32
> select OLD_SIGSUSPEND
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index 37c2ccbefecd..d91618641be6 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -103,4 +103,8 @@ config OF_OVERLAY
> config OF_NUMA
> bool
>
> +config OF_DMA_DEFAULT_COHERENT
> + # arches should select this if DMA is coherent by default for OF devices
> + bool
> +
> endif # OF
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 99c1b8058559..e8a39c3ec4d4 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -995,12 +995,16 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
> * @np: device node
> *
> * It returns true if "dma-coherent" property was found
> - * for this device in DT.
> + * for this device in the DT, or if DMA is coherent by
> + * default for OF devices on the current platform.
> */
> bool of_dma_is_coherent(struct device_node *np)
> {
> struct device_node *node = of_node_get(np);
>
> + if (IS_ENABLED(CONFIG_OF_DMA_DEFAULT_COHERENT))
> + return true;
> +
> while (node) {
> if (of_property_read_bool(node, "dma-coherent")) {
> of_node_put(node);
>
^ permalink raw reply
* Re: [PATCH v16 00/23] selftests, powerpc, x86: Memory Protection Keys
From: Dave Hansen @ 2020-01-27 15:42 UTC (permalink / raw)
To: Sandipan Das
Cc: linux-arch, fweimer, aneesh.kumar, x86, linuxram, linuxppc-dev,
mhocko, linux-mm, mingo, linux-kselftest, msuchanek, shuah,
bauerman
In-Reply-To: <8f14bee0-ab1c-fc90-dfdb-5128607b767f@linux.ibm.com>
On 1/27/20 2:11 AM, Sandipan Das wrote:
> Hi Dave,
>
> On 23/01/20 12:15 am, Dave Hansen wrote:
>> Still doesn't build for me:
>>
> I have this patch that hopefully fixes this. My understanding was
> that the vm tests are supposed to be generic but this has quite a
> bit of x86-specific conditional code which complicates things even
> though it is not used by any of the other tests.
>
> I'm not sure if we should keep x86 multilib build support for these
> selftests but I'll let the maintainers take a call.
How have you tested this patch (and the whole series for that matter)?
^ permalink raw reply
* [RFC] per-CPU usage in perf core-book3s
From: Sebastian Andrzej Siewior @ 2020-01-27 15:06 UTC (permalink / raw)
To: linux-kernel, linuxppc-dev
Cc: Mark Rutland, Peter Zijlstra, Arnaldo Carvalho de Melo,
Alexander Shishkin, Ingo Molnar, Paul Mackerras, Namhyung Kim,
Thomas Gleixner, Jiri Olsa
I've been looking at usage of per-CPU variable cpu_hw_events in
arch/powerpc/perf/core-book3s.c.
power_pmu_enable() and power_pmu_disable() (pmu::pmu_enable() and
pmu::pmu_disable()) are accessing the variable and the callbacks are
invoked always with disabled interrupts.
power_pmu_event_init() (pmu::event_init()) is invoked from preemptible
context and uses get_cpu_var() to obtain a stable pointer (by disabling
preemption).
pmu::pmu_enable() and pmu::pmu_disable() can be invoked via a hrtimer
(perf_mux_hrtimer_handler()) and it invokes pmu::pmu_enable() and
pmu::pmu_disable() as part of the callback.
Is there anything that prevents the timer callback to interrupt
pmu::event_init() while it is accessing per-CPU data?
Sebastian
^ permalink raw reply
* [PATCH] powerpc/64: system call implement the bulk of the logic in C fix
From: Nicholas Piggin @ 2020-01-27 14:17 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Michal Suchanek, Nicholas Piggin
This incremental patch fixes several soft-mask debug and unsafe
smp_processor_id messages due to tracing and false positives in
"unreconciled" code.
It also fixes a bug with syscall tracing functions that set registers
(e.g., PTRACE_SETREG) not setting GPRs properly.
There was a bug reported with the TM selftests, I haven't been able
to reproduce that one.
I can squash this into the main patch and resend the series if it
helps but the incremental helps to see the bug fixes.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/cputime.h | 39 +++++++++++++++++-------------
arch/powerpc/kernel/syscall_64.c | 26 ++++++++++++++------
2 files changed, 41 insertions(+), 24 deletions(-)
diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h
index c43614cffaac..6639a6847cc0 100644
--- a/arch/powerpc/include/asm/cputime.h
+++ b/arch/powerpc/include/asm/cputime.h
@@ -44,6 +44,28 @@ static inline unsigned long cputime_to_usecs(const cputime_t ct)
#ifdef CONFIG_PPC64
#define get_accounting(tsk) (&get_paca()->accounting)
static inline void arch_vtime_task_switch(struct task_struct *tsk) { }
+
+/*
+ * account_cpu_user_entry/exit runs "unreconciled", so can't trace,
+ * can't use use get_paca()
+ */
+static notrace inline void account_cpu_user_entry(void)
+{
+ unsigned long tb = mftb();
+ struct cpu_accounting_data *acct = &local_paca->accounting;
+
+ acct->utime += (tb - acct->starttime_user);
+ acct->starttime = tb;
+}
+static notrace inline void account_cpu_user_exit(void)
+{
+ unsigned long tb = mftb();
+ struct cpu_accounting_data *acct = &local_paca->accounting;
+
+ acct->stime += (tb - acct->starttime);
+ acct->starttime_user = tb;
+}
+
#else
#define get_accounting(tsk) (&task_thread_info(tsk)->accounting)
/*
@@ -60,23 +82,6 @@ static inline void arch_vtime_task_switch(struct task_struct *prev)
}
#endif
-static inline void account_cpu_user_entry(void)
-{
- unsigned long tb = mftb();
- struct cpu_accounting_data *acct = get_accounting(current);
-
- acct->utime += (tb - acct->starttime_user);
- acct->starttime = tb;
-}
-static inline void account_cpu_user_exit(void)
-{
- unsigned long tb = mftb();
- struct cpu_accounting_data *acct = get_accounting(current);
-
- acct->stime += (tb - acct->starttime);
- acct->starttime_user = tb;
-}
-
#endif /* __KERNEL__ */
#else /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
static inline void account_cpu_user_entry(void)
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 529393a1ff1e..cfe458adde07 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -19,7 +19,8 @@ extern void __noreturn tabort_syscall(void);
typedef long (*syscall_fn)(long, long, long, long, long, long);
-long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
+/* Has to run notrace because it is entered "unreconciled" */
+notrace long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
unsigned long r0, struct pt_regs *regs)
{
unsigned long ti_flags;
@@ -36,7 +37,7 @@ long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
#ifdef CONFIG_PPC_SPLPAR
if (IS_ENABLED(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) &&
firmware_has_feature(FW_FEATURE_SPLPAR)) {
- struct lppaca *lp = get_lppaca();
+ struct lppaca *lp = local_paca->lppaca_ptr;
if (unlikely(local_paca->dtl_ridx != be64_to_cpu(lp->dtl_idx)))
accumulate_stolen_time();
@@ -71,13 +72,22 @@ long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
* We use the return value of do_syscall_trace_enter() as the
* syscall number. If the syscall was rejected for any reason
* do_syscall_trace_enter() returns an invalid syscall number
- * and the test below against NR_syscalls will fail.
+ * and the test against NR_syscalls will fail and the return
+ * value to be used is in regs->gpr[3].
*/
r0 = do_syscall_trace_enter(regs);
- }
-
- if (unlikely(r0 >= NR_syscalls))
+ if (unlikely(r0 >= NR_syscalls))
+ return regs->gpr[3];
+ r3 = regs->gpr[3];
+ r4 = regs->gpr[4];
+ r5 = regs->gpr[5];
+ r6 = regs->gpr[6];
+ r7 = regs->gpr[7];
+ r8 = regs->gpr[8];
+
+ } else if (unlikely(r0 >= NR_syscalls)) {
return -ENOSYS;
+ }
/* May be faster to do array_index_nospec? */
barrier_nospec();
@@ -139,8 +149,10 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
regs->gpr[3] = r3;
}
- if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE))
+ if (unlikely(ti_flags & _TIF_SYSCALL_DOTRACE)) {
do_syscall_trace_leave(regs);
+ ret |= _TIF_RESTOREALL;
+ }
again:
local_irq_disable();
--
2.23.0
^ permalink raw reply related
* RE: [PATCH] bus: fsl-mc: add api to retrieve mc version
From: Laurentiu Tudor @ 2020-01-27 11:48 UTC (permalink / raw)
To: Andrei Botila, Stuart Yoder, Leo Li
Cc: Greg Kroah-Hartman, Andrei Botila, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
In-Reply-To: <1580123761-19536-1-git-send-email-andrei.botila@nxp.com>
> -----Original Message-----
> From: Andrei Botila <andrei.botila@nxp.com>
> Sent: Monday, January 27, 2020 1:16 PM
>
> Add a new api that returns Management Complex firmware version
> and make the required structure public. The api's first user will be
> the caam driver for setting prediction resistance bits.
>
> Signed-off-by: Andrei Botila <andrei.botila@nxp.com>
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
> ---
> drivers/bus/fsl-mc/fsl-mc-bus.c | 33 +++++++++++++++++----------------
> include/linux/fsl/mc.h | 16 ++++++++++++++++
> 2 files changed, 33 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-
> bus.c
> index a07cc19becdb..330c76181604 100644
> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
> @@ -26,6 +26,8 @@
> */
> #define FSL_MC_DEFAULT_DMA_MASK (~0ULL)
>
> +static struct fsl_mc_version mc_version;
> +
> /**
> * struct fsl_mc - Private data of a "fsl,qoriq-mc" platform device
> * @root_mc_bus_dev: fsl-mc device representing the root DPRC
> @@ -54,20 +56,6 @@ struct fsl_mc_addr_translation_range {
> phys_addr_t start_phys_addr;
> };
>
> -/**
> - * struct mc_version
> - * @major: Major version number: incremented on API compatibility changes
> - * @minor: Minor version number: incremented on API additions (that are
> - * backward compatible); reset when major version is incremented
> - * @revision: Internal revision number: incremented on implementation
> changes
> - * and/or bug fixes that have no impact on API
> - */
> -struct mc_version {
> - u32 major;
> - u32 minor;
> - u32 revision;
> -};
> -
> /**
> * fsl_mc_bus_match - device to driver matching callback
> * @dev: the fsl-mc device to match against
> @@ -338,7 +326,7 @@ EXPORT_SYMBOL_GPL(fsl_mc_driver_unregister);
> */
> static int mc_get_version(struct fsl_mc_io *mc_io,
> u32 cmd_flags,
> - struct mc_version *mc_ver_info)
> + struct fsl_mc_version *mc_ver_info)
> {
> struct fsl_mc_command cmd = { 0 };
> struct dpmng_rsp_get_version *rsp_params;
> @@ -363,6 +351,20 @@ static int mc_get_version(struct fsl_mc_io *mc_io,
> return 0;
> }
>
> +/**
> + * fsl_mc_get_version - function to retrieve the MC f/w version
> information
> + *
> + * Return: mc version when called after fsl-mc-bus probe; NULL otherwise.
> + */
> +struct fsl_mc_version *fsl_mc_get_version(void)
> +{
> + if (mc_version.major)
> + return &mc_version;
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(fsl_mc_get_version);
> +
> /**
> * fsl_mc_get_root_dprc - function to traverse to the root dprc
> */
> @@ -862,7 +864,6 @@ static int fsl_mc_bus_probe(struct platform_device
> *pdev)
> int container_id;
> phys_addr_t mc_portal_phys_addr;
> u32 mc_portal_size;
> - struct mc_version mc_version;
> struct resource res;
>
> mc = devm_kzalloc(&pdev->dev, sizeof(*mc), GFP_KERNEL);
> diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h
> index 54d9436600c7..2b5f8366dbe1 100644
> --- a/include/linux/fsl/mc.h
> +++ b/include/linux/fsl/mc.h
> @@ -381,6 +381,22 @@ int __must_check __fsl_mc_driver_register(struct
> fsl_mc_driver *fsl_mc_driver,
>
> void fsl_mc_driver_unregister(struct fsl_mc_driver *driver);
>
> +/**
> + * struct fsl_mc_version
> + * @major: Major version number: incremented on API compatibility changes
> + * @minor: Minor version number: incremented on API additions (that are
> + * backward compatible); reset when major version is incremented
> + * @revision: Internal revision number: incremented on implementation
> changes
> + * and/or bug fixes that have no impact on API
> + */
> +struct fsl_mc_version {
> + u32 major;
> + u32 minor;
> + u32 revision;
> +};
> +
> +struct fsl_mc_version *fsl_mc_get_version(void);
> +
> int __must_check fsl_mc_portal_allocate(struct fsl_mc_device *mc_dev,
> u16 mc_io_flags,
> struct fsl_mc_io **new_mc_io);
> --
> 2.17.1
^ permalink raw reply
* [PATCH] bus: fsl-mc: add api to retrieve mc version
From: Andrei Botila @ 2020-01-27 11:16 UTC (permalink / raw)
To: Stuart Yoder, Laurentiu Tudor, Li Yang
Cc: Andrei Botila, linuxppc-dev, linux-kernel, linux-arm-kernel
Add a new api that returns Management Complex firmware version
and make the required structure public. The api's first user will be
the caam driver for setting prediction resistance bits.
Signed-off-by: Andrei Botila <andrei.botila@nxp.com>
---
drivers/bus/fsl-mc/fsl-mc-bus.c | 33 +++++++++++++++++----------------
include/linux/fsl/mc.h | 16 ++++++++++++++++
2 files changed, 33 insertions(+), 16 deletions(-)
diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index a07cc19becdb..330c76181604 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -26,6 +26,8 @@
*/
#define FSL_MC_DEFAULT_DMA_MASK (~0ULL)
+static struct fsl_mc_version mc_version;
+
/**
* struct fsl_mc - Private data of a "fsl,qoriq-mc" platform device
* @root_mc_bus_dev: fsl-mc device representing the root DPRC
@@ -54,20 +56,6 @@ struct fsl_mc_addr_translation_range {
phys_addr_t start_phys_addr;
};
-/**
- * struct mc_version
- * @major: Major version number: incremented on API compatibility changes
- * @minor: Minor version number: incremented on API additions (that are
- * backward compatible); reset when major version is incremented
- * @revision: Internal revision number: incremented on implementation changes
- * and/or bug fixes that have no impact on API
- */
-struct mc_version {
- u32 major;
- u32 minor;
- u32 revision;
-};
-
/**
* fsl_mc_bus_match - device to driver matching callback
* @dev: the fsl-mc device to match against
@@ -338,7 +326,7 @@ EXPORT_SYMBOL_GPL(fsl_mc_driver_unregister);
*/
static int mc_get_version(struct fsl_mc_io *mc_io,
u32 cmd_flags,
- struct mc_version *mc_ver_info)
+ struct fsl_mc_version *mc_ver_info)
{
struct fsl_mc_command cmd = { 0 };
struct dpmng_rsp_get_version *rsp_params;
@@ -363,6 +351,20 @@ static int mc_get_version(struct fsl_mc_io *mc_io,
return 0;
}
+/**
+ * fsl_mc_get_version - function to retrieve the MC f/w version information
+ *
+ * Return: mc version when called after fsl-mc-bus probe; NULL otherwise.
+ */
+struct fsl_mc_version *fsl_mc_get_version(void)
+{
+ if (mc_version.major)
+ return &mc_version;
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(fsl_mc_get_version);
+
/**
* fsl_mc_get_root_dprc - function to traverse to the root dprc
*/
@@ -862,7 +864,6 @@ static int fsl_mc_bus_probe(struct platform_device *pdev)
int container_id;
phys_addr_t mc_portal_phys_addr;
u32 mc_portal_size;
- struct mc_version mc_version;
struct resource res;
mc = devm_kzalloc(&pdev->dev, sizeof(*mc), GFP_KERNEL);
diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h
index 54d9436600c7..2b5f8366dbe1 100644
--- a/include/linux/fsl/mc.h
+++ b/include/linux/fsl/mc.h
@@ -381,6 +381,22 @@ int __must_check __fsl_mc_driver_register(struct fsl_mc_driver *fsl_mc_driver,
void fsl_mc_driver_unregister(struct fsl_mc_driver *driver);
+/**
+ * struct fsl_mc_version
+ * @major: Major version number: incremented on API compatibility changes
+ * @minor: Minor version number: incremented on API additions (that are
+ * backward compatible); reset when major version is incremented
+ * @revision: Internal revision number: incremented on implementation changes
+ * and/or bug fixes that have no impact on API
+ */
+struct fsl_mc_version {
+ u32 major;
+ u32 minor;
+ u32 revision;
+};
+
+struct fsl_mc_version *fsl_mc_get_version(void);
+
int __must_check fsl_mc_portal_allocate(struct fsl_mc_device *mc_dev,
u16 mc_io_flags,
struct fsl_mc_io **new_mc_io);
--
2.17.1
^ permalink raw reply related
* [PATCH] powerpc/32s: Fix CPU wake-up from sleep mode
From: Christophe Leroy @ 2020-01-27 10:42 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linuxppc-dev, linux-kernel
Commit f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and
rename TI_CPU") broke the CPU wake-up from sleep mode (i.e. when
_TLF_SLEEPING is set) by delaying the tovirt(r2, r2).
This is because r2 is not restored by fast_exception_return. It used
to work (by chance ?) because CPU wake-up interrupt never comes from
user, so r2 is expected to point to 'current' on return.
Commit e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access
Protection") broke it even more by clobbering r0 which is not
restored by fast_exception_return either.
Use r6 instead of r0. This is possible because r3-r6 are restored by
fast_exception_return and only r3-r5 are used for exception arguments.
For r2 it could be converted back to virtual address, but stay on the
safe side and restore it from the stack instead. It should be live
in the cache at that moment, so loading from the stack should make
no difference compared to converting it from phys to virt.
Fixes: f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU")
Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/kernel/entry_32.S | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 73b80143ffac..27e2afce8b78 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -180,7 +180,7 @@ transfer_to_handler:
2: /* if from kernel, check interrupted DOZE/NAP mode and
* check for stack overflow
*/
- kuap_save_and_lock r11, r12, r9, r2, r0
+ kuap_save_and_lock r11, r12, r9, r2, r6
addi r2, r12, -THREAD
#ifndef CONFIG_VMAP_STACK
lwz r9,KSP_LIMIT(r12)
@@ -288,6 +288,7 @@ reenable_mmu:
rlwinm r9,r9,0,~MSR_EE
lwz r12,_LINK(r11) /* and return to address in LR */
kuap_restore r11, r2, r3, r4, r5
+ lwz r2, GPR2(r11)
b fast_exception_return
#endif
--
2.25.0
^ permalink raw reply related
* Re: [PATCH v16 00/23] selftests, powerpc, x86: Memory Protection Keys
From: Sandipan Das @ 2020-01-27 10:11 UTC (permalink / raw)
To: Dave Hansen
Cc: linux-arch, fweimer, aneesh.kumar, x86, linuxram, linuxppc-dev,
mhocko, linux-mm, mingo, linux-kselftest, msuchanek, shuah,
bauerman
In-Reply-To: <3ceb2814-f8b0-ec6b-3c24-ec72297a99f5@intel.com>
Hi Dave,
On 23/01/20 12:15 am, Dave Hansen wrote:
> Still doesn't build for me:
>
I have this patch that hopefully fixes this. My understanding was
that the vm tests are supposed to be generic but this has quite a
bit of x86-specific conditional code which complicates things even
though it is not used by any of the other tests.
I'm not sure if we should keep x86 multilib build support for these
selftests but I'll let the maintainers take a call.
From a5609f79e5d5164c99c3cb599e14ca620de9c8d4 Mon Sep 17 00:00:00 2001
From: Sandipan Das <sandipan@linux.ibm.com>
Date: Sat, 18 Jan 2020 15:59:04 +0530
Subject: [PATCH] selftests: vm: pkeys: Fix multilib builds for x86
This ensures that both 32-bit and 64-bit binaries are generated
when this is built on a x86_64 system that has both 32-bit and
64-bit libraries. Most of the changes have been borrowed from
tools/testing/selftests/x86/Makefile.
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
tools/testing/selftests/vm/Makefile | 72 +++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)
diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
index 4e9c741be6af..82031f84af21 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -18,7 +18,30 @@ TEST_GEN_FILES += on-fault-limit
TEST_GEN_FILES += thuge-gen
TEST_GEN_FILES += transhuge-stress
TEST_GEN_FILES += userfaultfd
+
+ifeq ($(ARCH),x86_64)
+CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh $(CC) ../x86/trivial_32bit_program.c -m32)
+CAN_BUILD_X86_64 := $(shell ./../x86/check_cc.sh $(CC) ../x86/trivial_64bit_program.c)
+CAN_BUILD_WITH_NOPIE := $(shell ./../x86/check_cc.sh $(CC) ../x86/trivial_program.c -no-pie)
+
+TARGETS := protection_keys
+BINARIES_32 := $(TARGETS:%=%_32)
+BINARIES_64 := $(TARGETS:%=%_64)
+
+ifeq ($(CAN_BUILD_WITH_NOPIE),1)
+CFLAGS += -no-pie
+endif
+
+ifeq ($(CAN_BUILD_I386),1)
+TEST_GEN_FILES += $(BINARIES_32)
+endif
+
+ifeq ($(CAN_BUILD_X86_64),1)
+TEST_GEN_FILES += $(BINARIES_64)
+endif
+else
TEST_GEN_FILES += protection_keys
+endif
ifneq (,$(filter $(ARCH),arm64 ia64 mips64 parisc64 ppc64 riscv64 s390x sh64 sparc64 x86_64))
TEST_GEN_FILES += va_128TBswitch
@@ -32,6 +55,55 @@ TEST_FILES := test_vmalloc.sh
KSFT_KHDR_INSTALL := 1
include ../lib.mk
+ifeq ($(ARCH),x86_64)
+BINARIES_32 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_32))
+BINARIES_64 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_64))
+
+define gen-target-rule-32
+$(1) $(1)_32: $(OUTPUT)/$(1)_32
+.PHONY: $(1) $(1)_32
+endef
+
+define gen-target-rule-64
+$(1) $(1)_64: $(OUTPUT)/$(1)_64
+.PHONY: $(1) $(1)_64
+endef
+
+ifeq ($(CAN_BUILD_I386),1)
+$(BINARIES_32): CFLAGS += -m32
+$(BINARIES_32): LDLIBS += -lrt -ldl -lm
+$(BINARIES_32): %_32: %.c
+ $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(notdir $^) $(LDLIBS) -o $@
+$(foreach t,$(TARGETS),$(eval $(call gen-target-rule-32,$(t))))
+endif
+
+ifeq ($(CAN_BUILD_X86_64),1)
+$(BINARIES_64): CFLAGS += -m64
+$(BINARIES_64): LDLIBS += -lrt -ldl
+$(BINARIES_64): %_64: %.c
+ $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(notdir $^) $(LDLIBS) -o $@
+$(foreach t,$(TARGETS),$(eval $(call gen-target-rule-64,$(t))))
+endif
+
+# x86_64 users should be encouraged to install 32-bit libraries
+ifeq ($(CAN_BUILD_I386)$(CAN_BUILD_X86_64),01)
+all: warn_32bit_failure
+
+warn_32bit_failure:
+ @echo "Warning: you seem to have a broken 32-bit build" 2>&1; \
+ echo "environment. This will reduce test coverage of 64-bit" 2>&1; \
+ echo "kernels. If you are using a Debian-like distribution," 2>&1; \
+ echo "try:"; 2>&1; \
+ echo ""; \
+ echo " apt-get install gcc-multilib libc6-i386 libc6-dev-i386"; \
+ echo ""; \
+ echo "If you are using a Fedora-like distribution, try:"; \
+ echo ""; \
+ echo " yum install glibc-devel.*i686"; \
+ exit 0;
+endif
+endif
+
$(OUTPUT)/userfaultfd: LDLIBS += -lpthread
$(OUTPUT)/mlock-random-test: LDLIBS += -lcap
--
2.24.1
This can also be viewed at:
https://github.com/sandip4n/linux/commit/a5609f79e5d5164c99c3cb599e14ca620de9c8d4
- Sandipan
^ permalink raw reply related
* Re: [PATCH v4 7/9] parisc/perf: open access for CAP_SYS_PERFMON privileged process
From: Helge Deller @ 2020-01-27 8:52 UTC (permalink / raw)
To: Alexey Budankov, Peter Zijlstra, Arnaldo Carvalho de Melo,
Ingo Molnar, jani.nikula@linux.intel.com,
joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com,
Alexei Starovoitov, Benjamin Herrenschmidt, Paul Mackerras,
Michael Ellerman, james.bottomley@hansenpartnership.com,
Serge Hallyn, James Morris, Will Deacon, Mark Rutland,
Casey Schaufler, Robert Richter
Cc: Song Liu, Alexander Shishkin, Stephane Eranian, Jiri Olsa,
Andi Kleen, Igor Lubashev, oprofile-list, Kees Cook, Jann Horn,
selinux@vger.kernel.org, intel-gfx@lists.freedesktop.org,
Lionel Landwerlin, Namhyung Kim, Thomas Gleixner,
linux-arm-kernel, Tvrtko Ursulin, linux-parisc@vger.kernel.org,
linux-kernel, linux-perf-users@vger.kernel.org,
linux-security-module@vger.kernel.org, bpf@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
In-Reply-To: <806e4881-5c22-5914-a656-5eeb65130dbe@linux.intel.com>
On 18.12.19 10:29, Alexey Budankov wrote:
>
> Open access to monitoring for CAP_SYS_PERFMON privileged processes.
> For backward compatibility reasons access to the monitoring remains open
> for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure
> monitoring is discouraged with respect to CAP_SYS_PERFMON capability.
>
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Helge Deller <deller@gmx.de>
> ---
> arch/parisc/kernel/perf.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/parisc/kernel/perf.c b/arch/parisc/kernel/perf.c
> index 676683641d00..c4208d027794 100644
> --- a/arch/parisc/kernel/perf.c
> +++ b/arch/parisc/kernel/perf.c
> @@ -300,7 +300,7 @@ static ssize_t perf_write(struct file *file, const char __user *buf,
> else
> return -EFAULT;
>
> - if (!capable(CAP_SYS_ADMIN))
> + if (!perfmon_capable())
> return -EACCES;
>
> if (count != sizeof(uint32_t))
>
^ permalink raw reply
* Re: [PATCH] of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc
From: Ulf Hansson @ 2020-01-27 7:22 UTC (permalink / raw)
To: Michael Ellerman
Cc: DTML, Linux Kernel Mailing List, linuxppc-dev, Rob Herring,
Christian Zigotzky, Christoph Hellwig
In-Reply-To: <20200126115247.13402-1-mpe@ellerman.id.au>
On Sun, 26 Jan 2020 at 12:53, Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> There's an OF helper called of_dma_is_coherent(), which checks if a
> device has a "dma-coherent" property to see if the device is coherent
> for DMA.
>
> But on some platforms devices are coherent by default, and on some
> platforms it's not possible to update existing device trees to add the
> "dma-coherent" property.
>
> So add a Kconfig symbol to allow arch code to tell
> of_dma_is_coherent() that devices are coherent by default, regardless
> of the presence of the property.
>
> Select that symbol on powerpc when NOT_COHERENT_CACHE is not set, ie.
> when the system has a coherent cache.
>
> Fixes: 92ea637edea3 ("of: introduce of_dma_is_coherent() helper")
> Cc: stable@vger.kernel.org # v3.16+
> Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Thanks Michael for helping out fixing and this! The patch looks good to me.
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Kind regards
Uffe
> ---
> arch/powerpc/Kconfig | 1 +
> drivers/of/Kconfig | 4 ++++
> drivers/of/address.c | 6 +++++-
> 3 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 1ec34e16ed65..19f5aa8ac9a3 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -238,6 +238,7 @@ config PPC
> select NEED_DMA_MAP_STATE if PPC64 || NOT_COHERENT_CACHE
> select NEED_SG_DMA_LENGTH
> select OF
> + select OF_DMA_DEFAULT_COHERENT if !NOT_COHERENT_CACHE
> select OF_EARLY_FLATTREE
> select OLD_SIGACTION if PPC32
> select OLD_SIGSUSPEND
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index 37c2ccbefecd..d91618641be6 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -103,4 +103,8 @@ config OF_OVERLAY
> config OF_NUMA
> bool
>
> +config OF_DMA_DEFAULT_COHERENT
> + # arches should select this if DMA is coherent by default for OF devices
> + bool
> +
> endif # OF
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 99c1b8058559..e8a39c3ec4d4 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -995,12 +995,16 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
> * @np: device node
> *
> * It returns true if "dma-coherent" property was found
> - * for this device in DT.
> + * for this device in the DT, or if DMA is coherent by
> + * default for OF devices on the current platform.
> */
> bool of_dma_is_coherent(struct device_node *np)
> {
> struct device_node *node = of_node_get(np);
>
> + if (IS_ENABLED(CONFIG_OF_DMA_DEFAULT_COHERENT))
> + return true;
> +
> while (node) {
> if (of_property_read_bool(node, "dma-coherent")) {
> of_node_put(node);
> --
> 2.21.1
>
^ permalink raw reply
* Re: [PATCH v2 2/9] net: wireless: rtl818x: Constify ioreadX() iomem argument (as in generic implementation)
From: Kalle Valo @ 2020-01-26 15:11 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: Rich Felker, Jiri Slaby, Geert Uytterhoeven, Michael S. Tsirkin,
David Airlie, Jason Wang, dri-devel, virtualization,
James E.J. Bottomley, netdev, Paul Mackerras, linux-arch,
Dave Jiang, Yoshinori Sato, Helge Deller, linux-sh,
Alexey Brodkin, Krzysztof Kozlowski, Ben Skeggs, nouveau,
Dave Airlie, Matt Turner, linux-snps-arc, Nick Kossifidis,
Allen Hubbe, Arnd Bergmann, linux-alpha, Ivan Kokshaysky,
Thomas Gleixner, Mauro Carvalho Chehab, Richard Henderson,
linux-parisc, Vineet Gupta, linux-wireless, linux-kernel,
Luis Chamberlain, Daniel Vetter, Jon Mason, linux-ntb,
linux-media, linuxppc-dev, David S. Miller
In-Reply-To: <20200108200528.4614-3-krzk@kernel.org>
Krzysztof Kozlowski <krzk@kernel.org> wrote:
> The ioreadX() helpers have inconsistent interface. On some architectures
> void *__iomem address argument is a pointer to const, on some not.
>
> Implementations of ioreadX() do not modify the memory under the address
> so they can be converted to a "const" version for const-safety and
> consistency among architectures.
>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
I assume this and patch 9 are going via some other tree so dropping them
from my patchwork queue.
--
https://patchwork.kernel.org/patch/11324461/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply
* [powerpc:merge] BUILD INCOMPLETE b43d1d8a77b5d5d82f8930aa5b101378df00ccca
From: kbuild test robot @ 2020-01-26 13:27 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git merge
branch HEAD: b43d1d8a77b5d5d82f8930aa5b101378df00ccca Automatic merge of branches 'master', 'next' and 'fixes' into merge
TIMEOUT after 2940m
Sorry we cannot finish the testset for your branch within a reasonable time.
It's our fault -- either some build server is down or some build worker is busy
doing bisects for _other_ trees. The branch will get more complete coverage and
possible error reports when our build infrastructure is restored or catches up.
There will be no more build success notification for this branch head, but you
can expect reasonably good test coverage after waiting for 1 day.
configs timed out: 14
mips 32r2_defconfig
mips 64r6el_defconfig
mips allmodconfig
mips allnoconfig
mips allyesconfig
mips fuloong2e_defconfig
mips malta_kvm_defconfig
s390 alldefconfig
s390 allmodconfig
s390 allnoconfig
s390 allyesconfig
s390 debug_defconfig
s390 defconfig
s390 zfcpdump_defconfig
configs tested: 120
configs skipped: 0
x86_64 randconfig-c003-20200126
alpha defconfig
csky defconfig
nds32 allnoconfig
nds32 defconfig
i386 alldefconfig
i386 allnoconfig
i386 allyesconfig
i386 defconfig
ia64 alldefconfig
ia64 allmodconfig
ia64 allnoconfig
ia64 allyesconfig
ia64 defconfig
x86_64 lkp
x86_64 rhel
x86_64 rhel-7.6
x86_64 fedora-25
x86_64 kexec
x86_64 rhel-7.2-clear
arc randconfig-a001-20200125
arm randconfig-a001-20200125
arm64 randconfig-a001-20200125
ia64 randconfig-a001-20200125
powerpc randconfig-a001-20200125
sparc randconfig-a001-20200125
powerpc defconfig
m68k multi_defconfig
m68k m5475evb_defconfig
h8300 h8300h-sim_defconfig
h8300 edosk2674_defconfig
m68k sun3_defconfig
h8300 h8s-sim_defconfig
m68k allmodconfig
csky randconfig-a001-20200124
openrisc randconfig-a001-20200124
s390 randconfig-a001-20200124
sh randconfig-a001-20200124
xtensa randconfig-a001-20200124
arm allmodconfig
arm64 allmodconfig
riscv allmodconfig
riscv allnoconfig
riscv allyesconfig
riscv defconfig
riscv nommu_virt_defconfig
riscv rv32_defconfig
parisc allnoconfig
parisc allyesonfig
parisc b180_defconfig
parisc c3000_defconfig
parisc defconfig
h8300 randconfig-a001-20200125
nios2 randconfig-a001-20200125
c6x randconfig-a001-20200125
sparc64 randconfig-a001-20200125
microblaze randconfig-a001-20200125
sh allmodconfig
sh allnoconfig
sh rsk7269_defconfig
sh sh7785lcr_32bit_defconfig
sh titan_defconfig
sparc allyesconfig
sparc defconfig
sparc64 allmodconfig
sparc64 allnoconfig
sparc64 allyesconfig
sparc64 defconfig
arc allyesconfig
arc defconfig
microblaze mmu_defconfig
microblaze nommu_defconfig
powerpc allnoconfig
powerpc ppc64_defconfig
powerpc rhel-kconfig
csky randconfig-a001-20200125
openrisc randconfig-a001-20200125
s390 randconfig-a001-20200125
xtensa randconfig-a001-20200125
x86_64 randconfig-a001-20200125
x86_64 randconfig-a002-20200125
x86_64 randconfig-a003-20200125
i386 randconfig-a001-20200125
i386 randconfig-a002-20200125
i386 randconfig-a003-20200125
c6x evmc6678_defconfig
c6x allyesconfig
um defconfig
um i386_defconfig
um x86_64_defconfig
arm allnoconfig
arm allyesconfig
arm at91_dt_defconfig
arm efm32_defconfig
arm exynos_defconfig
arm multi_v5_defconfig
arm multi_v7_defconfig
arm shmobile_defconfig
arm sunxi_defconfig
arm64 allnoconfig
arm64 allyesconfig
arm64 defconfig
arc randconfig-a001-20200124
arm randconfig-a001-20200124
arm64 randconfig-a001-20200124
ia64 randconfig-a001-20200124
powerpc randconfig-a001-20200124
sparc randconfig-a001-20200124
nios2 10m50_defconfig
nios2 3c120_defconfig
openrisc or1ksim_defconfig
openrisc simple_smp_defconfig
xtensa common_defconfig
xtensa iss_defconfig
x86_64 randconfig-f003-20200126
x86_64 randconfig-f001-20200126
x86_64 randconfig-f002-20200126
i386 randconfig-f002-20200126
i386 randconfig-f003-20200126
i386 randconfig-f001-20200126
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation
^ permalink raw reply
* [powerpc:next-test] BUILD SUCCESS 28f66938c6e709ebca86ac01a69080c81900bdfd
From: kbuild test robot @ 2020-01-26 13:27 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next-test
branch HEAD: 28f66938c6e709ebca86ac01a69080c81900bdfd selftests/eeh: Bump EEH wait time to 60s
elapsed time: 2939m
configs tested: 246
configs skipped: 0
The following configs have been built successfully.
More configs may be tested in the coming days.
alpha defconfig
csky defconfig
nds32 allnoconfig
nds32 defconfig
i386 alldefconfig
i386 allnoconfig
i386 allyesconfig
i386 defconfig
x86_64 randconfig-g001-20200126
x86_64 randconfig-g002-20200126
x86_64 randconfig-g003-20200126
i386 randconfig-g001-20200126
i386 randconfig-g002-20200126
i386 randconfig-g003-20200126
x86_64 randconfig-a001-20200126
x86_64 randconfig-a002-20200126
x86_64 randconfig-a003-20200126
i386 randconfig-a001-20200126
i386 randconfig-a002-20200126
i386 randconfig-a003-20200126
x86_64 randconfig-c001-20200126
x86_64 randconfig-c002-20200126
x86_64 randconfig-c003-20200126
i386 randconfig-c001-20200126
i386 randconfig-c002-20200126
i386 randconfig-c003-20200126
alpha randconfig-a001-20200125
m68k randconfig-a001-20200125
mips randconfig-a001-20200125
nds32 randconfig-a001-20200125
parisc randconfig-a001-20200125
riscv randconfig-a001-20200125
x86_64 randconfig-f001-20200126
x86_64 randconfig-f002-20200126
x86_64 randconfig-f003-20200126
i386 randconfig-f001-20200126
i386 randconfig-f002-20200126
i386 randconfig-f003-20200126
s390 alldefconfig
s390 allmodconfig
s390 allnoconfig
s390 allyesconfig
s390 debug_defconfig
s390 defconfig
s390 zfcpdump_defconfig
c6x allyesconfig
c6x evmc6678_defconfig
nios2 10m50_defconfig
nios2 3c120_defconfig
openrisc or1ksim_defconfig
openrisc simple_smp_defconfig
xtensa common_defconfig
xtensa iss_defconfig
sh allmodconfig
sh allnoconfig
sh rsk7269_defconfig
sh sh7785lcr_32bit_defconfig
sh titan_defconfig
sparc allyesconfig
sparc defconfig
sparc64 allmodconfig
sparc64 allnoconfig
sparc64 allyesconfig
sparc64 defconfig
x86_64 randconfig-e001-20200125
x86_64 randconfig-e002-20200125
x86_64 randconfig-e003-20200125
i386 randconfig-e001-20200125
i386 randconfig-e002-20200125
i386 randconfig-e003-20200125
riscv allmodconfig
riscv allnoconfig
riscv allyesconfig
riscv defconfig
riscv nommu_virt_defconfig
riscv rv32_defconfig
x86_64 randconfig-b001-20200126
x86_64 randconfig-b002-20200126
x86_64 randconfig-b003-20200126
i386 randconfig-b001-20200126
i386 randconfig-b002-20200126
i386 randconfig-b003-20200126
alpha randconfig-a001-20200126
m68k randconfig-a001-20200126
mips randconfig-a001-20200126
nds32 randconfig-a001-20200126
parisc randconfig-a001-20200126
riscv randconfig-a001-20200126
um defconfig
um i386_defconfig
um x86_64_defconfig
ia64 alldefconfig
ia64 allmodconfig
ia64 allnoconfig
ia64 allyesconfig
ia64 defconfig
x86_64 randconfig-c001-20200125
x86_64 randconfig-c002-20200125
x86_64 randconfig-c003-20200125
i386 randconfig-c001-20200125
i386 randconfig-c002-20200125
i386 randconfig-c003-20200125
x86_64 randconfig-h001-20200126
x86_64 randconfig-h002-20200126
x86_64 randconfig-h003-20200126
i386 randconfig-h001-20200126
i386 randconfig-h002-20200126
i386 randconfig-h003-20200126
powerpc defconfig
x86_64 randconfig-b001-20200125
x86_64 randconfig-b002-20200125
x86_64 randconfig-b003-20200125
i386 randconfig-b001-20200125
i386 randconfig-b002-20200125
i386 randconfig-b003-20200125
parisc allnoconfig
parisc allyesonfig
parisc b180_defconfig
parisc c3000_defconfig
parisc defconfig
csky randconfig-a001-20200125
openrisc randconfig-a001-20200125
s390 randconfig-a001-20200125
xtensa randconfig-a001-20200125
h8300 edosk2674_defconfig
h8300 h8300h-sim_defconfig
h8300 h8s-sim_defconfig
m68k allmodconfig
m68k m5475evb_defconfig
m68k multi_defconfig
m68k sun3_defconfig
arm allmodconfig
arm64 allmodconfig
csky randconfig-a001-20200126
openrisc randconfig-a001-20200126
s390 randconfig-a001-20200126
sh randconfig-a001-20200126
xtensa randconfig-a001-20200126
arc allyesconfig
arc defconfig
microblaze mmu_defconfig
microblaze nommu_defconfig
powerpc allnoconfig
powerpc ppc64_defconfig
powerpc rhel-kconfig
arc randconfig-a001-20200125
arm randconfig-a001-20200125
arm64 randconfig-a001-20200125
ia64 randconfig-a001-20200125
powerpc randconfig-a001-20200125
sparc randconfig-a001-20200125
c6x randconfig-a001-20200126
h8300 randconfig-a001-20200126
microblaze randconfig-a001-20200126
nios2 randconfig-a001-20200126
sparc64 randconfig-a001-20200126
arc randconfig-a001-20200126
arm randconfig-a001-20200126
arm64 randconfig-a001-20200126
ia64 randconfig-a001-20200126
powerpc randconfig-a001-20200126
sparc randconfig-a001-20200126
arm allnoconfig
arm allyesconfig
arm at91_dt_defconfig
arm efm32_defconfig
arm exynos_defconfig
arm multi_v5_defconfig
arm multi_v7_defconfig
arm shmobile_defconfig
arm sunxi_defconfig
arm64 allnoconfig
arm64 allyesconfig
arm64 defconfig
x86_64 fedora-25
x86_64 kexec
x86_64 lkp
x86_64 rhel
x86_64 rhel-7.2-clear
x86_64 rhel-7.6
x86_64 randconfig-e001-20200126
x86_64 randconfig-e002-20200126
x86_64 randconfig-e003-20200126
i386 randconfig-e001-20200126
i386 randconfig-e002-20200126
i386 randconfig-e003-20200126
csky randconfig-a001-20200124
openrisc randconfig-a001-20200124
s390 randconfig-a001-20200124
sh randconfig-a001-20200124
xtensa randconfig-a001-20200124
x86_64 randconfig-d001-20200126
x86_64 randconfig-d002-20200126
x86_64 randconfig-d003-20200126
i386 randconfig-d001-20200126
i386 randconfig-d002-20200126
i386 randconfig-d003-20200126
mips 32r2_defconfig
mips 64r6el_defconfig
mips allmodconfig
mips allnoconfig
mips allyesconfig
mips fuloong2e_defconfig
mips malta_kvm_defconfig
x86_64 randconfig-a001-20200125
x86_64 randconfig-a002-20200125
x86_64 randconfig-a003-20200125
i386 randconfig-a001-20200125
i386 randconfig-a002-20200125
i386 randconfig-a003-20200125
x86_64 randconfig-d001-20200125
x86_64 randconfig-d002-20200125
x86_64 randconfig-d003-20200125
i386 randconfig-d001-20200125
i386 randconfig-d002-20200125
i386 randconfig-d003-20200125
c6x randconfig-a001-20200125
h8300 randconfig-a001-20200125
microblaze randconfig-a001-20200125
nios2 randconfig-a001-20200125
sparc64 randconfig-a001-20200125
x86_64 randconfig-f001-20200125
x86_64 randconfig-f002-20200125
x86_64 randconfig-f003-20200125
i386 randconfig-f001-20200125
i386 randconfig-f002-20200125
i386 randconfig-f003-20200125
x86_64 randconfig-h001-20200125
x86_64 randconfig-h002-20200125
x86_64 randconfig-h003-20200125
i386 randconfig-h001-20200125
i386 randconfig-h002-20200125
i386 randconfig-h003-20200125
sh randconfig-a001-20200125
arc randconfig-a001-20200124
arm randconfig-a001-20200124
arm64 randconfig-a001-20200124
ia64 randconfig-a001-20200124
powerpc randconfig-a001-20200124
sparc randconfig-a001-20200124
x86_64 randconfig-g001-20200125
x86_64 randconfig-g002-20200125
x86_64 randconfig-g003-20200125
i386 randconfig-g001-20200125
i386 randconfig-g002-20200125
i386 randconfig-g003-20200125
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation
^ permalink raw reply
* [PATCH] of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc
From: Michael Ellerman @ 2020-01-26 11:52 UTC (permalink / raw)
To: robh+dt
Cc: devicetree, ulf.hansson, linux-kernel, linuxppc-dev, chzigotzky,
hch
There's an OF helper called of_dma_is_coherent(), which checks if a
device has a "dma-coherent" property to see if the device is coherent
for DMA.
But on some platforms devices are coherent by default, and on some
platforms it's not possible to update existing device trees to add the
"dma-coherent" property.
So add a Kconfig symbol to allow arch code to tell
of_dma_is_coherent() that devices are coherent by default, regardless
of the presence of the property.
Select that symbol on powerpc when NOT_COHERENT_CACHE is not set, ie.
when the system has a coherent cache.
Fixes: 92ea637edea3 ("of: introduce of_dma_is_coherent() helper")
Cc: stable@vger.kernel.org # v3.16+
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/Kconfig | 1 +
drivers/of/Kconfig | 4 ++++
drivers/of/address.c | 6 +++++-
3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1ec34e16ed65..19f5aa8ac9a3 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -238,6 +238,7 @@ config PPC
select NEED_DMA_MAP_STATE if PPC64 || NOT_COHERENT_CACHE
select NEED_SG_DMA_LENGTH
select OF
+ select OF_DMA_DEFAULT_COHERENT if !NOT_COHERENT_CACHE
select OF_EARLY_FLATTREE
select OLD_SIGACTION if PPC32
select OLD_SIGSUSPEND
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 37c2ccbefecd..d91618641be6 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -103,4 +103,8 @@ config OF_OVERLAY
config OF_NUMA
bool
+config OF_DMA_DEFAULT_COHERENT
+ # arches should select this if DMA is coherent by default for OF devices
+ bool
+
endif # OF
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 99c1b8058559..e8a39c3ec4d4 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -995,12 +995,16 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
* @np: device node
*
* It returns true if "dma-coherent" property was found
- * for this device in DT.
+ * for this device in the DT, or if DMA is coherent by
+ * default for OF devices on the current platform.
*/
bool of_dma_is_coherent(struct device_node *np)
{
struct device_node *node = of_node_get(np);
+ if (IS_ENABLED(CONFIG_OF_DMA_DEFAULT_COHERENT))
+ return true;
+
while (node) {
if (of_property_read_bool(node, "dma-coherent")) {
of_node_put(node);
--
2.21.1
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