Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
On 10/25/2019 02:22 PM, Christophe Leroy wrote:
>
>
> Le 25/10/2019 à 10:24, Anshuman Khandual a écrit :
>>
>>
>> On 10/25/2019 12:41 PM, Christophe Leroy wrote:
>>>
>>>
>>> Le 25/10/2019 à 07:52, Qian Cai a écrit :
> On Oct 24, 2019, at 11:45 PM, Anshuman Khandual
> wrote:
>
> Nothing specific. But just tested this with x86 defconfig with relevant
> configs
> which are required for this test. Not sure if it involved W=1.
No, it will not. It needs to run like,
make W=1 -j 64 2>/tmp/warns
>>>
>>> Are we talking about this peace of code ?
>>>
>>> +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;
>>> +
>>> + WARN_ON((random_vaddr > TASK_SIZE) ||
>>> + (random_vaddr < FIRST_USER_ADDRESS));
>>> + return random_vaddr;
>>> +}
>>> +
>>>
>>> ramdom_vaddr is unsigned,
>>> random_pages is unsigned and lower than total_user_pages
>>>
>>> So the max value random_vaddr can get is FIRST_USER_ADDRESS + ((TASK_SIZE -
>>> FIRST_USER_ADDRESS - 1) / PAGE_SIZE) * PAGE_SIZE = TASK_SIZE - 1
>>> And the min value random_vaddr can get is FIRST_USER_ADDRESS (that's when
>>> random_pages = 0)
>>
>> That's right.
>>
>>>
>>> So the WARN_ON() is just unneeded, isn't it ?
>>
>> It is just a sanity check on possible vaddr values before it's corresponding
>> page table mappings could be created. If it's worth to drop this in favor of
>> avoiding these unwanted warning messages on x86, will go ahead with it as it
>> is not super important.
>>
>
> But you are checking what ? That the compiler does calculation correctly or
> what ?
IIRC, probably this was for later if and when the vaddr calculation becomes
dependent on other factors rather than this simple arithmetic involving start
and end of process address space on a platform.
> As mentionned just above, based on the calculation done, what you are testing
> cannot happen, so I'm having a hard time understanding what kind of sanity
> check it can be.
You are right.
>
> Can you give an exemple of a situation which could trigger the warning ?
I was mistaken. We dont need those checks for now, hence will drop them next
time.
>
> Christophe
>
Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
Le 25/10/2019 à 10:24, Anshuman Khandual a écrit :
On 10/25/2019 12:41 PM, Christophe Leroy wrote:
Le 25/10/2019 à 07:52, Qian Cai a écrit :
On Oct 24, 2019, at 11:45 PM, Anshuman Khandual
wrote:
Nothing specific. But just tested this with x86 defconfig with relevant configs
which are required for this test. Not sure if it involved W=1.
No, it will not. It needs to run like,
make W=1 -j 64 2>/tmp/warns
Are we talking about this peace of code ?
+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;
+
+ WARN_ON((random_vaddr > TASK_SIZE) ||
+ (random_vaddr < FIRST_USER_ADDRESS));
+ return random_vaddr;
+}
+
ramdom_vaddr is unsigned,
random_pages is unsigned and lower than total_user_pages
So the max value random_vaddr can get is FIRST_USER_ADDRESS + ((TASK_SIZE -
FIRST_USER_ADDRESS - 1) / PAGE_SIZE) * PAGE_SIZE = TASK_SIZE - 1
And the min value random_vaddr can get is FIRST_USER_ADDRESS (that's when
random_pages = 0)
That's right.
So the WARN_ON() is just unneeded, isn't it ?
It is just a sanity check on possible vaddr values before it's corresponding
page table mappings could be created. If it's worth to drop this in favor of
avoiding these unwanted warning messages on x86, will go ahead with it as it
is not super important.
But you are checking what ? That the compiler does calculation correctly
or what ?
As mentionned just above, based on the calculation done, what you are
testing cannot happen, so I'm having a hard time understanding what kind
of sanity check it can be.
Can you give an exemple of a situation which could trigger the warning ?
Christophe
Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
On 10/25/2019 12:41 PM, Christophe Leroy wrote:
>
>
> Le 25/10/2019 à 07:52, Qian Cai a écrit :
>>
>>
>>> On Oct 24, 2019, at 11:45 PM, Anshuman Khandual
>>> wrote:
>>>
>>> Nothing specific. But just tested this with x86 defconfig with relevant
>>> configs
>>> which are required for this test. Not sure if it involved W=1.
>>
>> No, it will not. It needs to run like,
>>
>> make W=1 -j 64 2>/tmp/warns
>>
>
> Are we talking about this peace of code ?
>
> +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;
> +
> + WARN_ON((random_vaddr > TASK_SIZE) ||
> + (random_vaddr < FIRST_USER_ADDRESS));
> + return random_vaddr;
> +}
> +
>
> ramdom_vaddr is unsigned,
> random_pages is unsigned and lower than total_user_pages
>
> So the max value random_vaddr can get is FIRST_USER_ADDRESS + ((TASK_SIZE -
> FIRST_USER_ADDRESS - 1) / PAGE_SIZE) * PAGE_SIZE = TASK_SIZE - 1
> And the min value random_vaddr can get is FIRST_USER_ADDRESS (that's when
> random_pages = 0)
That's right.
>
> So the WARN_ON() is just unneeded, isn't it ?
It is just a sanity check on possible vaddr values before it's corresponding
page table mappings could be created. If it's worth to drop this in favor of
avoiding these unwanted warning messages on x86, will go ahead with it as it
is not super important.
>
> Christophe
>
Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
Le 25/10/2019 à 07:52, Qian Cai a écrit :
On Oct 24, 2019, at 11:45 PM, Anshuman Khandual
wrote:
Nothing specific. But just tested this with x86 defconfig with relevant configs
which are required for this test. Not sure if it involved W=1.
No, it will not. It needs to run like,
make W=1 -j 64 2>/tmp/warns
Are we talking about this peace of code ?
+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;
+
+ WARN_ON((random_vaddr > TASK_SIZE) ||
+ (random_vaddr < FIRST_USER_ADDRESS));
+ return random_vaddr;
+}
+
ramdom_vaddr is unsigned,
random_pages is unsigned and lower than total_user_pages
So the max value random_vaddr can get is FIRST_USER_ADDRESS +
((TASK_SIZE - FIRST_USER_ADDRESS - 1) / PAGE_SIZE) * PAGE_SIZE =
TASK_SIZE - 1
And the min value random_vaddr can get is FIRST_USER_ADDRESS (that's
when random_pages = 0)
So the WARN_ON() is just unneeded, isn't it ?
Christophe
Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
On 10/25/2019 11:22 AM, Qian Cai wrote: > > >> On Oct 24, 2019, at 11:45 PM, Anshuman Khandual >> wrote: >> >> Nothing specific. But just tested this with x86 defconfig with relevant >> configs >> which are required for this test. Not sure if it involved W=1. > > No, it will not. It needs to run like, > > make W=1 -j 64 2>/tmp/warns Ahh, so we explicitly ask for it. Unfortunately compiler still flags it as an warning. Just wondering why this is still a problem if the second condition for an OR expression is always false. Because evaluation still needs to be performed for the first condition anyways, before arriving at the result. DESCEND objtool CALLscripts/atomic/check-atomics.sh CALLscripts/checksyscalls.sh CHK include/generated/compile.h CC mm/debug_vm_pgtable.o In file included from ./arch/x86/include/asm/bug.h:83:0, from ./include/linux/bug.h:5, from ./include/linux/mmdebug.h:5, from ./include/linux/gfp.h:5, from mm/debug_vm_pgtable.c:13: mm/debug_vm_pgtable.c: In function ‘get_random_vaddr’: mm/debug_vm_pgtable.c:314:17: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] (random_vaddr < FIRST_USER_ADDRESS)); ^ ./include/asm-generic/bug.h:113:25: note: in definition of macro ‘WARN_ON’ int __ret_warn_on = !!(condition);\ ^ As you mentioned GCC is quite stubborn here. Anyways, lets keep it unchanged.
Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
> On Oct 24, 2019, at 11:45 PM, Anshuman Khandual > wrote: > > Nothing specific. But just tested this with x86 defconfig with relevant > configs > which are required for this test. Not sure if it involved W=1. No, it will not. It needs to run like, make W=1 -j 64 2>/tmp/warns
Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
On 10/24/2019 10:21 PM, Qian Cai wrote: > > >> On Oct 24, 2019, at 10:50 AM, Anshuman Khandual >> wrote: >> >> Changes in V7: >> >> - 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 > > It would be interesting to know if you actually tested out to see if the > warning went away. As far I can tell, the GCC is quite stubborn there, so I > am not going to insist. > Nothing specific. But just tested this with x86 defconfig with relevant configs which are required for this test. Not sure if it involved W=1. The problem is, there is no other or better way to have both the conditional checks in place while also reducing the chances this warning. IMHO both the conditional checks are required.
Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
> On Oct 24, 2019, at 10:50 AM, Anshuman Khandual > wrote: > > Changes in V7: > > - 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 It would be interesting to know if you actually tested out to see if the warning went away. As far I can tell, the GCC is quite stubborn there, so I am not going to insist.
Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
On 10/22/2019 12:41 PM, Christophe Leroy wrote: > > > On 10/21/2019 02:42 AM, Anshuman Khandual 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. >> >> 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 >> Cc: Vlastimil Babka >> Cc: Greg Kroah-Hartman >> Cc: Thomas Gleixner >> Cc: Mike Rapoport >> Cc: Jason Gunthorpe >> Cc: Dan Williams >> Cc: Peter Zijlstra >> Cc: Michal Hocko >> Cc: Mark Rutland >> Cc: Mark Brown >> Cc: Steven Price >> Cc: Ard Biesheuvel >> Cc: Masahiro Yamada >> Cc: Kees Cook >> Cc: Tetsuo Handa >> Cc: Matthew Wilcox >> Cc: Sri Krishna chowdary >> Cc: Dave Hansen >> Cc: Russell King - ARM Linux >> Cc: Michael Ellerman >> Cc: Paul Mackerras >> Cc: Martin Schwidefsky >> Cc: Heiko Carstens >> Cc: "David S. Miller" >> Cc: Vineet Gupta >> Cc: James Hogan >> Cc: Paul Burton >> Cc: Ralf Baechle >> Cc: Kirill A. Shutemov >> Cc: Gerald Schaefer >> Cc: Christophe Leroy >> Cc: Ingo Molnar >> Cc: linux-snps-...@lists.infradead.org >> Cc: linux-m...@vger.kernel.org >> Cc: linux-arm-ker...@lists.infradead.org >> Cc: linux-i...@vger.kernel.org >> Cc: linuxppc-dev@lists.ozlabs.org >> Cc: linux-s...@vger.kernel.org >> Cc: linux...@vger.kernel.org >> Cc: sparcli...@vger.kernel.org >> Cc: x...@kernel.org >> Cc: linux-ker...@vger.kernel.org >> >> Tested-by: Christophe Leroy #PPC32 >> Suggested-by: Catalin Marinas >> Signed-off-by: Andrew Morton >> Signed-off-by: Christophe Leroy >> Signed-off-by: Anshuman Khandual >> --- > > The cover letter have the exact same title as this patch. I think a cover > letter is not necessary for a singleton series. Right, but it became singleton series in this version :) > > The history (and any other information you don't want to include in the > commit message) can be added here, below the '---'. That way it is in the > mail but won't be included in the commit. I was aware about that but the change log here was big, hence just choose to have that separately in a cover letter. As you said, I guess the cover letter is probably not required anymore. Will add it here in the patch, next time around. > >> .../debug/debug-vm-pgtable/arch-support.txt | 34 ++ >> arch/arm64/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 | 21 ++ >> mm/Makefile | 1 + >> mm/debug_vm_pgtable.c | 388 >> + >> 9 files changed, 459 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 000..d6b8185 >> --- /dev/null >> +++ b/Documentation/features/debug/debug-vm-pgtable/arch-support.txt >> @@ -0,0 +1,34 @@ >> +# >> +# Feature name: debug-vm-pgtable >> +# Kconfig: ARCH_HAS_DEBUG_VM_PGTABLE >> +# description: arch supports pgtable tests for semantics >> compliance >> +# >> + ---
Re: [PATCH V7] mm/debug: Add tests validating architecture page table helpers
On 10/21/2019 02:42 AM, Anshuman Khandual 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. 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 Cc: Vlastimil Babka Cc: Greg Kroah-Hartman Cc: Thomas Gleixner Cc: Mike Rapoport Cc: Jason Gunthorpe Cc: Dan Williams Cc: Peter Zijlstra Cc: Michal Hocko Cc: Mark Rutland Cc: Mark Brown Cc: Steven Price Cc: Ard Biesheuvel Cc: Masahiro Yamada Cc: Kees Cook Cc: Tetsuo Handa Cc: Matthew Wilcox Cc: Sri Krishna chowdary Cc: Dave Hansen Cc: Russell King - ARM Linux Cc: Michael Ellerman Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: "David S. Miller" Cc: Vineet Gupta Cc: James Hogan Cc: Paul Burton Cc: Ralf Baechle Cc: Kirill A. Shutemov Cc: Gerald Schaefer Cc: Christophe Leroy Cc: Ingo Molnar Cc: linux-snps-...@lists.infradead.org Cc: linux-m...@vger.kernel.org Cc: linux-arm-ker...@lists.infradead.org Cc: linux-i...@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s...@vger.kernel.org Cc: linux...@vger.kernel.org Cc: sparcli...@vger.kernel.org Cc: x...@kernel.org Cc: linux-ker...@vger.kernel.org Tested-by: Christophe Leroy #PPC32 Suggested-by: Catalin Marinas Signed-off-by: Andrew Morton Signed-off-by: Christophe Leroy Signed-off-by: Anshuman Khandual --- The cover letter have the exact same title as this patch. I think a cover letter is not necessary for a singleton series. The history (and any other information you don't want to include in the commit message) can be added here, below the '---'. That way it is in the mail but won't be included in the commit. .../debug/debug-vm-pgtable/arch-support.txt| 34 ++ arch/arm64/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 | 21 ++ mm/Makefile| 1 + mm/debug_vm_pgtable.c | 388 + 9 files changed, 459 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 000..d6b8185 --- /dev/null +++ b/Documentation/features/debug/debug-vm-pgtable/arch-support.txt @@ -0,0 +1,34 @@ +# +# Feature name: debug-vm-pgtable +# Kconfig: ARCH_HAS_DEBUG_VM_PGTABLE +# description: arch supports pgtable tests for semantics compliance +# +--- +| arch |status| +--- +| alpha: | TODO | +| arc: | TODO | +| 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: | TODO | Say ok on ppc32 +| riscv: | TODO | +|s390: | TODO | +| sh: | TODO | +| sparc:
[PATCH V7] mm/debug: Add tests validating architecture page table helpers
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 Cc: Vlastimil Babka Cc: Greg Kroah-Hartman Cc: Thomas Gleixner Cc: Mike Rapoport Cc: Jason Gunthorpe Cc: Dan Williams Cc: Peter Zijlstra Cc: Michal Hocko Cc: Mark Rutland Cc: Mark Brown Cc: Steven Price Cc: Ard Biesheuvel Cc: Masahiro Yamada Cc: Kees Cook Cc: Tetsuo Handa Cc: Matthew Wilcox Cc: Sri Krishna chowdary Cc: Dave Hansen Cc: Russell King - ARM Linux Cc: Michael Ellerman Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: "David S. Miller" Cc: Vineet Gupta Cc: James Hogan Cc: Paul Burton Cc: Ralf Baechle Cc: Kirill A. Shutemov Cc: Gerald Schaefer Cc: Christophe Leroy Cc: Ingo Molnar Cc: linux-snps-...@lists.infradead.org Cc: linux-m...@vger.kernel.org Cc: linux-arm-ker...@lists.infradead.org Cc: linux-i...@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s...@vger.kernel.org Cc: linux...@vger.kernel.org Cc: sparcli...@vger.kernel.org Cc: x...@kernel.org Cc: linux-ker...@vger.kernel.org Tested-by: Christophe Leroy#PPC32 Suggested-by: Catalin Marinas Signed-off-by: Andrew Morton Signed-off-by: Christophe Leroy Signed-off-by: Anshuman Khandual --- .../debug/debug-vm-pgtable/arch-support.txt| 34 ++ arch/arm64/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 | 21 ++ mm/Makefile| 1 + mm/debug_vm_pgtable.c | 388 + 9 files changed, 459 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 000..d6b8185 --- /dev/null +++ b/Documentation/features/debug/debug-vm-pgtable/arch-support.txt @@ -0,0 +1,34 @@ +# +# Feature name: debug-vm-pgtable +# Kconfig: ARCH_HAS_DEBUG_VM_PGTABLE +# description: arch supports pgtable tests for semantics compliance +# +--- +| arch |status| +--- +| alpha: | TODO | +| arc: | TODO | +| 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: | TODO | +| riscv: | TODO | +|s390: | TODO | +| sh: | TODO | +| sparc: | TODO | +| um: | TODO | +| unicore32: | TODO | +| x86: | ok | +| xtensa: | TODO | +--- diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 1b6ea5a..ea62c87 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
[PATCH V7] mm/debug: Add tests validating architecture page table helpers
This series adds a test validation for architecture exported page table helpers. Patch in the series 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.ga56...@arrakis.emea.arm.com/ Needs to be applied on linux-next (next-20191017) after reverting all commits from V5 of this series. Changes in V7: - 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.khand...@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.khand...@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.khand...@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.khand...@arm.com/ Cc: Andrew Morton Cc: Vlastimil Babka Cc: Greg Kroah-Hartman Cc: Thomas Gleixner Cc: Mike Rapoport Cc: Jason Gunthorpe Cc: Dan Williams Cc: Peter Zijlstra Cc: Michal Hocko Cc: Mark Rutland Cc: Mark Brown Cc: Steven Price Cc: Ard Biesheuvel Cc: Masahiro Yamada Cc: Kees
