[PATCH RESEND 0/8] Fix mmap base in bottom-up mmap

[PATCH RESEND 0/8] Fix mmap base in bottom-up mmap

[Alexandre Ghiti]

This series fixes the fallback of the top-down mmap: in case of
failure, a bottom-up scheme can be tried as a last resort between
the top-down mmap base and the stack, hoping for a large unused stack
limit.

Lots of architectures and even mm code start this fallback
at TASK_UNMAPPED_BASE, which is useless since the top-down scheme
already failed on the whole address space: instead, simply use
mmap_base.

Along the way, it allows to get rid of of mmap_legacy_base and
mmap_compat_legacy_base from mm_struct.

Note that arm and mips already implement this behaviour.  

Alexandre Ghiti (8):
  s390: Start fallback of top-down mmap at mm->mmap_base
  sh: Start fallback of top-down mmap at mm->mmap_base
  sparc: Start fallback of top-down mmap at mm->mmap_base
  x86, hugetlbpage: Start fallback of top-down mmap at mm->mmap_base
  mm: Start fallback top-down mmap at mm->mmap_base
  parisc: Use mmap_base, not mmap_legacy_base, as low_limit for
    bottom-up mmap
  x86: Use mmap_*base, not mmap_*legacy_base, as low_limit for bottom-up
    mmap
  mm: Remove mmap_legacy_base and mmap_compat_legacy_code fields from
    mm_struct

 arch/parisc/kernel/sys_parisc.c  |  8 +++-----
 arch/s390/mm/mmap.c              |  2 +-
 arch/sh/mm/mmap.c                |  2 +-
 arch/sparc/kernel/sys_sparc_64.c |  2 +-
 arch/sparc/mm/hugetlbpage.c      |  2 +-
 arch/x86/include/asm/elf.h       |  2 +-
 arch/x86/kernel/sys_x86_64.c     |  4 ++--
 arch/x86/mm/hugetlbpage.c        |  7 ++++---
 arch/x86/mm/mmap.c               | 20 +++++++++-----------
 include/linux/mm_types.h         |  2 --
 mm/debug.c                       |  4 ++--
 mm/mmap.c                        |  2 +-
 12 files changed, 26 insertions(+), 31 deletions(-)

-- 
2.20.1

[PATCH RESEND 1/8] s390: Start fallback of top-down mmap at mm->mmap_base

[Alexandre Ghiti]

In case of mmap failure in top-down mode, there is no need to go through
the whole address space again for the bottom-up fallback: the goal of this
fallback is to find, as a last resort, space between the top-down mmap base
and the stack, which is the only place not covered by the top-down mmap.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
---
 arch/s390/mm/mmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index cbc718ba6d78..4a222969843b 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -166,7 +166,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 	if (addr & ~PAGE_MASK) {
 		VM_BUG_ON(addr != -ENOMEM);
 		info.flags = 0;
-		info.low_limit = TASK_UNMAPPED_BASE;
+		info.low_limit = mm->mmap_base;
 		info.high_limit = TASK_SIZE;
 		addr = vm_unmapped_area(&info);
 		if (addr & ~PAGE_MASK)
-- 
2.20.1

Re: [PATCH RESEND 1/8] s390: Start fallback of top-down mmap at mm->mmap_base

[Alex Ghiti]

Really sorry about that, my connection is weird this morning, I'll retry 
tomorrow.

Sorry again,

Alex

On 6/19/19 1:42 AM, Alexandre Ghiti wrote:
> In case of mmap failure in top-down mode, there is no need to go through
> the whole address space again for the bottom-up fallback: the goal of this
> fallback is to find, as a last resort, space between the top-down mmap base
> and the stack, which is the only place not covered by the top-down mmap.
>
> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
> ---
>   arch/s390/mm/mmap.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
> index cbc718ba6d78..4a222969843b 100644
> --- a/arch/s390/mm/mmap.c
> +++ b/arch/s390/mm/mmap.c
> @@ -166,7 +166,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
>   	if (addr & ~PAGE_MASK) {
>   		VM_BUG_ON(addr != -ENOMEM);
>   		info.flags = 0;
> -		info.low_limit = TASK_UNMAPPED_BASE;
> +		info.low_limit = mm->mmap_base;
>   		info.high_limit = TASK_SIZE;
>   		addr = vm_unmapped_area(&info);
>   		if (addr & ~PAGE_MASK)

Re: [PATCH RESEND 0/8] Fix mmap base in bottom-up mmap

[Alex Ghiti]

On 8/26/19 6:37 PM, Helge Deller wrote:
> On 26.08.19 09:34, Alexandre Ghiti wrote:
>> On 6/20/19 7:03 AM, Alexandre Ghiti wrote:
>>> This series fixes the fallback of the top-down mmap: in case of
>>> failure, a bottom-up scheme can be tried as a last resort between
>>> the top-down mmap base and the stack, hoping for a large unused stack
>>> limit.
>>>
>>> Lots of architectures and even mm code start this fallback
>>> at TASK_UNMAPPED_BASE, which is useless since the top-down scheme
>>> already failed on the whole address space: instead, simply use
>>> mmap_base.
>>>
>>> Along the way, it allows to get rid of of mmap_legacy_base and
>>> mmap_compat_legacy_base from mm_struct.
>>>
>>> Note that arm and mips already implement this behaviour.
>>>
>>> Alexandre Ghiti (8):
>>>    s390: Start fallback of top-down mmap at mm->mmap_base
>>>    sh: Start fallback of top-down mmap at mm->mmap_base
>>>    sparc: Start fallback of top-down mmap at mm->mmap_base
>>>    x86, hugetlbpage: Start fallback of top-down mmap at mm->mmap_base
>>>    mm: Start fallback top-down mmap at mm->mmap_base
>>>    parisc: Use mmap_base, not mmap_legacy_base, as low_limit for
>>>      bottom-up mmap
>>>    x86: Use mmap_*base, not mmap_*legacy_base, as low_limit for 
>>> bottom-up
>>>      mmap
>>>    mm: Remove mmap_legacy_base and mmap_compat_legacy_code fields from
>>>      mm_struct
>>>
>>>   arch/parisc/kernel/sys_parisc.c  |  8 +++-----
>>>   arch/s390/mm/mmap.c              |  2 +-
>>>   arch/sh/mm/mmap.c                |  2 +-
>>>   arch/sparc/kernel/sys_sparc_64.c |  2 +-
>>>   arch/sparc/mm/hugetlbpage.c      |  2 +-
>>>   arch/x86/include/asm/elf.h       |  2 +-
>>>   arch/x86/kernel/sys_x86_64.c     |  4 ++--
>>>   arch/x86/mm/hugetlbpage.c        |  7 ++++---
>>>   arch/x86/mm/mmap.c               | 20 +++++++++-----------
>>>   include/linux/mm_types.h         |  2 --
>>>   mm/debug.c                       |  4 ++--
>>>   mm/mmap.c                        |  2 +-
>>>   12 files changed, 26 insertions(+), 31 deletions(-)
>>>
>>
>> Any thoughts about that series ? As said before, this is just a 
>> preparatory patchset in order to
>> merge x86 mmap top down code with the generic version.
>
> I just tested your patch series successfully on the parisc
> architeture. You may add:
>
> Tested-by: Helge Deller <deller@gmx.de> # parisc

Thanks again Helge !

Alex


>
> Thanks!
> Helge

Re: [PATCH RESEND 0/8] Fix mmap base in bottom-up mmap

[Helge Deller]

On 26.08.19 09:34, Alexandre Ghiti wrote:
> On 6/20/19 7:03 AM, Alexandre Ghiti wrote:
>> This series fixes the fallback of the top-down mmap: in case of
>> failure, a bottom-up scheme can be tried as a last resort between
>> the top-down mmap base and the stack, hoping for a large unused stack
>> limit.
>>
>> Lots of architectures and even mm code start this fallback
>> at TASK_UNMAPPED_BASE, which is useless since the top-down scheme
>> already failed on the whole address space: instead, simply use
>> mmap_base.
>>
>> Along the way, it allows to get rid of of mmap_legacy_base and
>> mmap_compat_legacy_base from mm_struct.
>>
>> Note that arm and mips already implement this behaviour.
>>
>> Alexandre Ghiti (8):
>>    s390: Start fallback of top-down mmap at mm->mmap_base
>>    sh: Start fallback of top-down mmap at mm->mmap_base
>>    sparc: Start fallback of top-down mmap at mm->mmap_base
>>    x86, hugetlbpage: Start fallback of top-down mmap at mm->mmap_base
>>    mm: Start fallback top-down mmap at mm->mmap_base
>>    parisc: Use mmap_base, not mmap_legacy_base, as low_limit for
>>      bottom-up mmap
>>    x86: Use mmap_*base, not mmap_*legacy_base, as low_limit for bottom-up
>>      mmap
>>    mm: Remove mmap_legacy_base and mmap_compat_legacy_code fields from
>>      mm_struct
>>
>>   arch/parisc/kernel/sys_parisc.c  |  8 +++-----
>>   arch/s390/mm/mmap.c              |  2 +-
>>   arch/sh/mm/mmap.c                |  2 +-
>>   arch/sparc/kernel/sys_sparc_64.c |  2 +-
>>   arch/sparc/mm/hugetlbpage.c      |  2 +-
>>   arch/x86/include/asm/elf.h       |  2 +-
>>   arch/x86/kernel/sys_x86_64.c     |  4 ++--
>>   arch/x86/mm/hugetlbpage.c        |  7 ++++---
>>   arch/x86/mm/mmap.c               | 20 +++++++++-----------
>>   include/linux/mm_types.h         |  2 --
>>   mm/debug.c                       |  4 ++--
>>   mm/mmap.c                        |  2 +-
>>   12 files changed, 26 insertions(+), 31 deletions(-)
>>
>
> Any thoughts about that series ? As said before, this is just a preparatory patchset in order to
> merge x86 mmap top down code with the generic version.

I just tested your patch series successfully on the parisc
architeture. You may add:

Tested-by: Helge Deller <deller@gmx.de> # parisc

Thanks!
Helge

Re: [PATCH RESEND 0/8] Fix mmap base in bottom-up mmap

[Alexandre Ghiti]

On 6/20/19 7:03 AM, Alexandre Ghiti wrote:
> This series fixes the fallback of the top-down mmap: in case of
> failure, a bottom-up scheme can be tried as a last resort between
> the top-down mmap base and the stack, hoping for a large unused stack
> limit.
>
> Lots of architectures and even mm code start this fallback
> at TASK_UNMAPPED_BASE, which is useless since the top-down scheme
> already failed on the whole address space: instead, simply use
> mmap_base.
>
> Along the way, it allows to get rid of of mmap_legacy_base and
> mmap_compat_legacy_base from mm_struct.
>
> Note that arm and mips already implement this behaviour.
>
> Alexandre Ghiti (8):
>    s390: Start fallback of top-down mmap at mm->mmap_base
>    sh: Start fallback of top-down mmap at mm->mmap_base
>    sparc: Start fallback of top-down mmap at mm->mmap_base
>    x86, hugetlbpage: Start fallback of top-down mmap at mm->mmap_base
>    mm: Start fallback top-down mmap at mm->mmap_base
>    parisc: Use mmap_base, not mmap_legacy_base, as low_limit for
>      bottom-up mmap
>    x86: Use mmap_*base, not mmap_*legacy_base, as low_limit for bottom-up
>      mmap
>    mm: Remove mmap_legacy_base and mmap_compat_legacy_code fields from
>      mm_struct
>
>   arch/parisc/kernel/sys_parisc.c  |  8 +++-----
>   arch/s390/mm/mmap.c              |  2 +-
>   arch/sh/mm/mmap.c                |  2 +-
>   arch/sparc/kernel/sys_sparc_64.c |  2 +-
>   arch/sparc/mm/hugetlbpage.c      |  2 +-
>   arch/x86/include/asm/elf.h       |  2 +-
>   arch/x86/kernel/sys_x86_64.c     |  4 ++--
>   arch/x86/mm/hugetlbpage.c        |  7 ++++---
>   arch/x86/mm/mmap.c               | 20 +++++++++-----------
>   include/linux/mm_types.h         |  2 --
>   mm/debug.c                       |  4 ++--
>   mm/mmap.c                        |  2 +-
>   12 files changed, 26 insertions(+), 31 deletions(-)
>

Hi everyone,

Any thoughts about that series ? As said before, this is just a 
preparatory patchset in order to
merge x86 mmap top down code with the generic version.

Thanks for taking a look,

Alex

Re: [PATCH RESEND 0/8] Fix mmap base in bottom-up mmap

[Alexandre Ghiti]

On 6/20/19 7:03 AM, Alexandre Ghiti wrote:
> This series fixes the fallback of the top-down mmap: in case of
> failure, a bottom-up scheme can be tried as a last resort between
> the top-down mmap base and the stack, hoping for a large unused stack
> limit.
>
> Lots of architectures and even mm code start this fallback
> at TASK_UNMAPPED_BASE, which is useless since the top-down scheme
> already failed on the whole address space: instead, simply use
> mmap_base.
>
> Along the way, it allows to get rid of of mmap_legacy_base and
> mmap_compat_legacy_base from mm_struct.
>
> Note that arm and mips already implement this behaviour.
>
> Alexandre Ghiti (8):
>    s390: Start fallback of top-down mmap at mm->mmap_base
>    sh: Start fallback of top-down mmap at mm->mmap_base
>    sparc: Start fallback of top-down mmap at mm->mmap_base
>    x86, hugetlbpage: Start fallback of top-down mmap at mm->mmap_base
>    mm: Start fallback top-down mmap at mm->mmap_base
>    parisc: Use mmap_base, not mmap_legacy_base, as low_limit for
>      bottom-up mmap
>    x86: Use mmap_*base, not mmap_*legacy_base, as low_limit for bottom-up
>      mmap
>    mm: Remove mmap_legacy_base and mmap_compat_legacy_code fields from
>      mm_struct
>
>   arch/parisc/kernel/sys_parisc.c  |  8 +++-----
>   arch/s390/mm/mmap.c              |  2 +-
>   arch/sh/mm/mmap.c                |  2 +-
>   arch/sparc/kernel/sys_sparc_64.c |  2 +-
>   arch/sparc/mm/hugetlbpage.c      |  2 +-
>   arch/x86/include/asm/elf.h       |  2 +-
>   arch/x86/kernel/sys_x86_64.c     |  4 ++--
>   arch/x86/mm/hugetlbpage.c        |  7 ++++---
>   arch/x86/mm/mmap.c               | 20 +++++++++-----------
>   include/linux/mm_types.h         |  2 --
>   mm/debug.c                       |  4 ++--
>   mm/mmap.c                        |  2 +-
>   12 files changed, 26 insertions(+), 31 deletions(-)
>

Hi everyone,

This is just a preparatory series for the merging of x86 mmap top-down 
functions with
the generic ones (those should get into v5.3), if you could take some 
time to take a look,
that would be great :)

Thanks,

Alex

[PATCH RESEND 0/8] Fix mmap base in bottom-up mmap

[Alexandre Ghiti]

This series fixes the fallback of the top-down mmap: in case of
failure, a bottom-up scheme can be tried as a last resort between
the top-down mmap base and the stack, hoping for a large unused stack
limit.

Lots of architectures and even mm code start this fallback
at TASK_UNMAPPED_BASE, which is useless since the top-down scheme
already failed on the whole address space: instead, simply use
mmap_base.

Along the way, it allows to get rid of of mmap_legacy_base and
mmap_compat_legacy_base from mm_struct.

Note that arm and mips already implement this behaviour. 

Alexandre Ghiti (8):
  s390: Start fallback of top-down mmap at mm->mmap_base
  sh: Start fallback of top-down mmap at mm->mmap_base
  sparc: Start fallback of top-down mmap at mm->mmap_base
  x86, hugetlbpage: Start fallback of top-down mmap at mm->mmap_base
  mm: Start fallback top-down mmap at mm->mmap_base
  parisc: Use mmap_base, not mmap_legacy_base, as low_limit for
    bottom-up mmap
  x86: Use mmap_*base, not mmap_*legacy_base, as low_limit for bottom-up
    mmap
  mm: Remove mmap_legacy_base and mmap_compat_legacy_code fields from
    mm_struct

 arch/parisc/kernel/sys_parisc.c  |  8 +++-----
 arch/s390/mm/mmap.c              |  2 +-
 arch/sh/mm/mmap.c                |  2 +-
 arch/sparc/kernel/sys_sparc_64.c |  2 +-
 arch/sparc/mm/hugetlbpage.c      |  2 +-
 arch/x86/include/asm/elf.h       |  2 +-
 arch/x86/kernel/sys_x86_64.c     |  4 ++--
 arch/x86/mm/hugetlbpage.c        |  7 ++++---
 arch/x86/mm/mmap.c               | 20 +++++++++-----------
 include/linux/mm_types.h         |  2 --
 mm/debug.c                       |  4 ++--
 mm/mmap.c                        |  2 +-
 12 files changed, 26 insertions(+), 31 deletions(-)

-- 
2.20.1

[PATCH RESEND 0/8] Fix mmap base in bottom-up mmap

[Alexandre Ghiti]

(Sorry for the previous interrupted series) 

This series fixes the fallback of the top-down mmap: in case of
failure, a bottom-up scheme can be tried as a last resort between
the top-down mmap base and the stack, hoping for a large unused stack
limit.

Lots of architectures and even mm code start this fallback
at TASK_UNMAPPED_BASE, which is useless since the top-down scheme
already failed on the whole address space: instead, simply use
mmap_base.

Along the way, it allows to get rid of of mmap_legacy_base and
mmap_compat_legacy_base from mm_struct.

Note that arm and mips already implement this behaviour.

Alexandre Ghiti (8):
  s390: Start fallback of top-down mmap at mm->mmap_base
  sh: Start fallback of top-down mmap at mm->mmap_base
  sparc: Start fallback of top-down mmap at mm->mmap_base
  x86, hugetlbpage: Start fallback of top-down mmap at mm->mmap_base
  mm: Start fallback top-down mmap at mm->mmap_base
  parisc: Use mmap_base, not mmap_legacy_base, as low_limit for
    bottom-up mmap
  x86: Use mmap_*base, not mmap_*legacy_base, as low_limit for bottom-up
    mmap
  mm: Remove mmap_legacy_base and mmap_compat_legacy_code fields from
    mm_struct

 arch/parisc/kernel/sys_parisc.c  |  8 +++-----
 arch/s390/mm/mmap.c              |  2 +-
 arch/sh/mm/mmap.c                |  2 +-
 arch/sparc/kernel/sys_sparc_64.c |  2 +-
 arch/sparc/mm/hugetlbpage.c      |  2 +-
 arch/x86/include/asm/elf.h       |  2 +-
 arch/x86/kernel/sys_x86_64.c     |  4 ++--
 arch/x86/mm/hugetlbpage.c        |  7 ++++---
 arch/x86/mm/mmap.c               | 20 +++++++++-----------
 include/linux/mm_types.h         |  2 --
 mm/debug.c                       |  4 ++--
 mm/mmap.c                        |  2 +-
 12 files changed, 26 insertions(+), 31 deletions(-)

-- 
2.20.1