diff mbox series

[v4,07/10] powerpc/mm: Use generic_hugetlb_get_unmapped_area()

Message ID f292a83707b64c73fcb02a8708f18f09422f7eea.1638976229.git.christophe.leroy@csgroup.eu (mailing list archive)
State New
Headers show
Series Convert powerpc to default topdown mmap layout | expand

Commit Message

Christophe Leroy Dec. 8, 2021, 5:18 p.m. UTC
Use the generic version of arch_hugetlb_get_unmapped_area()
which is now available at all time.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/64/hugetlb.h |  4 --
 arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 55 --------------------
 arch/powerpc/mm/hugetlbpage.c                |  4 +-
 3 files changed, 1 insertion(+), 62 deletions(-)

Comments

Nicholas Piggin Dec. 9, 2021, 10:02 a.m. UTC | #1
Excerpts from Christophe Leroy's message of December 9, 2021 3:18 am:
> Use the generic version of arch_hugetlb_get_unmapped_area()
> which is now available at all time.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/include/asm/book3s/64/hugetlb.h |  4 --
>  arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 55 --------------------
>  arch/powerpc/mm/hugetlbpage.c                |  4 +-
>  3 files changed, 1 insertion(+), 62 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
> index 12e150e615b7..b37a28f62cf6 100644
> --- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
> +++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
> @@ -8,10 +8,6 @@
>   */
>  void radix__flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
>  void radix__local_flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
> -extern unsigned long
> -radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
> -				unsigned long len, unsigned long pgoff,
> -				unsigned long flags);
>  
>  extern void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
>  						unsigned long addr, pte_t *ptep,
> diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> index 23d3e08911d3..d2fb776febb4 100644
> --- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> +++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> @@ -41,61 +41,6 @@ void radix__flush_hugetlb_tlb_range(struct vm_area_struct *vma, unsigned long st
>  		radix__flush_tlb_range_psize(vma->vm_mm, start, end, psize);
>  }
>  
> -/*
> - * A vairant of hugetlb_get_unmapped_area doing topdown search
> - * FIXME!! should we do as x86 does or non hugetlb area does ?
> - * ie, use topdown or not based on mmap_is_legacy check ?
> - */
> -unsigned long
> -radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
> -				unsigned long len, unsigned long pgoff,
> -				unsigned long flags)
> -{
> -	struct mm_struct *mm = current->mm;
> -	struct vm_area_struct *vma;
> -	struct hstate *h = hstate_file(file);
> -	int fixed = (flags & MAP_FIXED);
> -	unsigned long high_limit;
> -	struct vm_unmapped_area_info info;
> -
> -	high_limit = DEFAULT_MAP_WINDOW;
> -	if (addr >= high_limit || (fixed && (addr + len > high_limit)))
> -		high_limit = TASK_SIZE;

I wonder if generic hugetlb_get_unmapped_area needs to have the
arch_get_mmap_end() added.

arm64 has arch_get_mmap_end() and !HAVE_ARCH_HUGETLB_UNMAPPED_AREA so
it looks like it has broken large address hint logic for hugetlbfs
mappings? x86-64 defines their own and does the same hinting for
normal and hugetlbfs mmap.

If we had that and defied arch_get_mmap_end(), then this patch should
work.

Thanks,
Nick
Christophe Leroy Dec. 16, 2021, 5:13 p.m. UTC | #2
Le 09/12/2021 à 11:02, Nicholas Piggin a écrit :
> Excerpts from Christophe Leroy's message of December 9, 2021 3:18 am:
>> Use the generic version of arch_hugetlb_get_unmapped_area()
>> which is now available at all time.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>   arch/powerpc/include/asm/book3s/64/hugetlb.h |  4 --
>>   arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 55 --------------------
>>   arch/powerpc/mm/hugetlbpage.c                |  4 +-
>>   3 files changed, 1 insertion(+), 62 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
>> index 12e150e615b7..b37a28f62cf6 100644
>> --- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
>> +++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
>> @@ -8,10 +8,6 @@
>>    */
>>   void radix__flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
>>   void radix__local_flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
>> -extern unsigned long
>> -radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
>> -				unsigned long len, unsigned long pgoff,
>> -				unsigned long flags);
>>   
>>   extern void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
>>   						unsigned long addr, pte_t *ptep,
>> diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
>> index 23d3e08911d3..d2fb776febb4 100644
>> --- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
>> +++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
>> @@ -41,61 +41,6 @@ void radix__flush_hugetlb_tlb_range(struct vm_area_struct *vma, unsigned long st
>>   		radix__flush_tlb_range_psize(vma->vm_mm, start, end, psize);
>>   }
>>   
>> -/*
>> - * A vairant of hugetlb_get_unmapped_area doing topdown search
>> - * FIXME!! should we do as x86 does or non hugetlb area does ?
>> - * ie, use topdown or not based on mmap_is_legacy check ?
>> - */
>> -unsigned long
>> -radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
>> -				unsigned long len, unsigned long pgoff,
>> -				unsigned long flags)
>> -{
>> -	struct mm_struct *mm = current->mm;
>> -	struct vm_area_struct *vma;
>> -	struct hstate *h = hstate_file(file);
>> -	int fixed = (flags & MAP_FIXED);
>> -	unsigned long high_limit;
>> -	struct vm_unmapped_area_info info;
>> -
>> -	high_limit = DEFAULT_MAP_WINDOW;
>> -	if (addr >= high_limit || (fixed && (addr + len > high_limit)))
>> -		high_limit = TASK_SIZE;
> 
> I wonder if generic hugetlb_get_unmapped_area needs to have the
> arch_get_mmap_end() added.
> 
> arm64 has arch_get_mmap_end() and !HAVE_ARCH_HUGETLB_UNMAPPED_AREA so
> it looks like it has broken large address hint logic for hugetlbfs
> mappings? x86-64 defines their own and does the same hinting for
> normal and hugetlbfs mmap.
> 
> If we had that and defied arch_get_mmap_end(), then this patch should
> work.
> 

As far as I can see, hugetlb_get_unmapped_area() variants used to be 
very similar to get_unmapped_area() until commit 1be7107fbe18 ("mm: 
larger stack guard gap, between vmas") and commit f6795053dac8 ("mm: 
mmap: Allow for "high" userspace addresses")

I see no reason why those changes couldn't apply to 
hugetlb_get_unmapped_area() as well.

Need to know what ARM64 think about it thought. Will, Catalin, any opinion ?

Christophe
Catalin Marinas Dec. 16, 2021, 6:55 p.m. UTC | #3
On Thu, Dec 16, 2021 at 05:13:47PM +0000, Christophe Leroy wrote:
> Le 09/12/2021 à 11:02, Nicholas Piggin a écrit :
> > Excerpts from Christophe Leroy's message of December 9, 2021 3:18 am:
> >> Use the generic version of arch_hugetlb_get_unmapped_area()
> >> which is now available at all time.
> >>
> >> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> >> ---
> >>   arch/powerpc/include/asm/book3s/64/hugetlb.h |  4 --
> >>   arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 55 --------------------
> >>   arch/powerpc/mm/hugetlbpage.c                |  4 +-
> >>   3 files changed, 1 insertion(+), 62 deletions(-)
> >>
> >> diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
> >> index 12e150e615b7..b37a28f62cf6 100644
> >> --- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
> >> +++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
> >> @@ -8,10 +8,6 @@
> >>    */
> >>   void radix__flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
> >>   void radix__local_flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
> >> -extern unsigned long
> >> -radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
> >> -				unsigned long len, unsigned long pgoff,
> >> -				unsigned long flags);
> >>   
> >>   extern void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> >>   						unsigned long addr, pte_t *ptep,
> >> diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> >> index 23d3e08911d3..d2fb776febb4 100644
> >> --- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> >> +++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> >> @@ -41,61 +41,6 @@ void radix__flush_hugetlb_tlb_range(struct vm_area_struct *vma, unsigned long st
> >>   		radix__flush_tlb_range_psize(vma->vm_mm, start, end, psize);
> >>   }
> >>   
> >> -/*
> >> - * A vairant of hugetlb_get_unmapped_area doing topdown search
> >> - * FIXME!! should we do as x86 does or non hugetlb area does ?
> >> - * ie, use topdown or not based on mmap_is_legacy check ?
> >> - */
> >> -unsigned long
> >> -radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
> >> -				unsigned long len, unsigned long pgoff,
> >> -				unsigned long flags)
> >> -{
> >> -	struct mm_struct *mm = current->mm;
> >> -	struct vm_area_struct *vma;
> >> -	struct hstate *h = hstate_file(file);
> >> -	int fixed = (flags & MAP_FIXED);
> >> -	unsigned long high_limit;
> >> -	struct vm_unmapped_area_info info;
> >> -
> >> -	high_limit = DEFAULT_MAP_WINDOW;
> >> -	if (addr >= high_limit || (fixed && (addr + len > high_limit)))
> >> -		high_limit = TASK_SIZE;
> > 
> > I wonder if generic hugetlb_get_unmapped_area needs to have the
> > arch_get_mmap_end() added.
> > 
> > arm64 has arch_get_mmap_end() and !HAVE_ARCH_HUGETLB_UNMAPPED_AREA so
> > it looks like it has broken large address hint logic for hugetlbfs
> > mappings? x86-64 defines their own and does the same hinting for
> > normal and hugetlbfs mmap.
> > 
> > If we had that and defied arch_get_mmap_end(), then this patch should
> > work.
> > 
> 
> As far as I can see, hugetlb_get_unmapped_area() variants used to be 
> very similar to get_unmapped_area() until commit 1be7107fbe18 ("mm: 
> larger stack guard gap, between vmas") and commit f6795053dac8 ("mm: 
> mmap: Allow for "high" userspace addresses")
> 
> I see no reason why those changes couldn't apply to 
> hugetlb_get_unmapped_area() as well.
> 
> Need to know what ARM64 think about it thought. Will, Catalin, any opinion ?

I think we should have fixed hugetlb_get_unmapped_area() as well when we
added support for 52-bit VA. The reason for commit f6795053dac8 was to
prevent normal mmap() from returning addresses above 48-bit by default
as some user-space had hard assumptions about this.

It's a slight ABI change if you do this for hugetlb_get_unmapped_area()
but I doubt anyone would notice. It's more likely that the current
behaviour would cause issues, so I'd rather have them consistent.
diff mbox series

Patch

diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
index 12e150e615b7..b37a28f62cf6 100644
--- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
+++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
@@ -8,10 +8,6 @@ 
  */
 void radix__flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
 void radix__local_flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
-extern unsigned long
-radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
-				unsigned long len, unsigned long pgoff,
-				unsigned long flags);
 
 extern void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
 						unsigned long addr, pte_t *ptep,
diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
index 23d3e08911d3..d2fb776febb4 100644
--- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
+++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
@@ -41,61 +41,6 @@  void radix__flush_hugetlb_tlb_range(struct vm_area_struct *vma, unsigned long st
 		radix__flush_tlb_range_psize(vma->vm_mm, start, end, psize);
 }
 
-/*
- * A vairant of hugetlb_get_unmapped_area doing topdown search
- * FIXME!! should we do as x86 does or non hugetlb area does ?
- * ie, use topdown or not based on mmap_is_legacy check ?
- */
-unsigned long
-radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
-				unsigned long len, unsigned long pgoff,
-				unsigned long flags)
-{
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma;
-	struct hstate *h = hstate_file(file);
-	int fixed = (flags & MAP_FIXED);
-	unsigned long high_limit;
-	struct vm_unmapped_area_info info;
-
-	high_limit = DEFAULT_MAP_WINDOW;
-	if (addr >= high_limit || (fixed && (addr + len > high_limit)))
-		high_limit = TASK_SIZE;
-
-	if (len & ~huge_page_mask(h))
-		return -EINVAL;
-	if (len > high_limit)
-		return -ENOMEM;
-
-	if (fixed) {
-		if (addr > high_limit - len)
-			return -ENOMEM;
-		if (prepare_hugepage_range(file, addr, len))
-			return -EINVAL;
-		return addr;
-	}
-
-	if (addr) {
-		addr = ALIGN(addr, huge_page_size(h));
-		vma = find_vma(mm, addr);
-		if (high_limit - len >= addr && addr >= mmap_min_addr &&
-		    (!vma || addr + len <= vm_start_gap(vma)))
-			return addr;
-	}
-	/*
-	 * We are always doing an topdown search here. Slice code
-	 * does that too.
-	 */
-	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
-	info.length = len;
-	info.low_limit = max(PAGE_SIZE, mmap_min_addr);
-	info.high_limit = mm->mmap_base + (high_limit - DEFAULT_MAP_WINDOW);
-	info.align_mask = PAGE_MASK & ~huge_page_mask(h);
-	info.align_offset = 0;
-
-	return vm_unmapped_area(&info);
-}
-
 void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
 					 unsigned long addr, pte_t *ptep,
 					 pte_t old_pte, pte_t pte)
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index f18b3a1d18f0..bfd7f4af1e58 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -553,11 +553,9 @@  unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 					unsigned long len, unsigned long pgoff,
 					unsigned long flags)
 {
-#ifdef CONFIG_PPC_RADIX_MMU
 	if (radix_enabled())
-		return radix__hugetlb_get_unmapped_area(file, addr, len,
+		return generic_hugetlb_get_unmapped_area(file, addr, len,
 						       pgoff, flags);
-#endif
 #ifdef CONFIG_PPC_64S_HASH_MMU
 	return slice_get_unmapped_area(addr, len, flags, file_to_psize(file), 1);
 #endif