| Message ID | 8b82565b407d04b6e6c4a564423a4e68bde6e39d.1649523076.git.christophe.leroy@csgroup.eu (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Convert powerpc to default topdown mmap layout (v10) | expand |
Le 09/04/2022 à 19:17, Christophe Leroy a écrit : > This is a complement of f6795053dac8 ("mm: mmap: Allow for "high" > userspace addresses") for hugetlb. > > This patch adds support for "high" userspace addresses that are > optionally supported on the system and have to be requested via a hint > mechanism ("high" addr parameter to mmap). > > Architectures such as powerpc and x86 achieve this by making changes to > their architectural versions of hugetlb_get_unmapped_area() function. > However, arm64 uses the generic version of that function. > > So take into account arch_get_mmap_base() and arch_get_mmap_end() in > hugetlb_get_unmapped_area(). To allow that, move those two macros > out of mm/mmap.c into include/linux/sched/mm.h > > If these macros are not defined in architectural code then they default > to (TASK_SIZE) and (base) so should not introduce any behavioural > changes to architectures that do not define them. > > For the time being, only ARM64 is affected by this change. > > From Catalin (ARM64): > 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. > > Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> > Cc: Steve Capper <steve.capper@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Fixes: f6795053dac8 ("mm: mmap: Allow for "high" userspace addresses") > Cc: <stable@vger.kernel.org> # 5.0.x > Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> > Acked-by: Andrew Morton <akpm@linux-foundation.org> This patch was merged in 5.18-rc4 See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5f24d5a579d1eace79d505b148808a850b417d4c The rest of the series is to be merged via powerpc tree. > --- > v10: > - Moved as first patch of the series so that it can be applied > separately as a flag and be easily applied back on stable. > - Added text from Catalin explaining why it is a fixup. > --- > fs/hugetlbfs/inode.c | 9 +++++---- > include/linux/sched/mm.h | 8 ++++++++ > mm/mmap.c | 8 -------- > 3 files changed, 13 insertions(+), 12 deletions(-) > > diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c > index 99c7477cee5c..dd3a088db11d 100644 > --- a/fs/hugetlbfs/inode.c > +++ b/fs/hugetlbfs/inode.c > @@ -206,7 +206,7 @@ hugetlb_get_unmapped_area_bottomup(struct file *file, unsigned long addr, > info.flags = 0; > info.length = len; > info.low_limit = current->mm->mmap_base; > - info.high_limit = TASK_SIZE; > + info.high_limit = arch_get_mmap_end(addr); > info.align_mask = PAGE_MASK & ~huge_page_mask(h); > info.align_offset = 0; > return vm_unmapped_area(&info); > @@ -222,7 +222,7 @@ hugetlb_get_unmapped_area_topdown(struct file *file, unsigned long addr, > info.flags = VM_UNMAPPED_AREA_TOPDOWN; > info.length = len; > info.low_limit = max(PAGE_SIZE, mmap_min_addr); > - info.high_limit = current->mm->mmap_base; > + info.high_limit = arch_get_mmap_base(addr, current->mm->mmap_base); > info.align_mask = PAGE_MASK & ~huge_page_mask(h); > info.align_offset = 0; > addr = vm_unmapped_area(&info); > @@ -237,7 +237,7 @@ hugetlb_get_unmapped_area_topdown(struct file *file, unsigned long addr, > VM_BUG_ON(addr != -ENOMEM); > info.flags = 0; > info.low_limit = current->mm->mmap_base; > - info.high_limit = TASK_SIZE; > + info.high_limit = arch_get_mmap_end(addr); > addr = vm_unmapped_area(&info); > } > > @@ -251,6 +251,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr, > struct mm_struct *mm = current->mm; > struct vm_area_struct *vma; > struct hstate *h = hstate_file(file); > + const unsigned long mmap_end = arch_get_mmap_end(addr); > > if (len & ~huge_page_mask(h)) > return -EINVAL; > @@ -266,7 +267,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr, > if (addr) { > addr = ALIGN(addr, huge_page_size(h)); > vma = find_vma(mm, addr); > - if (TASK_SIZE - len >= addr && > + if (mmap_end - len >= addr && > (!vma || addr + len <= vm_start_gap(vma))) > return addr; > } > diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h > index a80356e9dc69..1ad1f4bfa025 100644 > --- a/include/linux/sched/mm.h > +++ b/include/linux/sched/mm.h > @@ -136,6 +136,14 @@ static inline void mm_update_next_owner(struct mm_struct *mm) > #endif /* CONFIG_MEMCG */ > > #ifdef CONFIG_MMU > +#ifndef arch_get_mmap_end > +#define arch_get_mmap_end(addr) (TASK_SIZE) > +#endif > + > +#ifndef arch_get_mmap_base > +#define arch_get_mmap_base(addr, base) (base) > +#endif > + > extern void arch_pick_mmap_layout(struct mm_struct *mm, > struct rlimit *rlim_stack); > extern unsigned long > diff --git a/mm/mmap.c b/mm/mmap.c > index 3aa839f81e63..313b57d55a63 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -2117,14 +2117,6 @@ unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info) > return addr; > } > > -#ifndef arch_get_mmap_end > -#define arch_get_mmap_end(addr) (TASK_SIZE) > -#endif > - > -#ifndef arch_get_mmap_base > -#define arch_get_mmap_base(addr, base) (base) > -#endif > - > /* Get an address range which is currently unmapped. > * For shmat() with addr=0. > *
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 99c7477cee5c..dd3a088db11d 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -206,7 +206,7 @@ hugetlb_get_unmapped_area_bottomup(struct file *file, unsigned long addr, info.flags = 0; info.length = len; info.low_limit = current->mm->mmap_base; - info.high_limit = TASK_SIZE; + info.high_limit = arch_get_mmap_end(addr); info.align_mask = PAGE_MASK & ~huge_page_mask(h); info.align_offset = 0; return vm_unmapped_area(&info); @@ -222,7 +222,7 @@ hugetlb_get_unmapped_area_topdown(struct file *file, unsigned long addr, info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; info.low_limit = max(PAGE_SIZE, mmap_min_addr); - info.high_limit = current->mm->mmap_base; + info.high_limit = arch_get_mmap_base(addr, current->mm->mmap_base); info.align_mask = PAGE_MASK & ~huge_page_mask(h); info.align_offset = 0; addr = vm_unmapped_area(&info); @@ -237,7 +237,7 @@ hugetlb_get_unmapped_area_topdown(struct file *file, unsigned long addr, VM_BUG_ON(addr != -ENOMEM); info.flags = 0; info.low_limit = current->mm->mmap_base; - info.high_limit = TASK_SIZE; + info.high_limit = arch_get_mmap_end(addr); addr = vm_unmapped_area(&info); } @@ -251,6 +251,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr, struct mm_struct *mm = current->mm; struct vm_area_struct *vma; struct hstate *h = hstate_file(file); + const unsigned long mmap_end = arch_get_mmap_end(addr); if (len & ~huge_page_mask(h)) return -EINVAL; @@ -266,7 +267,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr, if (addr) { addr = ALIGN(addr, huge_page_size(h)); vma = find_vma(mm, addr); - if (TASK_SIZE - len >= addr && + if (mmap_end - len >= addr && (!vma || addr + len <= vm_start_gap(vma))) return addr; } diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index a80356e9dc69..1ad1f4bfa025 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -136,6 +136,14 @@ static inline void mm_update_next_owner(struct mm_struct *mm) #endif /* CONFIG_MEMCG */ #ifdef CONFIG_MMU +#ifndef arch_get_mmap_end +#define arch_get_mmap_end(addr) (TASK_SIZE) +#endif + +#ifndef arch_get_mmap_base +#define arch_get_mmap_base(addr, base) (base) +#endif + extern void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack); extern unsigned long diff --git a/mm/mmap.c b/mm/mmap.c index 3aa839f81e63..313b57d55a63 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2117,14 +2117,6 @@ unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info) return addr; } -#ifndef arch_get_mmap_end -#define arch_get_mmap_end(addr) (TASK_SIZE) -#endif - -#ifndef arch_get_mmap_base -#define arch_get_mmap_base(addr, base) (base) -#endif - /* Get an address range which is currently unmapped. * For shmat() with addr=0. *
This is a complement of f6795053dac8 ("mm: mmap: Allow for "high" userspace addresses") for hugetlb. This patch adds support for "high" userspace addresses that are optionally supported on the system and have to be requested via a hint mechanism ("high" addr parameter to mmap). Architectures such as powerpc and x86 achieve this by making changes to their architectural versions of hugetlb_get_unmapped_area() function. However, arm64 uses the generic version of that function. So take into account arch_get_mmap_base() and arch_get_mmap_end() in hugetlb_get_unmapped_area(). To allow that, move those two macros out of mm/mmap.c into include/linux/sched/mm.h If these macros are not defined in architectural code then they default to (TASK_SIZE) and (base) so should not introduce any behavioural changes to architectures that do not define them. For the time being, only ARM64 is affected by this change. From Catalin (ARM64): 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. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Steve Capper <steve.capper@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Fixes: f6795053dac8 ("mm: mmap: Allow for "high" userspace addresses") Cc: <stable@vger.kernel.org> # 5.0.x Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> --- v10: - Moved as first patch of the series so that it can be applied separately as a flag and be easily applied back on stable. - Added text from Catalin explaining why it is a fixup. --- fs/hugetlbfs/inode.c | 9 +++++---- include/linux/sched/mm.h | 8 ++++++++ mm/mmap.c | 8 -------- 3 files changed, 13 insertions(+), 12 deletions(-)