Messages in this thread | | | From | Alex Ghiti <> | Subject | Re: [PATCH RESEND 6/8] parisc: Use mmap_base, not mmap_legacy_base, as low_limit for bottom-up mmap | Date | Wed, 26 Jun 2019 01:20:51 -0400 |
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On 6/25/19 10:09 AM, Helge Deller wrote: > On 20.06.19 07:03, Alexandre Ghiti wrote: >> Bottom-up mmap scheme is used twice: >> >> - for legacy mode, in which mmap_legacy_base and mmap_base are equal. >> >> - in case of mmap failure in top-down mode, where 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. >> >> Then this commit removes the usage of mmap_legacy_base field from parisc >> code. >> >> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> > Boot-tested on parisc and seems to work nicely, thus: > > Acked-by: Helge Deller <deller@gmx.de>
Thanks Helge,
Alex
> > Helge > > > >> --- >> arch/parisc/kernel/sys_parisc.c | 8 +++----- >> 1 file changed, 3 insertions(+), 5 deletions(-) >> >> diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c >> index 5d458a44b09c..e987f3a8eb0b 100644 >> --- a/arch/parisc/kernel/sys_parisc.c >> +++ b/arch/parisc/kernel/sys_parisc.c >> @@ -119,7 +119,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, >> >> info.flags = 0; >> info.length = len; >> - info.low_limit = mm->mmap_legacy_base; >> + info.low_limit = mm->mmap_base; >> info.high_limit = mmap_upper_limit(NULL); >> info.align_mask = last_mmap ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0; >> info.align_offset = shared_align_offset(last_mmap, pgoff); >> @@ -240,13 +240,11 @@ static unsigned long mmap_legacy_base(void) >> */ >> void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) >> { >> - mm->mmap_legacy_base = mmap_legacy_base(); >> - mm->mmap_base = mmap_upper_limit(rlim_stack); >> - >> if (mmap_is_legacy()) { >> - mm->mmap_base = mm->mmap_legacy_base; >> + mm->mmap_base = mmap_legacy_base(); >> mm->get_unmapped_area = arch_get_unmapped_area; >> } else { >> + mm->mmap_base = mmap_upper_limit(rlim_stack); >> mm->get_unmapped_area = arch_get_unmapped_area_topdown; >> } >> } >>
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