[PATCH v3 2/9] arch/s390: Teach arch_get_unmapped_area{_topdown} to handle hugetlb mappings

From: Oscar Salvador
Date: Tue Sep 10 2024 - 04:01:06 EST


We want to stop special casing hugetlb mappings and make them go
through generic channels, so teach arch_get_unmapped_area{_topdown}
to handle those.
s390 specific hugetlb function does not set info.align_offset, so do
the same here for compatibility.

Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
---
arch/s390/mm/mmap.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index 96efa061ce01..33f3504be90b 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -17,6 +17,7 @@
#include <linux/random.h>
#include <linux/compat.h>
#include <linux/security.h>
+#include <linux/hugetlb.h>
#include <asm/elf.h>

static unsigned long stack_maxrandom_size(void)
@@ -73,6 +74,8 @@ static inline unsigned long mmap_base(unsigned long rnd,

static int get_align_mask(struct file *filp, unsigned long flags)
{
+ if (filp && is_file_hugepages(filp))
+ return huge_page_mask_align(filp);
if (!(current->flags & PF_RANDOMIZE))
return 0;
if (filp || (flags & MAP_SHARED))
@@ -106,7 +109,8 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
info.low_limit = mm->mmap_base;
info.high_limit = TASK_SIZE;
info.align_mask = get_align_mask(filp, flags);
- info.align_offset = pgoff << PAGE_SHIFT;
+ if (!(filp && is_file_hugepages(filp)))
+ info.align_offset = pgoff << PAGE_SHIFT;
addr = vm_unmapped_area(&info);
if (offset_in_page(addr))
return addr;
@@ -144,7 +148,8 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long ad
info.low_limit = PAGE_SIZE;
info.high_limit = mm->mmap_base;
info.align_mask = get_align_mask(filp, flags);
- info.align_offset = pgoff << PAGE_SHIFT;
+ if (!(filp && is_file_hugepages(filp)))
+ info.align_offset = pgoff << PAGE_SHIFT;
addr = vm_unmapped_area(&info);

/*
--
2.46.0