linux-kernel - [PATCH v4 2/8] hugetlbfs: Use arch_get_mmap

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Message-Id: <20210430203757.47653-1-amanieu@gmail.com>
Date:   Fri, 30 Apr 2021 21:37:51 +0100
From:   Amanieu d'Antras <amanieu@...il.com>
To:     unlisted-recipients:; (no To-header on input)
Cc:     Amanieu d'Antras <amanieu@...il.com>,
        Ryan Houdek <Houdek.Ryan@...-emu.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Steven Price <steven.price@....com>,
        Arnd Bergmann <arnd@...nel.org>,
        David Laight <David.Laight@...lab.com>,
        Mark Brown <broonie@...nel.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH v4 2/8] hugetlbfs: Use arch_get_mmap_* macros

hugetlb_get_unmapped_area should obey the same arch-specific constraints
as mmap when selecting an address.

Signed-off-by: Amanieu d'Antras <amanieu@...il.com>
Co-developed-by: Ryan Houdek <Houdek.Ryan@...-emu.org>
Signed-off-by: Ryan Houdek <Houdek.Ryan@...-emu.org>
---
 fs/hugetlbfs/inode.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 701c82c36138..526ccb524329 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -191,6 +191,18 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
  */
 
 #ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
+#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)		(current->mm->mmap_base)
+#endif
+
+#ifndef arch_get_mmap_base_topdown
+#define arch_get_mmap_base_topdown(addr)	(current->mm->mmap_base)
+#endif
+
 static unsigned long
 hugetlb_get_unmapped_area_bottomup(struct file *file, unsigned long addr,
 		unsigned long len, unsigned long pgoff, unsigned long flags)
@@ -200,8 +212,8 @@ 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.low_limit = arch_get_mmap_base(addr);
+	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);
@@ -217,7 +229,7 @@ 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_topdown(addr);
 	info.align_mask = PAGE_MASK & ~huge_page_mask(h);
 	info.align_offset = 0;
 	addr = vm_unmapped_area(&info);
@@ -231,8 +243,8 @@ hugetlb_get_unmapped_area_topdown(struct file *file, unsigned long addr,
 	if (unlikely(offset_in_page(addr))) {
 		VM_BUG_ON(addr != -ENOMEM);
 		info.flags = 0;
-		info.low_limit = current->mm->mmap_base;
-		info.high_limit = TASK_SIZE;
+		info.low_limit = arch_get_mmap_base(addr);
+		info.high_limit = arch_get_mmap_end(addr);
 		addr = vm_unmapped_area(&info);
 	}
 
-- 
2.31.1