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x86/hugetlb: Adjust to the new native/compat mmap bases

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Commit 1b028f784e introduced two mmap() bases for 32-bit syscalls and for
64-bit syscalls. The mmap() code in x86 was modified to handle the
separation, but the patch series missed to update the hugetlb code.

As a consequence a 32bit application mapping a file on hugetlbfs uses the
64-bit mmap base for address space allocation, which fails.

Adjust the hugetlb mapping code to use the proper bases depending on the
syscall invocation mode (64-bit or compat).

[ tglx: Massaged changelog and switched from asm/compat.h to linux/compat.h ]

Fixes: commit 1b028f784e ("x86/mm: Introduce mmap_compat_base() for 32-bit mmap()")
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: 0x7f454c46@gmail.com
Cc: linux-mm@kvack.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20170314114126.9280-1-dsafonov@virtuozzo.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Dmitry Safonov 2017-03-14 14:41:26 +03:00 committed by Thomas Gleixner
parent 06c830a483
commit e13b73dd9c
4 changed files with 21 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/include/asm/elf.h
View File

@ -305,6 +305,7 @@ static inline int mmap_is_ia32(void)
extern unsigned long tasksize_32bit(void);
extern unsigned long tasksize_64bit(void);
extern unsigned long get_mmap_base(int is_legacy);
#ifdef CONFIG_X86_32

12
arch/x86/kernel/sys_x86_64.c
View File

@ -100,18 +100,6 @@ out:
return error;
}
static unsigned long get_mmap_base(int is_legacy)
{
struct mm_struct *mm = current->mm;
#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES
if (in_compat_syscall())
return is_legacy ? mm->mmap_compat_legacy_base
: mm->mmap_compat_base;
#endif
return is_legacy ? mm->mmap_legacy_base : mm->mmap_base;
}
static void find_start_end(unsigned long flags, unsigned long *begin,
unsigned long *end)
{

9
arch/x86/mm/hugetlbpage.c
View File

@ -12,10 +12,12 @@
#include <linux/pagemap.h>
#include <linux/err.h>
#include <linux/sysctl.h>
#include <linux/compat.h>
#include <asm/mman.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>
#include <asm/elf.h>
#if 0 /* This is just for testing */
struct page *
@ -82,8 +84,9 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
info.flags = 0;
info.length = len;
info.low_limit = current->mm->mmap_legacy_base;
info.high_limit = TASK_SIZE;
info.low_limit = get_mmap_base(1);
info.high_limit = in_compat_syscall() ?
tasksize_32bit() : tasksize_64bit();
info.align_mask = PAGE_MASK & ~huge_page_mask(h);
info.align_offset = 0;
return vm_unmapped_area(&info);
@ -100,7 +103,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
info.low_limit = PAGE_SIZE;
info.high_limit = current->mm->mmap_base;
info.high_limit = get_mmap_base(0);
info.align_mask = PAGE_MASK & ~huge_page_mask(h);
info.align_offset = 0;
addr = vm_unmapped_area(&info);

14
arch/x86/mm/mmap.c
View File

@ -30,6 +30,7 @@
#include <linux/limits.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/compat.h>
#include <asm/elf.h>
struct va_alignment __read_mostly va_align = {
@ -153,6 +154,19 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
#endif
}
unsigned long get_mmap_base(int is_legacy)
{
struct mm_struct *mm = current->mm;
#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES
if (in_compat_syscall()) {
return is_legacy ? mm->mmap_compat_legacy_base
: mm->mmap_compat_base;
}
#endif
return is_legacy ? mm->mmap_legacy_base : mm->mmap_base;
}
const char *arch_vma_name(struct vm_area_struct *vma)
{
if (vma->vm_flags & VM_MPX)