Commit e13b73dd authored by Dmitry Safonov's avatar Dmitry Safonov Committed by Thomas Gleixner
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x86/hugetlb: Adjust to the new native/compat mmap bases 



Commit 1b028f78 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 1b028f78 ("x86/mm: Introduce mmap_compat_base() for 32-bit mmap()")
Reported-by: default avatarkernel test robot <xiaolong.ye@intel.com>
Signed-off-by: default avatarDmitry 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: default avatarThomas Gleixner <tglx@linutronix.de>
parent 06c830a4

arch/x86/include/asm/elf.h

+1 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/kernel/sys_x86_64.c

+0 −12
Original line number Diff line number Diff line
@@ -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)

{

arch/x86/mm/hugetlbpage.c

+6 −3
Original line number Diff line number Diff line
@@ -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);

arch/x86/mm/mmap.c

+14 −0
Original line number Diff line number Diff line
@@ -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)

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