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

Commit 1b028f784e8c 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 1b028f784e8c ("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>

diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index ac5be5ba8527921a55cf998c0b3f0f899a737e2e..d4d3ed456cb7b1559a8aa3da27e355269ada35a1 100644 (file)
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -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
 

diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index 63e89dfc808a6054addf05070f2a0ec70de89039..207b8f2582c75b7c80a882ffc92a720071c8277e 100644 (file)
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -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)
 {

diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index c5066a260803d4b6b3a91ef56df9220be57db539..302f43fd9c28c6d14652981d672569d57e3dea35 100644 (file)
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -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);

diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index 529ab79800afdbe3cc551e1f3c124684227e38b8..19ad095b41dfc823f6107bf1ee822fcecd56a74b 100644 (file)
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -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)