ARM: fix booting low-vectors machines

commit d8aa712c30148ba26fd89a5dc14de95d4c375184 upstream.

Commit f6f91b0d9fd9 (ARM: allow kuser helpers to be removed from the
vector page) required two pages for the vectors code.  Although the
code setting up the initial page tables was updated, the code which
allocates page tables for new processes wasn't, neither was the code
which tears down the mappings.  Fix this.

Fixes: f6f91b0d9fd9 ("ARM: allow kuser helpers to be removed from the vector page")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 9bcd262a900842dfc685991511d4850fb3601ff5..5aac06fcc97e43e80ad8ac568a04f41f3198a5a6 100644 (file)
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -58,7 +58,7 @@ extern void __pgd_error(const char *file, int line, pgd_t);
  * mapping to be mapped at.  This is particularly important for
  * non-high vector CPUs.
  */
-#define FIRST_USER_ADDRESS     PAGE_SIZE
+#define FIRST_USER_ADDRESS     (PAGE_SIZE * 2)
 
 /*
  * Use TASK_SIZE as the ceiling argument for free_pgtables() and

diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index 10062ceadd1cc40ca48cc59e83f2deb6fc3e07da..f0ef2f7d4ad7d30ace5c3299d77732287217d5f8 100644 (file)
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -146,7 +146,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 
        info.flags = VM_UNMAPPED_AREA_TOPDOWN;
        info.length = len;
-       info.low_limit = PAGE_SIZE;
+       info.low_limit = FIRST_USER_ADDRESS;
        info.high_limit = mm->mmap_base;
        info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
        info.align_offset = pgoff << PAGE_SHIFT;

diff --git a/arch/arm/mm/pgd.c b/arch/arm/mm/pgd.c
index 0acb089d0f70db818ce487fa67b0fb90b1b0b69d..1046b373d1aedb2823e3bb62f106681f9b63fc2a 100644 (file)
--- a/arch/arm/mm/pgd.c
+++ b/arch/arm/mm/pgd.c
@@ -87,7 +87,8 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
                init_pud = pud_offset(init_pgd, 0);
                init_pmd = pmd_offset(init_pud, 0);
                init_pte = pte_offset_map(init_pmd, 0);
-               set_pte_ext(new_pte, *init_pte, 0);
+               set_pte_ext(new_pte + 0, init_pte[0], 0);
+               set_pte_ext(new_pte + 1, init_pte[1], 0);
                pte_unmap(init_pte);
                pte_unmap(new_pte);
        }