From: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com
commit 3b4d07d2674f6b4a9281031f99d1f7efd325b16d upstream.
When doing top-down search the low_limit is not PAGE_SIZE but rather max(PAGE_SIZE, mmap_min_addr). This handle cases in which mmap_min_addr > PAGE_SIZE.
Fixes: fba2369e6ceb ("mm: use vm_unmapped_area() on powerpc architecture") Reviewed-by: Laurent Dufour ldufour@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V aneesh.kumar@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/mm/slice.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
--- a/arch/powerpc/mm/slice.c +++ b/arch/powerpc/mm/slice.c @@ -31,6 +31,7 @@ #include <linux/spinlock.h> #include <linux/export.h> #include <linux/hugetlb.h> +#include <linux/security.h> #include <asm/mman.h> #include <asm/mmu.h> #include <asm/copro.h> @@ -328,6 +329,7 @@ static unsigned long slice_find_area_top int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); unsigned long addr, found, prev; struct vm_unmapped_area_info info; + unsigned long min_addr = max(PAGE_SIZE, mmap_min_addr);
info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; @@ -344,7 +346,7 @@ static unsigned long slice_find_area_top if (high_limit > DEFAULT_MAP_WINDOW) addr += mm->context.addr_limit - DEFAULT_MAP_WINDOW;
- while (addr > PAGE_SIZE) { + while (addr > min_addr) { info.high_limit = addr; if (!slice_scan_available(addr - 1, available, 0, &addr)) continue; @@ -356,8 +358,8 @@ static unsigned long slice_find_area_top * Check if we need to reduce the range, or if we can * extend it to cover the previous available slice. */ - if (addr < PAGE_SIZE) - addr = PAGE_SIZE; + if (addr < min_addr) + addr = min_addr; else if (slice_scan_available(addr - 1, available, 0, &prev)) { addr = prev; goto prev_slice; @@ -479,7 +481,7 @@ unsigned long slice_get_unmapped_area(un addr = _ALIGN_UP(addr, page_size); slice_dbg(" aligned addr=%lx\n", addr); /* Ignore hint if it's too large or overlaps a VMA */ - if (addr > high_limit - len || + if (addr > high_limit - len || addr < mmap_min_addr || !slice_area_is_free(mm, addr, len)) addr = 0; }