3.16.70-rc1 review patch. If anyone has any objections, please let me know.
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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 [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- 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 @@ -30,6 +30,7 @@ #include <linux/err.h> #include <linux/spinlock.h> #include <linux/export.h> +#include <linux/security.h> #include <asm/mman.h> #include <asm/mmu.h> #include <asm/spu.h> @@ -313,6 +314,7 @@ 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; @@ -320,7 +322,7 @@ static unsigned long slice_find_area_top info.align_offset = 0;
addr = mm->mmap_base; - while (addr > PAGE_SIZE) { + while (addr > min_addr) { info.high_limit = addr; if (!slice_scan_available(addr - 1, available, 0, &addr)) continue; @@ -332,8 +334,8 @@ 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; @@ -415,7 +417,7 @@ unsigned long slice_get_unmapped_area(un addr = _ALIGN_UP(addr, 1ul << pshift); slice_dbg(" aligned addr=%lx\n", addr); /* Ignore hint if it's too large or overlaps a VMA */ - if (addr > mm->task_size - len || + if (addr > mm->task_size - len || addr < mmap_min_addr || !slice_area_is_free(mm, addr, len)) addr = 0; }