4.14-stable review patch. If anyone has any objections, please let me know.
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From: Nicholas Piggin npiggin@gmail.com
commit 85e3f1adcb9d49300b0a943bb93f9604be375bfb upstream.
Radix VA space allocations test addresses against mm->task_size which is 512TB, even in cases where the intention is to limit allocation to below 128TB.
This results in mmap with a hint address below 128TB but address + length above 128TB succeeding when it should fail (as hash does after the previous patch).
Set the high address limit to be considered up front, and base subsequent allocation checks on that consistently.
Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Signed-off-by: Nicholas Piggin npiggin@gmail.com Reviewed-by: Aneesh Kumar K.V aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/mm/hugetlbpage-radix.c | 26 +++++++++++------ arch/powerpc/mm/mmap.c | 55 +++++++++++++++++++++--------------- 2 files changed, 50 insertions(+), 31 deletions(-)
--- a/arch/powerpc/mm/hugetlbpage-radix.c +++ b/arch/powerpc/mm/hugetlbpage-radix.c @@ -49,17 +49,28 @@ radix__hugetlb_get_unmapped_area(struct struct mm_struct *mm = current->mm; struct vm_area_struct *vma; struct hstate *h = hstate_file(file); + int fixed = (flags & MAP_FIXED); + unsigned long high_limit; struct vm_unmapped_area_info info;
- if (unlikely(addr > mm->context.addr_limit && addr < TASK_SIZE)) - mm->context.addr_limit = TASK_SIZE; + high_limit = DEFAULT_MAP_WINDOW; + if (addr >= high_limit || (fixed && (addr + len > high_limit))) + high_limit = TASK_SIZE;
if (len & ~huge_page_mask(h)) return -EINVAL; - if (len > mm->task_size) + if (len > high_limit) return -ENOMEM; + if (fixed) { + if (addr > high_limit - len) + return -ENOMEM; + }
- if (flags & MAP_FIXED) { + if (unlikely(addr > mm->context.addr_limit && + mm->context.addr_limit != TASK_SIZE)) + mm->context.addr_limit = TASK_SIZE; + + if (fixed) { if (prepare_hugepage_range(file, addr, len)) return -EINVAL; return addr; @@ -68,7 +79,7 @@ radix__hugetlb_get_unmapped_area(struct if (addr) { addr = ALIGN(addr, huge_page_size(h)); vma = find_vma(mm, addr); - if (mm->task_size - len >= addr && + if (high_limit - len >= addr && (!vma || addr + len <= vm_start_gap(vma))) return addr; } @@ -79,12 +90,9 @@ radix__hugetlb_get_unmapped_area(struct info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; info.low_limit = PAGE_SIZE; - info.high_limit = current->mm->mmap_base; + info.high_limit = mm->mmap_base + (high_limit - DEFAULT_MAP_WINDOW); info.align_mask = PAGE_MASK & ~huge_page_mask(h); info.align_offset = 0;
- if (addr > DEFAULT_MAP_WINDOW) - info.high_limit += mm->context.addr_limit - DEFAULT_MAP_WINDOW; - return vm_unmapped_area(&info); } --- a/arch/powerpc/mm/mmap.c +++ b/arch/powerpc/mm/mmap.c @@ -106,22 +106,32 @@ radix__arch_get_unmapped_area(struct fil { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; + int fixed = (flags & MAP_FIXED); + unsigned long high_limit; struct vm_unmapped_area_info info;
+ high_limit = DEFAULT_MAP_WINDOW; + if (addr >= high_limit || (fixed && (addr + len > high_limit))) + high_limit = TASK_SIZE; + + if (len > high_limit) + return -ENOMEM; + if (fixed) { + if (addr > high_limit - len) + return -ENOMEM; + } + if (unlikely(addr > mm->context.addr_limit && mm->context.addr_limit != TASK_SIZE)) mm->context.addr_limit = TASK_SIZE;
- if (len > mm->task_size - mmap_min_addr) - return -ENOMEM; - - if (flags & MAP_FIXED) + if (fixed) return addr;
if (addr) { addr = PAGE_ALIGN(addr); vma = find_vma(mm, addr); - if (mm->task_size - len >= addr && addr >= mmap_min_addr && + if (high_limit - len >= addr && addr >= mmap_min_addr && (!vma || addr + len <= vm_start_gap(vma))) return addr; } @@ -129,13 +139,9 @@ radix__arch_get_unmapped_area(struct fil info.flags = 0; info.length = len; info.low_limit = mm->mmap_base; + info.high_limit = high_limit; info.align_mask = 0;
- if (unlikely(addr > DEFAULT_MAP_WINDOW)) - info.high_limit = mm->context.addr_limit; - else - info.high_limit = DEFAULT_MAP_WINDOW; - return vm_unmapped_area(&info); }
@@ -149,37 +155,42 @@ radix__arch_get_unmapped_area_topdown(st struct vm_area_struct *vma; struct mm_struct *mm = current->mm; unsigned long addr = addr0; + int fixed = (flags & MAP_FIXED); + unsigned long high_limit; struct vm_unmapped_area_info info;
+ high_limit = DEFAULT_MAP_WINDOW; + if (addr >= high_limit || (fixed && (addr + len > high_limit))) + high_limit = TASK_SIZE; + + if (len > high_limit) + return -ENOMEM; + if (fixed) { + if (addr > high_limit - len) + return -ENOMEM; + } + if (unlikely(addr > mm->context.addr_limit && mm->context.addr_limit != TASK_SIZE)) mm->context.addr_limit = TASK_SIZE;
- /* requested length too big for entire address space */ - if (len > mm->task_size - mmap_min_addr) - return -ENOMEM; - - if (flags & MAP_FIXED) + if (fixed) return addr;
- /* requesting a specific address */ if (addr) { addr = PAGE_ALIGN(addr); vma = find_vma(mm, addr); - if (mm->task_size - len >= addr && addr >= mmap_min_addr && - (!vma || addr + len <= vm_start_gap(vma))) + if (high_limit - len >= addr && addr >= mmap_min_addr && + (!vma || addr + len <= vm_start_gap(vma))) return addr; }
info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; info.low_limit = max(PAGE_SIZE, mmap_min_addr); - info.high_limit = mm->mmap_base; + info.high_limit = mm->mmap_base + (high_limit - DEFAULT_MAP_WINDOW); info.align_mask = 0;
- if (addr > DEFAULT_MAP_WINDOW) - info.high_limit += mm->context.addr_limit - DEFAULT_MAP_WINDOW; - addr = vm_unmapped_area(&info); if (!(addr & ~PAGE_MASK)) return addr;