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 6a72dc038b615229a1b285829d6c8378d15c2347 upstream.
When allocating VA space with a hint that crosses 128TB, the SLB addr_limit variable is not expanded if addr is not > 128TB, but the slice allocation looks at task_size, which is 512TB. This results in slice_check_fit() incorrectly succeeding because the slice_count truncates off bit 128 of the requested mask, so the comparison to the available mask succeeds.
Fix this by using mm->context.addr_limit instead of mm->task_size for testing allocation limits. This causes such allocations to fail.
Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Reported-by: Florian Weimer fweimer@redhat.com 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/slice.c | 50 +++++++++++++++++++++++------------------------- 1 file changed, 24 insertions(+), 26 deletions(-)
--- a/arch/powerpc/mm/slice.c +++ b/arch/powerpc/mm/slice.c @@ -96,7 +96,7 @@ static int slice_area_is_free(struct mm_ { struct vm_area_struct *vma;
- if ((mm->task_size - len) < addr) + if ((mm->context.addr_limit - len) < addr) return 0; vma = find_vma(mm, addr); return (!vma || (addr + len) <= vm_start_gap(vma)); @@ -133,7 +133,7 @@ static void slice_mask_for_free(struct m if (!slice_low_has_vma(mm, i)) ret->low_slices |= 1u << i;
- if (mm->task_size <= SLICE_LOW_TOP) + if (mm->context.addr_limit <= SLICE_LOW_TOP) return;
for (i = 0; i < GET_HIGH_SLICE_INDEX(mm->context.addr_limit); i++) @@ -412,25 +412,31 @@ unsigned long slice_get_unmapped_area(un struct slice_mask compat_mask; int fixed = (flags & MAP_FIXED); int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); + unsigned long page_size = 1UL << pshift; struct mm_struct *mm = current->mm; unsigned long newaddr; unsigned long high_limit;
- /* - * Check if we need to expland slice area. - */ - if (unlikely(addr >= mm->context.addr_limit && - mm->context.addr_limit != TASK_SIZE)) { - mm->context.addr_limit = TASK_SIZE; + high_limit = DEFAULT_MAP_WINDOW; + if (addr >= high_limit) + high_limit = TASK_SIZE; + + if (len > high_limit) + return -ENOMEM; + if (len & (page_size - 1)) + return -EINVAL; + if (fixed) { + if (addr & (page_size - 1)) + return -EINVAL; + if (addr > high_limit - len) + return -ENOMEM; + } + + if (high_limit > mm->context.addr_limit) { + mm->context.addr_limit = high_limit; on_each_cpu(slice_flush_segments, mm, 1); } - /* - * This mmap request can allocate upt to 512TB - */ - if (addr >= DEFAULT_MAP_WINDOW) - high_limit = mm->context.addr_limit; - else - high_limit = DEFAULT_MAP_WINDOW; + /* * init different masks */ @@ -446,27 +452,19 @@ unsigned long slice_get_unmapped_area(un
/* Sanity checks */ BUG_ON(mm->task_size == 0); + BUG_ON(mm->context.addr_limit == 0); VM_BUG_ON(radix_enabled());
slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize); slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d\n", addr, len, flags, topdown);
- if (len > mm->task_size) - return -ENOMEM; - if (len & ((1ul << pshift) - 1)) - return -EINVAL; - if (fixed && (addr & ((1ul << pshift) - 1))) - return -EINVAL; - if (fixed && addr > (mm->task_size - len)) - return -ENOMEM; - /* If hint, make sure it matches our alignment restrictions */ if (!fixed && addr) { - addr = _ALIGN_UP(addr, 1ul << pshift); + 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 > mm->task_size - len || + if (addr > high_limit - len || !slice_area_is_free(mm, addr, len)) addr = 0; }