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c453db6cd9
Commit 1be7107fbe ("mm: larger stack guard gap, between vmas") fixed
up all architectures to deal with the stack guard gap. But when nds32
was added to the tree, it forgot to do the same thing.
Resolve this by properly fixing up the nsd32's version of
arch_get_unmapped_area()
Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Qiang Liu <cyruscyliu@gmail.com>
Cc: stable <stable@vger.kernel.org>
Reported-by: iLifetruth <yixiaonn@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Link: https://lore.kernel.org/r/20210629104024.2293615-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
73 lines
1.8 KiB
C
73 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2005-2017 Andes Technology Corporation
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#include <linux/sched.h>
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#include <linux/mman.h>
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#include <linux/shm.h>
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#define COLOUR_ALIGN(addr,pgoff) \
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((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \
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(((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
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/*
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* We need to ensure that shared mappings are correctly aligned to
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* avoid aliasing issues with VIPT caches. We need to ensure that
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* a specific page of an object is always mapped at a multiple of
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* SHMLBA bytes.
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*
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* We unconditionally provide this function for all cases, however
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* in the VIVT case, we optimise out the alignment rules.
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*/
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unsigned long
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arch_get_unmapped_area(struct file *filp, unsigned long addr,
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unsigned long len, unsigned long pgoff,
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unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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int do_align = 0;
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struct vm_unmapped_area_info info;
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int aliasing = 0;
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if(IS_ENABLED(CONFIG_CPU_CACHE_ALIASING))
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aliasing = 1;
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/*
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* We only need to do colour alignment if either the I or D
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* caches alias.
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*/
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if (aliasing)
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do_align = filp || (flags & MAP_SHARED);
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/*
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* We enforce the MAP_FIXED case.
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*/
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if (flags & MAP_FIXED) {
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if (aliasing && flags & MAP_SHARED &&
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(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
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return -EINVAL;
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return addr;
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}
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if (len > TASK_SIZE)
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return -ENOMEM;
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if (addr) {
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if (do_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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else
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr &&
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(!vma || addr + len <= vm_start_gap(vma)))
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return addr;
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}
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info.flags = 0;
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info.length = len;
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info.low_limit = mm->mmap_base;
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info.high_limit = TASK_SIZE;
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info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
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info.align_offset = pgoff << PAGE_SHIFT;
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return vm_unmapped_area(&info);
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}
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