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    Subject[PATCH 39/64] arch/m68k: use mm locking wrappers
    Date
    From: Davidlohr Bueso <dave@stgolabs.net>

    This becomes quite straightforward with the mmrange in place.

    Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
    ---
    arch/m68k/kernel/sys_m68k.c | 18 +++++++++++-------
    arch/m68k/mm/fault.c | 8 ++++----
    2 files changed, 15 insertions(+), 11 deletions(-)

    diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c
    index 27e10af5153a..d151bd19385c 100644
    --- a/arch/m68k/kernel/sys_m68k.c
    +++ b/arch/m68k/kernel/sys_m68k.c
    @@ -378,6 +378,7 @@ asmlinkage int
    sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
    {
    int ret = -EINVAL;
    + DEFINE_RANGE_LOCK_FULL(mmrange);

    if (scope < FLUSH_SCOPE_LINE || scope > FLUSH_SCOPE_ALL ||
    cache & ~FLUSH_CACHE_BOTH)
    @@ -399,7 +400,7 @@ sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
    * Verify that the specified address region actually belongs
    * to this process.
    */
    - down_read(&current->mm->mmap_sem);
    + mm_read_lock(current->mm, &mmrange);
    vma = find_vma(current->mm, addr);
    if (!vma || addr < vma->vm_start || addr + len > vma->vm_end)
    goto out_unlock;
    @@ -450,7 +451,7 @@ sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
    }
    }
    out_unlock:
    - up_read(&current->mm->mmap_sem);
    + mm_read_unlock(current->mm, &mmrange);
    out:
    return ret;
    }
    @@ -461,6 +462,8 @@ asmlinkage int
    sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
    unsigned long __user * mem)
    {
    + DEFINE_RANGE_LOCK_FULL(mmrange);
    +
    /* This was borrowed from ARM's implementation. */
    for (;;) {
    struct mm_struct *mm = current->mm;
    @@ -470,7 +473,7 @@ sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
    spinlock_t *ptl;
    unsigned long mem_value;

    - down_read(&mm->mmap_sem);
    + mm_read_lock(mm, &mmrange);
    pgd = pgd_offset(mm, (unsigned long)mem);
    if (!pgd_present(*pgd))
    goto bad_access;
    @@ -493,11 +496,11 @@ sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
    __put_user(newval, mem);

    pte_unmap_unlock(pte, ptl);
    - up_read(&mm->mmap_sem);
    + mm_read_unlock(mm, &mmrange);
    return mem_value;

    bad_access:
    - up_read(&mm->mmap_sem);
    + mm_read_unlock(mm, &mmrange);
    /* This is not necessarily a bad access, we can get here if
    a memory we're trying to write to should be copied-on-write.
    Make the kernel do the necessary page stuff, then re-iterate.
    @@ -536,14 +539,15 @@ sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
    {
    struct mm_struct *mm = current->mm;
    unsigned long mem_value;
    + DEFINE_RANGE_LOCK_FULL(mmrange);

    - down_read(&mm->mmap_sem);
    + mm_read_lock(mm, &mmrange);

    mem_value = *mem;
    if (mem_value == oldval)
    *mem = newval;

    - up_read(&mm->mmap_sem);
    + mm_read_unlock(mm, &mmrange);
    return mem_value;
    }

    diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c
    index ec32a193726f..426d22924852 100644
    --- a/arch/m68k/mm/fault.c
    +++ b/arch/m68k/mm/fault.c
    @@ -90,7 +90,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
    if (user_mode(regs))
    flags |= FAULT_FLAG_USER;
    retry:
    - down_read(&mm->mmap_sem);
    + mm_read_lock(mm, &mmrange);

    vma = find_vma(mm, address);
    if (!vma)
    @@ -181,7 +181,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
    }
    }

    - up_read(&mm->mmap_sem);
    + mm_read_unlock(mm, &mmrange);
    return 0;

    /*
    @@ -189,7 +189,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
    * us unable to handle the page fault gracefully.
    */
    out_of_memory:
    - up_read(&mm->mmap_sem);
    + mm_read_unlock(mm, &mmrange);
    if (!user_mode(regs))
    goto no_context;
    pagefault_out_of_memory();
    @@ -218,6 +218,6 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
    current->thread.faddr = address;

    send_sig:
    - up_read(&mm->mmap_sem);
    + mm_read_unlock(mm, &mmrange);
    return send_fault_sig(regs);
    }
    --
    2.13.6
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