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    Subject[PATCH v11 11/14] uprobes, arm64: untag user pointers in find_active_uprobe
    From
    This patch is a part of a series that extends arm64 kernel ABI to allow to
    pass tagged user pointers (with the top byte set to something else other
    than 0x00) as syscall arguments.

    find_active_uprobe() uses provided user pointer (obtained via
    instruction_pointer(regs)) for vma lookups, which can only by done with
    untagged pointers.

    Untag the user pointer in this function.

    Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
    ---
    kernel/events/uprobes.c | 2 ++
    1 file changed, 2 insertions(+)

    diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
    index c5cde87329c7..d3a2716a813a 100644
    --- a/kernel/events/uprobes.c
    +++ b/kernel/events/uprobes.c
    @@ -1992,6 +1992,8 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
    struct uprobe *uprobe = NULL;
    struct vm_area_struct *vma;

    + bp_vaddr = untagged_addr(bp_vaddr);
    +
    down_read(&mm->mmap_sem);
    vma = find_vma(mm, bp_vaddr);
    if (vma && vma->vm_start <= bp_vaddr) {
    --
    2.21.0.360.g471c308f928-goog
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