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    SubjectRe: [PATCH] lkdtm: avoid printk() in recursive_loop()
    On Thu, Dec 16, 2021 at 12:16:19PM +0100, Ard Biesheuvel wrote:
    > On Thu, 7 Oct 2021 at 18:59, Kees Cook <keescook@chromium.org> wrote:
    > >
    > > On Thu, 7 Oct 2021 10:12:35 +0200, Ard Biesheuvel wrote:
    > > > The recursive_loop() function is intended as a diagnostic to ensure that
    > > > exhausting the stack is caught and mitigated. Currently, it uses
    > > > pr_info() to ensure that the function has side effects that the compiler
    > > > cannot simply optimize away, so that the stack footprint does not get
    > > > reduced inadvertently.
    > > >
    > > > The typical mitigation for stack overflow is to kill the task, and this
    > > > overflow may occur inside the call to pr_info(), which means it could be
    > > > holding the console lock when this happens. This means that the console
    > > > lock is never going to be released again, preventing the diagnostic
    > > > prints related to the stack overflow handling from being visible on the
    > > > console.
    > > >
    > > > [...]
    > >
    > > Applied to for-next/lkdtm, thanks!
    > >
    > > [1/1] lkdtm: avoid printk() in recursive_loop()
    > > https://git.kernel.org/kees/c/700fa7d22233
    > >
    >
    > Ping?

    Eek, I didn't send my -next pull to Greg yet. Done now; thanks for the
    ping! :)

    -Kees

    --
    Kees Cook

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