Re: [tip:x86/urgent] x86/dumpstack: Avoid uninitlized variable

From: Arnd Bergmann
Date: Mon Feb 05 2018 - 16:21:20 EST


On Fri, Feb 2, 2018 at 11:36 PM, tip-bot for Arnd Bergmann
<tipbot@xxxxxxxxx> wrote:
> Commit-ID: ebfc15019cfa72496c674ffcb0b8ef10790dcddc
> Gitweb: https://git.kernel.org/tip/ebfc15019cfa72496c674ffcb0b8ef10790dcddc
> Author: Arnd Bergmann <arnd@xxxxxxxx>
> AuthorDate: Fri, 2 Feb 2018 15:56:17 +0100
> Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> CommitDate: Fri, 2 Feb 2018 23:33:50 +0100
>
> x86/dumpstack: Avoid uninitlized variable
>
> In some configurations, 'partial' does not get initialized, as shown by
> this gcc-8 warning:
>
> arch/x86/kernel/dumpstack.c: In function 'show_trace_log_lvl':
> arch/x86/kernel/dumpstack.c:156:4: error: 'partial' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> show_regs_if_on_stack(&stack_info, regs, partial);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> This initializes it to false, to get the previous behavior in this case.
>
> Fixes: a9cdbe72c4e8 ("x86/dumpstack: Fix partial register dumps")


I just noticed my annotation got lost when I sent the patch. I originally
meant to ask Josh to double-check whether it should be 'false' or 'true'
here, or if we maybe need a larger change.

Josh, could you take a look? Unfortunately I did not really understand
your original commit, so I don't know what the safe choice is here
in those cases in which 'partial' is uninitialized.

Arnd