Messages in this thread | | | Date | Mon, 24 Feb 2020 13:58:58 +0100 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH] ppdev: Distribute switch variables for initialization |
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On Mon, Feb 24, 2020 at 12:34:12PM +0000, Sudip Mukherjee wrote: > On Wed, Feb 19, 2020 at 10:23:11PM -0800, Kees Cook wrote: > > Variables declared in a switch statement before any case statements > > cannot be automatically initialized with compiler instrumentation (as > > they are not part of any execution flow). With GCC's proposed automatic > > stack variable initialization feature, this triggers a warning (and they > > don't get initialized). Clang's automatic stack variable initialization > > (via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also > > doesn't initialize such variables[1]. Note that these warnings (or silent > > skipping) happen before the dead-store elimination optimization phase, > > so even when the automatic initializations are later elided in favor of > > direct initializations, the warnings remain. > > > > To avoid these problems, move such variables into the "case" where > > they're used or lift them up into the main function body. > > > > drivers/char/ppdev.c: In function ‘pp_do_ioctl’: > > drivers/char/ppdev.c:516:25: warning: statement will never be executed [-Wswitch-unreachable] > > 516 | struct ieee1284_info *info; > > | ^~~~ > > > > [1] https://bugs.llvm.org/show_bug.cgi?id=44916 > > > > Signed-off-by: Kees Cook <keescook@chromium.org> > > Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> > > Greg, Can you please take it in your tree...
Already taken :)
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