On Thu, Jun 4, 2020 at 10:20 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > On Thu, Jun 04, 2020 at 12:29:17PM -0700, Nick Desaulniers wrote: > > On Wed, Jun 3, 2020 at 4:32 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > > > > > Using uninitialized_var() is dangerous as it papers over real bugs[1] > > > (or can in the future), and suppresses unrelated compiler warnings (e.g. > > > "unused variable"). If the compiler thinks it is uninitialized, either > > > simply initialize the variable or make compiler changes. As a precursor > > > to removing[2] this[3] macro[4], just remove this variable since it was > > > actually unused: > > > > > > drivers/ide/ide-taskfile.c:232:34: warning: unused variable 'flags' [-Wunused-variable] > > > unsigned long uninitialized_var(flags); > > > ^ > > > > > > [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@xxxxxxxxxx/ > > > [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@xxxxxxxxxxxxxx/ > > > [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@xxxxxxxxxxxxxx/ > > > [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@xxxxxxxxxxxxxx/ > > > > > > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > > > > Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > > Thanks for the reviews! > > > Fixes ce1e518190ea ("ide: don't disable interrupts during kmap_atomic()") > > I originally avoided adding Fixes tags because I didn't want these > changes backported into a -stable without -Wmaybe-uninitialized > disabled, but in these cases (variable removal), that actually does make > sense. Thanks! > Fixes tag does not automatically mean it is "for-stable". [1] says: > Patches that fix a severe bug in a released kernel should be directed > toward the stable maintainers by putting a line like this:: > > Cc: stable@xxxxxxxxxxxxxxx - Sedat - [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst#n299
