Messages in this thread | | | Date | Sun, 5 Sep 2021 11:31:44 -0700 | From | Kees Cook <> | Subject | Re: [GIT PULL] overflow updates for v5.15-rc1 |
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On Sun, Sep 05, 2021 at 10:36:22AM -0700, Linus Torvalds wrote: > On Sun, Sep 5, 2021 at 12:38 AM Kees Cook <keescook@chromium.org> wrote: > > > > Yeech. Yeah, no, that was not expected at all. I even did test merge builds against your latest tree before sending the Pull Request. This has been in -next for weeks, too. > > Sadly, I don't think linux-next checks for warnings.
Oh, I thought I'd gotten such reports from sfr before, but certainly the 0day bot and others have yelled loudly about new warnings (from earlier iterations of this series in -next).
> I really want to enable -Werror at some point, but every time I think > I should, I just end up worrying about another random new compiler (or > a random old one). > > We do have -Werror in various configurations (and in some sub-trees).
Yup, I think ppc and drm?
> > What was the build environment? > > This is actually just bog-standard gcc-11.2 from F34, and an allmodconfig build.
Ah, fun. Yeah, I'm behind on versions, it seems. Default gcc version on latest stable Ubuntu release is 10.3. I will go retest on the devel release.
> > Seeing an unexpected "-Wunused-value" in your output makes me think I've got a compiler version blind-spot, with some different default flags.) > > There were lots of other ones too, I just pasted a small subset. Thne > full error log was 400+ lines. Most of those lines are just because of > the very verbose warnings. > > Three errors due to "-Werror=unused-value", but 17 each of variations on > > error: call to ‘__read_overflow’ declared with attribute error: > detected read beyond size of object (1st parameter) > > and > > warning: unsafe xyz() usage lacked '__read_overflow' warning > > warnings. > > Full 400+ lines (25kB) of errors/warnings messages attached in case > you care about the whole thing and can't easily reproduce.
Yeah, the tests are designed to freak out if it gets an unexpected warning (since it's trying to check for _expected_ warnings), but regardless, they were not at all supposed to be spewing like this immediately! :P
Sorry for the noise; I will get it cleaned up and re-sent.
-Kees
-- Kees Cook
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