Re: [PATCH v6 14/25] kbuild: lto: remove duplicate dependencies from .mod files

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Dec 3, 2020 at 10:00 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
>
> On Thu, Oct 15, 2020 at 7:50 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> >
> > On Mon, Oct 12, 2020 at 05:31:52PM -0700, Sami Tolvanen wrote:
> > > With LTO, llvm-nm prints out symbols for each archive member
> > > separately, which results in a lot of duplicate dependencies in the
> > > .mod file when CONFIG_TRIM_UNUSED_SYMS is enabled. When a module
> > > consists of several compilation units, the output can exceed the
> > > default xargs command size limit and split the dependency list to
> > > multiple lines, which results in used symbols getting trimmed.
> > >
> > > This change removes duplicate dependencies, which will reduce the
> > > probability of this happening and makes .mod files smaller and
> > > easier to read.
> > >
> > > Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
> > > Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> >
> > Hi Masahiro,
> >
> > This appears to be a general improvement as well. This looks like it can
> > land without depending on the rest of the series.
>
> It cannot.
> Adding "sort -u" is pointless without the rest of the series
> since the symbol duplication happens only with Clang LTO.
>
> This is not a solution.
> "reduce the probability of this happening" well describes it.
>
> I wrote a different patch.

Great, thanks for looking into this. I'll drop this patch from the next version.

Sami



[Index of Archives]     [Linux Kernel]     [Kernel Newbies]     [x86 Platform Driver]     [Netdev]     [Linux Wireless]     [Netfilter]     [Bugtraq]     [Linux Filesystems]     [Yosemite Discussion]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]

  Powered by Linux