| Message ID | 12825174.7oxZXDxNhV@wuerfel (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Arnd, On Tue, 2015-01-13 at 17:19 +0100, Arnd Bergmann wrote: > We've been getting this warning for ages: > > ./usr/include/linux/kexec.h:61: userspace cannot reference function or variable defined in the kernel > > There is no proper fix for this file, as the declaration is meant for > user space, not for the kernel, so we should work around it the > same way that we treat the seqbuf_dump() definition. For the seqbuf_dump() stuff there are apparently users. I forgot the details, but the sound people wanted to keep that declaration (and some related ancient things) in the header involved to keep some really ancient stuff buildable. But the kexec_load declaration isn't very useful for userspace, see the patch I submitted in http://lkml.kernel.org/r/1389791824.17407.9.camel@x220 . And After my attempt the export of that declaration has also been discussed in http://lkml.kernel.org/r/115373b6ac68ee7a305975896e1c4971e8e51d4c.1408731991.git.geoff@infradead.org In that last discussion no one has been able to point to an actual user of it. So, as far as I can tell, no one actually uses it. Which makes sense, because including this header by itself doesn't give one access to a useful definition of kexec_load. So why bother with the declaration? The last time that Geoff has been trying to get that patch applied should be http://lkml.kernel.org/r/b0702fc4186db21820d686e89afd6480560823db.1415837218.git.geoff@infradead.org I'd rather see that go in. > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > diff --git a/scripts/headers_check.pl b/scripts/headers_check.pl > index 62320f93e903..fb051848667c 100755 > --- a/scripts/headers_check.pl > +++ b/scripts/headers_check.pl > @@ -69,6 +69,10 @@ sub check_declarations > if ($line =~ m/^void seqbuf_dump\(void\);/) { > return; > } > + # user-only declaration from kexec.h > + if ($line =~ m/^extern int kexec_load/) { > + return; > + } > if ($line =~ m/^(\s*extern|unsigned|char|short|int|long|void)\b/) { > printf STDERR "$filename:$lineno: " . > "userspace cannot reference function or " . Regards, Paul Bolle -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tuesday 13 January 2015 18:13:32 Paul Bolle wrote: > > For the seqbuf_dump() stuff there are apparently users. I forgot the > details, but the sound people wanted to keep that declaration (and some > related ancient things) in the header involved to keep some really > ancient stuff buildable. > > But the kexec_load declaration isn't very useful for userspace, see the > patch I submitted in > http://lkml.kernel.org/r/1389791824.17407.9.camel@x220 . And After my > attempt the export of that declaration has also been discussed in > http://lkml.kernel.org/r/115373b6ac68ee7a305975896e1c4971e8e51d4c.1408731991.git.geoff@infradead.org > > In that last discussion no one has been able to point to an actual user > of it. So, as far as I can tell, no one actually uses it. Which makes > sense, because including this header by itself doesn't give one access > to a useful definition of kexec_load. So why bother with the > declaration? > > The last time that Geoff has been trying to get that patch applied > should be > http://lkml.kernel.org/r/b0702fc4186db21820d686e89afd6480560823db.1415837218.git.geoff@infradead.org I'd rather see that go in. > Fine with me as well. As long as we can find someone to take one of the patches, I'm happy. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[Dragging Andrew, Linus, and Maximilian into this thread.] On Tue, 2015-01-13 at 21:27 +0100, Arnd Bergmann wrote: > On Tuesday 13 January 2015 18:13:32 Paul Bolle wrote: > > The last time that Geoff has been trying to get that patch applied > > should be > > http://lkml.kernel.org/r/b0702fc4186db21820d686e89afd6480560823db.1415837218.git.geoff@infradead.org> > > I'd rather see that go in. > > Fine with me as well. As long as we can find someone to take one of > the patches, I'm happy. Since Geoff's patch (and my preceding, identical patch) basically is a partial revert of commit 29a5c67e7a78 ("kexec: export kexec.h to user space") that should probably be done by either Andrew or Linus. (This short thread starts at http://lkml.kernel.org/r/12825174.7oxZXDxNhV@wuerfel .) Paul Bolle -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 13 Jan 2015 22:05:11 +0100 Paul Bolle <pebolle@tiscali.nl> wrote: > [Dragging Andrew, Linus, and Maximilian into this thread.] > > On Tue, 2015-01-13 at 21:27 +0100, Arnd Bergmann wrote: > > On Tuesday 13 January 2015 18:13:32 Paul Bolle wrote: > > > The last time that Geoff has been trying to get that patch applied > > > should be > > > http://lkml.kernel.org/r/b0702fc4186db21820d686e89afd6480560823db.1415837218.git.geoff@infradead.org> > > > I'd rather see that go in. > > > > Fine with me as well. As long as we can find someone to take one of > > the patches, I'm happy. > > Since Geoff's patch (and my preceding, identical patch) basically is a > partial revert of commit 29a5c67e7a78 ("kexec: export kexec.h to user > space") that should probably be done by either Andrew or Linus. > > (This short thread starts at > http://lkml.kernel.org/r/12825174.7oxZXDxNhV@wuerfel .) hm, sorry, I can't imagine why I didn't process Geoff's patch series back in November. They all look good - I grabbed them. -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/scripts/headers_check.pl b/scripts/headers_check.pl index 62320f93e903..fb051848667c 100755 --- a/scripts/headers_check.pl +++ b/scripts/headers_check.pl @@ -69,6 +69,10 @@ sub check_declarations if ($line =~ m/^void seqbuf_dump\(void\);/) { return; } + # user-only declaration from kexec.h + if ($line =~ m/^extern int kexec_load/) { + return; + } if ($line =~ m/^(\s*extern|unsigned|char|short|int|long|void)\b/) { printf STDERR "$filename:$lineno: " . "userspace cannot reference function or " .
We've been getting this warning for ages: ./usr/include/linux/kexec.h:61: userspace cannot reference function or variable defined in the kernel There is no proper fix for this file, as the declaration is meant for user space, not for the kernel, so we should work around it the same way that we treat the seqbuf_dump() definition. Signed-off-by: Arnd Bergmann <arnd@arndb.de> -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html