* [PATCH 1/2] agpgart.h: do not include <stdlib.h> from exported header
@ 2022-03-28 17:21 Masahiro Yamada
2022-03-28 17:21 ` [PATCH 2/2] kbuild: forbid exported headers from including <stdint.h>, <stdbool.h> Masahiro Yamada
0 siblings, 1 reply; 5+ messages in thread
From: Masahiro Yamada @ 2022-03-28 17:21 UTC (permalink / raw)
To: linux-kbuild; +Cc: Arnd Bergmann, linux-kernel, Masahiro Yamada, David Airlie
Commit 35d0f1d54ecd ("include/uapi/linux/agpgart.h: include stdlib.h in
userspace") included <stdlib.h> to fix the unknown size_t error, but
I do not think it is the right fix.
This header already uses __kernel_size_t a few lines below.
Replace the remaining size_t, and stop including <stdlib.h>.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
include/uapi/linux/agpgart.h | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/include/uapi/linux/agpgart.h b/include/uapi/linux/agpgart.h
index f5251045181a..9cc3448c0b5b 100644
--- a/include/uapi/linux/agpgart.h
+++ b/include/uapi/linux/agpgart.h
@@ -52,7 +52,6 @@
#ifndef __KERNEL__
#include <linux/types.h>
-#include <stdlib.h>
struct agp_version {
__u16 major;
@@ -64,10 +63,10 @@ typedef struct _agp_info {
__u32 bridge_id; /* bridge vendor/device */
__u32 agp_mode; /* mode info of bridge */
unsigned long aper_base;/* base of aperture */
- size_t aper_size; /* size of aperture */
- size_t pg_total; /* max pages (swap + system) */
- size_t pg_system; /* max pages (system) */
- size_t pg_used; /* current pages used */
+ __kernel_size_t aper_size; /* size of aperture */
+ __kernel_size_t pg_total; /* max pages (swap + system) */
+ __kernel_size_t pg_system; /* max pages (system) */
+ __kernel_size_t pg_used; /* current pages used */
} agp_info;
typedef struct _agp_setup {
--
2.32.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] kbuild: forbid exported headers from including <stdint.h>, <stdbool.h>
2022-03-28 17:21 [PATCH 1/2] agpgart.h: do not include <stdlib.h> from exported header Masahiro Yamada
@ 2022-03-28 17:21 ` Masahiro Yamada
2022-03-29 6:04 ` Greg Kroah-Hartman
0 siblings, 1 reply; 5+ messages in thread
From: Masahiro Yamada @ 2022-03-28 17:21 UTC (permalink / raw)
To: linux-kbuild
Cc: Arnd Bergmann, linux-kernel, Masahiro Yamada, Dmitry V. Levin,
Elliot Berman, Geert Uytterhoeven, Greg Kroah-Hartman,
Nick Desaulniers
Some UAPI headers included <stdlib.h>, like this:
#ifndef __KERNEL__
#include <stdlib.h>
#endif
As it turned out, they just included it for no good reason.
After some fixes, now I can compile-test UAPI headers
(CONFIG_UAPI_HEADER_TEST=y) without <stdlib.h> included.
To avoid somebody getting it back again, this commit adds the dummy
header, usr/dummy-include/stdlib.h
I added $(srctree)/usr/dummy-include to the header search paths.
Because it is searched before the system directories, if someone
tries to include <stdlib.h>, they will see the error message.
While I am here, I also replaced $(objtree)/usr/include with $(obj), but
it is just a small refactoring.
If we achieve the situation where none of system headers is included
from exported kernel headers (i.e. kernel headers become self-contained),
we might be able to add -nostdinc, but that is much far from where we
stand now. (see many no-header-test lines in usr/include/Makefile)
As a realistic solution, you can forbid header inclusion individually by
putting a dummy header into usr/dummy-include/.
Currently, no header include <stdbool.h>. I put it as well before somebody
attempts to use it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
usr/dummy-include/stdbool.h | 7 +++++++
usr/dummy-include/stdlib.h | 7 +++++++
usr/include/Makefile | 2 +-
3 files changed, 15 insertions(+), 1 deletion(-)
create mode 100644 usr/dummy-include/stdbool.h
create mode 100644 usr/dummy-include/stdlib.h
diff --git a/usr/dummy-include/stdbool.h b/usr/dummy-include/stdbool.h
new file mode 100644
index 000000000000..54ff9e9c90ac
--- /dev/null
+++ b/usr/dummy-include/stdbool.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _STDBOOL_H
+#define _STDBOOL_H
+
+#error "Please do not include <stdbool.h> from exported headers"
+
+#endif /* _STDBOOL_H */
diff --git a/usr/dummy-include/stdlib.h b/usr/dummy-include/stdlib.h
new file mode 100644
index 000000000000..e8c21888e371
--- /dev/null
+++ b/usr/dummy-include/stdlib.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _STDLIB_H
+#define _STDLIB_H
+
+#error "Please do not include <stdlib.h> from exported headers"
+
+#endif /* _STDLIB_H */
diff --git a/usr/include/Makefile b/usr/include/Makefile
index fa9819e022b7..7740777b49f8 100644
--- a/usr/include/Makefile
+++ b/usr/include/Makefile
@@ -15,7 +15,7 @@ UAPI_CFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
# USERCFLAGS might contain sysroot location for CC.
UAPI_CFLAGS += $(USERCFLAGS)
-override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I$(objtree)/usr/include
+override c_flags = $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I $(obj) -I $(srctree)/usr/dummy-include
# The following are excluded for now because they fail to build.
#
--
2.32.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] kbuild: forbid exported headers from including <stdint.h>, <stdbool.h>
2022-03-28 17:21 ` [PATCH 2/2] kbuild: forbid exported headers from including <stdint.h>, <stdbool.h> Masahiro Yamada
@ 2022-03-29 6:04 ` Greg Kroah-Hartman
2022-03-29 7:16 ` Masahiro Yamada
0 siblings, 1 reply; 5+ messages in thread
From: Greg Kroah-Hartman @ 2022-03-29 6:04 UTC (permalink / raw)
To: Masahiro Yamada
Cc: linux-kbuild, Arnd Bergmann, linux-kernel, Dmitry V. Levin,
Elliot Berman, Geert Uytterhoeven, Nick Desaulniers
On Tue, Mar 29, 2022 at 02:21:30AM +0900, Masahiro Yamada wrote:
> Some UAPI headers included <stdlib.h>, like this:
>
> #ifndef __KERNEL__
> #include <stdlib.h>
> #endif
>
> As it turned out, they just included it for no good reason.
>
> After some fixes, now I can compile-test UAPI headers
> (CONFIG_UAPI_HEADER_TEST=y) without <stdlib.h> included.
>
> To avoid somebody getting it back again, this commit adds the dummy
> header, usr/dummy-include/stdlib.h
>
> I added $(srctree)/usr/dummy-include to the header search paths.
> Because it is searched before the system directories, if someone
> tries to include <stdlib.h>, they will see the error message.
>
> While I am here, I also replaced $(objtree)/usr/include with $(obj), but
> it is just a small refactoring.
>
> If we achieve the situation where none of system headers is included
> from exported kernel headers (i.e. kernel headers become self-contained),
> we might be able to add -nostdinc, but that is much far from where we
> stand now. (see many no-header-test lines in usr/include/Makefile)
>
> As a realistic solution, you can forbid header inclusion individually by
> putting a dummy header into usr/dummy-include/.
>
> Currently, no header include <stdbool.h>. I put it as well before somebody
> attempts to use it.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Nice work!
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] kbuild: forbid exported headers from including <stdint.h>, <stdbool.h>
2022-03-29 6:04 ` Greg Kroah-Hartman
@ 2022-03-29 7:16 ` Masahiro Yamada
2022-03-29 10:35 ` Greg Kroah-Hartman
0 siblings, 1 reply; 5+ messages in thread
From: Masahiro Yamada @ 2022-03-29 7:16 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Linux Kbuild mailing list, Arnd Bergmann,
Linux Kernel Mailing List, Dmitry V. Levin, Elliot Berman,
Geert Uytterhoeven, Nick Desaulniers
On Tue, Mar 29, 2022 at 3:04 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Tue, Mar 29, 2022 at 02:21:30AM +0900, Masahiro Yamada wrote:
> > Some UAPI headers included <stdlib.h>, like this:
> >
> > #ifndef __KERNEL__
> > #include <stdlib.h>
> > #endif
> >
> > As it turned out, they just included it for no good reason.
> >
> > After some fixes, now I can compile-test UAPI headers
> > (CONFIG_UAPI_HEADER_TEST=y) without <stdlib.h> included.
> >
> > To avoid somebody getting it back again, this commit adds the dummy
> > header, usr/dummy-include/stdlib.h
> >
> > I added $(srctree)/usr/dummy-include to the header search paths.
> > Because it is searched before the system directories, if someone
> > tries to include <stdlib.h>, they will see the error message.
> >
> > While I am here, I also replaced $(objtree)/usr/include with $(obj), but
> > it is just a small refactoring.
> >
> > If we achieve the situation where none of system headers is included
> > from exported kernel headers (i.e. kernel headers become self-contained),
> > we might be able to add -nostdinc, but that is much far from where we
> > stand now. (see many no-header-test lines in usr/include/Makefile)
> >
> > As a realistic solution, you can forbid header inclusion individually by
> > putting a dummy header into usr/dummy-include/.
> >
> > Currently, no header include <stdbool.h>. I put it as well before somebody
> > attempts to use it.
> >
> > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
>
> Nice work!
>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I made a mistake in the patch subject.
The correct title should be:
kbuild: forbid exported headers from including <stdlib.h>, <stdbool.h>
I will fix it in v2.
We cannot ban <stdint.h> for now because there are still some users.
A fix-up patch exists, but the fuse maintainer was opposed to it.
https://lore.kernel.org/lkml/20220318171405.2728855-1-cmllamas@google.com/
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] kbuild: forbid exported headers from including <stdint.h>, <stdbool.h>
2022-03-29 7:16 ` Masahiro Yamada
@ 2022-03-29 10:35 ` Greg Kroah-Hartman
0 siblings, 0 replies; 5+ messages in thread
From: Greg Kroah-Hartman @ 2022-03-29 10:35 UTC (permalink / raw)
To: Masahiro Yamada
Cc: Linux Kbuild mailing list, Arnd Bergmann,
Linux Kernel Mailing List, Dmitry V. Levin, Elliot Berman,
Geert Uytterhoeven, Nick Desaulniers
On Tue, Mar 29, 2022 at 04:16:02PM +0900, Masahiro Yamada wrote:
> On Tue, Mar 29, 2022 at 3:04 PM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Tue, Mar 29, 2022 at 02:21:30AM +0900, Masahiro Yamada wrote:
> > > Some UAPI headers included <stdlib.h>, like this:
> > >
> > > #ifndef __KERNEL__
> > > #include <stdlib.h>
> > > #endif
> > >
> > > As it turned out, they just included it for no good reason.
> > >
> > > After some fixes, now I can compile-test UAPI headers
> > > (CONFIG_UAPI_HEADER_TEST=y) without <stdlib.h> included.
> > >
> > > To avoid somebody getting it back again, this commit adds the dummy
> > > header, usr/dummy-include/stdlib.h
> > >
> > > I added $(srctree)/usr/dummy-include to the header search paths.
> > > Because it is searched before the system directories, if someone
> > > tries to include <stdlib.h>, they will see the error message.
> > >
> > > While I am here, I also replaced $(objtree)/usr/include with $(obj), but
> > > it is just a small refactoring.
> > >
> > > If we achieve the situation where none of system headers is included
> > > from exported kernel headers (i.e. kernel headers become self-contained),
> > > we might be able to add -nostdinc, but that is much far from where we
> > > stand now. (see many no-header-test lines in usr/include/Makefile)
> > >
> > > As a realistic solution, you can forbid header inclusion individually by
> > > putting a dummy header into usr/dummy-include/.
> > >
> > > Currently, no header include <stdbool.h>. I put it as well before somebody
> > > attempts to use it.
> > >
> > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> >
> > Nice work!
> >
> > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
>
> I made a mistake in the patch subject.
>
> The correct title should be:
>
> kbuild: forbid exported headers from including <stdlib.h>, <stdbool.h>
>
> I will fix it in v2.
Ah, missed that, yes.
> We cannot ban <stdint.h> for now because there are still some users.
>
> A fix-up patch exists, but the fuse maintainer was opposed to it.
> https://lore.kernel.org/lkml/20220318171405.2728855-1-cmllamas@google.com/
It's not ok for one lone file to break the rules that all other uapi
header files follow. I think that needs to be fixed, there is NOTHING
special about that one subsystem to justify this.
Uniformity is good, and should be followed, and I strongly think that
change needs to be accepted.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 5+ messages in thread
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2022-03-28 17:21 ` [PATCH 2/2] kbuild: forbid exported headers from including <stdint.h>, <stdbool.h> Masahiro Yamada
2022-03-29 6:04 ` Greg Kroah-Hartman
2022-03-29 7:16 ` Masahiro Yamada
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