I noticed that randconfig builds with gcc no longer produce a lot of
ccache hits, unlike with clang, and traced this back to plugins
now being enabled unconditionally if they are supported.
I am now working around this by adding
export CCACHE_COMPILERCHECK=/usr/bin/size -A %compiler%
to my top-level Makefile. This changes the heuristic that ccache uses
to determine whether the plugins are the same after a 'make clean'.
However, it also seems that being able to just turn off the plugins is
generally useful, at least for build testing it adds noticeable overhead
but does not find a lot of bugs additional bugs, and may be easier for
ccache users than my workaround.
Fixes: 9f671e58159a ("security: Create "kernel hardening" config area")
Signed-off-by: Arnd Bergmann <[email protected]>
---
scripts/gcc-plugins/Kconfig | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
index d33de0b9f4f5..e3569543bdac 100644
--- a/scripts/gcc-plugins/Kconfig
+++ b/scripts/gcc-plugins/Kconfig
@@ -14,8 +14,8 @@ config HAVE_GCC_PLUGINS
An arch should select this symbol if it supports building with
GCC plugins.
-config GCC_PLUGINS
- bool
+menuconfig GCC_PLUGINS
+ bool "GCC plugins"
depends on HAVE_GCC_PLUGINS
depends on PLUGIN_HOSTCC != ""
default y
@@ -25,8 +25,7 @@ config GCC_PLUGINS
See Documentation/core-api/gcc-plugins.rst for details.
-menu "GCC plugins"
- depends on GCC_PLUGINS
+if GCC_PLUGINS
config GCC_PLUGIN_CYC_COMPLEXITY
bool "Compute the cyclomatic complexity of a function" if EXPERT
@@ -113,4 +112,4 @@ config GCC_PLUGIN_ARM_SSP_PER_TASK
bool
depends on GCC_PLUGINS && ARM
-endmenu
+endif
--
2.20.0
On Wed, 11 Dec 2019 at 14:40, Arnd Bergmann <[email protected]> wrote:
>
> I noticed that randconfig builds with gcc no longer produce a lot of
> ccache hits, unlike with clang, and traced this back to plugins
> now being enabled unconditionally if they are supported.
>
> I am now working around this by adding
>
> export CCACHE_COMPILERCHECK=/usr/bin/size -A %compiler%
>
> to my top-level Makefile. This changes the heuristic that ccache uses
> to determine whether the plugins are the same after a 'make clean'.
>
> However, it also seems that being able to just turn off the plugins is
> generally useful, at least for build testing it adds noticeable overhead
> but does not find a lot of bugs additional bugs, and may be easier for
> ccache users than my workaround.
>
> Fixes: 9f671e58159a ("security: Create "kernel hardening" config area")
> Signed-off-by: Arnd Bergmann <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]>
> ---
> scripts/gcc-plugins/Kconfig | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
> index d33de0b9f4f5..e3569543bdac 100644
> --- a/scripts/gcc-plugins/Kconfig
> +++ b/scripts/gcc-plugins/Kconfig
> @@ -14,8 +14,8 @@ config HAVE_GCC_PLUGINS
> An arch should select this symbol if it supports building with
> GCC plugins.
>
> -config GCC_PLUGINS
> - bool
> +menuconfig GCC_PLUGINS
> + bool "GCC plugins"
> depends on HAVE_GCC_PLUGINS
> depends on PLUGIN_HOSTCC != ""
> default y
> @@ -25,8 +25,7 @@ config GCC_PLUGINS
>
> See Documentation/core-api/gcc-plugins.rst for details.
>
> -menu "GCC plugins"
> - depends on GCC_PLUGINS
> +if GCC_PLUGINS
>
> config GCC_PLUGIN_CYC_COMPLEXITY
> bool "Compute the cyclomatic complexity of a function" if EXPERT
> @@ -113,4 +112,4 @@ config GCC_PLUGIN_ARM_SSP_PER_TASK
> bool
> depends on GCC_PLUGINS && ARM
>
> -endmenu
> +endif
> --
> 2.20.0
>
On Wed, Dec 11, 2019 at 10:40 PM Arnd Bergmann <[email protected]> wrote:
>
> I noticed that randconfig builds with gcc no longer produce a lot of
> ccache hits, unlike with clang, and traced this back to plugins
> now being enabled unconditionally if they are supported.
>
> I am now working around this by adding
>
> export CCACHE_COMPILERCHECK=/usr/bin/size -A %compiler%
>
> to my top-level Makefile. This changes the heuristic that ccache uses
> to determine whether the plugins are the same after a 'make clean'.
>
> However, it also seems that being able to just turn off the plugins is
> generally useful, at least for build testing it adds noticeable overhead
> but does not find a lot of bugs additional bugs, and may be easier for
> ccache users than my workaround.
>
> Fixes: 9f671e58159a ("security: Create "kernel hardening" config area")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
Reviewed-by: Masahiro Yamada <[email protected]>
--
Best Regards
Masahiro Yamada
On Thu, Dec 12, 2019 at 5:52 AM Masahiro Yamada <[email protected]> wrote:
>
> On Wed, Dec 11, 2019 at 10:40 PM Arnd Bergmann <[email protected]> wrote:
> >
> > I noticed that randconfig builds with gcc no longer produce a lot of
> > ccache hits, unlike with clang, and traced this back to plugins
> > now being enabled unconditionally if they are supported.
> >
> > I am now working around this by adding
> >
> > export CCACHE_COMPILERCHECK=/usr/bin/size -A %compiler%
> >
> > to my top-level Makefile. This changes the heuristic that ccache uses
> > to determine whether the plugins are the same after a 'make clean'.
> >
> > However, it also seems that being able to just turn off the plugins is
> > generally useful, at least for build testing it adds noticeable overhead
> > but does not find a lot of bugs additional bugs, and may be easier for
> > ccache users than my workaround.
> >
> > Fixes: 9f671e58159a ("security: Create "kernel hardening" config area")
> > Signed-off-by: Arnd Bergmann <[email protected]>
>
> Reviewed-by: Masahiro Yamada <[email protected]>
On Wed, Dec 11, 2019 at 2:59 PM Ard Biesheuvel
<[email protected]> wrote:
>Acked-by: Ard Biesheuvel <[email protected]>
Thanks! Who would be the best person to pick up the patch?
Should I send it to Andrew?
Arnd
On Thu, Dec 12, 2019 at 10:59:40AM +0100, Arnd Bergmann wrote:
> On Thu, Dec 12, 2019 at 5:52 AM Masahiro Yamada <[email protected]> wrote:
> >
> > On Wed, Dec 11, 2019 at 10:40 PM Arnd Bergmann <[email protected]> wrote:
> > >
> > > I noticed that randconfig builds with gcc no longer produce a lot of
> > > ccache hits, unlike with clang, and traced this back to plugins
> > > now being enabled unconditionally if they are supported.
> > >
> > > I am now working around this by adding
> > >
> > > export CCACHE_COMPILERCHECK=/usr/bin/size -A %compiler%
> > >
> > > to my top-level Makefile. This changes the heuristic that ccache uses
> > > to determine whether the plugins are the same after a 'make clean'.
> > >
> > > However, it also seems that being able to just turn off the plugins is
> > > generally useful, at least for build testing it adds noticeable overhead
> > > but does not find a lot of bugs additional bugs, and may be easier for
> > > ccache users than my workaround.
> > >
> > > Fixes: 9f671e58159a ("security: Create "kernel hardening" config area")
> > > Signed-off-by: Arnd Bergmann <[email protected]>
> >
> > Reviewed-by: Masahiro Yamada <[email protected]>
>
> On Wed, Dec 11, 2019 at 2:59 PM Ard Biesheuvel
> <[email protected]> wrote:
> >Acked-by: Ard Biesheuvel <[email protected]>
>
> Thanks! Who would be the best person to pick up the patch?
> Should I send it to Andrew?
Acked-by: Kees Cook <[email protected]>
I can take it in my tree, or I'm happy to have Masahiro take it.
--
Kees Cook
On Fri, Dec 13, 2019 at 2:44 AM Kees Cook <[email protected]> wrote:
>
> On Thu, Dec 12, 2019 at 10:59:40AM +0100, Arnd Bergmann wrote:
> > On Thu, Dec 12, 2019 at 5:52 AM Masahiro Yamada <[email protected]> wrote:
> > >
> > > On Wed, Dec 11, 2019 at 10:40 PM Arnd Bergmann <[email protected]> wrote:
> > > >
> > > > I noticed that randconfig builds with gcc no longer produce a lot of
> > > > ccache hits, unlike with clang, and traced this back to plugins
> > > > now being enabled unconditionally if they are supported.
> > > >
> > > > I am now working around this by adding
> > > >
> > > > export CCACHE_COMPILERCHECK=/usr/bin/size -A %compiler%
> > > >
> > > > to my top-level Makefile. This changes the heuristic that ccache uses
> > > > to determine whether the plugins are the same after a 'make clean'.
> > > >
> > > > However, it also seems that being able to just turn off the plugins is
> > > > generally useful, at least for build testing it adds noticeable overhead
> > > > but does not find a lot of bugs additional bugs, and may be easier for
> > > > ccache users than my workaround.
> > > >
> > > > Fixes: 9f671e58159a ("security: Create "kernel hardening" config area")
> > > > Signed-off-by: Arnd Bergmann <[email protected]>
> > >
> > > Reviewed-by: Masahiro Yamada <[email protected]>
> >
> > On Wed, Dec 11, 2019 at 2:59 PM Ard Biesheuvel
> > <[email protected]> wrote:
> > >Acked-by: Ard Biesheuvel <[email protected]>
> >
> > Thanks! Who would be the best person to pick up the patch?
> > Should I send it to Andrew?
>
> Acked-by: Kees Cook <[email protected]>
>
> I can take it in my tree, or I'm happy to have Masahiro take it.
>
> --
> Kees Cook
Kees,
Please apply it to your tree.
Thanks.
--
Best Regards
Masahiro Yamada
On Sat, Dec 14, 2019 at 05:56:34PM +0900, Masahiro Yamada wrote:
> On Fri, Dec 13, 2019 at 2:44 AM Kees Cook <[email protected]> wrote:
> >
> > On Thu, Dec 12, 2019 at 10:59:40AM +0100, Arnd Bergmann wrote:
> > > On Thu, Dec 12, 2019 at 5:52 AM Masahiro Yamada <[email protected]> wrote:
> > > >
> > > > On Wed, Dec 11, 2019 at 10:40 PM Arnd Bergmann <[email protected]> wrote:
> > > > >
> > > > > I noticed that randconfig builds with gcc no longer produce a lot of
> > > > > ccache hits, unlike with clang, and traced this back to plugins
> > > > > now being enabled unconditionally if they are supported.
> > > > >
> > > > > I am now working around this by adding
> > > > >
> > > > > export CCACHE_COMPILERCHECK=/usr/bin/size -A %compiler%
> > > > >
> > > > > to my top-level Makefile. This changes the heuristic that ccache uses
> > > > > to determine whether the plugins are the same after a 'make clean'.
> > > > >
> > > > > However, it also seems that being able to just turn off the plugins is
> > > > > generally useful, at least for build testing it adds noticeable overhead
> > > > > but does not find a lot of bugs additional bugs, and may be easier for
> > > > > ccache users than my workaround.
> > > > >
> > > > > Fixes: 9f671e58159a ("security: Create "kernel hardening" config area")
> > > > > Signed-off-by: Arnd Bergmann <[email protected]>
> > > >
> > > > Reviewed-by: Masahiro Yamada <[email protected]>
> > >
> > > On Wed, Dec 11, 2019 at 2:59 PM Ard Biesheuvel
> > > <[email protected]> wrote:
> > > >Acked-by: Ard Biesheuvel <[email protected]>
> > >
> > > Thanks! Who would be the best person to pick up the patch?
> > > Should I send it to Andrew?
> >
> > Acked-by: Kees Cook <[email protected]>
> >
> > I can take it in my tree, or I'm happy to have Masahiro take it.
> >
> > --
> > Kees Cook
>
> Kees,
> Please apply it to your tree.
Thanks, applied!
--
Kees Cook