* [PATCH] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file
@ 2022-08-16 5:17 Andrew Donnellan
2022-08-16 12:14 ` Yury Norov
2022-08-16 19:25 ` Kees Cook
0 siblings, 2 replies; 5+ messages in thread
From: Andrew Donnellan @ 2022-08-16 5:17 UTC (permalink / raw)
To: linux-hardening, linuxppc-dev; +Cc: Erhard Furtner, Emese Revfy, Yury Norov
Commit 36d4b36b6959 ("lib/nodemask: inline next_node_in() and
node_random()") refactored some code by moving node_random() from
lib/nodemask.c to include/linux/nodemask.h, thus requiring nodemask.h to
include random.h, which conditionally defines add_latent_entropy()
depending on whether the macro LATENT_ENTROPY_PLUGIN is defined.
This broke the build on powerpc, where nodemask.h is indirectly included
in arch/powerpc/kernel/prom_init.c, part of the early boot machinery that
is excluded from the latent entropy plugin using
DISABLE_LATENT_ENTROPY_PLUGIN. It turns out that while we add a gcc flag
to disable the actual plugin, we don't undefine LATENT_ENTROPY_PLUGIN.
This leads to the following:
CC arch/powerpc/kernel/prom_init.o
In file included from ./include/linux/nodemask.h:97,
from ./include/linux/mmzone.h:17,
from ./include/linux/gfp.h:7,
from ./include/linux/xarray.h:15,
from ./include/linux/radix-tree.h:21,
from ./include/linux/idr.h:15,
from ./include/linux/kernfs.h:12,
from ./include/linux/sysfs.h:16,
from ./include/linux/kobject.h:20,
from ./include/linux/pci.h:35,
from arch/powerpc/kernel/prom_init.c:24:
./include/linux/random.h: In function 'add_latent_entropy':
./include/linux/random.h:25:46: error: 'latent_entropy' undeclared (first use in this function); did you mean 'add_latent_entropy'?
25 | add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy));
| ^~~~~~~~~~~~~~
| add_latent_entropy
./include/linux/random.h:25:46: note: each undeclared identifier is reported only once for each function it appears in
make[2]: *** [scripts/Makefile.build:249: arch/powerpc/kernel/prom_init.o] Fehler 1
make[1]: *** [scripts/Makefile.build:465: arch/powerpc/kernel] Fehler 2
make: *** [Makefile:1855: arch/powerpc] Error 2
Change the DISABLE_LATENT_ENTROPY_PLUGIN flags to undefine
LATENT_ENTROPY_PLUGIN for files where the plugin is disabled.
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Emese Revfy <re.emese@gmail.com>
Fixes: 36d4b36b6959 ("lib/nodemask: inline next_node_in() and node_random()")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216367
Link: https://lore.kernel.org/linuxppc-dev/alpine.DEB.2.22.394.2208152006320.289321@ramsan.of.borg/
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
scripts/Makefile.gcc-plugins | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins
index 692d64a70542..e4deaf5fa571 100644
--- a/scripts/Makefile.gcc-plugins
+++ b/scripts/Makefile.gcc-plugins
@@ -4,7 +4,7 @@ gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += latent_entropy_plugin.so
gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) \
+= -DLATENT_ENTROPY_PLUGIN
ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
- DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable
+ DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable -ULATENT_ENTROPY_PLUGIN
endif
export DISABLE_LATENT_ENTROPY_PLUGIN
--
2.30.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file
2022-08-16 5:17 [PATCH] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file Andrew Donnellan
@ 2022-08-16 12:14 ` Yury Norov
2022-08-17 3:09 ` Andrew Donnellan
2022-08-16 19:25 ` Kees Cook
1 sibling, 1 reply; 5+ messages in thread
From: Yury Norov @ 2022-08-16 12:14 UTC (permalink / raw)
To: Andrew Donnellan
Cc: Erhard Furtner, Emese Revfy, linuxppc-dev, linux-hardening
On Tue, Aug 16, 2022 at 03:17:20PM +1000, Andrew Donnellan wrote:
> Commit 36d4b36b6959 ("lib/nodemask: inline next_node_in() and
> node_random()") refactored some code by moving node_random() from
> lib/nodemask.c to include/linux/nodemask.h, thus requiring nodemask.h to
> include random.h, which conditionally defines add_latent_entropy()
> depending on whether the macro LATENT_ENTROPY_PLUGIN is defined.
>
> This broke the build on powerpc, where nodemask.h is indirectly included
> in arch/powerpc/kernel/prom_init.c, part of the early boot machinery that
> is excluded from the latent entropy plugin using
> DISABLE_LATENT_ENTROPY_PLUGIN. It turns out that while we add a gcc flag
> to disable the actual plugin, we don't undefine LATENT_ENTROPY_PLUGIN.
>
> This leads to the following:
>
> CC arch/powerpc/kernel/prom_init.o
> In file included from ./include/linux/nodemask.h:97,
> from ./include/linux/mmzone.h:17,
> from ./include/linux/gfp.h:7,
> from ./include/linux/xarray.h:15,
As a side note, xarray can go with gfp_types.h instead of gfp.h
> from ./include/linux/radix-tree.h:21,
> from ./include/linux/idr.h:15,
> from ./include/linux/kernfs.h:12,
> from ./include/linux/sysfs.h:16,
> from ./include/linux/kobject.h:20,
> from ./include/linux/pci.h:35,
> from arch/powerpc/kernel/prom_init.c:24:
> ./include/linux/random.h: In function 'add_latent_entropy':
> ./include/linux/random.h:25:46: error: 'latent_entropy' undeclared (first use in this function); did you mean 'add_latent_entropy'?
> 25 | add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy));
> | ^~~~~~~~~~~~~~
> | add_latent_entropy
> ./include/linux/random.h:25:46: note: each undeclared identifier is reported only once for each function it appears in
> make[2]: *** [scripts/Makefile.build:249: arch/powerpc/kernel/prom_init.o] Fehler 1
> make[1]: *** [scripts/Makefile.build:465: arch/powerpc/kernel] Fehler 2
> make: *** [Makefile:1855: arch/powerpc] Error 2
>
> Change the DISABLE_LATENT_ENTROPY_PLUGIN flags to undefine
> LATENT_ENTROPY_PLUGIN for files where the plugin is disabled.
>
> Cc: Yury Norov <yury.norov@gmail.com>
> Cc: Emese Revfy <re.emese@gmail.com>
> Fixes: 36d4b36b6959 ("lib/nodemask: inline next_node_in() and node_random()")
I think it rather fixes 38addce8b600ca33 ("gcc-plugins: Add
latent_entropy plugin").
For the rest,
Reviewed-by: Yury Norov <yury.norov@gmail.com>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216367
> Link: https://lore.kernel.org/linuxppc-dev/alpine.DEB.2.22.394.2208152006320.289321@ramsan.of.borg/
> Reported-by: Erhard Furtner <erhard_f@mailbox.org>
> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
> ---
> scripts/Makefile.gcc-plugins | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins
> index 692d64a70542..e4deaf5fa571 100644
> --- a/scripts/Makefile.gcc-plugins
> +++ b/scripts/Makefile.gcc-plugins
> @@ -4,7 +4,7 @@ gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += latent_entropy_plugin.so
> gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) \
> += -DLATENT_ENTROPY_PLUGIN
> ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
> - DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable
> + DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable -ULATENT_ENTROPY_PLUGIN
> endif
> export DISABLE_LATENT_ENTROPY_PLUGIN
>
> --
> 2.30.2
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file
2022-08-16 5:17 [PATCH] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file Andrew Donnellan
2022-08-16 12:14 ` Yury Norov
@ 2022-08-16 19:25 ` Kees Cook
2022-08-17 3:09 ` Andrew Donnellan
1 sibling, 1 reply; 5+ messages in thread
From: Kees Cook @ 2022-08-16 19:25 UTC (permalink / raw)
To: linuxppc-dev, linux-hardening, ajd; +Cc: erhard_f, Kees Cook, yury.norov
On Tue, 16 Aug 2022 15:17:20 +1000, Andrew Donnellan wrote:
> Commit 36d4b36b6959 ("lib/nodemask: inline next_node_in() and
> node_random()") refactored some code by moving node_random() from
> lib/nodemask.c to include/linux/nodemask.h, thus requiring nodemask.h to
> include random.h, which conditionally defines add_latent_entropy()
> depending on whether the macro LATENT_ENTROPY_PLUGIN is defined.
>
> This broke the build on powerpc, where nodemask.h is indirectly included
> in arch/powerpc/kernel/prom_init.c, part of the early boot machinery that
> is excluded from the latent entropy plugin using
> DISABLE_LATENT_ENTROPY_PLUGIN. It turns out that while we add a gcc flag
> to disable the actual plugin, we don't undefine LATENT_ENTROPY_PLUGIN.
>
> [...]
Applied to for-next/hardening, thanks!
[1/1] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file
https://git.kernel.org/kees/c/2d08c71d2c79
--
Kees Cook
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file
2022-08-16 12:14 ` Yury Norov
@ 2022-08-17 3:09 ` Andrew Donnellan
0 siblings, 0 replies; 5+ messages in thread
From: Andrew Donnellan @ 2022-08-17 3:09 UTC (permalink / raw)
To: Yury Norov; +Cc: Erhard Furtner, Emese Revfy, linuxppc-dev, linux-hardening
On Tue, 2022-08-16 at 05:14 -0700, Yury Norov wrote:
> On Tue, Aug 16, 2022 at 03:17:20PM +1000, Andrew Donnellan wrote:
> > Commit 36d4b36b6959 ("lib/nodemask: inline next_node_in() and
> > node_random()") refactored some code by moving node_random() from
> > lib/nodemask.c to include/linux/nodemask.h, thus requiring
> > nodemask.h to
> > include random.h, which conditionally defines add_latent_entropy()
> > depending on whether the macro LATENT_ENTROPY_PLUGIN is defined.
> >
> > This broke the build on powerpc, where nodemask.h is indirectly
> > included
> > in arch/powerpc/kernel/prom_init.c, part of the early boot
> > machinery that
> > is excluded from the latent entropy plugin using
> > DISABLE_LATENT_ENTROPY_PLUGIN. It turns out that while we add a gcc
> > flag
> > to disable the actual plugin, we don't undefine
> > LATENT_ENTROPY_PLUGIN.
> >
> > This leads to the following:
> >
> > CC arch/powerpc/kernel/prom_init.o
> > In file included from ./include/linux/nodemask.h:97,
> > from ./include/linux/mmzone.h:17,
> > from ./include/linux/gfp.h:7,
> > from ./include/linux/xarray.h:15,
>
> As a side note, xarray can go with gfp_types.h instead of gfp.h
Indeed, I just saw your patch to fix this.
>
> > Fixes: 36d4b36b6959 ("lib/nodemask: inline next_node_in() and
> > node_random()")
>
> I think it rather fixes 38addce8b600ca33 ("gcc-plugins: Add
> latent_entropy plugin").
You're right, I was in a rush and should have tagged that
appropriately.
>
> For the rest,
> Reviewed-by: Yury Norov <yury.norov@gmail.com>
Thanks!
--
Andrew Donnellan OzLabs, ADL Canberra
ajd@linux.ibm.com IBM Australia Limited
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file
2022-08-16 19:25 ` Kees Cook
@ 2022-08-17 3:09 ` Andrew Donnellan
0 siblings, 0 replies; 5+ messages in thread
From: Andrew Donnellan @ 2022-08-17 3:09 UTC (permalink / raw)
To: Kees Cook, linuxppc-dev, linux-hardening; +Cc: erhard_f, yury.norov
On Tue, 2022-08-16 at 12:25 -0700, Kees Cook wrote:
> Applied to for-next/hardening, thanks!
>
> [1/1] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin
> disabled for a file
> https://git.kernel.org/kees/c/2d08c71d2c79
>
Thanks Kees!
Can we make sure this lands in rc2?
--
Andrew Donnellan OzLabs, ADL Canberra
ajd@linux.ibm.com IBM Australia Limited
^ permalink raw reply [flat|nested] 5+ messages in thread
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2022-08-16 5:17 [PATCH] gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file Andrew Donnellan
2022-08-16 12:14 ` Yury Norov
2022-08-17 3:09 ` Andrew Donnellan
2022-08-16 19:25 ` Kees Cook
2022-08-17 3:09 ` Andrew Donnellan
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