[PATCH 0/3] fortify: fix various issues in test_fortify Makefile

[PATCH 0/3] fortify: fix various issues in test_fortify Makefile

[Masahiro Yamada]

Applicable to v6.10 tag.



Masahiro Yamada (3):
  fortify: use if_changed_dep to record header dependency in *.cmd files
  fortify: refactor test_fortify Makefile to fix some build problems
  fortify: move test_fortify.sh to lib/test_fortify/

 MAINTAINERS                                   |  1 -
 lib/.gitignore                                |  2 -
 lib/Makefile                                  | 38 +------------------
 lib/test_fortify/.gitignore                   |  2 +
 lib/test_fortify/Makefile                     | 25 ++++++++++++
 {scripts => lib/test_fortify}/test_fortify.sh |  0
 6 files changed, 28 insertions(+), 40 deletions(-)
 create mode 100644 lib/test_fortify/.gitignore
 create mode 100644 lib/test_fortify/Makefile
 rename {scripts => lib/test_fortify}/test_fortify.sh (100%)

-- 
2.43.0

[PATCH 1/3] fortify: use if_changed_dep to record header dependency in *.cmd files

[Masahiro Yamada]

After building with CONFIG_FORTIFY_SOURCE=y, many .*.d files are left
in lib/test_fortify/ because the compiler outputs header dependencies
into *.d without fixdep being invoked.

When compiling C files, if_changed_dep should be used so that the
auto-generated header dependencies are recorded in .*.cmd files.

Currently, if_changed is incorrectly used, and only two headers are
hard-coded in lib/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 lib/Makefile | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/Makefile b/lib/Makefile
index 30337431d10e..429b259b5b64 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -408,11 +408,9 @@ targets += $(TEST_FORTIFY_LOGS)
 clean-files += $(TEST_FORTIFY_LOGS)
 clean-files += $(addsuffix .o, $(TEST_FORTIFY_LOGS))
 $(obj)/test_fortify/%.log: $(src)/test_fortify/%.c \
-			   $(src)/test_fortify/test_fortify.h \
-			   $(srctree)/include/linux/fortify-string.h \
 			   $(srctree)/scripts/test_fortify.sh \
 			   FORCE
-	$(call if_changed,test_fortify)
+	$(call if_changed_dep,test_fortify)
 
 quiet_cmd_gen_fortify_log = GEN     $@
       cmd_gen_fortify_log = cat </dev/null $(filter-out FORCE,$^) 2>/dev/null > $@ || true
-- 
2.43.0

[PATCH 2/3] fortify: refactor test_fortify Makefile to fix some build problems

[Masahiro Yamada]

There are some issues in the test_fortify Makefile code.

Problem 1: cc-disable-warning invokes compiler dozens of times

To see how many times the cc-disable-warning is evaluated, change
this code:

  $(call cc-disable-warning,fortify-source)

to:

  $(call cc-disable-warning,$(shell touch /tmp/fortify-$$$$)fortify-source)

Then, build the kernel with CONFIG_FORTIFY_SOURCE=y. You will see a
large number of '/tmp/fortify-<PID>' files created:

  $ ls -1 /tmp/fortify-* | wc
       80      80    1600

This means the compiler was invoked 80 times just for checking the
-Wno-fortify-source flag support.

$(call cc-disable-warning,fortify-source) should be added to a simple
variable instead of a recursive variable.

Problem 2: do not recompile string.o when the test code is updated

The test cases are independent of the kernel. However, when the test
code is updated, $(obj)/string.o is rebuilt and vmlinux is relinked
due to this dependency:

  $(obj)/string.o: $(obj)/$(TEST_FORTIFY_LOG)

always-y is suitable for building the log files.

Problem 3: redundant code

  clean-files += $(addsuffix .o, $(TEST_FORTIFY_LOGS))

... is unneeded because the top Makefile globally cleans *.o files.

This commit fixes these issues and makes the code readable.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 lib/.gitignore              |  2 --
 lib/Makefile                | 36 +-----------------------------------
 lib/test_fortify/.gitignore |  2 ++
 lib/test_fortify/Makefile   | 25 +++++++++++++++++++++++++
 4 files changed, 28 insertions(+), 37 deletions(-)
 create mode 100644 lib/test_fortify/.gitignore
 create mode 100644 lib/test_fortify/Makefile

diff --git a/lib/.gitignore b/lib/.gitignore
index 54596b634ecb..101a4aa92fb5 100644
--- a/lib/.gitignore
+++ b/lib/.gitignore
@@ -5,5 +5,3 @@
 /gen_crc32table
 /gen_crc64table
 /oid_registry_data.c
-/test_fortify.log
-/test_fortify/*.log
diff --git a/lib/Makefile b/lib/Makefile
index 429b259b5b64..689adbeb6c4c 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -393,38 +393,4 @@ obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
 
 obj-$(CONFIG_FIRMWARE_TABLE) += fw_table.o
 
-# FORTIFY_SOURCE compile-time behavior tests
-TEST_FORTIFY_SRCS = $(wildcard $(src)/test_fortify/*-*.c)
-TEST_FORTIFY_LOGS = $(patsubst $(src)/%.c, %.log, $(TEST_FORTIFY_SRCS))
-TEST_FORTIFY_LOG = test_fortify.log
-
-quiet_cmd_test_fortify = TEST    $@
-      cmd_test_fortify = $(CONFIG_SHELL) $(srctree)/scripts/test_fortify.sh \
-			$< $@ "$(NM)" $(CC) $(c_flags) \
-			$(call cc-disable-warning,fortify-source) \
-			-DKBUILD_EXTRA_WARN1
-
-targets += $(TEST_FORTIFY_LOGS)
-clean-files += $(TEST_FORTIFY_LOGS)
-clean-files += $(addsuffix .o, $(TEST_FORTIFY_LOGS))
-$(obj)/test_fortify/%.log: $(src)/test_fortify/%.c \
-			   $(srctree)/scripts/test_fortify.sh \
-			   FORCE
-	$(call if_changed_dep,test_fortify)
-
-quiet_cmd_gen_fortify_log = GEN     $@
-      cmd_gen_fortify_log = cat </dev/null $(filter-out FORCE,$^) 2>/dev/null > $@ || true
-
-targets += $(TEST_FORTIFY_LOG)
-clean-files += $(TEST_FORTIFY_LOG)
-$(obj)/$(TEST_FORTIFY_LOG): $(addprefix $(obj)/, $(TEST_FORTIFY_LOGS)) FORCE
-	$(call if_changed,gen_fortify_log)
-
-# Fake dependency to trigger the fortify tests.
-ifeq ($(CONFIG_FORTIFY_SOURCE),y)
-$(obj)/string.o: $(obj)/$(TEST_FORTIFY_LOG)
-endif
-
-# Some architectures define __NO_FORTIFY if __SANITIZE_ADDRESS__ is undefined.
-# Pass CFLAGS_KASAN to avoid warnings.
-$(foreach x, $(patsubst %.log,%.o,$(TEST_FORTIFY_LOGS)), $(eval KASAN_SANITIZE_$(x) := y))
+subdir-$(CONFIG_FORTIFY_SOURCE) += test_fortify
diff --git a/lib/test_fortify/.gitignore b/lib/test_fortify/.gitignore
new file mode 100644
index 000000000000..c1ba37d14b50
--- /dev/null
+++ b/lib/test_fortify/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/*.log
diff --git a/lib/test_fortify/Makefile b/lib/test_fortify/Makefile
new file mode 100644
index 000000000000..8c5bee33ee36
--- /dev/null
+++ b/lib/test_fortify/Makefile
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0
+
+ccflags-y := $(call cc-disable-warning,fortify-source)
+
+quiet_cmd_test_fortify = TEST    $@
+      cmd_test_fortify = $(CONFIG_SHELL) $(srctree)/scripts/test_fortify.sh \
+			$< $@ "$(NM)" $(CC) $(c_flags) -DKBUILD_EXTRA_WARN1
+
+$(obj)/%.log: $(src)/%.c $(srctree)/scripts/test_fortify.sh FORCE
+	$(call if_changed_dep,test_fortify)
+
+logs = $(patsubst $(src)/%.c, %.log, $(wildcard $(src)/*-*.c))
+targets += $(logs)
+
+quiet_cmd_gen_fortify_log = CAT     $@
+      cmd_gen_fortify_log = cat $(or $(real-prereqs),/dev/null) > $@
+
+$(obj)/test_fortify.log: $(addprefix $(obj)/, $(logs)) FORCE
+	$(call if_changed,gen_fortify_log)
+
+always-y += test_fortify.log
+
+# Some architectures define __NO_FORTIFY if __SANITIZE_ADDRESS__ is undefined.
+# Pass CFLAGS_KASAN to avoid warnings.
+KASAN_SANITIZE := y
-- 
2.43.0

[PATCH 3/3] fortify: move test_fortify.sh to lib/test_fortify/

[Masahiro Yamada]

This script is only used in lib/test_fortify/.

There is no reason to keep it in scripts/.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 MAINTAINERS                                   | 1 -
 lib/test_fortify/Makefile                     | 4 ++--
 {scripts => lib/test_fortify}/test_fortify.sh | 0
 3 files changed, 2 insertions(+), 3 deletions(-)
 rename {scripts => lib/test_fortify}/test_fortify.sh (100%)

diff --git a/MAINTAINERS b/MAINTAINERS
index 958e935449e5..b68386515067 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8598,7 +8598,6 @@ F:	include/linux/fortify-string.h
 F:	lib/fortify_kunit.c
 F:	lib/memcpy_kunit.c
 F:	lib/test_fortify/*
-F:	scripts/test_fortify.sh
 K:	\b__NO_FORTIFY\b
 
 FPGA DFL DRIVERS
diff --git a/lib/test_fortify/Makefile b/lib/test_fortify/Makefile
index 8c5bee33ee36..399cae880e1d 100644
--- a/lib/test_fortify/Makefile
+++ b/lib/test_fortify/Makefile
@@ -3,10 +3,10 @@
 ccflags-y := $(call cc-disable-warning,fortify-source)
 
 quiet_cmd_test_fortify = TEST    $@
-      cmd_test_fortify = $(CONFIG_SHELL) $(srctree)/scripts/test_fortify.sh \
+      cmd_test_fortify = $(CONFIG_SHELL) $(src)/test_fortify.sh \
 			$< $@ "$(NM)" $(CC) $(c_flags) -DKBUILD_EXTRA_WARN1
 
-$(obj)/%.log: $(src)/%.c $(srctree)/scripts/test_fortify.sh FORCE
+$(obj)/%.log: $(src)/%.c $(src)/test_fortify.sh FORCE
 	$(call if_changed_dep,test_fortify)
 
 logs = $(patsubst $(src)/%.c, %.log, $(wildcard $(src)/*-*.c))
diff --git a/scripts/test_fortify.sh b/lib/test_fortify/test_fortify.sh
similarity index 100%
rename from scripts/test_fortify.sh
rename to lib/test_fortify/test_fortify.sh
-- 
2.43.0

Re: [PATCH 0/3] fortify: fix various issues in test_fortify Makefile

[Kees Cook]

On Mon, Jul 15, 2024 at 11:45:22PM +0900, Masahiro Yamada wrote:
> Applicable to v6.10 tag.
> 
> 
> 
> Masahiro Yamada (3):
>   fortify: use if_changed_dep to record header dependency in *.cmd files
>   fortify: refactor test_fortify Makefile to fix some build problems
>   fortify: move test_fortify.sh to lib/test_fortify/

Thanks for this improvement! I will take this into the hardening tree
after -rc2, unless you would prefer to send this during the merge window
based on your tree? (The fix you sent for the v6.10 release means my
trees based on -rc2 can't apply this series...)

-Kees

-- 
Kees Cook

Re: [PATCH 0/3] fortify: fix various issues in test_fortify Makefile

[Masahiro Yamada]

On Tue, Jul 16, 2024 at 1:07 AM Kees Cook <kees@kernel.org> wrote:
>
> On Mon, Jul 15, 2024 at 11:45:22PM +0900, Masahiro Yamada wrote:
> > Applicable to v6.10 tag.
> >
> >
> >
> > Masahiro Yamada (3):
> >   fortify: use if_changed_dep to record header dependency in *.cmd files
> >   fortify: refactor test_fortify Makefile to fix some build problems
> >   fortify: move test_fortify.sh to lib/test_fortify/
>
> Thanks for this improvement! I will take this into the hardening tree
> after -rc2, unless you would prefer to send this during the merge window
> based on your tree? (The fix you sent for the v6.10 release means my
> trees based on -rc2 can't apply this series...)



No problem.

This patch set is not urgent.




>
> -Kees

>
> --
> Kees Cook



--
Best Regards
Masahiro Yamada

Re: [PATCH 1/3] fortify: use if_changed_dep to record header dependency in *.cmd files

[kernel test robot]

Hi Masahiro,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.10 next-20240716]
[cannot apply to akpm-mm/mm-nonmm-unstable kees/for-next/hardening kees/for-next/pstore kees/for-next/kspp]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Masahiro-Yamada/fortify-use-if_changed_dep-to-record-header-dependency-in-cmd-files/20240715-224820
base:   linus/master
patch link:    https://lore.kernel.org/r/20240715144529.101634-2-masahiroy%40kernel.org
patch subject: [PATCH 1/3] fortify: use if_changed_dep to record header dependency in *.cmd files
config: i386-randconfig-004-20240716 (https://download.01.org/0day-ci/archive/20240717/202407170104.dCe5MKsA-lkp@intel.com/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240717/202407170104.dCe5MKsA-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202407170104.dCe5MKsA-lkp@intel.com/

All errors (new ones prefixed by >>):

>> fixdep: error opening file: lib/test_fortify/.write_overflow-memcpy.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.read_overflow2-memcmp.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.read_overflow-memchr.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.write_overflow-strcpy-lit.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.read_overflow2-memmove.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.write_overflow-strncpy-src.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.read_overflow-memcmp.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.read_overflow-memscan.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.write_overflow-strcpy.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.write_overflow-memmove.log.d: No such file or directory
--
>> fixdep: error opening file: lib/test_fortify/.write_overflow-memset.log.d: No such file or directory
..

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 1/3] fortify: use if_changed_dep to record header dependency in *.cmd files

[Masahiro Yamada]

On Wed, Jul 17, 2024 at 2:51 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Masahiro,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on linus/master]
> [also build test ERROR on v6.10 next-20240716]
> [cannot apply to akpm-mm/mm-nonmm-unstable kees/for-next/hardening kees/for-next/pstore kees/for-next/kspp]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Masahiro-Yamada/fortify-use-if_changed_dep-to-record-header-dependency-in-cmd-files/20240715-224820
> base:   linus/master
> patch link:    https://lore.kernel.org/r/20240715144529.101634-2-masahiroy%40kernel.org
> patch subject: [PATCH 1/3] fortify: use if_changed_dep to record header dependency in *.cmd files
> config: i386-randconfig-004-20240716 (https://download.01.org/0day-ci/archive/20240717/202407170104.dCe5MKsA-lkp@intel.com/config)
> compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240717/202407170104.dCe5MKsA-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202407170104.dCe5MKsA-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> >> fixdep: error opening file: lib/test_fortify/.write_overflow-memcpy.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.read_overflow2-memcmp.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.read_overflow-memchr.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.write_overflow-strcpy-lit.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.read_overflow2-memmove.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.write_overflow-strncpy-src.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.read_overflow-memcmp.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.read_overflow-memscan.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.write_overflow-strcpy.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.write_overflow-memmove.log.d: No such file or directory
> --
> >> fixdep: error opening file: lib/test_fortify/.write_overflow-memset.log.d: No such file or directory
> ..



This issue seems to occur with GCC <=7


$ echo 'void b(void) __attribute__((__error__(""))); void a(void) {
b(); }' | gcc -Wp,-MMD,test.d -c -o /dev/null -x c -


did not create *.d with GCC <= 7.

I do not see the issue with GCC >= 8 or Clang.


One quick solution is to skip the test for GCC <= 7.





>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
>


-- 
Best Regards
Masahiro Yamada

Re: [PATCH 1/3] fortify: use if_changed_dep to record header dependency in *.cmd files

[Kees Cook]

On Wed, Jul 17, 2024 at 01:46:32PM +0900, Masahiro Yamada wrote:
> On Wed, Jul 17, 2024 at 2:51 AM kernel test robot <lkp@intel.com> wrote:
> >
> > Hi Masahiro,
> >
> > kernel test robot noticed the following build errors:
> >
> > [auto build test ERROR on linus/master]
> > [also build test ERROR on v6.10 next-20240716]
> > [cannot apply to akpm-mm/mm-nonmm-unstable kees/for-next/hardening kees/for-next/pstore kees/for-next/kspp]
> > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > And when submitting patch, we suggest to use '--base' as documented in
> > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> >
> > url:    https://github.com/intel-lab-lkp/linux/commits/Masahiro-Yamada/fortify-use-if_changed_dep-to-record-header-dependency-in-cmd-files/20240715-224820
> > base:   linus/master
> > patch link:    https://lore.kernel.org/r/20240715144529.101634-2-masahiroy%40kernel.org
> > patch subject: [PATCH 1/3] fortify: use if_changed_dep to record header dependency in *.cmd files
> > config: i386-randconfig-004-20240716 (https://download.01.org/0day-ci/archive/20240717/202407170104.dCe5MKsA-lkp@intel.com/config)
> > compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240717/202407170104.dCe5MKsA-lkp@intel.com/reproduce)
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202407170104.dCe5MKsA-lkp@intel.com/
> >
> > All errors (new ones prefixed by >>):
> >
> > >> fixdep: error opening file: lib/test_fortify/.write_overflow-memcpy.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.read_overflow2-memcmp.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.read_overflow-memchr.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.write_overflow-strcpy-lit.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.read_overflow2-memmove.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.write_overflow-strncpy-src.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.read_overflow-memcmp.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.read_overflow-memscan.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.write_overflow-strcpy.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.write_overflow-memmove.log.d: No such file or directory
> > --
> > >> fixdep: error opening file: lib/test_fortify/.write_overflow-memset.log.d: No such file or directory
> > ..
> 
> 
> 
> This issue seems to occur with GCC <=7
> 
> 
> $ echo 'void b(void) __attribute__((__error__(""))); void a(void) {
> b(); }' | gcc -Wp,-MMD,test.d -c -o /dev/null -x c -
> 
> 
> did not create *.d with GCC <= 7.
> 
> I do not see the issue with GCC >= 8 or Clang.

Any idea why this happens here and not for other sources in the tree?

> One quick solution is to skip the test for GCC <= 7.

I'd be fine with that -- it is designed to catch regressions/misbehaviours
in newly release compilers so I don't mind dropping checks against older
versions.

-- 
Kees Cook

Re: [PATCH 1/3] fortify: use if_changed_dep to record header dependency in *.cmd files

[Masahiro Yamada]

On Thu, Jul 18, 2024 at 7:19 AM Kees Cook <kees@kernel.org> wrote:
>
> On Wed, Jul 17, 2024 at 01:46:32PM +0900, Masahiro Yamada wrote:
> > On Wed, Jul 17, 2024 at 2:51 AM kernel test robot <lkp@intel.com> wrote:
> > >
> > > Hi Masahiro,
> > >
> > > kernel test robot noticed the following build errors:
> > >
> > > [auto build test ERROR on linus/master]
> > > [also build test ERROR on v6.10 next-20240716]
> > > [cannot apply to akpm-mm/mm-nonmm-unstable kees/for-next/hardening kees/for-next/pstore kees/for-next/kspp]
> > > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > > And when submitting patch, we suggest to use '--base' as documented in
> > > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> > >
> > > url:    https://github.com/intel-lab-lkp/linux/commits/Masahiro-Yamada/fortify-use-if_changed_dep-to-record-header-dependency-in-cmd-files/20240715-224820
> > > base:   linus/master
> > > patch link:    https://lore.kernel.org/r/20240715144529.101634-2-masahiroy%40kernel.org
> > > patch subject: [PATCH 1/3] fortify: use if_changed_dep to record header dependency in *.cmd files
> > > config: i386-randconfig-004-20240716 (https://download.01.org/0day-ci/archive/20240717/202407170104.dCe5MKsA-lkp@intel.com/config)
> > > compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
> > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240717/202407170104.dCe5MKsA-lkp@intel.com/reproduce)
> > >
> > > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > > the same patch/commit), kindly add following tags
> > > | Reported-by: kernel test robot <lkp@intel.com>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202407170104.dCe5MKsA-lkp@intel.com/
> > >
> > > All errors (new ones prefixed by >>):
> > >
> > > >> fixdep: error opening file: lib/test_fortify/.write_overflow-memcpy.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.read_overflow2-memcmp.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.read_overflow-memchr.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.write_overflow-strcpy-lit.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.read_overflow2-memmove.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.write_overflow-strncpy-src.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.read_overflow-memcmp.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.read_overflow-memscan.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.write_overflow-strcpy.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.write_overflow-memmove.log.d: No such file or directory
> > > --
> > > >> fixdep: error opening file: lib/test_fortify/.write_overflow-memset.log.d: No such file or directory
> > > ..
> >
> >
> >
> > This issue seems to occur with GCC <=7
> >
> >
> > $ echo 'void b(void) __attribute__((__error__(""))); void a(void) {
> > b(); }' | gcc -Wp,-MMD,test.d -c -o /dev/null -x c -
> >
> >
> > did not create *.d with GCC <= 7.
> >
> > I do not see the issue with GCC >= 8 or Clang.
>
> Any idea why this happens here and not for other sources in the tree?


Because the logic is opposite.


For other locations, you need to write the correct code.
When it is compiled successfully, *.d is generated as well.



Under lib/test_fortify/, you intentionally incorrect code.
GCC emits a compile error, and test_fortify.sh checks
the error message.
I believe *.d should be still generated unless a pre-processor error occurs.





> > One quick solution is to skip the test for GCC <= 7.
>
> I'd be fine with that -- it is designed to catch regressions/misbehaviours
> in newly release compilers so I don't mind dropping checks against older
> versions.
>
> --
> Kees Cook



-- 
Best Regards
Masahiro Yamada