[Cocci] [PATCH v2 0/10] Symbol namespaces - RFC

[Cocci] [PATCH v2 0/10] Symbol namespaces - RFC

[Matthias Maennich]

As of Linux 5.3-rc4, there are 31203 [1] exported symbols in the kernel.
That is a growth of almost 1000 symbols since 4.17 (30206 [2]).  There
seems to be some consensus amongst kernel devs that the export surface
is too large, and hard to reason about.

Generally, these symbols fall in one of these categories:
1) Symbols actually meant for drivers
2) Symbols that are only exported because functionality is split over
   multiple modules, yet they really shouldn't be used by modules outside
   of their own subsystem
3) Symbols really only meant for in-tree use

When module developers try to upstream their code, it regularly turns
out that they are using exported symbols that they really shouldn't be
using. This problem is even bigger for drivers that are currently
out-of-tree, which may be using many symbols that they shouldn't be
using, and that break when those symbols are removed or modified.

This patch allows subsystem maintainers to partition their exported
symbols into separate namespaces, and module authors to import such
namespaces only when needed.

This allows subsystem maintainers to more easily limit availability of
these namespaced symbols to other parts of the kernel. It can also be
used to partition the set of exported symbols for documentation
purposes; for example, a set of symbols that is really only used for
debugging could be in a "SUBSYSTEM_DEBUG" namespace.

I continued the work mainly done by Martijn Coenen. In this v2 the
following changes have been introduced compared to v1 of this series:

- Rather than adding and evaluating separate sections __knsimport_NS,
  use modinfo tags to declare the namespaces a module introduces.
  Adjust modpost and the module loader accordingly.
- Also add support for reading multiple modinfo values for the same tag
  to allow list-like access to modinfo tags.
- The macros in export.h have been cleaned up to avoid redundancy in the
  macro parameters (ns, nspost, nspost2).
- The introduction of relative references in the ksymtab entries caused
  a rework of the macros to accommodate that configuration as well.
- Alignment of kernel_symbol in the ksymtab needed to be fixed to allow
  growing the kernel_symbol struct.
- Modpost does now also append the namespace suffix to the symbol
  entries in Module.symvers.
- The configuration option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS allows
  relaxing the enforcement of properly declared namespace imports at module
  loading time.
- Symbols can be collectively exported into a namespace by defining
  DEFAULT_SYMBOL_NAMESPACE in the corresponding Makefile.
- The requirement for a very recent coccinelle spatch has been lifted by
  simplifying the script.
- nsdeps does now ensures MODULE_IMPORT_NS statements are sorted when
  patching the module source files.
- Some minor bugs have been addressed in nsdeps to allow it to work with
  modules that have more than one source file.
- The RFC for the usb-storage symbols has been simplified by using
  DEFAULT_SYMBOL_NAMESPACE=USB_STORAGE rather than explicitly exporting each
  and every symbol into that new namespace.

This patch series was developed against v5.3-rc4.

[1] git grep "^EXPORT_SYMBOL\w*(" v5.3-rc4 | wc -l
[2] git grep "^EXPORT_SYMBOL\w*(" v4.17    | wc -l

Matthias Maennich (10):
  module: support reading multiple values per modinfo tag
  export: explicitly align struct kernel_symbol
  module: add support for symbol namespaces.
  modpost: add support for symbol namespaces
  module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
  export: allow definition default namespaces in Makefiles or sources
  modpost: add support for generating namespace dependencies
  scripts: Coccinelle script for namespace dependencies.
  usb-storage: remove single-use define for debugging
  RFC: usb-storage: export symbols in USB_STORAGE namespace

 MAINTAINERS                                 |   5 +
 Makefile                                    |  12 ++
 arch/m68k/include/asm/export.h              |   1 -
 drivers/usb/storage/Makefile                |   2 +
 drivers/usb/storage/alauda.c                |   1 +
 drivers/usb/storage/cypress_atacb.c         |   1 +
 drivers/usb/storage/datafab.c               |   1 +
 drivers/usb/storage/debug.h                 |   2 -
 drivers/usb/storage/ene_ub6250.c            |   1 +
 drivers/usb/storage/freecom.c               |   1 +
 drivers/usb/storage/isd200.c                |   1 +
 drivers/usb/storage/jumpshot.c              |   1 +
 drivers/usb/storage/karma.c                 |   1 +
 drivers/usb/storage/onetouch.c              |   1 +
 drivers/usb/storage/realtek_cr.c            |   1 +
 drivers/usb/storage/scsiglue.c              |   2 +-
 drivers/usb/storage/sddr09.c                |   1 +
 drivers/usb/storage/sddr55.c                |   1 +
 drivers/usb/storage/shuttle_usbat.c         |   1 +
 drivers/usb/storage/uas.c                   |   1 +
 include/asm-generic/export.h                |  14 +-
 include/linux/export.h                      |  92 +++++++++++--
 include/linux/module.h                      |   2 +
 init/Kconfig                                |  14 ++
 kernel/module.c                             |  67 ++++++++-
 scripts/Makefile.modpost                    |   4 +-
 scripts/coccinelle/misc/add_namespace.cocci |  23 ++++
 scripts/mod/modpost.c                       | 144 ++++++++++++++++++--
 scripts/mod/modpost.h                       |   9 ++
 scripts/nsdeps                              |  54 ++++++++
 30 files changed, 421 insertions(+), 40 deletions(-)
 create mode 100644 scripts/coccinelle/misc/add_namespace.cocci
 create mode 100644 scripts/nsdeps

-- 
2.23.0.rc1.153.gdeed80330f-goog

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[Cocci] [PATCH v2 08/10] scripts: Coccinelle script for namespace dependencies.

[Matthias Maennich]

A script that uses the '<module>.ns_deps' file generated by modpost to
automatically add the required symbol namespace dependencies to each
module.

Usage:
1) Move some symbols to a namespace with EXPORT_SYMBOL_NS() or define
   DEFAULT_SYMBOL_NAMESPACE
2) Run 'make' (or 'make modules') and get warnings about modules not
   importing that namespace.
3) Run 'make nsdeps' to automatically add required import statements
   to said modules.

This makes it easer for subsystem maintainers to introduce and maintain
symbol namespaces into their codebase.

Co-developed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Matthias Maennich <maennich@google.com>
---
 MAINTAINERS                                 |  5 ++
 Makefile                                    | 12 +++++
 scripts/Makefile.modpost                    |  4 +-
 scripts/coccinelle/misc/add_namespace.cocci | 23 +++++++++
 scripts/nsdeps                              | 54 +++++++++++++++++++++
 5 files changed, 97 insertions(+), 1 deletion(-)
 create mode 100644 scripts/coccinelle/misc/add_namespace.cocci
 create mode 100644 scripts/nsdeps

diff --git a/MAINTAINERS b/MAINTAINERS
index e81e60bd7c26..aa169070a052 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11414,6 +11414,11 @@ S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/nolibc.git
 F:	tools/include/nolibc/
 
+NSDEPS
+M:	Matthias Maennich <maennich@google.com>
+S:	Maintained
+F:	scripts/nsdeps
+
 NTB AMD DRIVER
 M:	Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
 L:	linux-ntb@googlegroups.com
diff --git a/Makefile b/Makefile
index 1b23f95db176..c5c3356e133c 100644
--- a/Makefile
+++ b/Makefile
@@ -1500,6 +1500,9 @@ help:
 	@echo  '  headerdep       - Detect inclusion cycles in headers'
 	@echo  '  coccicheck      - Check with Coccinelle'
 	@echo  ''
+	@echo  'Tools:'
+	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
+	@echo  ''
 	@echo  'Kernel selftest:'
 	@echo  '  kselftest       - Build and run kernel selftest (run as root)'
 	@echo  '                    Build, install, and boot kernel before'
@@ -1687,6 +1690,15 @@ quiet_cmd_tags = GEN     $@
 tags TAGS cscope gtags: FORCE
 	$(call cmd,tags)
 
+# Script to generate missing namespace dependencies
+# ---------------------------------------------------------------------------
+
+PHONY += nsdeps
+
+nsdeps:
+	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost nsdeps
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
+
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------
 
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 26e6574ecd08..743fe3a2e885 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -56,7 +56,8 @@ MODPOST = scripts/mod/modpost						\
 	$(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS)))	\
 	$(if $(KBUILD_EXTMOD),-o $(modulesymfile))			\
 	$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)			\
-	$(if $(KBUILD_MODPOST_WARN),-w)
+	$(if $(KBUILD_MODPOST_WARN),-w)					\
+	$(if $(filter nsdeps,$(MAKECMDGOALS)),-d)
 
 ifdef MODPOST_VMLINUX
 
@@ -134,6 +135,7 @@ $(modules): %.ko :%.o %.mod.o FORCE
 
 targets += $(modules)
 
+nsdeps: __modpost
 
 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
 # ---------------------------------------------------------------------------
diff --git a/scripts/coccinelle/misc/add_namespace.cocci b/scripts/coccinelle/misc/add_namespace.cocci
new file mode 100644
index 000000000000..c832bb6445a8
--- /dev/null
+++ b/scripts/coccinelle/misc/add_namespace.cocci
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+/// Adds missing MODULE_IMPORT_NS statements to source files
+///
+/// This script is usually called from scripts/nsdeps with -D ns=<namespace> to
+/// add a missing namespace tag to a module source file.
+///
+
+@has_ns_import@
+declarer name MODULE_IMPORT_NS;
+identifier virtual.ns;
+@@
+MODULE_IMPORT_NS(ns);
+
+// Add missing imports, but only adjacent to a MODULE_LICENSE statement.
+// That ensures we are adding it only to the main module source file.
+@do_import depends on !has_ns_import@
+declarer name MODULE_LICENSE;
+expression license;
+identifier virtual.ns;
+@@
+MODULE_LICENSE(license);
++ MODULE_IMPORT_NS(ns);
diff --git a/scripts/nsdeps b/scripts/nsdeps
new file mode 100644
index 000000000000..148db65a830f
--- /dev/null
+++ b/scripts/nsdeps
@@ -0,0 +1,54 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Linux kernel symbol namespace import generator
+#
+# This script requires at least spatch
+# version 1.0.4.
+SPATCH_REQ_VERSION="1.0.4"
+
+DIR="$(dirname $(readlink -f $0))/.."
+SPATCH="`which ${SPATCH:=spatch}`"
+if [ ! -x "$SPATCH" ]; then
+    echo 'spatch is part of the Coccinelle project and is available at http://coccinelle.lip6.fr/'
+    exit 1
+fi
+
+SPATCH_REQ_VERSION_NUM=$(echo $SPATCH_REQ_VERSION | ${DIR}/scripts/ld-version.sh)
+SPATCH_VERSION=$($SPATCH --version | head -1 | awk '{print $3}')
+SPATCH_VERSION_NUM=$(echo $SPATCH_VERSION | ${DIR}/scripts/ld-version.sh)
+
+if [ "$SPATCH_VERSION_NUM" -lt "$SPATCH_REQ_VERSION_NUM" ] ; then
+    echo 'spatch needs to be version 1.06 or higher'
+    exit 1
+fi
+
+generate_deps_for_ns() {
+    $SPATCH --very-quiet --in-place --sp-file \
+	    $srctree/scripts/coccinelle/misc/add_namespace.cocci -D ns=$1 $2
+}
+
+generate_deps() {
+    local mod_file=`echo $@ | sed -e 's/\.ns_deps/\.mod/'`
+    local mod_name=`cat $mod_file | sed -n 1p | sed -e 's/\/[^.]*$//'`
+    local mod_source_files=`cat $mod_file | sed -n 2p | sed -e 's/\.o/\.c/g'`
+    for ns in `cat $@`; do
+	echo "Adding namespace $ns to module $mod_name (if needed)."
+        generate_deps_for_ns $ns $mod_source_files
+	# sort the imports
+        for source_file in $mod_source_files; do
+            sed '/MODULE_IMPORT_NS/Q' $source_file > ${source_file}.tmp
+            offset=$(wc -l ${source_file}.tmp | awk '{print $1;}')
+            cat $source_file | grep MODULE_IMPORT_NS | sort -u >> ${source_file}.tmp
+            tail -n +$((offset +1)) ${source_file} | grep -v MODULE_IMPORT_NS >> ${source_file}.tmp
+            if ! diff -q ${source_file} ${source_file}.tmp; then
+                mv ${source_file}.tmp ${source_file}
+            else
+                rm ${source_file}.tmp
+            fi
+        done
+    done
+}
+
+for f in `find $srctree/.tmp_versions/ -name *.ns_deps`; do
+    generate_deps $f
+done
-- 
2.23.0.rc1.153.gdeed80330f-goog

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Re: [Cocci] [PATCH v2 08/10] scripts: Coccinelle script for namespace dependencies.

[Julia Lawall]

On Tue, 13 Aug 2019, Matthias Maennich wrote:

> A script that uses the '<module>.ns_deps' file generated by modpost to
> automatically add the required symbol namespace dependencies to each
> module.
>
> Usage:
> 1) Move some symbols to a namespace with EXPORT_SYMBOL_NS() or define
>    DEFAULT_SYMBOL_NAMESPACE
> 2) Run 'make' (or 'make modules') and get warnings about modules not
>    importing that namespace.
> 3) Run 'make nsdeps' to automatically add required import statements
>    to said modules.
>
> This makes it easer for subsystem maintainers to introduce and maintain
> symbol namespaces into their codebase.
>
> Co-developed-by: Martijn Coenen <maco@android.com>
> Signed-off-by: Martijn Coenen <maco@android.com>
> Signed-off-by: Matthias Maennich <maennich@google.com>

Acked-by: Julia Lawall <julia.lawall@lip6.fr>


> ---
>  MAINTAINERS                                 |  5 ++
>  Makefile                                    | 12 +++++
>  scripts/Makefile.modpost                    |  4 +-
>  scripts/coccinelle/misc/add_namespace.cocci | 23 +++++++++
>  scripts/nsdeps                              | 54 +++++++++++++++++++++
>  5 files changed, 97 insertions(+), 1 deletion(-)
>  create mode 100644 scripts/coccinelle/misc/add_namespace.cocci
>  create mode 100644 scripts/nsdeps
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e81e60bd7c26..aa169070a052 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11414,6 +11414,11 @@ S:	Maintained
>  T:	git git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/nolibc.git
>  F:	tools/include/nolibc/
>
> +NSDEPS
> +M:	Matthias Maennich <maennich@google.com>
> +S:	Maintained
> +F:	scripts/nsdeps
> +
>  NTB AMD DRIVER
>  M:	Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
>  L:	linux-ntb@googlegroups.com
> diff --git a/Makefile b/Makefile
> index 1b23f95db176..c5c3356e133c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1500,6 +1500,9 @@ help:
>  	@echo  '  headerdep       - Detect inclusion cycles in headers'
>  	@echo  '  coccicheck      - Check with Coccinelle'
>  	@echo  ''
> +	@echo  'Tools:'
> +	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
> +	@echo  ''
>  	@echo  'Kernel selftest:'
>  	@echo  '  kselftest       - Build and run kernel selftest (run as root)'
>  	@echo  '                    Build, install, and boot kernel before'
> @@ -1687,6 +1690,15 @@ quiet_cmd_tags = GEN     $@
>  tags TAGS cscope gtags: FORCE
>  	$(call cmd,tags)
>
> +# Script to generate missing namespace dependencies
> +# ---------------------------------------------------------------------------
> +
> +PHONY += nsdeps
> +
> +nsdeps:
> +	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost nsdeps
> +	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
> +
>  # Scripts to check various things for consistency
>  # ---------------------------------------------------------------------------
>
> diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
> index 26e6574ecd08..743fe3a2e885 100644
> --- a/scripts/Makefile.modpost
> +++ b/scripts/Makefile.modpost
> @@ -56,7 +56,8 @@ MODPOST = scripts/mod/modpost						\
>  	$(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS)))	\
>  	$(if $(KBUILD_EXTMOD),-o $(modulesymfile))			\
>  	$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)			\
> -	$(if $(KBUILD_MODPOST_WARN),-w)
> +	$(if $(KBUILD_MODPOST_WARN),-w)					\
> +	$(if $(filter nsdeps,$(MAKECMDGOALS)),-d)
>
>  ifdef MODPOST_VMLINUX
>
> @@ -134,6 +135,7 @@ $(modules): %.ko :%.o %.mod.o FORCE
>
>  targets += $(modules)
>
> +nsdeps: __modpost
>
>  # Add FORCE to the prequisites of a target to force it to be always rebuilt.
>  # ---------------------------------------------------------------------------
> diff --git a/scripts/coccinelle/misc/add_namespace.cocci b/scripts/coccinelle/misc/add_namespace.cocci
> new file mode 100644
> index 000000000000..c832bb6445a8
> --- /dev/null
> +++ b/scripts/coccinelle/misc/add_namespace.cocci
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +//
> +/// Adds missing MODULE_IMPORT_NS statements to source files
> +///
> +/// This script is usually called from scripts/nsdeps with -D ns=<namespace> to
> +/// add a missing namespace tag to a module source file.
> +///
> +
> +@has_ns_import@
> +declarer name MODULE_IMPORT_NS;
> +identifier virtual.ns;
> +@@
> +MODULE_IMPORT_NS(ns);
> +
> +// Add missing imports, but only adjacent to a MODULE_LICENSE statement.
> +// That ensures we are adding it only to the main module source file.
> +@do_import depends on !has_ns_import@
> +declarer name MODULE_LICENSE;
> +expression license;
> +identifier virtual.ns;
> +@@
> +MODULE_LICENSE(license);
> ++ MODULE_IMPORT_NS(ns);
> diff --git a/scripts/nsdeps b/scripts/nsdeps
> new file mode 100644
> index 000000000000..148db65a830f
> --- /dev/null
> +++ b/scripts/nsdeps
> @@ -0,0 +1,54 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Linux kernel symbol namespace import generator
> +#
> +# This script requires at least spatch
> +# version 1.0.4.
> +SPATCH_REQ_VERSION="1.0.4"
> +
> +DIR="$(dirname $(readlink -f $0))/.."
> +SPATCH="`which ${SPATCH:=spatch}`"
> +if [ ! -x "$SPATCH" ]; then
> +    echo 'spatch is part of the Coccinelle project and is available at http://coccinelle.lip6.fr/'
> +    exit 1
> +fi
> +
> +SPATCH_REQ_VERSION_NUM=$(echo $SPATCH_REQ_VERSION | ${DIR}/scripts/ld-version.sh)
> +SPATCH_VERSION=$($SPATCH --version | head -1 | awk '{print $3}')
> +SPATCH_VERSION_NUM=$(echo $SPATCH_VERSION | ${DIR}/scripts/ld-version.sh)
> +
> +if [ "$SPATCH_VERSION_NUM" -lt "$SPATCH_REQ_VERSION_NUM" ] ; then
> +    echo 'spatch needs to be version 1.06 or higher'
> +    exit 1
> +fi
> +
> +generate_deps_for_ns() {
> +    $SPATCH --very-quiet --in-place --sp-file \
> +	    $srctree/scripts/coccinelle/misc/add_namespace.cocci -D ns=$1 $2
> +}
> +
> +generate_deps() {
> +    local mod_file=`echo $@ | sed -e 's/\.ns_deps/\.mod/'`
> +    local mod_name=`cat $mod_file | sed -n 1p | sed -e 's/\/[^.]*$//'`
> +    local mod_source_files=`cat $mod_file | sed -n 2p | sed -e 's/\.o/\.c/g'`
> +    for ns in `cat $@`; do
> +	echo "Adding namespace $ns to module $mod_name (if needed)."
> +        generate_deps_for_ns $ns $mod_source_files
> +	# sort the imports
> +        for source_file in $mod_source_files; do
> +            sed '/MODULE_IMPORT_NS/Q' $source_file > ${source_file}.tmp
> +            offset=$(wc -l ${source_file}.tmp | awk '{print $1;}')
> +            cat $source_file | grep MODULE_IMPORT_NS | sort -u >> ${source_file}.tmp
> +            tail -n +$((offset +1)) ${source_file} | grep -v MODULE_IMPORT_NS >> ${source_file}.tmp
> +            if ! diff -q ${source_file} ${source_file}.tmp; then
> +                mv ${source_file}.tmp ${source_file}
> +            else
> +                rm ${source_file}.tmp
> +            fi
> +        done
> +    done
> +}
> +
> +for f in `find $srctree/.tmp_versions/ -name *.ns_deps`; do
> +    generate_deps $f
> +done
> --
> 2.23.0.rc1.153.gdeed80330f-goog
>
>
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Re: [Cocci] [PATCH v2 08/10] scripts: Coccinelle script for namespace dependencies.

[Greg KH]

On Tue, Aug 13, 2019 at 01:17:05PM +0100, Matthias Maennich wrote:
> A script that uses the '<module>.ns_deps' file generated by modpost to
> automatically add the required symbol namespace dependencies to each
> module.
> 
> Usage:
> 1) Move some symbols to a namespace with EXPORT_SYMBOL_NS() or define
>    DEFAULT_SYMBOL_NAMESPACE
> 2) Run 'make' (or 'make modules') and get warnings about modules not
>    importing that namespace.
> 3) Run 'make nsdeps' to automatically add required import statements
>    to said modules.
> 
> This makes it easer for subsystem maintainers to introduce and maintain
> symbol namespaces into their codebase.
> 
> Co-developed-by: Martijn Coenen <maco@android.com>
> Signed-off-by: Martijn Coenen <maco@android.com>
> Signed-off-by: Matthias Maennich <maennich@google.com>
> ---

I really can't express just how cool this patch is.  I was amazed when I
first saw it in action a long time ago, and still am.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Re: [Cocci] [PATCH v2 08/10] scripts: Coccinelle script for namespace dependencies.

[Himanshu Jha]

On Tue, Aug 13, 2019 at 01:17:05PM +0100, Matthias Maennich wrote:
> A script that uses the '<module>.ns_deps' file generated by modpost to
> automatically add the required symbol namespace dependencies to each
> module.
> 
> Usage:
> 1) Move some symbols to a namespace with EXPORT_SYMBOL_NS() or define
>    DEFAULT_SYMBOL_NAMESPACE
> 2) Run 'make' (or 'make modules') and get warnings about modules not
>    importing that namespace.
> 3) Run 'make nsdeps' to automatically add required import statements
>    to said modules.
> 
> This makes it easer for subsystem maintainers to introduce and maintain
> symbol namespaces into their codebase.
> 
> Co-developed-by: Martijn Coenen <maco@android.com>
> Signed-off-by: Martijn Coenen <maco@android.com>
> Signed-off-by: Matthias Maennich <maennich@google.com>
> ---

[]

>  MAINTAINERS                                 |  5 ++
>  Makefile                                    | 12 +++++
>  scripts/Makefile.modpost                    |  4 +-
>  scripts/coccinelle/misc/add_namespace.cocci | 23 +++++++++
>  scripts/nsdeps                              | 54 +++++++++++++++++++++
>  5 files changed, 97 insertions(+), 1 deletion(-)
>  create mode 100644 scripts/coccinelle/misc/add_namespace.cocci
>  create mode 100644 scripts/nsdeps

[]

> +if [ "$SPATCH_VERSION_NUM" -lt "$SPATCH_REQ_VERSION_NUM" ] ; then
> +    echo 'spatch needs to be version 1.06 or higher'

Nitpick: 1.0.6

> +    exit 1
> +fi


-- 
Himanshu Jha
Undergraduate Student
Department of Electronics & Communication
Guru Tegh Bahadur Institute of Technology
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Re: [Cocci] [PATCH v2 08/10] scripts: Coccinelle script for namespace dependencies.

[Matthias Maennich]

On Wed, Aug 14, 2019 at 12:06:11PM +0530, Himanshu Jha wrote:
>On Tue, Aug 13, 2019 at 01:17:05PM +0100, Matthias Maennich wrote:
>> A script that uses the '<module>.ns_deps' file generated by modpost to
>> automatically add the required symbol namespace dependencies to each
>> module.
>>
>> Usage:
>> 1) Move some symbols to a namespace with EXPORT_SYMBOL_NS() or define
>>    DEFAULT_SYMBOL_NAMESPACE
>> 2) Run 'make' (or 'make modules') and get warnings about modules not
>>    importing that namespace.
>> 3) Run 'make nsdeps' to automatically add required import statements
>>    to said modules.
>>
>> This makes it easer for subsystem maintainers to introduce and maintain
>> symbol namespaces into their codebase.
>>
>> Co-developed-by: Martijn Coenen <maco@android.com>
>> Signed-off-by: Martijn Coenen <maco@android.com>
>> Signed-off-by: Matthias Maennich <maennich@google.com>
>> ---
>
>[]
>
>>  MAINTAINERS                                 |  5 ++
>>  Makefile                                    | 12 +++++
>>  scripts/Makefile.modpost                    |  4 +-
>>  scripts/coccinelle/misc/add_namespace.cocci | 23 +++++++++
>>  scripts/nsdeps                              | 54 +++++++++++++++++++++
>>  5 files changed, 97 insertions(+), 1 deletion(-)
>>  create mode 100644 scripts/coccinelle/misc/add_namespace.cocci
>>  create mode 100644 scripts/nsdeps
>
>[]
>
>> +if [ "$SPATCH_VERSION_NUM" -lt "$SPATCH_REQ_VERSION_NUM" ] ; then
>> +    echo 'spatch needs to be version 1.06 or higher'
>
>Nitpick: 1.0.6
>

Good catch! Thanks!
Actually it needs to be even 1.0.4, so I will just use
$SPATCH_REQ_VERSION from above.

>> +    exit 1
>> +fi
>
>
>-- 
>Himanshu Jha
>Undergraduate Student
>Department of Electronics & Communication
>Guru Tegh Bahadur Institute of Technology
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Re: [Cocci] [v2 08/10] scripts: Coccinelle script for namespace dependencies

[Markus Elfring]

+# This script requires at least spatch
+# version 1.0.4.

How do you think about to avoid the duplicate specification of this identification?

Regards,
Markus
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Re: [Cocci] [v2 08/10] scripts: Coccinelle script for namespace dependencies

[Matthias Maennich]

On Wed, Aug 14, 2019 at 02:00:23PM +0200, Markus Elfring wrote:
>+# This script requires at least spatch
>+# version 1.0.4.
>
>How do you think about to avoid the duplicate specification of this identification?
>

That is a good idea. I will reduce the patch to

+# This script requires a minimum spatch version.
+SPATCH_REQ_VERSION="1.0.4"

and use $SPATCH_REQ_VERSION when diagnosing this issue further down.

Cheers,
Matthias
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Re: [Cocci] [PATCH v3 08/11] scripts: Coccinelle script for namespace dependencies.

[Jessica Yu]

+++ Matthias Maennich [21/08/19 12:49 +0100]:
>A script that uses the '<module>.ns_deps' files generated by modpost to
>automatically add the required symbol namespace dependencies to each
>module.
>
>Usage:
>1) Move some symbols to a namespace with EXPORT_SYMBOL_NS() or define
>   DEFAULT_SYMBOL_NAMESPACE
>2) Run 'make' (or 'make modules') and get warnings about modules not
>   importing that namespace.
>3) Run 'make nsdeps' to automatically add required import statements
>   to said modules.
>
>This makes it easer for subsystem maintainers to introduce and maintain
>symbol namespaces into their codebase.
>
>Co-developed-by: Martijn Coenen <maco@android.com>
>Signed-off-by: Martijn Coenen <maco@android.com>
>Acked-by: Julia Lawall <julia.lawall@lip6.fr>
>Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>Signed-off-by: Matthias Maennich <maennich@google.com>
>---
> MAINTAINERS                                 |  5 ++
> Makefile                                    | 12 +++++
> scripts/Makefile.modpost                    |  4 +-
> scripts/coccinelle/misc/add_namespace.cocci | 23 +++++++++
> scripts/nsdeps                              | 56 +++++++++++++++++++++
> 5 files changed, 99 insertions(+), 1 deletion(-)
> create mode 100644 scripts/coccinelle/misc/add_namespace.cocci
> create mode 100644 scripts/nsdeps
>
>diff --git a/MAINTAINERS b/MAINTAINERS
>index 08176d64eed5..dd5b37b49a07 100644
>--- a/MAINTAINERS
>+++ b/MAINTAINERS
>@@ -11428,6 +11428,11 @@ S:	Maintained
> T:	git git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/nolibc.git
> F:	tools/include/nolibc/
>
>+NSDEPS
>+M:	Matthias Maennich <maennich@google.com>
>+S:	Maintained
>+F:	scripts/nsdeps
>+
> NTB AMD DRIVER
> M:	Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> L:	linux-ntb@googlegroups.com
>diff --git a/Makefile b/Makefile
>index a89870188c09..40311f583ee1 100644
>--- a/Makefile
>+++ b/Makefile
>@@ -1500,6 +1500,9 @@ help:
> 	@echo  '  headerdep       - Detect inclusion cycles in headers'
> 	@echo  '  coccicheck      - Check with Coccinelle'
> 	@echo  ''
>+	@echo  'Tools:'
>+	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
>+	@echo  ''
> 	@echo  'Kernel selftest:'
> 	@echo  '  kselftest       - Build and run kernel selftest (run as root)'
> 	@echo  '                    Build, install, and boot kernel before'
>@@ -1687,6 +1690,15 @@ quiet_cmd_tags = GEN     $@
> tags TAGS cscope gtags: FORCE
> 	$(call cmd,tags)
>
>+# Script to generate missing namespace dependencies
>+# ---------------------------------------------------------------------------
>+
>+PHONY += nsdeps
>+
>+nsdeps:
>+	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost nsdeps
>+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
>+
> # Scripts to check various things for consistency
> # ---------------------------------------------------------------------------
>
>diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
>index 26e6574ecd08..743fe3a2e885 100644
>--- a/scripts/Makefile.modpost
>+++ b/scripts/Makefile.modpost
>@@ -56,7 +56,8 @@ MODPOST = scripts/mod/modpost						\
> 	$(if $(KBUILD_EXTMOD),$(addprefix -e ,$(KBUILD_EXTRA_SYMBOLS)))	\
> 	$(if $(KBUILD_EXTMOD),-o $(modulesymfile))			\
> 	$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E)			\
>-	$(if $(KBUILD_MODPOST_WARN),-w)
>+	$(if $(KBUILD_MODPOST_WARN),-w)					\
>+	$(if $(filter nsdeps,$(MAKECMDGOALS)),-d)
>
> ifdef MODPOST_VMLINUX
>
>@@ -134,6 +135,7 @@ $(modules): %.ko :%.o %.mod.o FORCE
>
> targets += $(modules)
>
>+nsdeps: __modpost
>
> # Add FORCE to the prequisites of a target to force it to be always rebuilt.
> # ---------------------------------------------------------------------------
>diff --git a/scripts/coccinelle/misc/add_namespace.cocci b/scripts/coccinelle/misc/add_namespace.cocci
>new file mode 100644
>index 000000000000..c832bb6445a8
>--- /dev/null
>+++ b/scripts/coccinelle/misc/add_namespace.cocci
>@@ -0,0 +1,23 @@
>+// SPDX-License-Identifier: GPL-2.0-only
>+//
>+/// Adds missing MODULE_IMPORT_NS statements to source files
>+///
>+/// This script is usually called from scripts/nsdeps with -D ns=<namespace> to
>+/// add a missing namespace tag to a module source file.
>+///
>+
>+@has_ns_import@
>+declarer name MODULE_IMPORT_NS;
>+identifier virtual.ns;
>+@@
>+MODULE_IMPORT_NS(ns);
>+
>+// Add missing imports, but only adjacent to a MODULE_LICENSE statement.
>+// That ensures we are adding it only to the main module source file.
>+@do_import depends on !has_ns_import@
>+declarer name MODULE_LICENSE;
>+expression license;
>+identifier virtual.ns;
>+@@
>+MODULE_LICENSE(license);
>++ MODULE_IMPORT_NS(ns);
>diff --git a/scripts/nsdeps b/scripts/nsdeps
>new file mode 100644
>index 000000000000..3b5995a61e65
>--- /dev/null
>+++ b/scripts/nsdeps
>@@ -0,0 +1,56 @@
>+#!/bin/bash
>+# SPDX-License-Identifier: GPL-2.0
>+# Linux kernel symbol namespace import generator
>+#
>+# This script requires a minimum spatch version.
>+SPATCH_REQ_VERSION="1.0.4"
>+
>+DIR="$(dirname $(readlink -f $0))/.."
>+SPATCH="`which ${SPATCH:=spatch}`"
>+if [ ! -x "$SPATCH" ]; then
>+	echo 'spatch is part of the Coccinelle project and is available at http://coccinelle.lip6.fr/'
>+	exit 1
>+fi
>+
>+SPATCH_REQ_VERSION_NUM=$(echo $SPATCH_REQ_VERSION | ${DIR}/scripts/ld-version.sh)
>+SPATCH_VERSION=$($SPATCH --version | head -1 | awk '{print $3}')
>+SPATCH_VERSION_NUM=$(echo $SPATCH_VERSION | ${DIR}/scripts/ld-version.sh)
>+
>+if [ "$SPATCH_VERSION_NUM" -lt "$SPATCH_REQ_VERSION_NUM" ] ; then
>+	echo "spatch needs to be version $SPATCH_REQ_VERSION or higher"
>+	exit 1
>+fi
>+
>+generate_deps_for_ns() {
>+	$SPATCH --very-quiet --in-place --sp-file \
>+		$srctree/scripts/coccinelle/misc/add_namespace.cocci -D ns=$1 $2
>+}
>+
>+generate_deps() {
>+	local mod_name=`basename $@ .ko`
>+	local mod_file=`echo $@ | sed -e 's/\.ko/\.mod/'`
>+	local ns_deps_file=`echo $@ | sed -e 's/\.ko/\.ns_deps/'`
>+	if [ ! -f "$ns_deps_file" ]; then return; fi
>+	local mod_source_files=`cat $mod_file | sed -n 1p | sed -e 's/\.o/\.c/g'`
>+	for ns in `cat $ns_deps_file`; do
>+		echo "Adding namespace $ns to module $mod_name (if needed)."
>+		generate_deps_for_ns $ns $mod_source_files
>+		# sort the imports
>+		for source_file in $mod_source_files; do
>+			sed '/MODULE_IMPORT_NS/Q' $source_file > ${source_file}.tmp
>+			offset=$(wc -l ${source_file}.tmp | awk '{print $1;}')
>+			cat $source_file | grep MODULE_IMPORT_NS | sort -u >> ${source_file}.tmp
>+			tail -n +$((offset +1)) ${source_file} | grep -v MODULE_IMPORT_NS >> ${source_file}.tmp
>+			if ! diff -q ${source_file} ${source_file}.tmp; then
>+				mv ${source_file}.tmp ${source_file}
>+			else
>+				rm ${source_file}.tmp
>+			fi
>+		done
>+	done
>+}
>+
>+for f in `cat $srctree/modules.order`; do
>+	generate_deps $f
>+done

Hi Matthias!

I normally build outside of the source tree (make O=..) and I think
that choked up the nsdeps script a bit. For example when I run
'make nsdeps O=/tmp/linux' I get:

   cat: /home/jeyu/linux/modules.order: No such file or directory

I just changed $srctree/modules.order to $objtree/modules.order and
that fixed it for me. Also, I had to prefix $source_file in the script
with $srctree so that it'd find the right file to modify.

Thanks!

Jessica
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