[PATCH] depmod: create and use System.map.no_namespaces

Matthias Maennich
2019-10-04T09:57:57Z

depmod in its current version is not aware of symbol namespace in
ksymtab entries introduced with 8651ec01daed ("module: add support for
symbol namespaces."). They have the form

__ksymtab_NAMESPACE.symbol_name

A fix for kmod's depmod has been proposed [1]. In order to support older
versions of depmod as well, create a System.map.no_namespaces during
scripts/depmod.sh that has the pre-namespaces format. That way users do
not immediately upgrade the userspace tool.

[1] https://lore.kernel.org/linux-modules/20191004094136.166621-1-maennich@google.com/

Reported-by: Stefan Wahren <stefan.wahren@i2se.com>
Fixes: 8651ec01daed ("module: add support for symbol namespaces.")
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Lucas De Marchi <lucas.de.marchi@gmail.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Martijn Coenen <maco@android.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-modules@vger.kernel.org
Signed-off-by: Matthias Maennich <maennich@google.com>
---

Please note this depends on the new ksymtab entry format proposed in
https://lore.kernel.org/lkml/20191003075826.7478-2-yamada.masahiro@socionext.com/

That is likely to be merged soon as well as it fixes problems in 5.4-rc*, hence
this patch depends on it.

Cheers,
Matthias

.gitignore | 1 +
scripts/depmod.sh | 8 +++++++-
2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index 70580bdd352c..5ed58a7cb433 100644
--- a/.gitignore
+++ b/.gitignore
@@ -59,6 +59,7 @@ modules.order
/vmlinux-gdb.py
/vmlinuz
/System.map
+/System.map.no_namespaces
/Module.markers
/modules.builtin.modinfo

diff --git a/scripts/depmod.sh b/scripts/depmod.sh
index e083bcae343f..602e1af072c7 100755
--- a/scripts/depmod.sh
+++ b/scripts/depmod.sh
@@ -39,7 +39,13 @@ if $depmod_hack_needed; then
KERNELRELEASE=99.98.$KERNELRELEASE
fi

-set -- -ae -F System.map
+# Older versions of depmod do not support symbol namespaces in ksymtab entries,
+# hence create an alternative System.map with namespace patched out to use for
+# depmod. I.e. transform entries as follows:
+# __ksymtab_NAMESPACE.symbol_name -> __ksymtab_symbol_name
+sed 's/__ksymtab_.*\./__ksymtab_/' System.map > System.map.no_namespaces
+
+set -- -ae -F System.map.no_namespaces
if test -n "$INSTALL_MOD_PATH"; then
set -- "$@" -b "$INSTALL_MOD_PATH"
fi
--
2.23.0.581.g78d2f28ef7-goog