| Message ID | 20220502205105.919523-1-atomlin@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | module: Introduce module unload taint tracking | expand |
On Mon, May 02, 2022 at 09:51:02PM +0100, Aaron Tomlin wrote: > Hi Luis, > > This iteration is still based on the latest mcgrof/modules-next branch. > > I have decided still to use RCU even though no entry is ever removed from > the unloaded tainted modules list. That being said, if I understand > correctly, it is not safe in some instances to use 'module_mutex' in > print_modules(). So instead we disable preemption to ensure list traversal > with concurrent list manipulation e.g. list_add_rcu(), is safe too. > > Changes since v4 [1] > - Moved code to kernel/module/tracking.c > (Luis Chamberlain) > - Used only strcmp() in try_add_tainted_module() > (Christophe Leroy) > > Changes since v3 [2] > - Fixed kernel build error reported by kernel test robot i.e. moved > '#endif' outside 'if (!list_empty(&unloaded_tainted_modules))' > statement in the context of print_modules() > - Used strncmp() instead of memcmp() > (Oleksandr Natalenko) > - Removed the additional strlen() > (Christoph Lameter) > > Changes since v2 [3] > - Dropped RFC from subject > - Removed the newline i.e. "\n" in printk() > - Always include the tainted module's unload count > - Unconditionally display each unloaded tainted module > > Please let me know your thoughts. Thanks! Queued onto modules-testing. If no issues are found I'll push to modules-next soon after. Luis
Hi Luis, This iteration is still based on the latest mcgrof/modules-next branch. I have decided still to use RCU even though no entry is ever removed from the unloaded tainted modules list. That being said, if I understand correctly, it is not safe in some instances to use 'module_mutex' in print_modules(). So instead we disable preemption to ensure list traversal with concurrent list manipulation e.g. list_add_rcu(), is safe too. Changes since v4 [1] - Moved code to kernel/module/tracking.c (Luis Chamberlain) - Used only strcmp() in try_add_tainted_module() (Christophe Leroy) Changes since v3 [2] - Fixed kernel build error reported by kernel test robot i.e. moved '#endif' outside 'if (!list_empty(&unloaded_tainted_modules))' statement in the context of print_modules() - Used strncmp() instead of memcmp() (Oleksandr Natalenko) - Removed the additional strlen() (Christoph Lameter) Changes since v2 [3] - Dropped RFC from subject - Removed the newline i.e. "\n" in printk() - Always include the tainted module's unload count - Unconditionally display each unloaded tainted module Please let me know your thoughts. [1]: https://lore.kernel.org/all/20220425090841.3958494-1-atomlin@redhat.com/ [2]: https://lore.kernel.org/all/20220420115257.3498300-1-atomlin@redhat.com/ [3]: https://lore.kernel.org/all/20220419150334.3395019-1-atomlin@redhat.com/ Aaron Tomlin (3): module: Make module_flags_taint() accept a module's taints bitmap and usable outside core code module: Move module_assert_mutex_or_preempt() to internal.h module: Introduce module unload taint tracking init/Kconfig | 11 ++++++++ kernel/module/Makefile | 1 + kernel/module/internal.h | 34 ++++++++++++++++++++++ kernel/module/main.c | 24 ++++++---------- kernel/module/tracking.c | 61 ++++++++++++++++++++++++++++++++++++++++ 5 files changed, 116 insertions(+), 15 deletions(-) create mode 100644 kernel/module/tracking.c base-commit: eeaec7801c421e17edda6e45a32d4a5596b633da