This is a note to let you know that I've just added the patch titled
dyndbg: fix module.dyndbg handling
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dyndbg-fix-module.dyndbg-handling.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6bf2cf85b515bed8e5645a862399b950d0e0e93d
Author: Jim Cromie <jim.cromie@xxxxxxxxx>
Date: Sun Sep 4 15:40:39 2022 -0600
dyndbg: fix module.dyndbg handling
[ Upstream commit 85d6b66d31c35158364058ee98fb69ab5bb6a6b1 ]
For CONFIG_DYNAMIC_DEBUG=N, the ddebug_dyndbg_module_param_cb()
stub-fn is too permissive:
bash-5.1# modprobe drm JUNKdyndbg
bash-5.1# modprobe drm dyndbgJUNK
[ 42.933220] dyndbg param is supported only in CONFIG_DYNAMIC_DEBUG builds
[ 42.937484] ACPI: bus type drm_connector registered
This caused no ill effects, because unknown parameters are either
ignored by default with an "unknown parameter" warning, or ignored
because dyndbg allows its no-effect use on non-dyndbg builds.
But since the code has an explicit feedback message, it should be
issued accurately. Fix with strcmp for exact param-name match.
Fixes: b48420c1d301 dynamic_debug: make dynamic-debug work for module initialization
Reported-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Acked-by: Jason Baron <jbaron@xxxxxxxxxx>
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220904214134.408619-3-jim.cromie@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index dce631e678dd..f30b01aa9fa4 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -201,7 +201,7 @@ static inline int ddebug_remove_module(const char *mod)
static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
const char *modname)
{
- if (strstr(param, "dyndbg")) {
+ if (!strcmp(param, "dyndbg")) {
/* avoid pr_warn(), which wants pr_fmt() fully defined */
printk(KERN_WARNING "dyndbg param is supported only in "
"CONFIG_DYNAMIC_DEBUG builds\n");
