lkml.org 
[lkml]   [2022]   [Oct]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.4 137/255] dyndbg: fix module.dyndbg handling
    Date
    From: Jim Cromie <jim.cromie@gmail.com>

    [ 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@rasmusvillemoes.dk>
    Acked-by: Jason Baron <jbaron@akamai.com>
    Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
    Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
    Link: https://lore.kernel.org/r/20220904214134.408619-3-jim.cromie@gmail.com
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    include/linux/dynamic_debug.h | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
    index 4cf02ecd67de..65575143c89f 100644
    --- a/include/linux/dynamic_debug.h
    +++ b/include/linux/dynamic_debug.h
    @@ -191,7 +191,7 @@ 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");
    --
    2.35.1


    \
     
     \ /
      Last update: 2022-10-24 15:05    [W:4.020 / U:0.728 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site