diff options
author | Jim Cromie <jim.cromie@gmail.com> | 2022-09-04 15:40:45 -0600 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-07 16:58:23 +0200 |
commit | 683263a5e075aca81915a5abc0006a5435d3d54d (patch) | |
tree | 247df622efd57da766f2b8c7ee1a151011007538 /lib/test_dynamic_debug.c | |
parent | e75ef56f74965f426dd819a41336b640ffdd8fbc (diff) |
dyndbg: add test_dynamic_debug module
Provide a simple module to allow testing DYNAMIC_DEBUG behavior. It
calls do_prints() from module-init, and with a sysfs-node.
dmesg -C
dmesg -w &
modprobe test_dynamic_debug dyndbg=+p
echo 1 > /sys/module/dynamic_debug/parameters/verbose
cat /sys/module/test_dynamic_debug/parameters/do_prints
echo module test_dynamic_debug +mftl > /proc/dynamic_debug/control
echo junk > /sys/module/test_dynamic_debug/parameters/do_prints
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/20220904214134.408619-9-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib/test_dynamic_debug.c')
-rw-r--r-- | lib/test_dynamic_debug.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c new file mode 100644 index 000000000000..ba3882ca3e48 --- /dev/null +++ b/lib/test_dynamic_debug.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Kernel module for testing dynamic_debug + * + * Authors: + * Jim Cromie <jim.cromie@gmail.com> + */ + +#define pr_fmt(fmt) "test_dd: " fmt + +#include <linux/module.h> + +static void do_prints(void); /* device under test */ + +/* run tests by reading or writing sysfs node */ + +static int param_set_do_prints(const char *instr, const struct kernel_param *kp) +{ + do_prints(); + return 0; +} + +static int param_get_do_prints(char *buffer, const struct kernel_param *kp) +{ + do_prints(); + return scnprintf(buffer, PAGE_SIZE, "did do_prints\n"); +} + +static const struct kernel_param_ops param_ops_do_prints = { + .set = param_set_do_prints, + .get = param_get_do_prints, +}; + +module_param_cb(do_prints, ¶m_ops_do_prints, NULL, 0600); + +static void do_alpha(void) +{ + pr_debug("do alpha\n"); +} +static void do_beta(void) +{ + pr_debug("do beta\n"); +} + +static void do_prints(void) +{ + do_alpha(); + do_beta(); +} + +static int __init test_dynamic_debug_init(void) +{ + pr_debug("init start\n"); + + do_prints(); + + pr_debug("init done\n"); + return 0; +} + +static void __exit test_dynamic_debug_exit(void) +{ + pr_debug("exiting\n"); +} + +module_init(test_dynamic_debug_init); +module_exit(test_dynamic_debug_exit); + +MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>"); +MODULE_LICENSE("GPL"); |