[PATCH v5 21/33] dyndbg: test DECLARE_DYNDBG_CLASSMAP, sysfs nodes

From: Jim Cromie
Date: Fri Aug 05 2022 - 17:56:45 EST

Demonstrate use of DECLARE_DYNDBG_CLASSMAP macro, and expose them as
sysfs-nodes for testing.

For each of the 4 class-map-types:

- declare a class-map of that type,
- declare the enum corresponding to those class-names
- share _base across 0..30 range
- add a __pr_debug_cls() call for each class-name
- declare 2 sysnodes for each class-map
for 'p' flag, and future 'T' flag

These declarations create the following sysfs parameter interface:

:#> pwd
/sys/module/test_dynamic_debug/parameters
:#> ls
T_disjoint_bits T_disjoint_names T_level_names T_level_num do_prints
p_disjoint_bits p_disjoint_names p_level_names p_level_num

NOTES:

The local wrapper macro is an api candidate, but there are already too
many parameters. OTOH, maybe related enum should be in there too,
since it has _base inter-dependencies.

The T_* params control the (future) T flag on the same class'd
pr_debug callsites as their p* counterparts. Using them will fail,
until the dyndbg-trace patches are added in.

:#> echo 1 > T_disjoint
[ 28.792489] dyndbg: disjoint: 0x1 > test_dynamic_debug.T_D2
[ 28.793848] dyndbg: query 0: "class D2_CORE +T" mod:*
[ 28.795086] dyndbg: split into words: "class" "D2_CORE" "+T"
[ 28.796467] dyndbg: op='+'
[ 28.797148] dyndbg: unknown flag 'T'
[ 28.798021] dyndbg: flags parse failed
[ 28.798947] dyndbg: processed 1 queries, with 0 matches, 1 errs
[ 28.800378] dyndbg: bit_0: -22 matches on class: D2_CORE -> 0x1
[ 28.801959] dyndbg: test_dynamic_debug.T_D2: updated 0x0 -> 0x1
[ 28.803974] dyndbg: total matches: -22

Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
lib/test_dynamic_debug.c | 125 ++++++++++++++++++++++++++++++++++-----
1 file changed, 110 insertions(+), 15 deletions(-)

diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index ba3882ca3e48..8dd250ad022b 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -10,57 +10,152 @@

#include <linux/module.h>

-static void do_prints(void); /* device under test */
-
-/* run tests by reading or writing sysfs node */
+/* run tests by reading or writing sysfs node: do_prints */

+static void do_prints(void); /* device under test */
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, &param_ops_do_prints, NULL, 0600);

-static void do_alpha(void)
+/*
+ * Using the CLASSMAP api:
+ * - classmaps must have corresponding enum
+ * - enum symbols must match/correlate with class-name strings in the map.
+ * - base must equal enum's 1st value
+ * - multiple maps must set their base to share the 0-30 class_id space !!
+ * (build-bug-on tips welcome)
+ * Additionally, here:
+ * - tie together sysname, mapname, bitsname, flagsname
+ */
+#define DD_SYS_WRAP(_model, _flags) \
+ static unsigned long bits_##_model; \
+ static struct ddebug_class_param _flags##_model = { \
+ .bits = &bits_##_model, \
+ .flags = #_flags, \
+ .map = &map_##_model, \
+ }; \
+ module_param_cb(_flags##_##_model, &param_ops_dyndbg_classes, &_flags##_model, 0600)
+
+/* numeric input, independent bits */
+enum cat_disjoint_bits {
+ D2_CORE = 0,
+ D2_DRIVER,
+ D2_KMS,
+ D2_PRIME,
+ D2_ATOMIC,
+ D2_VBL,
+ D2_STATE,
+ D2_LEASE,
+ D2_DP,
+ D2_DRMRES };
+DECLARE_DYNDBG_CLASSMAP(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, 0,
+ "D2_CORE",
+ "D2_DRIVER",
+ "D2_KMS",
+ "D2_PRIME",
+ "D2_ATOMIC",
+ "D2_VBL",
+ "D2_STATE",
+ "D2_LEASE",
+ "D2_DP",
+ "D2_DRMRES");
+DD_SYS_WRAP(disjoint_bits, p);
+DD_SYS_WRAP(disjoint_bits, T);
+
+/* symbolic input, independent bits */
+enum cat_disjoint_names { LOW = 11, MID, HI };
+DECLARE_DYNDBG_CLASSMAP(map_disjoint_names, DD_CLASS_TYPE_DISJOINT_NAMES, 10,
+ "LOW", "MID", "HI");
+DD_SYS_WRAP(disjoint_names, p);
+DD_SYS_WRAP(disjoint_names, T);
+
+/* numeric verbosity, V2 > V1 related */
+enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 };
+DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
+ "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
+DD_SYS_WRAP(level_num, p);
+DD_SYS_WRAP(level_num, T);
+
+/* symbolic verbosity */
+enum cat_level_names { L0 = 22, L1, L2, L3, L4, L5, L6, L7 };
+DECLARE_DYNDBG_CLASSMAP(map_level_names, DD_CLASS_TYPE_LEVEL_NAMES, 22,
+ "L0", "L1", "L2", "L3", "L4", "L5", "L6", "L7");
+DD_SYS_WRAP(level_names, p);
+DD_SYS_WRAP(level_names, T);
+
+/* stand-in for all pr_debug etc */
+#define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
+
+static void do_cats(void)
{
- pr_debug("do alpha\n");
+ pr_debug("doing categories\n");
+
+ prdbg(LOW);
+ prdbg(MID);
+ prdbg(HI);
+
+ prdbg(D2_CORE);
+ prdbg(D2_DRIVER);
+ prdbg(D2_KMS);
+ prdbg(D2_PRIME);
+ prdbg(D2_ATOMIC);
+ prdbg(D2_VBL);
+ prdbg(D2_STATE);
+ prdbg(D2_LEASE);
+ prdbg(D2_DP);
+ prdbg(D2_DRMRES);
}
-static void do_beta(void)
+
+static void do_levels(void)
{
- pr_debug("do beta\n");
+ pr_debug("doing levels\n");
+
+ prdbg(V1);
+ prdbg(V2);
+ prdbg(V3);
+ prdbg(V4);
+ prdbg(V5);
+ prdbg(V6);
+ prdbg(V7);
+
+ prdbg(L1);
+ prdbg(L2);
+ prdbg(L3);
+ prdbg(L4);
+ prdbg(L5);
+ prdbg(L6);
+ prdbg(L7);
}

static void do_prints(void)
{
- do_alpha();
- do_beta();
+ do_cats();
+ do_levels();
}

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");
+ pr_debug("exited\n");
}

module_init(test_dynamic_debug_init);
--
2.37.1