[PATCH v8 20/43] dyndbg: tighten fn-sig of ddebug_apply_class_bitmap
From: Jim Cromie via B4 Relay <devnull+jim.cromie.gmail.com@kernel.org>
Date: 2026-09-05 18:14:06
Also in:
b4-sent, dri-devel, linux-arch, linux-doc, linux-kselftest, linux-modules, lkml
Subsystem:
dynamic debug, library code, the rest · Maintainers:
Jason Baron, Jim Cromie, Andrew Morton, Linus Torvalds
From: Jim Cromie <jim.cromie@gmail.com> old_bits arg is currently a pointer to the input bits, but this could allow inadvertent changes to the input by the fn. Disallow this. And constify new_bits while here. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com> --- v2: move RvB after SoB --- lib/dynamic_debug.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 82c4d60d931e..e0e3cadd82bd 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c@@ -620,7 +620,8 @@ static int ddebug_exec_queries(char *query, const char *modname) /* apply a new class-param setting */ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp, - unsigned long *new_bits, unsigned long *old_bits, + const unsigned long *new_bits, + const unsigned long old_bits, const char *query_modname) { #define QUERY_SIZE 128
@@ -629,12 +630,12 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp, int matches = 0; int bi, ct; - if (*new_bits != *old_bits) + if (*new_bits != old_bits) v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, - *old_bits, query_modname ?: "'*'"); + old_bits, query_modname ?: "'*'"); for (bi = 0; bi < map->length; bi++) { - if (test_bit(bi, new_bits) == test_bit(bi, old_bits)) + if (test_bit(bi, new_bits) == test_bit(bi, &old_bits)) continue; snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
@@ -646,9 +647,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp, v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi, ct, map->class_names[bi], *new_bits); } - if (*new_bits != *old_bits) + if (*new_bits != old_bits) v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, - *old_bits, query_modname ?: "'*'"); + old_bits, query_modname ?: "'*'"); return matches; }
@@ -690,7 +691,7 @@ static int param_set_dyndbg_module_classes(const char *instr, } old_val = READ_ONCE(*dcp->bits); v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp)); - totct += ddebug_apply_class_bitmap(dcp, &inrep, &old_val, mod_name); + totct += ddebug_apply_class_bitmap(dcp, &inrep, old_val, mod_name); WRITE_ONCE(*dcp->bits, inrep); break; case DD_CLASS_TYPE_LEVEL_NUM:
@@ -704,7 +705,7 @@ static int param_set_dyndbg_module_classes(const char *instr, old_bits = CLASSMAP_BITMASK(old_val); new_bits = CLASSMAP_BITMASK(inrep); v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp)); - totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, mod_name); + totct += ddebug_apply_class_bitmap(dcp, &new_bits, old_bits, mod_name); WRITE_ONCE(*dcp->lvl, inrep); break; default:
--
2.55.0