[PATCH 10/16] dyndbg: refactor ddebug_read_flags out of ddebug_parse_flags

From: Jim Cromie
Date: Fri Jun 05 2020 - 12:28:08 EST


Currently, ddebug_parse_flags accepts [+-=][pflmt_]+ as flag-spec
strings. If we allow [pflmt_]*[+-=][pflmt_]+ instead, the (new) 1st
flagset can be used as a filter to select callsites, before applying
changes in the 2nd flagset. 1st step is to split out the flags-reader
so we can use it again.

The point of this is to allow user to compose an arbitrary set of
changes, by marking callsites with [fmlt] flags, and then to
activate that composed set in a single query.

#> echo '=_' > control # clear all flags
#> echo 'module usb* +fmlt' > control # build the marked set, repeat
#> echo 'fmlt+p' > control # activate

Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
lib/dynamic_debug.c | 37 +++++++++++++++++++++++--------------
1 file changed, 23 insertions(+), 14 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 8f250c67acbe..005b8221a9d6 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -413,6 +413,26 @@ static int ddebug_parse_query(char *words[], int nwords,
return 0;
}

+static int ddebug_read_flags(const char *str, unsigned int *flags)
+{
+ int i;
+
+ for (; *str ; ++str) {
+ for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
+ if (*str == opt_array[i].opt_char) {
+ *flags |= opt_array[i].flag;
+ break;
+ }
+ }
+ if (i < 0) {
+ pr_err("unknown flag '%c' in \"%s\"\n", *str, str);
+ return -EINVAL;
+ }
+ }
+ vpr_info("flags=0x%x\n", *flags);
+ return 0;
+}
+
/*
* Parse `str' as a flags specification, format [-+=][p]+.
* Sets up *maskp and *flagsp to be used when changing the
@@ -423,7 +443,7 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
unsigned int *maskp)
{
unsigned flags = 0;
- int op = '=', i;
+ int op;

switch (*str) {
case '+':
@@ -437,19 +457,8 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
}
vpr_info("op='%c'\n", op);

- for (; *str ; ++str) {
- for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
- if (*str == opt_array[i].opt_char) {
- flags |= opt_array[i].flag;
- break;
- }
- }
- if (i < 0) {
- pr_err("unknown flag '%c' in \"%s\"\n", *str, str);
- return -EINVAL;
- }
- }
- vpr_info("flags=0x%x\n", flags);
+ if (ddebug_read_flags(str, &flags))
+ return -EINVAL;

/* calculate final *flagsp, *maskp according to mask and op */
switch (op) {
--
2.26.2