[PATCH v2 15/24] dyndbg: extend ddebug_parse_flags to accept optional leading filter-flags

From: Jim Cromie
Date: Sat Jun 13 2020 - 11:59:13 EST


change ddebug_parse_flags to accept optional filterflags before OP.
this now sets the parameter added in ~1
---
.../admin-guide/dynamic-debug-howto.rst | 18 +++++++----
lib/dynamic_debug.c | 30 ++++++++++---------
2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 6c04aea8f4cd..4f343e6036f5 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -217,13 +217,19 @@ line
line -1605 // the 1605 lines from line 1 to line 1605
line 1600- // all lines from line 1600 to the end of the file

-The flags specification comprises a change operation followed
-by one or more flag characters. The change operation is one
-of the characters::
+Flags Specification::

- - remove the given flags
- + add the given flags
- = set the flags to the given flags
+ flagspec ::= filterflags? OP modflags
+ filterflags ::= flagset
+ modflags ::= flagset
+ flagset ::= ([pfmltu_] | [PFMLTU_])+ # also cant have pP etc
+ OP ::= [-+=]
+
+OP: modify callsites per following flagset::
+
+ - remove the following flags
+ + add the following flags
+ = set the flags to the following flags

The flags are::

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 0f393a930fdc..40436270d38a 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -441,34 +441,36 @@ static int ddebug_read_flags(const char *str, struct flagsettings *f)
}

/*
- * Parse `str' as a flags specification, format [-+=][p]+.
- * Sets up *maskp and *flagsp to be used when changing the
- * flags fields of matched _ddebug's. Returns 0 on success
- * or <0 on error.
+ * Parse `str' as a flags-spec, ie: [pfmlt_]*[-+=][pfmlt_]+
+ * Fills flagsettings provided. Returns 0 on success or <0 on error.
*/
-
static int ddebug_parse_flags(const char *str,
struct flagsettings *mods,
struct flagsettings *filter)
{
int op;
+ char *opp = strpbrk(str, "-+=");

- switch (*str) {
- case '+':
- case '-':
- case '=':
- op = *str++;
- break;
- default:
- pr_err("bad flag-op %c, at start of %s\n", *str, str);
+ if (!opp) {
+ pr_err("no OP given in %s\n", str);
return -EINVAL;
}
+ op = *opp;
vpr_info("op='%c'\n", op);

+ if (opp != str) {
+ /* filterflags precedes OP, grab it */
+ *opp++ = '\0';
+ if (ddebug_read_flags(str, filter))
+ return -EINVAL;
+ str = opp;
+ } else
+ str++;
+
if (ddebug_read_flags(str, mods))
return -EINVAL;

- /* calculate final flags, mask based upon op */
+ /* calculate final mods: flags, mask based upon op */
switch (op) {
case '=':
mods->mask = 0;
--
2.26.2