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From: Jim Cromie <jim.cromie@gmail.com>
To: jbaron@akamai.com, linux-kernel@vger.kernel.org,
	akpm@linuxfoundation.org
Cc: gregkh@linuxfoundation.org, linux@rasmusvillemoes.dk,
	Jim Cromie <jim.cromie@gmail.com>
Subject: [PATCH v4 09/16] dyndbg: refactor ddebug_read_flags out of ddebug_parse_flags
Date: Mon,  9 Dec 2019 19:27:35 -0700	[thread overview]
Message-ID: <20191210022742.822686-10-jim.cromie@gmail.com> (raw)
In-Reply-To: <20191210022742.822686-1-jim.cromie@gmail.com>

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@gmail.com>
---
 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 9fa6d4eeae5c..839f89b24474 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -414,6 +414,26 @@ 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
@@ -424,7 +444,7 @@ 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 '+':
@@ -438,19 +458,8 @@ 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) {
-- 
2.23.0


  parent reply	other threads:[~2019-12-10  2:28 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-10  2:27 [PATCH v4 00/16] dynamic-debug cleanups, 2 new features Jim Cromie
2019-12-10  2:27 ` [PATCH v4 01/16] dyndbg-docs: eschew file /full/path query in docs Jim Cromie
2019-12-10  2:27 ` [PATCH v4 02/16] dyndbg: drop obsolete comment on ddebug_proc_open Jim Cromie
2019-12-10  2:27 ` [PATCH v4 03/16] dyndbg: raise verbosity needed to enable ddebug_proc_* logging Jim Cromie
2019-12-10  2:27 ` [PATCH v4 04/16] dyndbg: rename __verbose section to __dyndbg Jim Cromie
2019-12-10  2:27 ` [PATCH v4 05/16] dyndbg: fix overcounting of ram used by dyndbg Jim Cromie
2019-12-10  2:27 ` [PATCH v4 06/16] dyndbg: fix a BUG_ON in ddebug_describe_flags Jim Cromie
2019-12-10 19:58   ` Jason Baron
2019-12-13  1:35     ` jim.cromie
2019-12-10  2:27 ` [PATCH v4 07/16] dyndbg: refactor parse_linerange out of ddebug_parse_query Jim Cromie
2019-12-10  2:27 ` [PATCH v4 08/16] dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100' Jim Cromie
2019-12-10  2:27 ` Jim Cromie [this message]
2019-12-10  2:27 ` [PATCH v4 10/16] dyndbg: combine flags & mask into a struct, use that Jim Cromie
2019-12-10  2:27 ` [PATCH v4 11/16] dyndbg: add filter parameter to ddebug_parse_flags Jim Cromie
2019-12-10  2:27 ` [PATCH v4 12/16] dyndbg: extend ddebug_parse_flags to accept optional filter-flags Jim Cromie
2019-12-10  2:27 ` [PATCH v4 13/16] dyndbg: prefer declarative init in caller, to memset in callee Jim Cromie
2019-12-10  2:27 ` [PATCH v4 14/16] dyndbg: add user-flag, negating-flags, and filtering on flags Jim Cromie
2019-12-10  2:27 ` [PATCH v4 15/16] dyndbg: allow negating flag-chars in modflags Jim Cromie
2019-12-10  2:27 ` [PATCH v4 16/16] dyndbg: make ddebug_tables list LIFO for add/remove_module Jim Cromie

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