Commit 84da83a6 authored by Jim Cromie's avatar Jim Cromie Committed by Greg Kroah-Hartman
Browse files

dyndbg: combine flags & mask into a struct, simplify with it 



flags & mask are used together everywhere, and are passed around
together between multiple functions; they belong together in a struct,
call that struct flag_settings.

Use struct flag_settings to rework 3 functions:
 - ddebug_exec_query - declares query and flag-settings,
   		     calls other 2, passing flags
 - ddebug_parse_flags - fills flag_settings and returns
 - ddebug_change - test all callsites against query,
   		   modify passing sites.

benefits:
 - bit-banging always needs flags & mask, best together.
 - simpler function signatures
 - 1 less parameter, less stack overhead

no functional changes

Acked-by: default avatar <jbaron@akamai.com>
Signed-off-by: default avatarJim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20200719231058.1586423-16-jim.cromie@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 14775b04

lib/dynamic_debug.c

+24 −21
Original line number Diff line number Diff line
@@ -62,6 +62,11 @@ struct ddebug_iter { 
	unsigned int idx;

};



struct flag_settings {

	unsigned int flags;

	unsigned int mask;

};



static DEFINE_MUTEX(ddebug_lock);

static LIST_HEAD(ddebug_tables);

static int verbose;
@@ -141,7 +146,7 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg) 
 * logs the changes.  Takes ddebug_lock.

 */

static int ddebug_change(const struct ddebug_query *query,

			unsigned int flags, unsigned int mask)

			 struct flag_settings *modifiers)

{

	int i;

	struct ddebug_table *dt;
@@ -190,14 +195,14 @@ static int ddebug_change(const struct ddebug_query *query, 


			nfound++;



			newflags = (dp->flags & mask) | flags;

			newflags = (dp->flags & modifiers->mask) | modifiers->flags;

			if (newflags == dp->flags)

				continue;

#ifdef CONFIG_JUMP_LABEL

			if (dp->flags & _DPRINTK_FLAGS_PRINT) {

				if (!(flags & _DPRINTK_FLAGS_PRINT))

				if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT))

					static_branch_disable(&dp->key.dd_key_true);

			} else if (flags & _DPRINTK_FLAGS_PRINT)

			} else if (modifiers->flags & _DPRINTK_FLAGS_PRINT)

				static_branch_enable(&dp->key.dd_key_true);

#endif

			dp->flags = newflags;
@@ -431,11 +436,9 @@ static int ddebug_parse_query(char *words[], int nwords, 
 * flags fields of matched _ddebug's.  Returns 0 on success

 * or <0 on error.

 */

static int ddebug_parse_flags(const char *str, unsigned int *flagsp,

			       unsigned int *maskp)

static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)

{

	unsigned flags = 0;

	int op = '=', i;

	int op, i;



	switch (*str) {

	case '+':
@@ -452,7 +455,7 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, 
	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;

				modifiers->flags |= opt_array[i].flag;

				break;

			}

		}
@@ -461,30 +464,30 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, 
			return -EINVAL;

		}

	}

	vpr_info("flags=0x%x\n", flags);

	vpr_info("flags=0x%x\n", modifiers->flags);



	/* calculate final *flagsp, *maskp according to mask and op */

	/* calculate final flags, mask based upon op */

	switch (op) {

	case '=':

		*maskp = 0;

		*flagsp = flags;

		/* modifiers->flags already set */

		modifiers->mask = 0;

		break;

	case '+':

		*maskp = ~0U;

		*flagsp = flags;

		modifiers->mask = ~0U;

		break;

	case '-':

		*maskp = ~flags;

		*flagsp = 0;

		modifiers->mask = ~modifiers->flags;

		modifiers->flags = 0;

		break;

	}

	vpr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);

	vpr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);



	return 0;

}



static int ddebug_exec_query(char *query_string, const char *modname)

{

	unsigned int flags = 0, mask = 0;

	struct flag_settings modifiers = {};

	struct ddebug_query query = {};

#define MAXWORDS 9

	int nwords, nfound;
@@ -496,7 +499,7 @@ static int ddebug_exec_query(char *query_string, const char *modname) 
		return -EINVAL;

	}

	/* check flags 1st (last arg) so query is pairs of spec,val */

	if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) {

	if (ddebug_parse_flags(words[nwords-1], &modifiers)) {

		pr_err("flags parse failed\n");

		return -EINVAL;

	}
@@ -505,7 +508,7 @@ static int ddebug_exec_query(char *query_string, const char *modname) 
		return -EINVAL;

	}

	/* actually go and implement the change */

	nfound = ddebug_change(&query, flags, mask);

	nfound = ddebug_change(&query, &modifiers);

	vpr_info_dq(&query, nfound ? "applied" : "no-match");



	return nfound;

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