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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: <jbaron@akamai.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20200719231058.1586423-16-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jim Cromie 2020-07-19 17:10:55 -06:00 committed by Greg Kroah-Hartman
parent 14775b0496
commit 84da83a6ff
1 changed files with 24 additions and 21 deletions
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45
lib/dynamic_debug.c
View File

@ -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;