From: Jim Cromie jim.cromie@gmail.com
[ Upstream commit f678ce8cc3cb2ad29df75d8824c74f36398ba871 ]
ddebug_describe_flags() currently fills a caller provided string buffer, after testing its size (also passed) in a BUG_ON. Fix this by replacing them with a known-big-enough string buffer wrapped in a struct, and passing that instead.
Also simplify ddebug_describe_flags() flags parameter from a struct to a member in that struct, and hoist the member deref up to the caller. This makes the function reusable (soon) where flags are unpacked.
Acked-by: jbaron@akamai.com Signed-off-by: Jim Cromie jim.cromie@gmail.com Link: https://lore.kernel.org/r/20200719231058.1586423-8-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- lib/dynamic_debug.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index c7c96bc7654af..91c451e0f4741 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -85,22 +85,22 @@ static struct { unsigned flag:8; char opt_char; } opt_array[] = { { _DPRINTK_FLAGS_NONE, '_' }, };
+struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; }; + /* format a string into buf[] which describes the _ddebug's flags */ -static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, - size_t maxlen) +static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb) { - char *p = buf; + char *p = fb->buf; int i;
- BUG_ON(maxlen < 6); for (i = 0; i < ARRAY_SIZE(opt_array); ++i) - if (dp->flags & opt_array[i].flag) + if (flags & opt_array[i].flag) *p++ = opt_array[i].opt_char; - if (p == buf) + if (p == fb->buf) *p++ = '_'; *p = '\0';
- return buf; + return fb->buf; }
#define vpr_info(fmt, ...) \ @@ -142,7 +142,7 @@ static int ddebug_change(const struct ddebug_query *query, struct ddebug_table *dt; unsigned int newflags; unsigned int nfound = 0; - char flagbuf[10]; + struct flagsbuf fbuf;
/* search for matching ddebugs */ mutex_lock(&ddebug_lock); @@ -199,8 +199,7 @@ static int ddebug_change(const struct ddebug_query *query, vpr_info("changed %s:%d [%s]%s =%s\n", trim_prefix(dp->filename), dp->lineno, dt->mod_name, dp->function, - ddebug_describe_flags(dp, flagbuf, - sizeof(flagbuf))); + ddebug_describe_flags(dp->flags, &fbuf)); } } mutex_unlock(&ddebug_lock); @@ -779,7 +778,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p) { struct ddebug_iter *iter = m->private; struct _ddebug *dp = p; - char flagsbuf[10]; + struct flagsbuf flags;
vpr_info("called m=%p p=%p\n", m, p);
@@ -792,7 +791,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p) seq_printf(m, "%s:%u [%s]%s =%s "", trim_prefix(dp->filename), dp->lineno, iter->table->mod_name, dp->function, - ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf))); + ddebug_describe_flags(dp->flags, &flags)); seq_escape(m, dp->format, "\t\r\n""); seq_puts(m, ""\n");