From: Jim Cromie <jim.cromie@gmail.com>
To: jbaron@akamai.com, linux-kernel@vger.kernel.org
Cc: linux@rasmusvillemoes.dk, greg@kroah.com,
Jim Cromie <jim.cromie@gmail.com>
Subject: [PATCH 06/16] dyndbg: fix a BUG_ON in ddebug_describe_flags
Date: Wed, 27 Nov 2019 10:50:58 -0700 [thread overview]
Message-ID: <20191127175058.1351461-1-jim.cromie@gmail.com> (raw)
ddebug_describe_flags currently fills a caller provided string buffer,
after testing its size (also passed) in a BUG_ON.
Fix this with a struct containing a known-big-enough string buffer,
and passing it instead.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
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 b5fb0aa0fbc3..0e4783e11755 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -62,6 +62,8 @@ struct ddebug_iter {
unsigned int idx;
};
+struct flagsbuf { char buf[12]; }; /* big enough to hold all the flags */
+
static DEFINE_MUTEX(ddebug_lock);
static LIST_HEAD(ddebug_tables);
static int verbose;
@@ -88,21 +90,19 @@ static struct { unsigned flag:8; char opt_char; } opt_array[] = {
};
/* 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 vnpr_info(lvl, fmt, ...) \
@@ -148,7 +148,7 @@ 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 flags;
/* search for matching ddebugs */
mutex_lock(&ddebug_lock);
@@ -205,8 +205,7 @@ 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, &flags));
}
}
mutex_unlock(&ddebug_lock);
@@ -820,7 +819,7 @@ 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;
v9pr_info("called m=%p p=%p\n", m, p);
@@ -833,7 +832,7 @@ 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");
--
2.23.0
next reply other threads:[~2019-11-27 17:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-27 17:50 Jim Cromie [this message]
2019-12-02 17:37 ` [PATCH 06/16] dyndbg: fix a BUG_ON in ddebug_describe_flags kbuild test robot
2020-06-05 16:26 [PATCH 00/16] dynamic_debug: cleanups, 2 features Jim Cromie
2020-06-05 16:26 ` [PATCH 06/16] dyndbg: fix a BUG_ON in ddebug_describe_flags Jim Cromie
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