| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20231103131011.1316396-11-lb@semihalf.com>
Date: Fri, 3 Nov 2023 14:10:09 +0100
From: Łukasz Bartosik <lb@...ihalf.com>
To: Jason Baron <jbaron@...mai.com>, Jim Cromie <jim.cromie@...il.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Kees Cook <keescook@...omium.org>,
Douglas Anderson <dianders@...omium.org>
Cc: Guenter Roeck <groeck@...gle.com>,
Yaniv Tzoreff <yanivt@...gle.com>,
Benson Leung <bleung@...gle.com>,
Steven Rostedt <rostedt@...dmis.org>,
Vincent Whitchurch <vincent.whitchurch@...s.com>,
Pekka Paalanen <ppaalanen@...il.com>,
Sean Paul <seanpaul@...omium.org>,
Daniel Vetter <daniel@...ll.ch>, linux-kernel@...r.kernel.org,
upstream@...ihalf.com
Subject: [PATCH v1 10/12] dyndbg: add processing of T(race) flag argument
Add processing of argument provided to T(race) flag.
The argument value determines destination of debug logs:
0 - debug logs will be written to prdbg and devdbg trace events
[1..255] - debug logs will be written to trace instance
A user can provide trace destination by folowing T flag with
":" and trace destination value in range [0..255], for example:
echo "module thunderbolt =pT:7" > /sys/kernel/debug/dynamic_debug/control
echo "module thunderbolt =lT:7,p" > /sys/kernel/debug/dynamic_debug/control
When T flag with argument is followed by other flags then the next flag has
to be preceded with ",".
When no value is provided trace destination defaults to 0, for example:
echo "module thunderbolt =T" > /sys/kernel/debug/dynamic_debug/control
echo "module thunderbolt =lTp" > /sys/kernel/debug/dynamic_debug/control
Signed-off-by: Łukasz Bartosik <lb@...ihalf.com>
---
lib/dynamic_debug.c | 105 +++++++++++++++++++++++++++++++++++++-------
1 file changed, 90 insertions(+), 15 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 3218ab078a76..c5cd28e74a02 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -71,6 +71,7 @@ struct ddebug_iter {
struct flag_settings {
unsigned int flags;
unsigned int mask;
+ unsigned int trace_dst;
};
static DEFINE_MUTEX(ddebug_lock);
@@ -111,9 +112,67 @@ static inline const char *trim_prefix(const char *path)
return path + skip;
}
-static const struct { unsigned flag:8; char opt_char; } opt_array[] = {
+typedef const char* (*read_flag_args_f)(const char *, struct flag_settings *);
+typedef char* (*show_flag_args_f)(struct dd_ctrl *, char *);
+
+/*
+ * Maximum number of characters representing value
+ * of flag T argument in human readable form - ":255,"
+ */
+#define FLAG_T_ARGS_LEN 5
+
+static const
+char *read_T_args(const char *str, struct flag_settings *modifiers)
+{
+ char *end, args[FLAG_T_ARGS_LEN];
+ int len;
+
+ if (*(str+1) != ':')
+ return str;
+
+ str += 2;
+ end = strchr(str, ',');
+ if (end && *(end + 1) == '\0')
+ return NULL;
+
+ if (end)
+ len = end - str;
+ else
+ len = strlen(str);
+
+ if (len > FLAG_T_ARGS_LEN - 1)
+ return NULL;
+
+ memcpy(args, str, len);
+ args[len] = '\0';
+ if (kstrtouint(args, 10, &modifiers->trace_dst) < 0)
+ return NULL;
+
+ if (modifiers->trace_dst > TRACE_DST_MAX)
+ return NULL;
+
+ return end ? end : str + len;
+}
+
+char *show_T_args(struct dd_ctrl *ctrl, char *p)
+{
+ int n;
+
+ n = snprintf(p, FLAG_T_ARGS_LEN, ":%u", ctrl->trace_dst);
+ WARN_ONCE(n < 0, "printing T flag args value failed\n");
+
+ return n < 0 ? p : p + n;
+}
+
+static const struct
+{
+ unsigned flag:8;
+ char opt_char;
+ read_flag_args_f read_args;
+ show_flag_args_f show_args;
+} opt_array[] = {
{ _DPRINTK_FLAGS_PRINTK, 'p' },
- { _DPRINTK_FLAGS_TRACE, 'T' },
+ { _DPRINTK_FLAGS_TRACE, 'T', read_T_args, show_T_args},
{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
{ _DPRINTK_FLAGS_INCL_SOURCENAME, 's' },
@@ -122,22 +181,30 @@ static const struct { unsigned flag:8; char opt_char; } opt_array[] = {
{ _DPRINTK_FLAGS_NONE, '_' },
};
-struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; };
+struct ctrlbuf { char buf[ARRAY_SIZE(opt_array)+FLAG_T_ARGS_LEN+1]; };
/* format a string into buf[] which describes the _ddebug's flags */
-static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb)
+static char *ddebug_describe_ctrl(struct dd_ctrl *ctrl, struct ctrlbuf *cb)
{
- char *p = fb->buf;
+ show_flag_args_f show_args = NULL;
+ char *p = cb->buf;
int i;
for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
- if (flags & opt_array[i].flag)
+ if (ctrl->flags & opt_array[i].flag) {
+ if (show_args)
+ *p++ = ',';
*p++ = opt_array[i].opt_char;
- if (p == fb->buf)
+ show_args = opt_array[i].show_args;
+ if (show_args)
+ p = show_args(ctrl, p);
+ }
+
+ if (p == cb->buf)
*p++ = '_';
*p = '\0';
- return fb->buf;
+ return cb->buf;
}
#define vnpr_info(lvl, fmt, ...) \
@@ -202,7 +269,7 @@ static int ddebug_change(const struct ddebug_query *query,
struct ddebug_table *dt;
unsigned int nfound = 0;
struct dd_ctrl nctrl = {0};
- struct flagsbuf fbuf, nbuf;
+ struct ctrlbuf cbuf, nbuf;
struct ddebug_class_map *map = NULL;
int __outvar valid_class;
@@ -268,7 +335,8 @@ static int ddebug_change(const struct ddebug_query *query,
nfound++;
nctrl.flags = (get_flags(dp) & modifiers->mask) | modifiers->flags;
- if (!memcmp(&nctrl, get_ctrl(dp), sizeof(struct dd_ctrl)))
+ nctrl.trace_dst = modifiers->trace_dst;
+ if (!memcmp(&nctrl, get_ctrl(dp), sizeof(nctrl)))
continue;
#ifdef CONFIG_JUMP_LABEL
if (get_flags(dp) & _DPRINTK_FLAGS_ENABLED) {
@@ -281,8 +349,8 @@ static int ddebug_change(const struct ddebug_query *query,
v4pr_info("changed %s:%d [%s]%s %s => %s\n",
trim_prefix(dp->filename), dp->lineno,
dt->mod_name, dp->function,
- ddebug_describe_flags(get_flags(dp), &fbuf),
- ddebug_describe_flags(nctrl.flags, &nbuf));
+ ddebug_describe_ctrl(&dp->ctrl, &cbuf),
+ ddebug_describe_ctrl(&nctrl, &nbuf));
set_ctrl(dp, &nctrl);
}
}
@@ -507,6 +575,7 @@ static int ddebug_parse_query(char *words[], int nwords,
*/
static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
{
+ read_flag_args_f read_args;
int op, i;
switch (*str) {
@@ -525,6 +594,12 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
if (*str == opt_array[i].opt_char) {
modifiers->flags |= opt_array[i].flag;
+ read_args = opt_array[i].read_args;
+ if (read_args) {
+ str = read_args(str, modifiers);
+ if (!str)
+ return -EINVAL;
+ }
break;
}
}
@@ -533,7 +608,7 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
return -EINVAL;
}
}
- v3pr_info("flags=0x%x\n", modifiers->flags);
+ v3pr_info("flags=0x%x, trace dest=0x%x\n", modifiers->flags, modifiers->trace_dst);
/* calculate final flags, mask based upon op */
switch (op) {
@@ -1257,7 +1332,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
{
struct ddebug_iter *iter = m->private;
struct _ddebug *dp = p;
- struct flagsbuf flags;
+ struct ctrlbuf cbuf;
char const *class;
if (p == SEQ_START_TOKEN) {
@@ -1269,7 +1344,7 @@ 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(get_flags(dp), &flags));
+ ddebug_describe_ctrl(&dp->ctrl, &cbuf));
seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
seq_puts(m, "\"");
--
2.42.0.869.gea05f2083d-goog
Powered by blists - more mailing lists