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-rw-r--r--lib/Kconfig.debug42
-rw-r--r--lib/dma-debug.c3
-rw-r--r--lib/dynamic_debug.c270
-rw-r--r--lib/kobject_uevent.c19
4 files changed, 232 insertions, 102 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 8745ac7d1f7..05037dc9bde 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -166,18 +166,21 @@ config LOCKUP_DETECTOR
hard and soft lockups.
Softlockups are bugs that cause the kernel to loop in kernel
- mode for more than 60 seconds, without giving other tasks a
+ mode for more than 20 seconds, without giving other tasks a
chance to run. The current stack trace is displayed upon
detection and the system will stay locked up.
Hardlockups are bugs that cause the CPU to loop in kernel mode
- for more than 60 seconds, without letting other interrupts have a
+ for more than 10 seconds, without letting other interrupts have a
chance to run. The current stack trace is displayed upon detection
and the system will stay locked up.
The overhead should be minimal. A periodic hrtimer runs to
- generate interrupts and kick the watchdog task every 10-12 seconds.
- An NMI is generated every 60 seconds or so to check for hardlockups.
+ generate interrupts and kick the watchdog task every 4 seconds.
+ An NMI is generated every 10 seconds or so to check for hardlockups.
+
+ The frequency of hrtimer and NMI events and the soft and hard lockup
+ thresholds can be controlled through the sysctl watchdog_thresh.
config HARDLOCKUP_DETECTOR
def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
@@ -189,7 +192,8 @@ config BOOTPARAM_HARDLOCKUP_PANIC
help
Say Y here to enable the kernel to panic on "hard lockups",
which are bugs that cause the kernel to loop in kernel
- mode with interrupts disabled for more than 60 seconds.
+ mode with interrupts disabled for more than 10 seconds (configurable
+ using the watchdog_thresh sysctl).
Say N if unsure.
@@ -206,8 +210,8 @@ config BOOTPARAM_SOFTLOCKUP_PANIC
help
Say Y here to enable the kernel to panic on "soft lockups",
which are bugs that cause the kernel to loop in kernel
- mode for more than 60 seconds, without giving other tasks a
- chance to run.
+ mode for more than 20 seconds (configurable using the watchdog_thresh
+ sysctl), without giving other tasks a chance to run.
The panic can be used in combination with panic_timeout,
to cause the system to reboot automatically after a
@@ -927,6 +931,30 @@ config RCU_CPU_STALL_VERBOSE
Say Y if you want to enable such checks.
+config RCU_CPU_STALL_INFO
+ bool "Print additional diagnostics on RCU CPU stall"
+ depends on (TREE_RCU || TREE_PREEMPT_RCU) && DEBUG_KERNEL
+ default n
+ help
+ For each stalled CPU that is aware of the current RCU grace
+ period, print out additional per-CPU diagnostic information
+ regarding scheduling-clock ticks, idle state, and,
+ for RCU_FAST_NO_HZ kernels, idle-entry state.
+
+ Say N if you are unsure.
+
+ Say Y if you want to enable such diagnostics.
+
+config RCU_TRACE
+ bool "Enable tracing for RCU"
+ depends on DEBUG_KERNEL
+ help
+ This option provides tracing in RCU which presents stats
+ in debugfs for debugging RCU implementation.
+
+ Say Y here if you want to enable RCU tracing
+ Say N if you are unsure.
+
config KPROBES_SANITY_TEST
bool "Kprobes sanity tests"
depends on DEBUG_KERNEL
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index fea790a2b17..13ef2338be4 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -170,7 +170,7 @@ static bool driver_filter(struct device *dev)
return false;
/* driver filter on but not yet initialized */
- drv = get_driver(dev->driver);
+ drv = dev->driver;
if (!drv)
return false;
@@ -185,7 +185,6 @@ static bool driver_filter(struct device *dev)
}
read_unlock_irqrestore(&driver_name_lock, flags);
- put_driver(drv);
return ret;
}
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index dcdade39e47..310c753cf83 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -60,6 +60,7 @@ struct ddebug_iter {
static DEFINE_MUTEX(ddebug_lock);
static LIST_HEAD(ddebug_tables);
static int verbose = 0;
+module_param(verbose, int, 0644);
/* Return the last part of a pathname */
static inline const char *basename(const char *path)
@@ -68,12 +69,24 @@ static inline const char *basename(const char *path)
return tail ? tail+1 : path;
}
+/* Return the path relative to source root */
+static inline const char *trim_prefix(const char *path)
+{
+ int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
+
+ if (strncmp(path, __FILE__, skip))
+ skip = 0; /* prefix mismatch, don't skip */
+
+ return path + skip;
+}
+
static struct { unsigned flag:8; char opt_char; } opt_array[] = {
{ _DPRINTK_FLAGS_PRINT, 'p' },
{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
{ _DPRINTK_FLAGS_INCL_LINENO, 'l' },
{ _DPRINTK_FLAGS_INCL_TID, 't' },
+ { _DPRINTK_FLAGS_NONE, '_' },
};
/* format a string into buf[] which describes the _ddebug's flags */
@@ -83,58 +96,74 @@ static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
char *p = buf;
int i;
- BUG_ON(maxlen < 4);
+ BUG_ON(maxlen < 6);
for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
if (dp->flags & opt_array[i].flag)
*p++ = opt_array[i].opt_char;
if (p == buf)
- *p++ = '-';
+ *p++ = '_';
*p = '\0';
return buf;
}
+#define vpr_info_dq(q, msg) \
+do { \
+ if (verbose) \
+ /* trim last char off format print */ \
+ pr_info("%s: func=\"%s\" file=\"%s\" " \
+ "module=\"%s\" format=\"%.*s\" " \
+ "lineno=%u-%u", \
+ msg, \
+ q->function ? q->function : "", \
+ q->filename ? q->filename : "", \
+ q->module ? q->module : "", \
+ (int)(q->format ? strlen(q->format) - 1 : 0), \
+ q->format ? q->format : "", \
+ q->first_lineno, q->last_lineno); \
+} while (0)
+
/*
- * Search the tables for _ddebug's which match the given
- * `query' and apply the `flags' and `mask' to them. Tells
- * the user which ddebug's were changed, or whether none
- * were matched.
+ * Search the tables for _ddebug's which match the given `query' and
+ * apply the `flags' and `mask' to them. Returns number of matching
+ * callsites, normally the same as number of changes. If verbose,
+ * logs the changes. Takes ddebug_lock.
*/
-static void ddebug_change(const struct ddebug_query *query,
- unsigned int flags, unsigned int mask)
+static int ddebug_change(const struct ddebug_query *query,
+ unsigned int flags, unsigned int mask)
{
int i;
struct ddebug_table *dt;
unsigned int newflags;
unsigned int nfound = 0;
- char flagbuf[8];
+ char flagbuf[10];
/* search for matching ddebugs */
mutex_lock(&ddebug_lock);
list_for_each_entry(dt, &ddebug_tables, link) {
/* match against the module name */
- if (query->module != NULL &&
- strcmp(query->module, dt->mod_name))
+ if (query->module && strcmp(query->module, dt->mod_name))
continue;
for (i = 0 ; i < dt->num_ddebugs ; i++) {
struct _ddebug *dp = &dt->ddebugs[i];
/* match against the source filename */
- if (query->filename != NULL &&
+ if (query->filename &&
strcmp(query->filename, dp->filename) &&
- strcmp(query->filename, basename(dp->filename)))
+ strcmp(query->filename, basename(dp->filename)) &&
+ strcmp(query->filename, trim_prefix(dp->filename)))
continue;
/* match against the function */
- if (query->function != NULL &&
+ if (query->function &&
strcmp(query->function, dp->function))
continue;
/* match against the format */
- if (query->format != NULL &&
- strstr(dp->format, query->format) == NULL)
+ if (query->format &&
+ !strstr(dp->format, query->format))
continue;
/* match against the line number range */
@@ -151,13 +180,9 @@ static void ddebug_change(const struct ddebug_query *query,
if (newflags == dp->flags)
continue;
dp->flags = newflags;
- if (newflags)
- dp->enabled = 1;
- else
- dp->enabled = 0;
if (verbose)
- pr_info("changed %s:%d [%s]%s %s\n",
- dp->filename, dp->lineno,
+ pr_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)));
@@ -167,6 +192,8 @@ static void ddebug_change(const struct ddebug_query *query,
if (!nfound && verbose)
pr_info("no matches for query\n");
+
+ return nfound;
}
/*
@@ -186,8 +213,10 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
buf = skip_spaces(buf);
if (!*buf)
break; /* oh, it was trailing whitespace */
+ if (*buf == '#')
+ break; /* token starts comment, skip rest of line */
- /* Run `end' over a word, either whitespace separated or quoted */
+ /* find `end' of word, whitespace separated or quoted */
if (*buf == '"' || *buf == '\'') {
int quote = *buf++;
for (end = buf ; *end && *end != quote ; end++)
@@ -199,8 +228,8 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
;
BUG_ON(end == buf);
}
- /* Here `buf' is the start of the word, `end' is one past the end */
+ /* `buf' is start of word, `end' is one past its end */
if (nwords == maxwords)
return -EINVAL; /* ran out of words[] before bytes */
if (*end)
@@ -279,6 +308,19 @@ static char *unescape(char *str)
return str;
}
+static int check_set(const char **dest, char *src, char *name)
+{
+ int rc = 0;
+
+ if (*dest) {
+ rc = -EINVAL;
+ pr_err("match-spec:%s val:%s overridden by %s",
+ name, *dest, src);
+ }
+ *dest = src;
+ return rc;
+}
+
/*
* Parse words[] as a ddebug query specification, which is a series
* of (keyword, value) pairs chosen from these possibilities:
@@ -290,11 +332,15 @@ static char *unescape(char *str)
* format <escaped-string-to-find-in-format>
* line <lineno>
* line <first-lineno>-<last-lineno> // where either may be empty
+ *
+ * Only 1 of each type is allowed.
+ * Returns 0 on success, <0 on error.
*/
static int ddebug_parse_query(char *words[], int nwords,
struct ddebug_query *query)
{
unsigned int i;
+ int rc;
/* check we have an even number of words */
if (nwords % 2 != 0)
@@ -303,41 +349,43 @@ static int ddebug_parse_query(char *words[], int nwords,
for (i = 0 ; i < nwords ; i += 2) {
if (!strcmp(words[i], "func"))
- query->function = words[i+1];
+ rc = check_set(&query->function, words[i+1], "func");
else if (!strcmp(words[i], "file"))
- query->filename = words[i+1];
+ rc = check_set(&query->filename, words[i+1], "file");
else if (!strcmp(words[i], "module"))
- query->module = words[i+1];
+ rc = check_set(&query->module, words[i+1], "module");
else if (!strcmp(words[i], "format"))
- query->format = unescape(words[i+1]);
+ rc = check_set(&query->format, unescape(words[i+1]),
+ "format");
else if (!strcmp(words[i], "line")) {
char *first = words[i+1];
char *last = strchr(first, '-');
+ if (query->first_lineno || query->last_lineno) {
+ pr_err("match-spec:line given 2 times\n");
+ return -EINVAL;
+ }
if (last)
*last++ = '\0';
if (parse_lineno(first, &query->first_lineno) < 0)
return -EINVAL;
- if (last != NULL) {
+ if (last) {
/* range <first>-<last> */
- if (parse_lineno(last, &query->last_lineno) < 0)
+ if (parse_lineno(last, &query->last_lineno)
+ < query->first_lineno) {
+ pr_err("last-line < 1st-line\n");
return -EINVAL;
+ }
} else {
query->last_lineno = query->first_lineno;
}
} else {
- if (verbose)
- pr_err("unknown keyword \"%s\"\n", words[i]);
+ pr_err("unknown keyword \"%s\"\n", words[i]);
return -EINVAL;
}
+ if (rc)
+ return rc;
}
-
- if (verbose)
- pr_info("q->function=\"%s\" q->filename=\"%s\" "
- "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n",
- query->function, query->filename,
- query->module, query->format, query->first_lineno,
- query->last_lineno);
-
+ vpr_info_dq(query, "parsed");
return 0;
}
@@ -375,8 +423,6 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
if (i < 0)
return -EINVAL;
}
- if (flags == 0)
- return -EINVAL;
if (verbose)
pr_info("flags=0x%x\n", flags);
@@ -405,7 +451,7 @@ static int ddebug_exec_query(char *query_string)
unsigned int flags = 0, mask = 0;
struct ddebug_query query;
#define MAXWORDS 9
- int nwords;
+ int nwords, nfound;
char *words[MAXWORDS];
nwords = ddebug_tokenize(query_string, words, MAXWORDS);
@@ -417,8 +463,47 @@ static int ddebug_exec_query(char *query_string)
return -EINVAL;
/* actually go and implement the change */
- ddebug_change(&query, flags, mask);
- return 0;
+ nfound = ddebug_change(&query, flags, mask);
+ vpr_info_dq((&query), (nfound) ? "applied" : "no-match");
+
+ return nfound;
+}
+
+/* handle multiple queries in query string, continue on error, return
+ last error or number of matching callsites. Module name is either
+ in param (for boot arg) or perhaps in query string.
+*/
+static int ddebug_exec_queries(char *query)
+{
+ char *split;
+ int i, errs = 0, exitcode = 0, rc, nfound = 0;
+
+ for (i = 0; query; query = split) {
+ split = strpbrk(query, ";\n");
+ if (split)
+ *split++ = '\0';
+
+ query = skip_spaces(query);
+ if (!query || !*query || *query == '#')
+ continue;
+
+ if (verbose)
+ pr_info("query %d: \"%s\"\n", i, query);
+
+ rc = ddebug_exec_query(query);
+ if (rc < 0) {
+ errs++;
+ exitcode = rc;
+ } else
+ nfound += rc;
+ i++;
+ }
+ pr_info("processed %d queries, with %d matches, %d errs\n",
+ i, nfound, errs);
+
+ if (exitcode)
+ return exitcode;
+ return nfound;
}
#define PREFIX_SIZE 64
@@ -452,7 +537,8 @@ static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
pos += snprintf(buf + pos, remaining(pos), "%s:",
desc->function);
if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
- pos += snprintf(buf + pos, remaining(pos), "%d:", desc->lineno);
+ pos += snprintf(buf + pos, remaining(pos), "%d:",
+ desc->lineno);
if (pos - pos_after_tid)
pos += snprintf(buf + pos, remaining(pos), " ");
if (pos >= PREFIX_SIZE)
@@ -527,14 +613,16 @@ EXPORT_SYMBOL(__dynamic_netdev_dbg);
#endif
-static __initdata char ddebug_setup_string[1024];
+#define DDEBUG_STRING_SIZE 1024
+static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
+
static __init int ddebug_setup_query(char *str)
{
- if (strlen(str) >= 1024) {
+ if (strlen(str) >= DDEBUG_STRING_SIZE) {
pr_warn("ddebug boot param string too large\n");
return 0;
}
- strcpy(ddebug_setup_string, str);
+ strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
return 1;
}
@@ -544,25 +632,33 @@ __setup("ddebug_query=", ddebug_setup_query);
* File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the
* command text from userspace, parses and executes it.
*/
+#define USER_BUF_PAGE 4096
static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
size_t len, loff_t *offp)
{
- char tmpbuf[256];
+ char *tmpbuf;
int ret;
if (len == 0)
return 0;
- /* we don't check *offp -- multiple writes() are allowed */
- if (len > sizeof(tmpbuf)-1)
+ if (len > USER_BUF_PAGE - 1) {
+ pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
return -E2BIG;
- if (copy_from_user(tmpbuf, ubuf, len))
+ }
+ tmpbuf = kmalloc(len + 1, GFP_KERNEL);
+ if (!tmpbuf)
+ return -ENOMEM;
+ if (copy_from_user(tmpbuf, ubuf, len)) {
+ kfree(tmpbuf);
return -EFAULT;
+ }
tmpbuf[len] = '\0';
if (verbose)
pr_info("read %d bytes from userspace\n", (int)len);
- ret = ddebug_exec_query(tmpbuf);
- if (ret)
+ ret = ddebug_exec_queries(tmpbuf);
+ kfree(tmpbuf);
+ if (ret < 0)
return ret;
*offp += len;
@@ -668,7 +764,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
{
struct ddebug_iter *iter = m->private;
struct _ddebug *dp = p;
- char flagsbuf[8];
+ char flagsbuf[10];
if (verbose)
pr_info("called m=%p p=%p\n", m, p);
@@ -679,10 +775,10 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
return 0;
}
- seq_printf(m, "%s:%u [%s]%s %s \"",
- dp->filename, dp->lineno,
- iter->table->mod_name, dp->function,
- ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
+ 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)));
seq_escape(m, dp->format, "\t\r\n\"");
seq_puts(m, "\"\n");
@@ -708,10 +804,11 @@ static const struct seq_operations ddebug_proc_seqops = {
};
/*
- * File_ops->open method for <debugfs>/dynamic_debug/control. Does the seq_file
- * setup dance, and also creates an iterator to walk the _ddebugs.
- * Note that we create a seq_file always, even for O_WRONLY files
- * where it's not needed, as doing so simplifies the ->release method.
+ * File_ops->open method for <debugfs>/dynamic_debug/control. Does
+ * the seq_file setup dance, and also creates an iterator to walk the
+ * _ddebugs. Note that we create a seq_file always, even for O_WRONLY
+ * files where it's not needed, as doing so simplifies the ->release
+ * method.
*/
static int ddebug_proc_open(struct inode *inode, struct file *file)
{
@@ -846,33 +943,40 @@ static int __init dynamic_debug_init(void)
int ret = 0;
int n = 0;
- if (__start___verbose != __stop___verbose) {
- iter = __start___verbose;
- modname = iter->modname;
- iter_start = iter;
- for (; iter < __stop___verbose; iter++) {
- if (strcmp(modname, iter->modname)) {
- ret = ddebug_add_module(iter_start, n, modname);
- if (ret)
- goto out_free;
- n = 0;
- modname = iter->modname;
- iter_start = iter;
- }
- n++;
+ if (__start___verbose == __stop___verbose) {
+ pr_warn("_ddebug table is empty in a "
+ "CONFIG_DYNAMIC_DEBUG build");
+ return 1;
+ }
+ iter = __start___verbose;
+ modname = iter->modname;
+ iter_start = iter;
+ for (; iter < __stop___verbose; iter++) {
+ if (strcmp(modname, iter->modname)) {
+ ret = ddebug_add_module(iter_start, n, modname);
+ if (ret)
+ goto out_free;
+ n = 0;
+ modname = iter->modname;
+ iter_start = iter;
}
- ret = ddebug_add_module(iter_start, n, modname);
+ n++;
}
+ ret = ddebug_add_module(iter_start, n, modname);
+ if (ret)
+ goto out_free;
/* ddebug_query boot param got passed -> set it up */
if (ddebug_setup_string[0] != '\0') {
- ret = ddebug_exec_query(ddebug_setup_string);
- if (ret)
+ ret = ddebug_exec_queries(ddebug_setup_string);
+ if (ret < 0)
pr_warn("Invalid ddebug boot param %s",
ddebug_setup_string);
else
- pr_info("ddebug initialized with string %s",
- ddebug_setup_string);
+ pr_info("%d changes by ddebug_query\n", ret);
+
+ /* keep tables even on ddebug_query parse error */
+ ret = 0;
}
out_free:
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index e66e9b63261..75cbdb52bf5 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -29,16 +29,17 @@
u64 uevent_seqnum;
char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
-static DEFINE_SPINLOCK(sequence_lock);
#ifdef CONFIG_NET
struct uevent_sock {
struct list_head list;
struct sock *sk;
};
static LIST_HEAD(uevent_sock_list);
-static DEFINE_MUTEX(uevent_sock_mutex);
#endif
+/* This lock protects uevent_seqnum and uevent_sock_list */
+static DEFINE_MUTEX(uevent_sock_mutex);
+
/* the strings here must match the enum in include/linux/kobject.h */
static const char *kobject_actions[] = {
[KOBJ_ADD] = "add",
@@ -136,7 +137,6 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
struct kobject *top_kobj;
struct kset *kset;
const struct kset_uevent_ops *uevent_ops;
- u64 seq;
int i = 0;
int retval = 0;
#ifdef CONFIG_NET
@@ -243,17 +243,16 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
else if (action == KOBJ_REMOVE)
kobj->state_remove_uevent_sent = 1;
+ mutex_lock(&uevent_sock_mutex);
/* we will send an event, so request a new sequence number */
- spin_lock(&sequence_lock);
- seq = ++uevent_seqnum;
- spin_unlock(&sequence_lock);
- retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);
- if (retval)
+ retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
+ if (retval) {
+ mutex_unlock(&uevent_sock_mutex);
goto exit;
+ }
#if defined(CONFIG_NET)
/* send netlink message */
- mutex_lock(&uevent_sock_mutex);
list_for_each_entry(ue_sk, &uevent_sock_list, list) {
struct sock *uevent_sock = ue_sk->sk;
struct sk_buff *skb;
@@ -290,8 +289,8 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
} else
retval = -ENOMEM;
}
- mutex_unlock(&uevent_sock_mutex);
#endif
+ mutex_unlock(&uevent_sock_mutex);
/* call uevent_helper, usually only enabled during early boot */
if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-02 08:02:29 +0000