#include <linux/poll.h>
#include <linux/irq_work.h>
#include <linux/utsname.h>
+#include <linux/ctype.h>
#include <asm/uaccess.h>
int console_printk[4] = {
CONSOLE_LOGLEVEL_DEFAULT, /* console_loglevel */
- DEFAULT_MESSAGE_LOGLEVEL, /* default_message_loglevel */
+ MESSAGE_LOGLEVEL_DEFAULT, /* default_message_loglevel */
CONSOLE_LOGLEVEL_MIN, /* minimum_console_loglevel */
CONSOLE_LOGLEVEL_DEFAULT, /* default_console_loglevel */
};
* This is used for debugging the mess that is the VT code by
* keeping track if we have the console semaphore held. It's
* definitely not the perfect debug tool (we don't know if _WE_
- * hold it are racing, but it helps tracking those weird code
- * path in the console code where we end up in places I want
- * locked without the console sempahore held
+ * hold it and are racing, but it helps tracking those weird code
+ * paths in the console code where we end up in places I want
+ * locked without the console sempahore held).
*/
static int console_locked, console_suspended;
* the overall length of the record.
*
* The heads to the first and last entry in the buffer, as well as the
- * sequence numbers of these both entries are maintained when messages
- * are stored..
+ * sequence numbers of these entries are maintained when messages are
+ * stored.
*
* If the heads indicate available messages, the length in the header
* tells the start next message. A length == 0 for the next message
static u32 clear_idx;
#define PREFIX_MAX 32
-#define LOG_LINE_MAX 1024 - PREFIX_MAX
+#define LOG_LINE_MAX (1024 - PREFIX_MAX)
/* record buffer */
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
#define LOG_ALIGN __alignof__(struct printk_log)
#endif
#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
+#define __LOG_CPU_MAX_BUF_LEN (1 << CONFIG_LOG_CPU_MAX_BUF_SHIFT)
static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
static char *log_buf = __log_buf;
static u32 log_buf_len = __LOG_BUF_LEN;
while (log_first_seq < log_next_seq) {
if (logbuf_has_space(msg_size, false))
return 0;
- /* drop old messages until we have enough continuous space */
+ /* drop old messages until we have enough contiguous space */
log_first_idx = log_next(log_first_idx);
log_first_seq++;
}
return msg->text_len;
}
-#ifdef CONFIG_SECURITY_DMESG_RESTRICT
-int dmesg_restrict = 1;
-#else
-int dmesg_restrict;
-#endif
+int dmesg_restrict = IS_ENABLED(CONFIG_SECURITY_DMESG_RESTRICT);
static int syslog_action_restricted(int type)
{
/* requested log_buf_len from kernel cmdline */
static unsigned long __initdata new_log_buf_len;
-/* save requested log_buf_len since it's too early to process it */
-static int __init log_buf_len_setup(char *str)
+/* we practice scaling the ring buffer by powers of 2 */
+static void __init log_buf_len_update(unsigned size)
{
- unsigned size = memparse(str, &str);
-
if (size)
size = roundup_pow_of_two(size);
if (size > log_buf_len)
new_log_buf_len = size;
+}
+
+/* save requested log_buf_len since it's too early to process it */
+static int __init log_buf_len_setup(char *str)
+{
+ unsigned size = memparse(str, &str);
+
+ log_buf_len_update(size);
return 0;
}
early_param("log_buf_len", log_buf_len_setup);
+static void __init log_buf_add_cpu(void)
+{
+ unsigned int cpu_extra;
+
+ /*
+ * archs should set up cpu_possible_bits properly with
+ * set_cpu_possible() after setup_arch() but just in
+ * case lets ensure this is valid.
+ */
+ if (num_possible_cpus() == 1)
+ return;
+
+ cpu_extra = (num_possible_cpus() - 1) * __LOG_CPU_MAX_BUF_LEN;
+
+ /* by default this will only continue through for large > 64 CPUs */
+ if (cpu_extra <= __LOG_BUF_LEN / 2)
+ return;
+
+ pr_info("log_buf_len individual max cpu contribution: %d bytes\n",
+ __LOG_CPU_MAX_BUF_LEN);
+ pr_info("log_buf_len total cpu_extra contributions: %d bytes\n",
+ cpu_extra);
+ pr_info("log_buf_len min size: %d bytes\n", __LOG_BUF_LEN);
+
+ log_buf_len_update(cpu_extra + __LOG_BUF_LEN);
+}
+
void __init setup_log_buf(int early)
{
unsigned long flags;
char *new_log_buf;
int free;
+ if (log_buf != __log_buf)
+ return;
+
+ if (!early && !new_log_buf_len)
+ log_buf_add_cpu();
+
if (!new_log_buf_len)
return;
memcpy(log_buf, __log_buf, __LOG_BUF_LEN);
raw_spin_unlock_irqrestore(&logbuf_lock, flags);
- pr_info("log_buf_len: %d\n", log_buf_len);
+ pr_info("log_buf_len: %d bytes\n", log_buf_len);
pr_info("early log buf free: %d(%d%%)\n",
free, (free * 100) / __LOG_BUF_LEN);
}
}
#endif
-#if defined(CONFIG_PRINTK_TIME)
-static bool printk_time = 1;
-#else
-static bool printk_time;
-#endif
+static bool printk_time = IS_ENABLED(CONFIG_PRINTK_TIME);
module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
static size_t print_time(u64 ts, char *buf)
* for pending data, not the size; return the count of
* records, not the length.
*/
- error = log_next_idx - syslog_idx;
+ error = log_next_seq - syslog_seq;
} else {
u64 seq = syslog_seq;
u32 idx = syslog_idx;
/*
* Can we actually use the console at this time on this cpu?
*
- * Console drivers may assume that per-cpu resources have
- * been allocated. So unless they're explicitly marked as
- * being able to cope (CON_ANYTIME) don't call them until
- * this CPU is officially up.
+ * Console drivers may assume that per-cpu resources have been allocated. So
+ * unless they're explicitly marked as being able to cope (CON_ANYTIME) don't
+ * call them until this CPU is officially up.
*/
static inline int can_use_console(unsigned int cpu)
{
* console_lock held, and 'console_locked' set) if it
* is successful, false otherwise.
*/
-static int console_trylock_for_printk(unsigned int cpu)
+static int console_trylock_for_printk(void)
{
+ unsigned int cpu = smp_processor_id();
+
if (!console_trylock())
return 0;
/*
struct task_struct *owner; /* task of first print*/
u64 ts_nsec; /* time of first print */
u8 level; /* log level of first message */
- u8 facility; /* log level of first message */
+ u8 facility; /* log facility of first message */
enum log_flags flags; /* prefix, newline flags */
bool flushed:1; /* buffer sealed and committed */
} cont;
*/
if (!oops_in_progress && !lockdep_recursing(current)) {
recursion_bug = 1;
- goto out_restore_irqs;
+ local_irq_restore(flags);
+ return 0;
}
zap_locks();
}
logbuf_cpu = UINT_MAX;
raw_spin_unlock(&logbuf_lock);
+ lockdep_on();
+ local_irq_restore(flags);
/* If called from the scheduler, we can not call up(). */
if (!in_sched) {
+ lockdep_off();
+ /*
+ * Disable preemption to avoid being preempted while holding
+ * console_sem which would prevent anyone from printing to
+ * console
+ */
+ preempt_disable();
+
/*
* Try to acquire and then immediately release the console
* semaphore. The release will print out buffers and wake up
* /dev/kmsg and syslog() users.
*/
- if (console_trylock_for_printk(this_cpu))
+ if (console_trylock_for_printk())
console_unlock();
+ preempt_enable();
+ lockdep_on();
}
- lockdep_on();
-out_restore_irqs:
- local_irq_restore(flags);
return printed_len;
}
EXPORT_SYMBOL(vprintk_emit);
#define LOG_LINE_MAX 0
#define PREFIX_MAX 0
-#define LOG_LINE_MAX 0
+
static u64 syslog_seq;
static u32 syslog_idx;
static u64 console_seq;
return 0;
}
/*
- * Set up a list of consoles. Called from init/main.c
+ * Set up a console. Called via do_early_param() in init/main.c
+ * for each "console=" parameter in the boot command line.
*/
static int __init console_setup(char *str)
{
- char buf[sizeof(console_cmdline[0].name) + 4]; /* 4 for index */
+ char buf[sizeof(console_cmdline[0].name) + 4]; /* 4 for "ttyS" */
char *s, *options, *brl_options = NULL;
int idx;
strncpy(buf, str, sizeof(buf) - 1);
}
buf[sizeof(buf) - 1] = 0;
- if ((options = strchr(str, ',')) != NULL)
+ options = strchr(str, ',');
+ if (options)
*(options++) = 0;
#ifdef __sparc__
if (!strcmp(str, "ttya"))
strcpy(buf, "ttyS1");
#endif
for (s = buf; *s; s++)
- if ((*s >= '0' && *s <= '9') || *s == ',')
+ if (isdigit(*s) || *s == ',')
break;
idx = simple_strtoul(s, NULL, 10);
*s = 0;
i++, c++)
if (strcmp(c->name, name) == 0 && c->index == idx) {
strlcpy(c->name, name_new, sizeof(c->name));
- c->name[sizeof(c->name) - 1] = 0;
c->options = options;
c->index = idx_new;
return i;
/**
* console_trylock - try to lock the console system for exclusive use.
*
- * Tried to acquire a lock which guarantees that the caller has
- * exclusive access to the console system and the console_drivers list.
+ * Try to acquire a lock which guarantees that the caller has exclusive
+ * access to the console system and the console_drivers list.
*
* returns 1 on success, and 0 on failure to acquire the lock.
*/
bool printk_timed_ratelimit(unsigned long *caller_jiffies,
unsigned int interval_msecs)
{
- if (*caller_jiffies == 0
- || !time_in_range(jiffies, *caller_jiffies,
- *caller_jiffies
- + msecs_to_jiffies(interval_msecs))) {
- *caller_jiffies = jiffies;
- return true;
- }
- return false;
+ unsigned long elapsed = jiffies - *caller_jiffies;
+
+ if (*caller_jiffies && elapsed <= msecs_to_jiffies(interval_msecs))
+ return false;
+
+ *caller_jiffies = jiffies;
+ return true;
}
EXPORT_SYMBOL(printk_timed_ratelimit);
git.openpandora.org / pandora-kernel.git / blobdiff