6 files changed, 114 insertions, 69 deletions

diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 8e9bc9c3dbb7..c447cd9848d1 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -106,7 +106,7 @@ static inline struct audit_entry *audit_init_entry(u32 field_count)
         if (unlikely(!entry))
                 return NULL;
 
-        fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
+        fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
         if (unlikely(!fields)) {
                 kfree(entry);
                 return NULL;
@@ -160,7 +160,7 @@ static __u32 *classes[AUDIT_SYSCALL_CLASSES];
 
 int __init audit_register_class(int class, unsigned *list)
 {
-        __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
+        __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
         if (!p)
                 return -ENOMEM;
         while (*list != ~0U) {
diff --git a/kernel/exit.c b/kernel/exit.c
index e5c4668f1799..88c6b3e42583 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -455,6 +455,7 @@ static void exit_mm(struct task_struct * tsk)
         task_unlock(tsk);
         mm_update_next_owner(mm);
         mmput(mm);
+        clear_thread_flag(TIF_MEMDIE);
 }
 
 /*
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 13e839dbca07..de1a6bb6861d 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -45,6 +45,7 @@
 #include <linux/poll.h>
 #include <linux/irq_work.h>
 #include <linux/utsname.h>
+#include <linux/ctype.h>
 
 #include <asm/uaccess.h>
 
@@ -56,7 +57,7 @@
 
 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 */
 };
@@ -113,9 +114,9 @@ static int __down_trylock_console_sem(unsigned long ip)
  * 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;
 
@@ -146,8 +147,8 @@ static int console_may_schedule;
  * 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
@@ -257,7 +258,7 @@ static u64 clear_seq;
 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)
@@ -266,6 +267,7 @@ static u32 clear_idx;
 #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;
@@ -344,7 +346,7 @@ static int log_make_free_space(u32 msg_size)
         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++;
         }
@@ -453,11 +455,7 @@ static int log_store(int facility, int level,
         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)
 {
@@ -828,34 +826,74 @@ void log_buf_kexec_setup(void)
 /* 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;
 
         if (early) {
                 new_log_buf =
-                        memblock_virt_alloc(new_log_buf_len, PAGE_SIZE);
+                        memblock_virt_alloc(new_log_buf_len, LOG_ALIGN);
         } else {
-                new_log_buf = memblock_virt_alloc_nopanic(new_log_buf_len, 0);
+                new_log_buf = memblock_virt_alloc_nopanic(new_log_buf_len,
+                                                          LOG_ALIGN);
         }
 
         if (unlikely(!new_log_buf)) {
@@ -872,7 +910,7 @@ void __init setup_log_buf(int early)
         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);
 }
@@ -881,7 +919,7 @@ static bool __read_mostly ignore_loglevel;
 
 static int __init ignore_loglevel_setup(char *str)
 {
-        ignore_loglevel = 1;
+        ignore_loglevel = true;
         pr_info("debug: ignoring loglevel setting.\n");
 
         return 0;
@@ -947,11 +985,7 @@ static inline void boot_delay_msec(int level)
 }
 #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)
@@ -1310,7 +1344,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
                          * 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;
@@ -1416,10 +1450,9 @@ static int have_callable_console(void)
 /*
  * 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)
 {
@@ -1432,8 +1465,10 @@ 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;
         /*
@@ -1476,7 +1511,7 @@ static struct cont {
         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;
@@ -1608,7 +1643,8 @@ asmlinkage int vprintk_emit(int facility, int level,
                  */
                 if (!oops_in_progress && !lockdep_recursing(current)) {
                         recursion_bug = 1;
-                        goto out_restore_irqs;
+                        local_irq_restore(flags);
+                        return 0;
                 }
                 zap_locks();
         }
@@ -1716,21 +1752,30 @@ asmlinkage int vprintk_emit(int facility, int level,
 
         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);
@@ -1802,7 +1847,7 @@ EXPORT_SYMBOL(printk);
 
 #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;
@@ -1881,11 +1926,12 @@ static int __add_preferred_console(char *name, int idx, char *options,
         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;
 
@@ -1902,7 +1948,8 @@ static int __init console_setup(char *str)
                 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"))
@@ -1911,7 +1958,7 @@ static int __init console_setup(char *str)
                 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;
@@ -1950,7 +1997,6 @@ int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, cha
              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;
@@ -1959,12 +2005,12 @@ int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, cha
         return -1;
 }
 
-bool console_suspend_enabled = 1;
+bool console_suspend_enabled = true;
 EXPORT_SYMBOL(console_suspend_enabled);
 
 static int __init console_suspend_disable(char *str)
 {
-        console_suspend_enabled = 0;
+        console_suspend_enabled = false;
         return 1;
 }
 __setup("no_console_suspend", console_suspend_disable);
@@ -2045,8 +2091,8 @@ EXPORT_SYMBOL(console_lock);
 /**
  * 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.
  */
@@ -2618,14 +2664,13 @@ EXPORT_SYMBOL(__printk_ratelimit);
 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);
 
diff --git a/kernel/smp.c b/kernel/smp.c
index 487653b5844f..aff8aa14f547 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -670,7 +670,7 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
                         if (cond_func(cpu, info)) {
                                 ret = smp_call_function_single(cpu, func,
                                                                 info, wait);
-                                WARN_ON_ONCE(!ret);
+                                WARN_ON_ONCE(ret);
                         }
                 preempt_enable();
         }
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 75b22e22a72c..75875a741b5e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1240,8 +1240,7 @@ static struct ctl_table vm_table[] = {
                 .maxlen         = sizeof(unsigned long),
                 .mode           = 0644,
                 .proc_handler   = hugetlb_sysctl_handler,
-                .extra1         = (void *)&hugetlb_zero,
-                .extra2         = (void *)&hugetlb_infinity,
+                .extra1         = &zero,
         },
 #ifdef CONFIG_NUMA
         {
@@ -1250,8 +1249,7 @@ static struct ctl_table vm_table[] = {
                 .maxlen         = sizeof(unsigned long),
                 .mode           = 0644,
                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
-                .extra1         = (void *)&hugetlb_zero,
-                .extra2         = (void *)&hugetlb_infinity,
+                .extra1         = &zero,
         },
 #endif
          {
@@ -1274,8 +1272,7 @@ static struct ctl_table vm_table[] = {
                 .maxlen         = sizeof(unsigned long),
                 .mode           = 0644,
                 .proc_handler   = hugetlb_overcommit_handler,
-                .extra1         = (void *)&hugetlb_zero,
-                .extra2         = (void *)&hugetlb_infinity,
+                .extra1         = &zero,
         },
 #endif
         {
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index c3319bd1b040..51b29e9d2ba6 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -260,9 +260,11 @@ static void watchdog_overflow_callback(struct perf_event *event,
                         return;
 
                 if (hardlockup_panic)
-                        panic("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+                        panic("Watchdog detected hard LOCKUP on cpu %d",
+                              this_cpu);
                 else
-                        WARN(1, "Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+                        WARN(1, "Watchdog detected hard LOCKUP on cpu %d",
+                             this_cpu);
 
                 __this_cpu_write(hard_watchdog_warn, true);
                 return;
@@ -345,7 +347,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
                         }
                 }
 
-                printk(KERN_EMERG "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
+                pr_emerg("BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
                         smp_processor_id(), duration,
                         current->comm, task_pid_nr(current));
                 print_modules();
@@ -484,7 +486,7 @@ static int watchdog_nmi_enable(unsigned int cpu)
         if (PTR_ERR(event) == -EOPNOTSUPP)
                 pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
         else if (PTR_ERR(event) == -ENOENT)
-                pr_warning("disabled (cpu%i): hardware events not enabled\n",
+                pr_warn("disabled (cpu%i): hardware events not enabled\n",
                          cpu);
         else
                 pr_err("disabled (cpu%i): unable to create perf event: %ld\n",