16 files changed, 365 insertions, 212 deletions

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 1adf62b39b96..07ce18ca71e0 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -27,6 +27,9 @@
  * version 2. This program is licensed "as is" without any warranty of any
  * kind, whether express or implied.
  */
+
+#define pr_fmt(fmt) "KGDB: " fmt
+
 #include <linux/pid_namespace.h>
 #include <linux/clocksource.h>
 #include <linux/serial_core.h>
@@ -196,8 +199,8 @@ int __weak kgdb_validate_break_address(unsigned long addr)
                 return err;
         err = kgdb_arch_remove_breakpoint(&tmp);
         if (err)
-                printk(KERN_ERR "KGDB: Critical breakpoint error, kernel "
-                   "memory destroyed at: %lx", addr);
+                pr_err("Critical breakpoint error, kernel memory destroyed at: %lx\n",
+                       addr);
         return err;
 }
 
@@ -256,8 +259,8 @@ int dbg_activate_sw_breakpoints(void)
                 error = kgdb_arch_set_breakpoint(&kgdb_break[i]);
                 if (error) {
                         ret = error;
-                        printk(KERN_INFO "KGDB: BP install failed: %lx",
-                               kgdb_break[i].bpt_addr);
+                        pr_info("BP install failed: %lx\n",
+                                kgdb_break[i].bpt_addr);
                         continue;
                 }
 
@@ -319,8 +322,8 @@ int dbg_deactivate_sw_breakpoints(void)
                         continue;
                 error = kgdb_arch_remove_breakpoint(&kgdb_break[i]);
                 if (error) {
-                        printk(KERN_INFO "KGDB: BP remove failed: %lx\n",
-                               kgdb_break[i].bpt_addr);
+                        pr_info("BP remove failed: %lx\n",
+                                kgdb_break[i].bpt_addr);
                         ret = error;
                 }
 
@@ -367,7 +370,7 @@ int dbg_remove_all_break(void)
                         goto setundefined;
                 error = kgdb_arch_remove_breakpoint(&kgdb_break[i]);
                 if (error)
-                        printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n",
+                        pr_err("breakpoint remove failed: %lx\n",
                                kgdb_break[i].bpt_addr);
 setundefined:
                 kgdb_break[i].state = BP_UNDEFINED;
@@ -400,9 +403,9 @@ static int kgdb_io_ready(int print_wait)
         if (print_wait) {
 #ifdef CONFIG_KGDB_KDB
                 if (!dbg_kdb_mode)
-                        printk(KERN_CRIT "KGDB: waiting... or $3#33 for KDB\n");
+                        pr_crit("waiting... or $3#33 for KDB\n");
 #else
-                printk(KERN_CRIT "KGDB: Waiting for remote debugger\n");
+                pr_crit("Waiting for remote debugger\n");
 #endif
         }
         return 1;
@@ -430,8 +433,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
                 exception_level = 0;
                 kgdb_skipexception(ks->ex_vector, ks->linux_regs);
                 dbg_activate_sw_breakpoints();
-                printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n",
-                        addr);
+                pr_crit("re-enter error: breakpoint removed %lx\n", addr);
                 WARN_ON_ONCE(1);
 
                 return 1;
@@ -444,7 +446,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
                 panic("Recursive entry to debugger");
         }
 
-        printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n");
+        pr_crit("re-enter exception: ALL breakpoints killed\n");
 #ifdef CONFIG_KGDB_KDB
         /* Allow kdb to debug itself one level */
         return 0;
@@ -471,6 +473,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
         int cpu;
         int trace_on = 0;
         int online_cpus = num_online_cpus();
+        u64 time_left;
 
         kgdb_info[ks->cpu].enter_kgdb++;
         kgdb_info[ks->cpu].exception_state |= exception_state;
@@ -595,9 +598,13 @@ return_normal:
         /*
          * Wait for the other CPUs to be notified and be waiting for us:
          */
-        while (kgdb_do_roundup && (atomic_read(&masters_in_kgdb) +
-                                atomic_read(&slaves_in_kgdb)) != online_cpus)
+        time_left = loops_per_jiffy * HZ;
+        while (kgdb_do_roundup && --time_left &&
+               (atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) !=
+                   online_cpus)
                 cpu_relax();
+        if (!time_left)
+                pr_crit("KGDB: Timed out waiting for secondary CPUs.\n");
 
         /*
          * At this point the primary processor is completely
@@ -795,15 +802,15 @@ static struct console kgdbcons = {
 static void sysrq_handle_dbg(int key)
 {
         if (!dbg_io_ops) {
-                printk(KERN_CRIT "ERROR: No KGDB I/O module available\n");
+                pr_crit("ERROR: No KGDB I/O module available\n");
                 return;
         }
         if (!kgdb_connected) {
 #ifdef CONFIG_KGDB_KDB
                 if (!dbg_kdb_mode)
-                        printk(KERN_CRIT "KGDB or $3#33 for KDB\n");
+                        pr_crit("KGDB or $3#33 for KDB\n");
 #else
-                printk(KERN_CRIT "Entering KGDB\n");
+                pr_crit("Entering KGDB\n");
 #endif
         }
 
@@ -945,7 +952,7 @@ static void kgdb_initial_breakpoint(void)
 {
         kgdb_break_asap = 0;
 
-        printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n");
+        pr_crit("Waiting for connection from remote gdb...\n");
         kgdb_breakpoint();
 }
 
@@ -964,8 +971,7 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
         if (dbg_io_ops) {
                 spin_unlock(&kgdb_registration_lock);
 
-                printk(KERN_ERR "kgdb: Another I/O driver is already "
-                                "registered with KGDB.\n");
+                pr_err("Another I/O driver is already registered with KGDB\n");
                 return -EBUSY;
         }
 
@@ -981,8 +987,7 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
 
         spin_unlock(&kgdb_registration_lock);
 
-        printk(KERN_INFO "kgdb: Registered I/O driver %s.\n",
-               new_dbg_io_ops->name);
+        pr_info("Registered I/O driver %s\n", new_dbg_io_ops->name);
 
         /* Arm KGDB now. */
         kgdb_register_callbacks();
@@ -1017,8 +1022,7 @@ void kgdb_unregister_io_module(struct kgdb_io *old_dbg_io_ops)
 
         spin_unlock(&kgdb_registration_lock);
 
-        printk(KERN_INFO
-                "kgdb: Unregistered I/O driver %s, debugger disabled.\n",
+        pr_info("Unregistered I/O driver %s, debugger disabled\n",
                 old_dbg_io_ops->name);
 }
 EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index b20d544f20c2..e1dbf4a2c69e 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -531,22 +531,29 @@ void __init kdb_initbptab(void)
         for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++)
                 bp->bp_free = 1;
 
-        kdb_register_repeat("bp", kdb_bp, "[<vaddr>]",
-                "Set/Display breakpoints", 0, KDB_REPEAT_NO_ARGS);
-        kdb_register_repeat("bl", kdb_bp, "[<vaddr>]",
-                "Display breakpoints", 0, KDB_REPEAT_NO_ARGS);
+        kdb_register_flags("bp", kdb_bp, "[<vaddr>]",
+                "Set/Display breakpoints", 0,
+                KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
+        kdb_register_flags("bl", kdb_bp, "[<vaddr>]",
+                "Display breakpoints", 0,
+                KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
         if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)
-                kdb_register_repeat("bph", kdb_bp, "[<vaddr>]",
-                "[datar [length]|dataw [length]]   Set hw brk", 0, KDB_REPEAT_NO_ARGS);
-        kdb_register_repeat("bc", kdb_bc, "<bpnum>",
-                "Clear Breakpoint", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("be", kdb_bc, "<bpnum>",
-                "Enable Breakpoint", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("bd", kdb_bc, "<bpnum>",
-                "Disable Breakpoint", 0, KDB_REPEAT_NONE);
-
-        kdb_register_repeat("ss", kdb_ss, "",
-                "Single Step", 1, KDB_REPEAT_NO_ARGS);
+                kdb_register_flags("bph", kdb_bp, "[<vaddr>]",
+                "[datar [length]|dataw [length]]   Set hw brk", 0,
+                KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
+        kdb_register_flags("bc", kdb_bc, "<bpnum>",
+                "Clear Breakpoint", 0,
+                KDB_ENABLE_FLOW_CTRL);
+        kdb_register_flags("be", kdb_bc, "<bpnum>",
+                "Enable Breakpoint", 0,
+                KDB_ENABLE_FLOW_CTRL);
+        kdb_register_flags("bd", kdb_bc, "<bpnum>",
+                "Disable Breakpoint", 0,
+                KDB_ENABLE_FLOW_CTRL);
+
+        kdb_register_flags("ss", kdb_ss, "",
+                "Single Step", 1,
+                KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
         /*
          * Architecture dependent initialization.
          */
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index 8859ca34dcfe..15e1a7af5dd0 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -129,6 +129,10 @@ int kdb_stub(struct kgdb_state *ks)
                 ks->pass_exception = 1;
                 KDB_FLAG_SET(CATASTROPHIC);
         }
+        /* set CATASTROPHIC if the system contains unresponsive processors */
+        for_each_online_cpu(i)
+                if (!kgdb_info[i].enter_kgdb)
+                        KDB_FLAG_SET(CATASTROPHIC);
         if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) {
                 KDB_STATE_CLEAR(SSBPT);
                 KDB_STATE_CLEAR(DOING_SS);
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 379650b984f8..f191bddf64b8 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -12,6 +12,7 @@
  */
 
 #include <linux/ctype.h>
+#include <linux/types.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/kmsg_dump.h>
@@ -23,6 +24,7 @@
 #include <linux/vmalloc.h>
 #include <linux/atomic.h>
 #include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/mm.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
@@ -42,6 +44,12 @@
 #include <linux/slab.h>
 #include "kdb_private.h"
 
+#undef  MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "kdb."
+
+static int kdb_cmd_enabled = CONFIG_KDB_DEFAULT_ENABLE;
+module_param_named(cmd_enable, kdb_cmd_enabled, int, 0600);
+
 #define GREP_LEN 256
 char kdb_grep_string[GREP_LEN];
 int kdb_grepping_flag;
@@ -121,6 +129,7 @@ static kdbmsg_t kdbmsgs[] = {
         KDBMSG(BADLENGTH, "Invalid length field"),
         KDBMSG(NOBP, "No Breakpoint exists"),
         KDBMSG(BADADDR, "Invalid address"),
+        KDBMSG(NOPERM, "Permission denied"),
 };
 #undef KDBMSG
 
@@ -188,6 +197,26 @@ struct task_struct *kdb_curr_task(int cpu)
 }
 
 /*
+ * Check whether the flags of the current command and the permissions
+ * of the kdb console has allow a command to be run.
+ */
+static inline bool kdb_check_flags(kdb_cmdflags_t flags, int permissions,
+                                   bool no_args)
+{
+        /* permissions comes from userspace so needs massaging slightly */
+        permissions &= KDB_ENABLE_MASK;
+        permissions |= KDB_ENABLE_ALWAYS_SAFE;
+
+        /* some commands change group when launched with no arguments */
+        if (no_args)
+                permissions |= permissions << KDB_ENABLE_NO_ARGS_SHIFT;
+
+        flags |= KDB_ENABLE_ALL;
+
+        return permissions & flags;
+}
+
+/*
  * kdbgetenv - This function will return the character string value of
  *      an environment variable.
  * Parameters:
@@ -476,6 +505,15 @@ int kdbgetaddrarg(int argc, const char **argv, int *nextarg,
         kdb_symtab_t symtab;
 
         /*
+         * If the enable flags prohibit both arbitrary memory access
+         * and flow control then there are no reasonable grounds to
+         * provide symbol lookup.
+         */
+        if (!kdb_check_flags(KDB_ENABLE_MEM_READ | KDB_ENABLE_FLOW_CTRL,
+                             kdb_cmd_enabled, false))
+                return KDB_NOPERM;
+
+        /*
          * Process arguments which follow the following syntax:
          *
          *  symbol | numeric-address [+/- numeric-offset]
@@ -641,8 +679,13 @@ static int kdb_defcmd2(const char *cmdstr, const char *argv0)
                 if (!s->count)
                         s->usable = 0;
                 if (s->usable)
-                        kdb_register(s->name, kdb_exec_defcmd,
-                                     s->usage, s->help, 0);
+                        /* macros are always safe because when executed each
+                         * internal command re-enters kdb_parse() and is
+                         * safety checked individually.
+                         */
+                        kdb_register_flags(s->name, kdb_exec_defcmd, s->usage,
+                                           s->help, 0,
+                                           KDB_ENABLE_ALWAYS_SAFE);
                 return 0;
         }
         if (!s->usable)
@@ -1003,25 +1046,22 @@ int kdb_parse(const char *cmdstr)
 
         if (i < kdb_max_commands) {
                 int result;
+
+                if (!kdb_check_flags(tp->cmd_flags, kdb_cmd_enabled, argc <= 1))
+                        return KDB_NOPERM;
+
                 KDB_STATE_SET(CMD);
                 result = (*tp->cmd_func)(argc-1, (const char **)argv);
                 if (result && ignore_errors && result > KDB_CMD_GO)
                         result = 0;
                 KDB_STATE_CLEAR(CMD);
-                switch (tp->cmd_repeat) {
-                case KDB_REPEAT_NONE:
-                        argc = 0;
-                        if (argv[0])
-                                *(argv[0]) = '\0';
-                        break;
-                case KDB_REPEAT_NO_ARGS:
-                        argc = 1;
-                        if (argv[1])
-                                *(argv[1]) = '\0';
-                        break;
-                case KDB_REPEAT_WITH_ARGS:
-                        break;
-                }
+
+                if (tp->cmd_flags & KDB_REPEAT_WITH_ARGS)
+                        return result;
+
+                argc = tp->cmd_flags & KDB_REPEAT_NO_ARGS ? 1 : 0;
+                if (argv[argc])
+                        *(argv[argc]) = '\0';
                 return result;
         }
 
@@ -1921,10 +1961,14 @@ static int kdb_rm(int argc, const char **argv)
  */
 static int kdb_sr(int argc, const char **argv)
 {
+        bool check_mask =
+            !kdb_check_flags(KDB_ENABLE_ALL, kdb_cmd_enabled, false);
+
         if (argc != 1)
                 return KDB_ARGCOUNT;
+
         kdb_trap_printk++;
-        __handle_sysrq(*argv[1], false);
+        __handle_sysrq(*argv[1], check_mask);
         kdb_trap_printk--;
 
         return 0;
@@ -2157,6 +2201,8 @@ static void kdb_cpu_status(void)
         for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
                 if (!cpu_online(i)) {
                         state = 'F';    /* cpu is offline */
+                } else if (!kgdb_info[i].enter_kgdb) {
+                        state = 'D';    /* cpu is online but unresponsive */
                 } else {
                         state = ' ';    /* cpu is responding to kdb */
                         if (kdb_task_state_char(KDB_TSK(i)) == 'I')
@@ -2210,7 +2256,7 @@ static int kdb_cpu(int argc, const char **argv)
         /*
          * Validate cpunum
          */
-        if ((cpunum > NR_CPUS) || !cpu_online(cpunum))
+        if ((cpunum > NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
                 return KDB_BADCPUNUM;
 
         dbg_switch_cpu = cpunum;
@@ -2375,6 +2421,8 @@ static int kdb_help(int argc, const char **argv)
                         return 0;
                 if (!kt->cmd_name)
                         continue;
+                if (!kdb_check_flags(kt->cmd_flags, kdb_cmd_enabled, true))
+                        continue;
                 if (strlen(kt->cmd_usage) > 20)
                         space = "\n                                    ";
                 kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name,
@@ -2629,7 +2677,7 @@ static int kdb_grep_help(int argc, const char **argv)
 }
 
 /*
- * kdb_register_repeat - This function is used to register a kernel
+ * kdb_register_flags - This function is used to register a kernel
  *      debugger command.
  * Inputs:
  *      cmd     Command name
@@ -2641,12 +2689,12 @@ static int kdb_grep_help(int argc, const char **argv)
  *      zero for success, one if a duplicate command.
  */
 #define kdb_command_extend 50   /* arbitrary */
-int kdb_register_repeat(char *cmd,
-                        kdb_func_t func,
-                        char *usage,
-                        char *help,
-                        short minlen,
-                        kdb_repeat_t repeat)
+int kdb_register_flags(char *cmd,
+                       kdb_func_t func,
+                       char *usage,
+                       char *help,
+                       short minlen,
+                       kdb_cmdflags_t flags)
 {
         int i;
         kdbtab_t *kp;
@@ -2694,19 +2742,18 @@ int kdb_register_repeat(char *cmd,
         kp->cmd_func   = func;
         kp->cmd_usage  = usage;
         kp->cmd_help   = help;
-        kp->cmd_flags  = 0;
         kp->cmd_minlen = minlen;
-        kp->cmd_repeat = repeat;
+        kp->cmd_flags  = flags;
 
         return 0;
 }
-EXPORT_SYMBOL_GPL(kdb_register_repeat);
+EXPORT_SYMBOL_GPL(kdb_register_flags);
 
 
 /*
  * kdb_register - Compatibility register function for commands that do
  *      not need to specify a repeat state.  Equivalent to
- *      kdb_register_repeat with KDB_REPEAT_NONE.
+ *      kdb_register_flags with flags set to 0.
  * Inputs:
  *      cmd     Command name
  *      func    Function to execute the command
@@ -2721,8 +2768,7 @@ int kdb_register(char *cmd,
              char *help,
              short minlen)
 {
-        return kdb_register_repeat(cmd, func, usage, help, minlen,
-                                   KDB_REPEAT_NONE);
+        return kdb_register_flags(cmd, func, usage, help, minlen, 0);
 }
 EXPORT_SYMBOL_GPL(kdb_register);
 
@@ -2764,80 +2810,109 @@ static void __init kdb_inittab(void)
         for_each_kdbcmd(kp, i)
                 kp->cmd_name = NULL;
 
-        kdb_register_repeat("md", kdb_md, "<vaddr>",
+        kdb_register_flags("md", kdb_md, "<vaddr>",
           "Display Memory Contents, also mdWcN, e.g. md8c1", 1,
-                            KDB_REPEAT_NO_ARGS);
-        kdb_register_repeat("mdr", kdb_md, "<vaddr> <bytes>",
-          "Display Raw Memory", 0, KDB_REPEAT_NO_ARGS);
-        kdb_register_repeat("mdp", kdb_md, "<paddr> <bytes>",
-          "Display Physical Memory", 0, KDB_REPEAT_NO_ARGS);
-        kdb_register_repeat("mds", kdb_md, "<vaddr>",
-          "Display Memory Symbolically", 0, KDB_REPEAT_NO_ARGS);
-        kdb_register_repeat("mm", kdb_mm, "<vaddr> <contents>",
-          "Modify Memory Contents", 0, KDB_REPEAT_NO_ARGS);
-        kdb_register_repeat("go", kdb_go, "[<vaddr>]",
-          "Continue Execution", 1, KDB_REPEAT_NONE);
-        kdb_register_repeat("rd", kdb_rd, "",
-          "Display Registers", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("rm", kdb_rm, "<reg> <contents>",
-          "Modify Registers", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("ef", kdb_ef, "<vaddr>",
-          "Display exception frame", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("bt", kdb_bt, "[<vaddr>]",
-          "Stack traceback", 1, KDB_REPEAT_NONE);
-        kdb_register_repeat("btp", kdb_bt, "<pid>",
-          "Display stack for process <pid>", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
-          "Backtrace all processes matching state flag", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("btc", kdb_bt, "",
-          "Backtrace current process on each cpu", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("btt", kdb_bt, "<vaddr>",
+          KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
+        kdb_register_flags("mdr", kdb_md, "<vaddr> <bytes>",
+          "Display Raw Memory", 0,
+          KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
+        kdb_register_flags("mdp", kdb_md, "<paddr> <bytes>",
+          "Display Physical Memory", 0,
+          KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
+        kdb_register_flags("mds", kdb_md, "<vaddr>",
+          "Display Memory Symbolically", 0,
+          KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
+        kdb_register_flags("mm", kdb_mm, "<vaddr> <contents>",
+          "Modify Memory Contents", 0,
+          KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS);
+        kdb_register_flags("go", kdb_go, "[<vaddr>]",
+          "Continue Execution", 1,
+          KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
+        kdb_register_flags("rd", kdb_rd, "",
+          "Display Registers", 0,
+          KDB_ENABLE_REG_READ);
+        kdb_register_flags("rm", kdb_rm, "<reg> <contents>",
+          "Modify Registers", 0,
+          KDB_ENABLE_REG_WRITE);
+        kdb_register_flags("ef", kdb_ef, "<vaddr>",
+          "Display exception frame", 0,
+          KDB_ENABLE_MEM_READ);
+        kdb_register_flags("bt", kdb_bt, "[<vaddr>]",
+          "Stack traceback", 1,
+          KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
+        kdb_register_flags("btp", kdb_bt, "<pid>",
+          "Display stack for process <pid>", 0,
+          KDB_ENABLE_INSPECT);
+        kdb_register_flags("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
+          "Backtrace all processes matching state flag", 0,
+          KDB_ENABLE_INSPECT);
+        kdb_register_flags("btc", kdb_bt, "",
+          "Backtrace current process on each cpu", 0,
+          KDB_ENABLE_INSPECT);
+        kdb_register_flags("btt", kdb_bt, "<vaddr>",
           "Backtrace process given its struct task address", 0,
-                            KDB_REPEAT_NONE);
-        kdb_register_repeat("env", kdb_env, "",
-          "Show environment variables", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("set", kdb_set, "",
-          "Set environment variables", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("help", kdb_help, "",
-          "Display Help Message", 1, KDB_REPEAT_NONE);
-        kdb_register_repeat("?", kdb_help, "",
-          "Display Help Message", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("cpu", kdb_cpu, "<cpunum>",
-          "Switch to new cpu", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("kgdb", kdb_kgdb, "",
-          "Enter kgdb mode", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("ps", kdb_ps, "[<flags>|A]",
-          "Display active task list", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("pid", kdb_pid, "<pidnum>",
-          "Switch to another task", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("reboot", kdb_reboot, "",
-          "Reboot the machine immediately", 0, KDB_REPEAT_NONE);
+          KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
+        kdb_register_flags("env", kdb_env, "",
+          "Show environment variables", 0,
+          KDB_ENABLE_ALWAYS_SAFE);
+        kdb_register_flags("set", kdb_set, "",
+          "Set environment variables", 0,
+          KDB_ENABLE_ALWAYS_SAFE);
+        kdb_register_flags("help", kdb_help, "",
+          "Display Help Message", 1,
+          KDB_ENABLE_ALWAYS_SAFE);
+        kdb_register_flags("?", kdb_help, "",
+          "Display Help Message", 0,
+          KDB_ENABLE_ALWAYS_SAFE);
+        kdb_register_flags("cpu", kdb_cpu, "<cpunum>",
+          "Switch to new cpu", 0,
+          KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
+        kdb_register_flags("kgdb", kdb_kgdb, "",
+          "Enter kgdb mode", 0, 0);
+        kdb_register_flags("ps", kdb_ps, "[<flags>|A]",
+          "Display active task list", 0,
+          KDB_ENABLE_INSPECT);
+        kdb_register_flags("pid", kdb_pid, "<pidnum>",
+          "Switch to another task", 0,
+          KDB_ENABLE_INSPECT);
+        kdb_register_flags("reboot", kdb_reboot, "",
+          "Reboot the machine immediately", 0,
+          KDB_ENABLE_REBOOT);
 #if defined(CONFIG_MODULES)
-        kdb_register_repeat("lsmod", kdb_lsmod, "",
-          "List loaded kernel modules", 0, KDB_REPEAT_NONE);
+        kdb_register_flags("lsmod", kdb_lsmod, "",
+          "List loaded kernel modules", 0,
+          KDB_ENABLE_INSPECT);
 #endif
 #if defined(CONFIG_MAGIC_SYSRQ)
-        kdb_register_repeat("sr", kdb_sr, "<key>",
-          "Magic SysRq key", 0, KDB_REPEAT_NONE);
+        kdb_register_flags("sr", kdb_sr, "<key>",
+          "Magic SysRq key", 0,
+          KDB_ENABLE_ALWAYS_SAFE);
 #endif
 #if defined(CONFIG_PRINTK)
-        kdb_register_repeat("dmesg", kdb_dmesg, "[lines]",
-          "Display syslog buffer", 0, KDB_REPEAT_NONE);
+        kdb_register_flags("dmesg", kdb_dmesg, "[lines]",
+          "Display syslog buffer", 0,
+          KDB_ENABLE_ALWAYS_SAFE);
 #endif
         if (arch_kgdb_ops.enable_nmi) {
-                kdb_register_repeat("disable_nmi", kdb_disable_nmi, "",
-                  "Disable NMI entry to KDB", 0, KDB_REPEAT_NONE);
-        }
-        kdb_register_repeat("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
-          "Define a set of commands, down to endefcmd", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("kill", kdb_kill, "<-signal> <pid>",
-          "Send a signal to a process", 0, KDB_REPEAT_NONE);
-        kdb_register_repeat("summary", kdb_summary, "",
-          "Summarize the system", 4, KDB_REPEAT_NONE);
-        kdb_register_repeat("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
-          "Display per_cpu variables", 3, KDB_REPEAT_NONE);
-        kdb_register_repeat("grephelp", kdb_grep_help, "",
-          "Display help on | grep", 0, KDB_REPEAT_NONE);
+                kdb_register_flags("disable_nmi", kdb_disable_nmi, "",
+                  "Disable NMI entry to KDB", 0,
+                  KDB_ENABLE_ALWAYS_SAFE);
+        }
+        kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
+          "Define a set of commands, down to endefcmd", 0,
+          KDB_ENABLE_ALWAYS_SAFE);
+        kdb_register_flags("kill", kdb_kill, "<-signal> <pid>",
+          "Send a signal to a process", 0,
+          KDB_ENABLE_SIGNAL);
+        kdb_register_flags("summary", kdb_summary, "",
+          "Summarize the system", 4,
+          KDB_ENABLE_ALWAYS_SAFE);
+        kdb_register_flags("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
+          "Display per_cpu variables", 3,
+          KDB_ENABLE_MEM_READ);
+        kdb_register_flags("grephelp", kdb_grep_help, "",
+          "Display help on | grep", 0,
+          KDB_ENABLE_ALWAYS_SAFE);
 }
 
 /* Execute any commands defined in kdb_cmds.  */
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 7afd3c8c41d5..eaacd1693954 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -172,10 +172,9 @@ typedef struct _kdbtab {
         kdb_func_t cmd_func;            /* Function to execute command */
         char    *cmd_usage;             /* Usage String for this command */
         char    *cmd_help;              /* Help message for this command */
-        short    cmd_flags;             /* Parsing flags */
         short    cmd_minlen;            /* Minimum legal # command
                                          * chars required */
-        kdb_repeat_t cmd_repeat;        /* Does command auto repeat on enter? */
+        kdb_cmdflags_t cmd_flags;       /* Command behaviour flags */
 } kdbtab_t;
 
 extern int kdb_bt(int, const char **);  /* KDB display back trace */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4c1ee7f2bebc..882f835a0d85 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4461,18 +4461,14 @@ perf_output_sample_regs(struct perf_output_handle *handle,
 }
 
 static void perf_sample_regs_user(struct perf_regs *regs_user,
-                                  struct pt_regs *regs)
+                                  struct pt_regs *regs,
+                                  struct pt_regs *regs_user_copy)
 {
-        if (!user_mode(regs)) {
-                if (current->mm)
-                        regs = task_pt_regs(current);
-                else
-                        regs = NULL;
-        }
-
-        if (regs) {
-                regs_user->abi  = perf_reg_abi(current);
+        if (user_mode(regs)) {
+                regs_user->abi = perf_reg_abi(current);
                 regs_user->regs = regs;
+        } else if (current->mm) {
+                perf_get_regs_user(regs_user, regs, regs_user_copy);
         } else {
                 regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
                 regs_user->regs = NULL;
@@ -4951,7 +4947,8 @@ void perf_prepare_sample(struct perf_event_header *header,
         }
 
         if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
-                perf_sample_regs_user(&data->regs_user, regs);
+                perf_sample_regs_user(&data->regs_user, regs,
+                                      &data->regs_user_copy);
 
         if (sample_type & PERF_SAMPLE_REGS_USER) {
                 /* regs dump ABI info */
diff --git a/kernel/exit.c b/kernel/exit.c
index 1ea4369890a3..6806c55475ee 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1287,9 +1287,15 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
 static int wait_consider_task(struct wait_opts *wo, int ptrace,
                                 struct task_struct *p)
 {
+        /*
+         * We can race with wait_task_zombie() from another thread.
+         * Ensure that EXIT_ZOMBIE -> EXIT_DEAD/EXIT_TRACE transition
+         * can't confuse the checks below.
+         */
+        int exit_state = ACCESS_ONCE(p->exit_state);
         int ret;
 
-        if (unlikely(p->exit_state == EXIT_DEAD))
+        if (unlikely(exit_state == EXIT_DEAD))
                 return 0;
 
         ret = eligible_child(wo, p);
@@ -1310,7 +1316,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
                 return 0;
         }
 
-        if (unlikely(p->exit_state == EXIT_TRACE)) {
+        if (unlikely(exit_state == EXIT_TRACE)) {
                 /*
                  * ptrace == 0 means we are the natural parent. In this case
                  * we should clear notask_error, debugger will notify us.
@@ -1337,7 +1343,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
         }
 
         /* slay zombie? */
-        if (p->exit_state == EXIT_ZOMBIE) {
+        if (exit_state == EXIT_ZOMBIE) {
                 /* we don't reap group leaders with subthreads */
                 if (!delay_group_leader(p)) {
                         /*
diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c
index 5cf6731b98e9..3ef3736002d8 100644
--- a/kernel/locking/mutex-debug.c
+++ b/kernel/locking/mutex-debug.c
@@ -80,13 +80,13 @@ void debug_mutex_unlock(struct mutex *lock)
                         DEBUG_LOCKS_WARN_ON(lock->owner != current);
 
                 DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
-                mutex_clear_owner(lock);
         }
 
         /*
          * __mutex_slowpath_needs_to_unlock() is explicitly 0 for debug
          * mutexes so that we can do it here after we've verified state.
          */
+        mutex_clear_owner(lock);
         atomic_set(&lock->count, 1);
 }
 
diff --git a/kernel/range.c b/kernel/range.c
index 322ea8e93e4b..82cfc285b046 100644
--- a/kernel/range.c
+++ b/kernel/range.c
@@ -113,12 +113,12 @@ static int cmp_range(const void *x1, const void *x2)
 {
         const struct range *r1 = x1;
         const struct range *r2 = x2;
-        s64 start1, start2;
 
-        start1 = r1->start;
-        start2 = r2->start;
-
-        return start1 - start2;
+        if (r1->start < r2->start)
+                return -1;
+        if (r1->start > r2->start)
+                return 1;
+        return 0;
 }
 
 int clean_sort_range(struct range *range, int az)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b5797b78add6..c0accc00566e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7113,9 +7113,6 @@ void __init sched_init(void)
 #ifdef CONFIG_RT_GROUP_SCHED
         alloc_size += 2 * nr_cpu_ids * sizeof(void **);
 #endif
-#ifdef CONFIG_CPUMASK_OFFSTACK
-        alloc_size += num_possible_cpus() * cpumask_size();
-#endif
         if (alloc_size) {
                 ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
 
@@ -7135,13 +7132,13 @@ void __init sched_init(void)
                 ptr += nr_cpu_ids * sizeof(void **);
 
 #endif /* CONFIG_RT_GROUP_SCHED */
+        }
 #ifdef CONFIG_CPUMASK_OFFSTACK
-                for_each_possible_cpu(i) {
-                        per_cpu(load_balance_mask, i) = (void *)ptr;
-                        ptr += cpumask_size();
-                }
-#endif /* CONFIG_CPUMASK_OFFSTACK */
+        for_each_possible_cpu(i) {
+                per_cpu(load_balance_mask, i) = (cpumask_var_t)kzalloc_node(
+                        cpumask_size(), GFP_KERNEL, cpu_to_node(i));
         }
+#endif /* CONFIG_CPUMASK_OFFSTACK */
 
         init_rt_bandwidth(&def_rt_bandwidth,
                         global_rt_period(), global_rt_runtime());
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index e5db8c6feebd..b52092f2636d 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -570,24 +570,7 @@ void init_dl_task_timer(struct sched_dl_entity *dl_se)
 static
 int dl_runtime_exceeded(struct rq *rq, struct sched_dl_entity *dl_se)
 {
-        int dmiss = dl_time_before(dl_se->deadline, rq_clock(rq));
-        int rorun = dl_se->runtime <= 0;
-
-        if (!rorun && !dmiss)
-                return 0;
-
-        /*
-         * If we are beyond our current deadline and we are still
-         * executing, then we have already used some of the runtime of
-         * the next instance. Thus, if we do not account that, we are
-         * stealing bandwidth from the system at each deadline miss!
-         */
-        if (dmiss) {
-                dl_se->runtime = rorun ? dl_se->runtime : 0;
-                dl_se->runtime -= rq_clock(rq) - dl_se->deadline;
-        }
-
-        return 1;
+        return (dl_se->runtime <= 0);
 }
 
 extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq);
@@ -826,10 +809,10 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se,
          * parameters of the task might need updating. Otherwise,
          * we want a replenishment of its runtime.
          */
-        if (!dl_se->dl_new && flags & ENQUEUE_REPLENISH)
-                replenish_dl_entity(dl_se, pi_se);
-        else
+        if (dl_se->dl_new || flags & ENQUEUE_WAKEUP)
                 update_dl_entity(dl_se, pi_se);
+        else if (flags & ENQUEUE_REPLENISH)
+                replenish_dl_entity(dl_se, pi_se);
 
         __enqueue_dl_entity(dl_se);
 }
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index df2cdf77f899..40667cbf371b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4005,6 +4005,10 @@ void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force)
 
 static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
 {
+        /* init_cfs_bandwidth() was not called */
+        if (!cfs_b->throttled_cfs_rq.next)
+                return;
+
         hrtimer_cancel(&cfs_b->period_timer);
         hrtimer_cancel(&cfs_b->slack_timer);
 }
@@ -4424,7 +4428,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
                  * wl = S * s'_i; see (2)
                  */
                 if (W > 0 && w < W)
-                        wl = (w * tg->shares) / W;
+                        wl = (w * (long)tg->shares) / W;
                 else
                         wl = tg->shares;
 
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 929a733d302e..224e768bdc73 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2497,12 +2497,14 @@ static void ftrace_run_update_code(int command)
 }
 
 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
-                                   struct ftrace_hash *old_hash)
+                                   struct ftrace_ops_hash *old_hash)
 {
         ops->flags |= FTRACE_OPS_FL_MODIFYING;
-        ops->old_hash.filter_hash = old_hash;
+        ops->old_hash.filter_hash = old_hash->filter_hash;
+        ops->old_hash.notrace_hash = old_hash->notrace_hash;
         ftrace_run_update_code(command);
         ops->old_hash.filter_hash = NULL;
+        ops->old_hash.notrace_hash = NULL;
         ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
 }
 
@@ -3579,7 +3581,7 @@ static struct ftrace_ops trace_probe_ops __read_mostly =
 
 static int ftrace_probe_registered;
 
-static void __enable_ftrace_function_probe(struct ftrace_hash *old_hash)
+static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash)
 {
         int ret;
         int i;
@@ -3637,6 +3639,7 @@ int
 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
                               void *data)
 {
+        struct ftrace_ops_hash old_hash_ops;
         struct ftrace_func_probe *entry;
         struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
         struct ftrace_hash *old_hash = *orig_hash;
@@ -3658,6 +3661,10 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 
         mutex_lock(&trace_probe_ops.func_hash->regex_lock);
 
+        old_hash_ops.filter_hash = old_hash;
+        /* Probes only have filters */
+        old_hash_ops.notrace_hash = NULL;
+
         hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
         if (!hash) {
                 count = -ENOMEM;
@@ -3718,7 +3725,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 
         ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
 
-        __enable_ftrace_function_probe(old_hash);
+        __enable_ftrace_function_probe(&old_hash_ops);
 
         if (!ret)
                 free_ftrace_hash_rcu(old_hash);
@@ -4006,10 +4013,34 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
 }
 
 static void ftrace_ops_update_code(struct ftrace_ops *ops,
-                                   struct ftrace_hash *old_hash)
+                                   struct ftrace_ops_hash *old_hash)
 {
-        if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled)
+        struct ftrace_ops *op;
+
+        if (!ftrace_enabled)
+                return;
+
+        if (ops->flags & FTRACE_OPS_FL_ENABLED) {
                 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
+                return;
+        }
+
+        /*
+         * If this is the shared global_ops filter, then we need to
+         * check if there is another ops that shares it, is enabled.
+         * If so, we still need to run the modify code.
+         */
+        if (ops->func_hash != &global_ops.local_hash)
+                return;
+
+        do_for_each_ftrace_op(op, ftrace_ops_list) {
+                if (op->func_hash == &global_ops.local_hash &&
+                    op->flags & FTRACE_OPS_FL_ENABLED) {
+                        ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
+                        /* Only need to do this once */
+                        return;
+                }
+        } while_for_each_ftrace_op(op);
 }
 
 static int
@@ -4017,6 +4048,7 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
                 unsigned long ip, int remove, int reset, int enable)
 {
         struct ftrace_hash **orig_hash;
+        struct ftrace_ops_hash old_hash_ops;
         struct ftrace_hash *old_hash;
         struct ftrace_hash *hash;
         int ret;
@@ -4053,9 +4085,11 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
 
         mutex_lock(&ftrace_lock);
         old_hash = *orig_hash;
+        old_hash_ops.filter_hash = ops->func_hash->filter_hash;
+        old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
         ret = ftrace_hash_move(ops, enable, orig_hash, hash);
         if (!ret) {
-                ftrace_ops_update_code(ops, old_hash);
+                ftrace_ops_update_code(ops, &old_hash_ops);
                 free_ftrace_hash_rcu(old_hash);
         }
         mutex_unlock(&ftrace_lock);
@@ -4267,6 +4301,7 @@ static void __init set_ftrace_early_filters(void)
 int ftrace_regex_release(struct inode *inode, struct file *file)
 {
         struct seq_file *m = (struct seq_file *)file->private_data;
+        struct ftrace_ops_hash old_hash_ops;
         struct ftrace_iterator *iter;
         struct ftrace_hash **orig_hash;
         struct ftrace_hash *old_hash;
@@ -4300,10 +4335,12 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
 
                 mutex_lock(&ftrace_lock);
                 old_hash = *orig_hash;
+                old_hash_ops.filter_hash = iter->ops->func_hash->filter_hash;
+                old_hash_ops.notrace_hash = iter->ops->func_hash->notrace_hash;
                 ret = ftrace_hash_move(iter->ops, filter_hash,
                                        orig_hash, iter->hash);
                 if (!ret) {
-                        ftrace_ops_update_code(iter->ops, old_hash);
+                        ftrace_ops_update_code(iter->ops, &old_hash_ops);
                         free_ftrace_hash_rcu(old_hash);
                 }
                 mutex_unlock(&ftrace_lock);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2e767972e99c..4a9079b9f082 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6918,7 +6918,6 @@ void __init trace_init(void)
                         tracepoint_printk = 0;
         }
         tracer_alloc_buffers();
-        init_ftrace_syscalls();
         trace_event_init();     
 }
 
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 366a78a3e61e..b03a0ea77b99 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2429,12 +2429,39 @@ static __init int event_trace_memsetup(void)
         return 0;
 }
 
+static __init void
+early_enable_events(struct trace_array *tr, bool disable_first)
+{
+        char *buf = bootup_event_buf;
+        char *token;
+        int ret;
+
+        while (true) {
+                token = strsep(&buf, ",");
+
+                if (!token)
+                        break;
+                if (!*token)
+                        continue;
+
+                /* Restarting syscalls requires that we stop them first */
+                if (disable_first)
+                        ftrace_set_clr_event(tr, token, 0);
+
+                ret = ftrace_set_clr_event(tr, token, 1);
+                if (ret)
+                        pr_warn("Failed to enable trace event: %s\n", token);
+
+                /* Put back the comma to allow this to be called again */
+                if (buf)
+                        *(buf - 1) = ',';
+        }
+}
+
 static __init int event_trace_enable(void)
 {
         struct trace_array *tr = top_trace_array();
         struct ftrace_event_call **iter, *call;
-        char *buf = bootup_event_buf;
-        char *token;
         int ret;
 
         if (!tr)
@@ -2456,18 +2483,7 @@ static __init int event_trace_enable(void)
          */
         __trace_early_add_events(tr);
 
-        while (true) {
-                token = strsep(&buf, ",");
-
-                if (!token)
-                        break;
-                if (!*token)
-                        continue;
-
-                ret = ftrace_set_clr_event(tr, token, 1);
-                if (ret)
-                        pr_warn("Failed to enable trace event: %s\n", token);
-        }
+        early_enable_events(tr, false);
 
         trace_printk_start_comm();
 
@@ -2478,6 +2494,31 @@ static __init int event_trace_enable(void)
         return 0;
 }
 
+/*
+ * event_trace_enable() is called from trace_event_init() first to
+ * initialize events and perhaps start any events that are on the
+ * command line. Unfortunately, there are some events that will not
+ * start this early, like the system call tracepoints that need
+ * to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
+ * is called before pid 1 starts, and this flag is never set, making
+ * the syscall tracepoint never get reached, but the event is enabled
+ * regardless (and not doing anything).
+ */
+static __init int event_trace_enable_again(void)
+{
+        struct trace_array *tr;
+
+        tr = top_trace_array();
+        if (!tr)
+                return -ENODEV;
+
+        early_enable_events(tr, true);
+
+        return 0;
+}
+
+early_initcall(event_trace_enable_again);
+
 static __init int event_trace_init(void)
 {
         struct trace_array *tr;
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
index b0b1c44e923a..3ccf5c2c1320 100644
--- a/kernel/trace/trace_kdb.c
+++ b/kernel/trace/trace_kdb.c
@@ -132,8 +132,8 @@ static int kdb_ftdump(int argc, const char **argv)
 
 static __init int kdb_ftrace_register(void)
 {
-        kdb_register_repeat("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
-                            "Dump ftrace log", 0, KDB_REPEAT_NONE);
+        kdb_register_flags("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
+                            "Dump ftrace log", 0, KDB_ENABLE_ALWAYS_SAFE);
         return 0;
 }