3 files changed, 158 insertions, 12 deletions

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 153562d0b93c..d95721f33702 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -138,6 +138,13 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
                      !blk_tracer_enabled))
                 return;
 
+        /*
+         * If the BLK_TC_NOTIFY action mask isn't set, don't send any note
+         * message to the trace.
+         */
+        if (!(bt->act_mask & BLK_TC_NOTIFY))
+                return;
+
         local_irq_save(flags);
         buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
         va_start(args, fmt);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f3dadae83883..888b611897d3 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3328,7 +3328,7 @@ static int start_graph_tracing(void)
         /* The cpu_boot init_task->ret_stack will never be freed */
         for_each_online_cpu(cpu) {
                 if (!idle_task(cpu)->ret_stack)
-                        ftrace_graph_init_task(idle_task(cpu));
+                        ftrace_graph_init_idle_task(idle_task(cpu), cpu);
         }
 
         do {
@@ -3418,6 +3418,49 @@ void unregister_ftrace_graph(void)
         mutex_unlock(&ftrace_lock);
 }
 
+static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
+
+static void
+graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
+{
+        atomic_set(&t->tracing_graph_pause, 0);
+        atomic_set(&t->trace_overrun, 0);
+        t->ftrace_timestamp = 0;
+        /* make curr_ret_stack visable before we add the ret_stack */
+        smp_wmb();
+        t->ret_stack = ret_stack;
+}
+
+/*
+ * Allocate a return stack for the idle task. May be the first
+ * time through, or it may be done by CPU hotplug online.
+ */
+void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
+{
+        t->curr_ret_stack = -1;
+        /*
+         * The idle task has no parent, it either has its own
+         * stack or no stack at all.
+         */
+        if (t->ret_stack)
+                WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
+
+        if (ftrace_graph_active) {
+                struct ftrace_ret_stack *ret_stack;
+
+                ret_stack = per_cpu(idle_ret_stack, cpu);
+                if (!ret_stack) {
+                        ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
+                                            * sizeof(struct ftrace_ret_stack),
+                                            GFP_KERNEL);
+                        if (!ret_stack)
+                                return;
+                        per_cpu(idle_ret_stack, cpu) = ret_stack;
+                }
+                graph_init_task(t, ret_stack);
+        }
+}
+
 /* Allocate a return stack for newly created task */
 void ftrace_graph_init_task(struct task_struct *t)
 {
@@ -3433,12 +3476,7 @@ void ftrace_graph_init_task(struct task_struct *t)
                                 GFP_KERNEL);
                 if (!ret_stack)
                         return;
-                atomic_set(&t->tracing_graph_pause, 0);
-                atomic_set(&t->trace_overrun, 0);
-                t->ftrace_timestamp = 0;
-                /* make curr_ret_stack visable before we add the ret_stack */
-                smp_wmb();
-                t->ret_stack = ret_stack;
+                graph_init_task(t, ret_stack);
         }
 }
 
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 2dec9bcde8b4..8435b43b1782 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -353,6 +353,43 @@ static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
         kfree(data);
 }
 
+/* Bitfield fetch function */
+struct bitfield_fetch_param {
+        struct fetch_param orig;
+        unsigned char hi_shift;
+        unsigned char low_shift;
+};
+
+#define DEFINE_FETCH_bitfield(type)                                     \
+static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
+                                            void *data, void *dest)     \
+{                                                                       \
+        struct bitfield_fetch_param *bprm = data;                       \
+        type buf = 0;                                                   \
+        call_fetch(&bprm->orig, regs, &buf);                            \
+        if (buf) {                                                      \
+                buf <<= bprm->hi_shift;                                 \
+                buf >>= bprm->low_shift;                                \
+        }                                                               \
+        *(type *)dest = buf;                                            \
+}
+DEFINE_BASIC_FETCH_FUNCS(bitfield)
+#define fetch_bitfield_string NULL
+#define fetch_bitfield_string_size NULL
+
+static __kprobes void
+free_bitfield_fetch_param(struct bitfield_fetch_param *data)
+{
+        /*
+         * Don't check the bitfield itself, because this must be the
+         * last fetch function.
+         */
+        if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+                free_deref_fetch_param(data->orig.data);
+        else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+                free_symbol_cache(data->orig.data);
+        kfree(data);
+}
 /* Default (unsigned long) fetch type */
 #define __DEFAULT_FETCH_TYPE(t) u##t
 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
@@ -367,6 +404,7 @@ enum {
         FETCH_MTD_memory,
         FETCH_MTD_symbol,
         FETCH_MTD_deref,
+        FETCH_MTD_bitfield,
         FETCH_MTD_END,
 };
 
@@ -387,6 +425,7 @@ ASSIGN_FETCH_FUNC(retval, ftype),			\
 ASSIGN_FETCH_FUNC(memory, ftype),                       \
 ASSIGN_FETCH_FUNC(symbol, ftype),                       \
 ASSIGN_FETCH_FUNC(deref, ftype),                        \
+ASSIGN_FETCH_FUNC(bitfield, ftype),                     \
           }                                             \
         }
 
@@ -430,9 +469,33 @@ static const struct fetch_type *find_fetch_type(const char *type)
         if (!type)
                 type = DEFAULT_FETCH_TYPE_STR;
 
+        /* Special case: bitfield */
+        if (*type == 'b') {
+                unsigned long bs;
+                type = strchr(type, '/');
+                if (!type)
+                        goto fail;
+                type++;
+                if (strict_strtoul(type, 0, &bs))
+                        goto fail;
+                switch (bs) {
+                case 8:
+                        return find_fetch_type("u8");
+                case 16:
+                        return find_fetch_type("u16");
+                case 32:
+                        return find_fetch_type("u32");
+                case 64:
+                        return find_fetch_type("u64");
+                default:
+                        goto fail;
+                }
+        }
+
         for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
                 if (strcmp(type, fetch_type_table[i].name) == 0)
                         return &fetch_type_table[i];
+fail:
         return NULL;
 }
 
@@ -586,7 +649,9 @@ error:
 
 static void free_probe_arg(struct probe_arg *arg)
 {
-        if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
+        if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
+                free_bitfield_fetch_param(arg->fetch.data);
+        else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
                 free_deref_fetch_param(arg->fetch.data);
         else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
                 free_symbol_cache(arg->fetch.data);
@@ -767,16 +832,15 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
                 }
                 break;
         case '+':       /* deref memory */
+                arg++;  /* Skip '+', because strict_strtol() rejects it. */
         case '-':
                 tmp = strchr(arg, '(');
                 if (!tmp)
                         break;
                 *tmp = '\0';
-                ret = strict_strtol(arg + 1, 0, &offset);
+                ret = strict_strtol(arg, 0, &offset);
                 if (ret)
                         break;
-                if (arg[0] == '-')
-                        offset = -offset;
                 arg = tmp + 1;
                 tmp = strrchr(arg, ')');
                 if (tmp) {
@@ -807,6 +871,41 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
         return ret;
 }
 
+#define BYTES_TO_BITS(nb)       ((BITS_PER_LONG * (nb)) / sizeof(long))
+
+/* Bitfield type needs to be parsed into a fetch function */
+static int __parse_bitfield_probe_arg(const char *bf,
+                                      const struct fetch_type *t,
+                                      struct fetch_param *f)
+{
+        struct bitfield_fetch_param *bprm;
+        unsigned long bw, bo;
+        char *tail;
+
+        if (*bf != 'b')
+                return 0;
+
+        bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
+        if (!bprm)
+                return -ENOMEM;
+        bprm->orig = *f;
+        f->fn = t->fetch[FETCH_MTD_bitfield];
+        f->data = (void *)bprm;
+
+        bw = simple_strtoul(bf + 1, &tail, 0);  /* Use simple one */
+        if (bw == 0 || *tail != '@')
+                return -EINVAL;
+
+        bf = tail + 1;
+        bo = simple_strtoul(bf, &tail, 0);
+        if (tail == bf || *tail != '/')
+                return -EINVAL;
+
+        bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
+        bprm->low_shift = bprm->hi_shift + bo;
+        return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
+}
+
 /* String length checking wrapper */
 static int parse_probe_arg(char *arg, struct trace_probe *tp,
                            struct probe_arg *parg, int is_return)
@@ -836,6 +935,8 @@ static int parse_probe_arg(char *arg, struct trace_probe *tp,
         parg->offset = tp->size;
         tp->size += parg->type->size;
         ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
+        if (ret >= 0 && t != NULL)
+                ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
         if (ret >= 0) {
                 parg->fetch_size.fn = get_fetch_size_function(parg->type,
                                                               parg->fetch.fn);
@@ -1130,7 +1231,7 @@ static int command_trace_probe(const char *buf)
         return ret;
 }
 
-#define WRITE_BUFSIZE 128
+#define WRITE_BUFSIZE 4096
 
 static ssize_t probes_write(struct file *file, const char __user *buffer,
                             size_t count, loff_t *ppos)