Merge tag 'for-v3.17/omap-clock-a' of git://git.kernel.org/pub/scm/linux/kernel/git...

[cascardo/linux.git] / kernel / trace / trace_uprobe.c

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index c082a74..3c9b97e 100644 (file)
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -108,8 +108,8 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
  * Uprobes-specific fetch functions
  */
 #define DEFINE_FETCH_stack(type)                                       \
-static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
-                                         void *offset, void *dest)     \
+static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,         \
+                                        void *offset, void *dest)      \
 {                                                                      \
        *(type *)dest = (type)get_user_stack_nth(regs,                  \
                                              ((unsigned long)offset)); \
@@ -120,8 +120,8 @@ DEFINE_BASIC_FETCH_FUNCS(stack)
 #define fetch_stack_string_size        NULL
 
 #define DEFINE_FETCH_memory(type)                                      \
-static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
-                                               void *addr, void *dest) \
+static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,                \
+                                         void *addr, void *dest)       \
 {                                                                      \
        type retval;                                                    \
        void __user *vaddr = (void __force __user *) addr;              \
@@ -136,8 +136,8 @@ DEFINE_BASIC_FETCH_FUNCS(memory)
  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
  * length and relative data location.
  */
-static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
-                                                     void *addr, void *dest)
+static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
+                                           void *addr, void *dest)
 {
        long ret;
        u32 rloc = *(u32 *)dest;
@@ -158,8 +158,8 @@ static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
        }
 }
 
-static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
-                                                     void *addr, void *dest)
+static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
+                                                void *addr, void *dest)
 {
        int len;
        void __user *vaddr = (void __force __user *) addr;
@@ -184,8 +184,8 @@ static unsigned long translate_user_vaddr(void *file_offset)
 }
 
 #define DEFINE_FETCH_file_offset(type)                                 \
-static __kprobes void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs,\
-                                       void *offset, void *dest)       \
+static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs,   \
+                                              void *offset, void *dest)\
 {                                                                      \
        void *vaddr = (void *)translate_user_vaddr(offset);             \
                                                                        \
@@ -893,6 +893,9 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
        int ret;
 
        if (file) {
+               if (tu->tp.flags & TP_FLAG_PROFILE)
+                       return -EINTR;
+
                link = kmalloc(sizeof(*link), GFP_KERNEL);
                if (!link)
                        return -ENOMEM;
@@ -901,29 +904,40 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
                list_add_tail_rcu(&link->list, &tu->tp.files);
 
                tu->tp.flags |= TP_FLAG_TRACE;
-       } else
-               tu->tp.flags |= TP_FLAG_PROFILE;
+       } else {
+               if (tu->tp.flags & TP_FLAG_TRACE)
+                       return -EINTR;
 
-       ret = uprobe_buffer_enable();
-       if (ret < 0)
-               return ret;
+               tu->tp.flags |= TP_FLAG_PROFILE;
+       }
 
        WARN_ON(!uprobe_filter_is_empty(&tu->filter));
 
        if (enabled)
                return 0;
 
+       ret = uprobe_buffer_enable();
+       if (ret)
+               goto err_flags;
+
        tu->consumer.filter = filter;
        ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
-       if (ret) {
-               if (file) {
-                       list_del(&link->list);
-                       kfree(link);
-                       tu->tp.flags &= ~TP_FLAG_TRACE;
-               } else
-                       tu->tp.flags &= ~TP_FLAG_PROFILE;
-       }
+       if (ret)
+               goto err_buffer;
+
+       return 0;
 
+ err_buffer:
+       uprobe_buffer_disable();
+
+ err_flags:
+       if (file) {
+               list_del(&link->list);
+               kfree(link);
+               tu->tp.flags &= ~TP_FLAG_TRACE;
+       } else {
+               tu->tp.flags &= ~TP_FLAG_PROFILE;
+       }
        return ret;
 }
 
@@ -1009,56 +1023,60 @@ uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
        return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm);
 }
 
-static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
+static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
 {
        bool done;
 
        write_lock(&tu->filter.rwlock);
        if (event->hw.tp_target) {
-               /*
-                * event->parent != NULL means copy_process(), we can avoid
-                * uprobe_apply(). current->mm must be probed and we can rely
-                * on dup_mmap() which preserves the already installed bp's.
-                *
-                * attr.enable_on_exec means that exec/mmap will install the
-                * breakpoints we need.
-                */
+               list_del(&event->hw.tp_list);
                done = tu->filter.nr_systemwide ||
-                       event->parent || event->attr.enable_on_exec ||
+                       (event->hw.tp_target->flags & PF_EXITING) ||
                        uprobe_filter_event(tu, event);
-               list_add(&event->hw.tp_list, &tu->filter.perf_events);
        } else {
+               tu->filter.nr_systemwide--;
                done = tu->filter.nr_systemwide;
-               tu->filter.nr_systemwide++;
        }
        write_unlock(&tu->filter.rwlock);
 
        if (!done)
-               uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
+               return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
 
        return 0;
 }
 
-static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
+static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
 {
        bool done;
+       int err;
 
        write_lock(&tu->filter.rwlock);
        if (event->hw.tp_target) {
-               list_del(&event->hw.tp_list);
+               /*
+                * event->parent != NULL means copy_process(), we can avoid
+                * uprobe_apply(). current->mm must be probed and we can rely
+                * on dup_mmap() which preserves the already installed bp's.
+                *
+                * attr.enable_on_exec means that exec/mmap will install the
+                * breakpoints we need.
+                */
                done = tu->filter.nr_systemwide ||
-                       (event->hw.tp_target->flags & PF_EXITING) ||
+                       event->parent || event->attr.enable_on_exec ||
                        uprobe_filter_event(tu, event);
+               list_add(&event->hw.tp_list, &tu->filter.perf_events);
        } else {
-               tu->filter.nr_systemwide--;
                done = tu->filter.nr_systemwide;
+               tu->filter.nr_systemwide++;
        }
        write_unlock(&tu->filter.rwlock);
 
-       if (!done)
-               uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
-
-       return 0;
+       err = 0;
+       if (!done) {
+               err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
+               if (err)
+                       uprobe_perf_close(tu, event);
+       }
+       return err;
 }
 
 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
@@ -1197,12 +1215,6 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
 
        current->utask->vaddr = (unsigned long) &udd;
 
-#ifdef CONFIG_PERF_EVENTS
-       if ((tu->tp.flags & TP_FLAG_TRACE) == 0 &&
-           !uprobe_perf_filter(&tu->consumer, 0, current->mm))
-               return UPROBE_HANDLER_REMOVE;
-#endif
-
        if (WARN_ON_ONCE(!uprobe_cpu_buffer))
                return 0;