diff options
| -rw-r--r-- | drivers/oprofile/buffer_sync.c | 30 | ||||
| -rw-r--r-- | kernel/fork.c | 1 |
2 files changed, 17 insertions, 14 deletions
diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c index d93b2b6b1f7a..82f7000a285d 100644 --- a/drivers/oprofile/buffer_sync.c +++ b/drivers/oprofile/buffer_sync.c @@ -21,6 +21,7 @@ * objects. */ +#include <linux/file.h> #include <linux/mm.h> #include <linux/workqueue.h> #include <linux/notifier.h> @@ -224,10 +225,18 @@ static inline unsigned long fast_get_dcookie(struct path *path) static unsigned long get_exec_dcookie(struct mm_struct *mm) { unsigned long cookie = NO_COOKIE; + struct file *exe_file; - if (mm && mm->exe_file) - cookie = fast_get_dcookie(&mm->exe_file->f_path); + if (!mm) + goto done; + + exe_file = get_mm_exe_file(mm); + if (!exe_file) + goto done; + cookie = fast_get_dcookie(&exe_file->f_path); + fput(exe_file); +done: return cookie; } @@ -236,6 +245,8 @@ static unsigned long get_exec_dcookie(struct mm_struct *mm) * pair that can then be added to the global event buffer. We make * sure to do this lookup before a mm->mmap modification happens so * we don't lose track. + * + * The caller must ensure the mm is not nil (ie: not a kernel thread). */ static unsigned long lookup_dcookie(struct mm_struct *mm, unsigned long addr, off_t *offset) @@ -243,6 +254,7 @@ lookup_dcookie(struct mm_struct *mm, unsigned long addr, off_t *offset) unsigned long cookie = NO_COOKIE; struct vm_area_struct *vma; + down_read(&mm->mmap_sem); for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) { if (addr < vma->vm_start || addr >= vma->vm_end) @@ -262,6 +274,7 @@ lookup_dcookie(struct mm_struct *mm, unsigned long addr, off_t *offset) if (!vma) cookie = INVALID_COOKIE; + up_read(&mm->mmap_sem); return cookie; } @@ -402,20 +415,9 @@ static void release_mm(struct mm_struct *mm) { if (!mm) return; - up_read(&mm->mmap_sem); mmput(mm); } - -static struct mm_struct *take_tasks_mm(struct task_struct *task) -{ - struct mm_struct *mm = get_task_mm(task); - if (mm) - down_read(&mm->mmap_sem); - return mm; -} - - static inline int is_code(unsigned long val) { return val == ESCAPE_CODE; @@ -532,7 +534,7 @@ void sync_buffer(int cpu) new = (struct task_struct *)val; oldmm = mm; release_mm(oldmm); - mm = take_tasks_mm(new); + mm = get_task_mm(new); if (mm != oldmm) cookie = get_exec_dcookie(mm); add_user_ctx_switch(new, cookie); diff --git a/kernel/fork.c b/kernel/fork.c index 0d23e76a0c61..03c1eaaa6ef5 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -752,6 +752,7 @@ struct file *get_mm_exe_file(struct mm_struct *mm) rcu_read_unlock(); return exe_file; } +EXPORT_SYMBOL(get_mm_exe_file); /** * get_task_mm - acquire a reference to the task's mm |