trace-cmd: Add calc_page_offset() helper routine

Use calc_page_offset() to performe the:

	offset & (handle->page_size - 1)

to prevent any typos and bugs.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/trace-input.c b/trace-input.c
index 3191510..ce7bd09 100644
--- a/trace-input.c
+++ b/trace-input.c
@@ -517,6 +517,11 @@ static int calc_index(struct tracecmd_input *handle,
         return (unsigned long)ptr - (unsigned long)handle->cpu_data[cpu].page->map;
 }
 
+static unsigned long long calc_page_offset(struct tracecmd_input *handle,
+                                           unsigned long long offset)
+{
+        return offset & ~(handle->page_size - 1);
+}
 
 static int read_page(struct tracecmd_input *handle, off64_t offset,
                      void *map)
@@ -876,7 +881,7 @@ find_and_peek_event(struct tracecmd_input *handle, unsigned long long offset,
                 return NULL;
 
         /* Move this cpu index to point to this offest */
-        page_offset = offset & ~(handle->page_size - 1);
+        page_offset = calc_page_offset(handle, offset);
 
         if (get_page(handle, cpu, page_offset) < 0)
                 return NULL;
@@ -924,7 +929,7 @@ tracecmd_read_at(struct tracecmd_input *handle, unsigned long long offset,
         unsigned long long page_offset;
         int cpu;
 
-        page_offset = offset & ~(handle->page_size - 1);
+        page_offset = calc_page_offset(handle, offset);
 
         /* check to see if we have this page already */
         for (cpu = 0; cpu < handle->cpus; cpu++) {
@@ -969,7 +974,7 @@ int tracecmd_refresh_record(struct tracecmd_input *handle,
         int index;
         int ret;
 
-        page_offset = record->offset & ~(handle->page_size - 1);
+        page_offset = calc_page_offset(handle, record->offset);
         index = record->offset & (handle->page_size - 1);
 
         ret =get_page(handle, record->cpu, page_offset);
@@ -1150,7 +1155,7 @@ tracecmd_set_cpu_to_timestamp(struct tracecmd_input *handle, int cpu,
                         end = next;
 
                 next = start + (end - start) / 2;
-                next &= ~(handle->page_size - 1);
+                next = calc_page_offset(handle, next);
 
                 /* Prevent an infinite loop if start and end are a page off */
                 if (next == start)
@@ -1206,7 +1211,7 @@ int tracecmd_set_cursor(struct tracecmd_input *handle,
                 return -1;      /* cpu does not have this offset. */
 
         /* Move this cpu index to point to this offest */
-        page_offset = offset & ~(handle->page_size - 1);
+        page_offset = calc_page_offset(handle, offset);
 
         if (get_page(handle, cpu, page_offset) < 0)
                 return -1;