Re: [PATCH v2 3/7][next] printk: ringbuffer: relocate get_data()

2020-08-25 Thread Petr Mladek
On Mon 2020-08-24 12:41:34, John Ogness wrote:
> Move the internal get_data() function as-is above prb_reserve() so
> that a later change can make use of the static function.
> 
> Signed-off-by: John Ogness 

Reviewed-by: Petr Mladek 

Best Regards,
Petr

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[PATCH v2 3/7][next] printk: ringbuffer: relocate get_data()

2020-08-24 Thread John Ogness
Move the internal get_data() function as-is above prb_reserve() so
that a later change can make use of the static function.

Signed-off-by: John Ogness 
---
 kernel/printk/printk_ringbuffer.c | 116 +++---
 1 file changed, 58 insertions(+), 58 deletions(-)

diff --git a/kernel/printk/printk_ringbuffer.c 
b/kernel/printk/printk_ringbuffer.c
index d339ff7647da..86af38c2cf77 100644
--- a/kernel/printk/printk_ringbuffer.c
+++ b/kernel/printk/printk_ringbuffer.c
@@ -1038,6 +1038,64 @@ static unsigned int space_used(struct prb_data_ring 
*data_ring,
DATA_SIZE(data_ring) - DATA_INDEX(data_ring, blk_lpos->begin));
 }
 
+/*
+ * Given @blk_lpos, return a pointer to the writer data from the data block
+ * and calculate the size of the data part. A NULL pointer is returned if
+ * @blk_lpos specifies values that could never be legal.
+ *
+ * This function (used by readers) performs strict validation on the lpos
+ * values to possibly detect bugs in the writer code. A WARN_ON_ONCE() is
+ * triggered if an internal error is detected.
+ */
+static const char *get_data(struct prb_data_ring *data_ring,
+   struct prb_data_blk_lpos *blk_lpos,
+   unsigned int *data_size)
+{
+   struct prb_data_block *db;
+
+   /* Data-less data block description. */
+   if (LPOS_DATALESS(blk_lpos->begin) && LPOS_DATALESS(blk_lpos->next)) {
+   if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {
+   *data_size = 0;
+   return "";
+   }
+   return NULL;
+   }
+
+   /* Regular data block: @begin less than @next and in same wrap. */
+   if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, 
blk_lpos->next) &&
+   blk_lpos->begin < blk_lpos->next) {
+   db = to_block(data_ring, blk_lpos->begin);
+   *data_size = blk_lpos->next - blk_lpos->begin;
+
+   /* Wrapping data block: @begin is one wrap behind @next. */
+   } else if (DATA_WRAPS(data_ring, blk_lpos->begin + 
DATA_SIZE(data_ring)) ==
+  DATA_WRAPS(data_ring, blk_lpos->next)) {
+   db = to_block(data_ring, 0);
+   *data_size = DATA_INDEX(data_ring, blk_lpos->next);
+
+   /* Illegal block description. */
+   } else {
+   WARN_ON_ONCE(1);
+   return NULL;
+   }
+
+   /* A valid data block will always be aligned to the ID size. */
+   if (WARN_ON_ONCE(blk_lpos->begin != ALIGN(blk_lpos->begin, 
sizeof(db->id))) ||
+   WARN_ON_ONCE(blk_lpos->next != ALIGN(blk_lpos->next, 
sizeof(db->id {
+   return NULL;
+   }
+
+   /* A valid data block will always have at least an ID. */
+   if (WARN_ON_ONCE(*data_size < sizeof(db->id)))
+   return NULL;
+
+   /* Subtract block ID space from size to reflect data size. */
+   *data_size -= sizeof(db->id);
+
+   return >data[0];
+}
+
 /**
  * prb_reserve() - Reserve space in the ringbuffer.
  *
@@ -1192,64 +1250,6 @@ void prb_commit(struct prb_reserved_entry *e)
local_irq_restore(e->irqflags);
 }
 
-/*
- * Given @blk_lpos, return a pointer to the writer data from the data block
- * and calculate the size of the data part. A NULL pointer is returned if
- * @blk_lpos specifies values that could never be legal.
- *
- * This function (used by readers) performs strict validation on the lpos
- * values to possibly detect bugs in the writer code. A WARN_ON_ONCE() is
- * triggered if an internal error is detected.
- */
-static const char *get_data(struct prb_data_ring *data_ring,
-   struct prb_data_blk_lpos *blk_lpos,
-   unsigned int *data_size)
-{
-   struct prb_data_block *db;
-
-   /* Data-less data block description. */
-   if (LPOS_DATALESS(blk_lpos->begin) && LPOS_DATALESS(blk_lpos->next)) {
-   if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {
-   *data_size = 0;
-   return "";
-   }
-   return NULL;
-   }
-
-   /* Regular data block: @begin less than @next and in same wrap. */
-   if (DATA_WRAPS(data_ring, blk_lpos->begin) == DATA_WRAPS(data_ring, 
blk_lpos->next) &&
-   blk_lpos->begin < blk_lpos->next) {
-   db = to_block(data_ring, blk_lpos->begin);
-   *data_size = blk_lpos->next - blk_lpos->begin;
-
-   /* Wrapping data block: @begin is one wrap behind @next. */
-   } else if (DATA_WRAPS(data_ring, blk_lpos->begin + 
DATA_SIZE(data_ring)) ==
-  DATA_WRAPS(data_ring, blk_lpos->next)) {
-   db = to_block(data_ring, 0);
-   *data_size = DATA_INDEX(data_ring, blk_lpos->next);
-
-   /* Illegal block description. */
-   } else {
-   WARN_ON_ONCE(1);
-   return NULL;
-   }
-
-   /* A valid