Cleanup: clarify strcpy/strcpy_from_user local variables

[lttng-modules.git] / src / lib / ringbuffer / ring_buffer_backend.c

diff --git a/src/lib/ringbuffer/ring_buffer_backend.c b/src/lib/ringbuffer/ring_buffer_backend.c
index 76f9b4252a3a6bd58d88ee09d42b442627e4f69e..cbc931df04b2682a29b02f3afa8e5cd60318474b 100644 (file)
--- a/src/lib/ringbuffer/ring_buffer_backend.c
+++ b/src/lib/ringbuffer/ring_buffer_backend.c
@@ -653,26 +653,20 @@ EXPORT_SYMBOL_GPL(_lib_ring_buffer_memset);
  * @offset : offset within the buffer
  * @src : source address
  * @len : length to write
- * @pagecpy : page size copied so far
  * @pad : character to use for padding
  */
 void _lib_ring_buffer_strcpy(struct lttng_kernel_ring_buffer_backend *bufb,
-                       size_t offset, const char *src, size_t len,
-                       size_t pagecpy, int pad)
+                       size_t offset, const char *src, size_t len, int pad)
 {
        struct channel_backend *chanb = &bufb->chan->backend;
        const struct lttng_kernel_ring_buffer_config *config = &chanb->config;
-       size_t sbidx, index;
+       size_t sbidx, index, bytes_left_in_page;
        struct lttng_kernel_ring_buffer_backend_pages *rpages;
        unsigned long sb_bindex, id;
-       int src_terminated = 0;
+       bool src_terminated = false;
 
        CHAN_WARN_ON(chanb, !len);
-       offset += pagecpy;
        do {
-               len -= pagecpy;
-               if (!src_terminated)
-                       src += pagecpy;
                sbidx = offset >> chanb->subbuf_size_order;
                index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT;
 
@@ -682,7 +676,7 @@ void _lib_ring_buffer_strcpy(struct lttng_kernel_ring_buffer_backend *bufb,
                 */
                CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
 
-               pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
+               bytes_left_in_page = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
                id = bufb->buf_wsb[sbidx].id;
                sb_bindex = subbuffer_id_get_index(config, id);
                rpages = bufb->array[sb_bindex];
@@ -692,8 +686,8 @@ void _lib_ring_buffer_strcpy(struct lttng_kernel_ring_buffer_backend *bufb,
                if (likely(!src_terminated)) {
                        size_t count, to_copy;
 
-                       to_copy = pagecpy;
-                       if (pagecpy == len)
+                       to_copy = bytes_left_in_page;
+                       if (bytes_left_in_page == len)
                                to_copy--;      /* Final '\0' */
                        count = lib_ring_buffer_do_strcpy(config,
                                        rpages->p[index].virt
@@ -705,7 +699,7 @@ void _lib_ring_buffer_strcpy(struct lttng_kernel_ring_buffer_backend *bufb,
                                size_t pad_len = to_copy - count;
 
                                /* Next pages will have padding */
-                               src_terminated = 1;
+                               src_terminated = true;
                                lib_ring_buffer_do_memset(rpages->p[index].virt
                                                + (offset & ~PAGE_MASK),
                                        pad, pad_len);
@@ -714,15 +708,19 @@ void _lib_ring_buffer_strcpy(struct lttng_kernel_ring_buffer_backend *bufb,
                } else {
                        size_t pad_len;
 
-                       pad_len = pagecpy;
-                       if (pagecpy == len)
+                       pad_len = bytes_left_in_page;
+                       if (bytes_left_in_page == len)
                                pad_len--;      /* Final '\0' */
                        lib_ring_buffer_do_memset(rpages->p[index].virt
                                        + (offset & ~PAGE_MASK),
                                pad, pad_len);
                        offset += pad_len;
                }
-       } while (unlikely(len != pagecpy));
+               len -= bytes_left_in_page;
+               if (!src_terminated)
+                       src += bytes_left_in_page;
+       } while (unlikely(len));
+
        /* Ending '\0' */
        lib_ring_buffer_do_memset(rpages->p[index].virt + (offset & ~PAGE_MASK),
                        '\0', 1);
@@ -869,7 +867,6 @@ EXPORT_SYMBOL_GPL(_lib_ring_buffer_copy_from_user_inatomic);
  * @offset : offset within the buffer
  * @src : source address
  * @len : length to write
- * @pagecpy : page size copied so far
  * @pad : character to use for padding
  *
  * This function deals with userspace pointers, it should never be called
@@ -877,21 +874,16 @@ EXPORT_SYMBOL_GPL(_lib_ring_buffer_copy_from_user_inatomic);
  * previously.
  */
 void _lib_ring_buffer_strcpy_from_user_inatomic(struct lttng_kernel_ring_buffer_backend *bufb,
-               size_t offset, const char __user *src, size_t len,
-               size_t pagecpy, int pad)
+               size_t offset, const char __user *src, size_t len, int pad)
 {
        struct channel_backend *chanb = &bufb->chan->backend;
        const struct lttng_kernel_ring_buffer_config *config = &chanb->config;
-       size_t sbidx, index;
+       size_t sbidx, index, bytes_left_in_page;
        struct lttng_kernel_ring_buffer_backend_pages *rpages;
        unsigned long sb_bindex, id;
-       int src_terminated = 0;
+       bool src_terminated = false;
 
-       offset += pagecpy;
        do {
-               len -= pagecpy;
-               if (!src_terminated)
-                       src += pagecpy;
                sbidx = offset >> chanb->subbuf_size_order;
                index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT;
 
@@ -901,7 +893,7 @@ void _lib_ring_buffer_strcpy_from_user_inatomic(struct lttng_kernel_ring_buffer_
                 */
                CHAN_WARN_ON(chanb, offset >= chanb->buf_size);
 
-               pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
+               bytes_left_in_page = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK));
                id = bufb->buf_wsb[sbidx].id;
                sb_bindex = subbuffer_id_get_index(config, id);
                rpages = bufb->array[sb_bindex];
@@ -911,8 +903,8 @@ void _lib_ring_buffer_strcpy_from_user_inatomic(struct lttng_kernel_ring_buffer_
                if (likely(!src_terminated)) {
                        size_t count, to_copy;
 
-                       to_copy = pagecpy;
-                       if (pagecpy == len)
+                       to_copy = bytes_left_in_page;
+                       if (bytes_left_in_page == len)
                                to_copy--;      /* Final '\0' */
                        count = lib_ring_buffer_do_strcpy_from_user_inatomic(config,
                                        rpages->p[index].virt
@@ -924,7 +916,7 @@ void _lib_ring_buffer_strcpy_from_user_inatomic(struct lttng_kernel_ring_buffer_
                                size_t pad_len = to_copy - count;
 
                                /* Next pages will have padding */
-                               src_terminated = 1;
+                               src_terminated = true;
                                lib_ring_buffer_do_memset(rpages->p[index].virt
                                                + (offset & ~PAGE_MASK),
                                        pad, pad_len);
@@ -933,15 +925,19 @@ void _lib_ring_buffer_strcpy_from_user_inatomic(struct lttng_kernel_ring_buffer_
                } else {
                        size_t pad_len;
 
-                       pad_len = pagecpy;
-                       if (pagecpy == len)
+                       pad_len = bytes_left_in_page;
+                       if (bytes_left_in_page == len)
                                pad_len--;      /* Final '\0' */
                        lib_ring_buffer_do_memset(rpages->p[index].virt
                                        + (offset & ~PAGE_MASK),
                                pad, pad_len);
                        offset += pad_len;
                }
-       } while (unlikely(len != pagecpy));
+               len -= bytes_left_in_page;
+               if (!src_terminated)
+                       src += bytes_left_in_page;
+       } while (unlikely(len));
+
        /* Ending '\0' */
        lib_ring_buffer_do_memset(rpages->p[index].virt + (offset & ~PAGE_MASK),
                        '\0', 1);