Blackfin arch: Fix bug - do not overflow the buffer given to us which tends to happen...

Singed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

diff --git a/arch/blackfin/mm/blackfin_sram.c b/arch/blackfin/mm/blackfin_sram.c
index 3246f91c7baa40bc87fc30436b9ec7022092b356..8f6fdc245330da43efe1affb7a17f972dcb54510 100644 (file)
--- a/arch/blackfin/mm/blackfin_sram.c
+++ b/arch/blackfin/mm/blackfin_sram.c
@@ -549,13 +549,16 @@ EXPORT_SYMBOL(sram_alloc_with_lsl);
 /* Once we get a real allocator, we'll throw all of this away.
  * Until then, we need some sort of visibility into the L1 alloc.
  */
-static void _l1sram_proc_read(char *buf, int *len, const char *desc,
+/* Need to keep line of output the same.  Currently, that is 44 bytes
+ * (including newline).
+ */
+static int _l1sram_proc_read(char *buf, int *len, int count, const char *desc,
                struct l1_sram_piece *pfree, const int array_size)
 {
        int i;
 
-       *len += sprintf(&buf[*len], "--- L1 %-14s Size  PID State\n", desc);
-       for (i = 0; i < array_size; ++i) {
+       *len += sprintf(&buf[*len], "--- L1 %-14s Size   PID State     \n", desc);
+       for (i = 0; i < array_size && *len < count; ++i) {
                const char *alloc_type;
                switch (pfree[i].flag) {
                case SRAM_SLT_NULL:      alloc_type = "NULL"; break;
@@ -563,31 +566,42 @@ static void _l1sram_proc_read(char *buf, int *len, const char *desc,
                case SRAM_SLT_ALLOCATED: alloc_type = "ALLOCATED"; break;
                default:                 alloc_type = "????"; break;
                }
-               *len += sprintf(&buf[*len], "%p-%p %8i %4i %s\n",
+               /* if we've got a lot of space to cover, omit things */
+               if ((PAGE_SIZE - 1024) < (CONFIG_L1_MAX_PIECE + 1) * 4 * 44 &&
+                   pfree[i].size == 0)
+                       continue;
+               *len += sprintf(&buf[*len], "%p-%p %8i %5i %-10s\n",
                        pfree[i].paddr, pfree[i].paddr + pfree[i].size,
                        pfree[i].size, pfree[i].pid, alloc_type);
        }
+       return (i != array_size);
 }
 static int l1sram_proc_read(char *buf, char **start, off_t offset, int count,
                int *eof, void *data)
 {
        int len = 0;
 
-       _l1sram_proc_read(buf, &len, "Scratchpad",
-                       l1_ssram, ARRAY_SIZE(l1_ssram));
+       if (_l1sram_proc_read(buf, &len, count, "Scratchpad",
+                       l1_ssram, ARRAY_SIZE(l1_ssram)))
+               goto not_done;
 #if L1_DATA_A_LENGTH != 0
-       _l1sram_proc_read(buf, &len, "Data A",
-                       l1_data_A_sram, ARRAY_SIZE(l1_data_A_sram));
+       if (_l1sram_proc_read(buf, &len, count, "Data A",
+                       l1_data_A_sram, ARRAY_SIZE(l1_data_A_sram)))
+               goto not_done;
 #endif
 #if L1_DATA_B_LENGTH != 0
-       _l1sram_proc_read(buf, &len, "Data B",
-                       l1_data_B_sram, ARRAY_SIZE(l1_data_B_sram));
+       if (_l1sram_proc_read(buf, &len, count, "Data B",
+                       l1_data_B_sram, ARRAY_SIZE(l1_data_B_sram)))
+               goto not_done;
 #endif
 #if L1_CODE_LENGTH != 0
-       _l1sram_proc_read(buf, &len, "Instruction",
-                       l1_inst_sram, ARRAY_SIZE(l1_inst_sram));
+       if (_l1sram_proc_read(buf, &len, count, "Instruction",
+                       l1_inst_sram, ARRAY_SIZE(l1_inst_sram)))
+               goto not_done;
 #endif
 
+       *eof = 1;
+ not_done:
        return len;
 }