Blackfin arch: Fix bug - do not overflow the buffer given to us which tends to happen when CONFIG_L1_MAX_PIECE is increased past its default
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 3246f91..8f6fdc2 100644
--- a/arch/blackfin/mm/blackfin_sram.c
+++ b/arch/blackfin/mm/blackfin_sram.c
@@ -549,13 +549,16 @@
/* 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 @@
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;
}