tracing: Fix reading strings from synthetic events

[linux-2.6-microblaze.git] / kernel / trace / trace_events_synth.c

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 5e8c07a..e310052 100644 (file)
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -17,6 +17,8 @@
 /* for gfp flag names */
 #include <linux/trace_events.h>
 #include <trace/events/mmflags.h>
+#include "trace_probe.h"
+#include "trace_probe_kernel.h"
 
 #include "trace_synth.h"
 
@@ -409,6 +411,7 @@ static unsigned int trace_string(struct synth_trace_event *entry,
 {
        unsigned int len = 0;
        char *str_field;
+       int ret;
 
        if (is_dynamic) {
                u32 data_offset;
@@ -417,19 +420,27 @@ static unsigned int trace_string(struct synth_trace_event *entry,
                data_offset += event->n_u64 * sizeof(u64);
                data_offset += data_size;
 
-               str_field = (char *)entry + data_offset;
-
-               len = strlen(str_val) + 1;
-               strscpy(str_field, str_val, len);
+               len = kern_fetch_store_strlen((unsigned long)str_val);
 
                data_offset |= len << 16;
                *(u32 *)&entry->fields[*n_u64] = data_offset;
 
+               ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
+
                (*n_u64)++;
        } else {
                str_field = (char *)&entry->fields[*n_u64];
 
-               strscpy(str_field, str_val, STR_VAR_LEN_MAX);
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+               if ((unsigned long)str_val < TASK_SIZE)
+                       ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX);
+               else
+#endif
+                       ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);
+
+               if (ret < 0)
+                       strcpy(str_field, FAULT_STRING);
+
                (*n_u64) += STR_VAR_LEN_MAX / sizeof(u64);
        }
 
@@ -462,7 +473,7 @@ static notrace void trace_event_raw_event_synth(void *__data,
                val_idx = var_ref_idx[field_pos];
                str_val = (char *)(long)var_ref_vals[val_idx];
 
-               len = strlen(str_val) + 1;
+               len = kern_fetch_store_strlen((unsigned long)str_val);
 
                fields_size += len;
        }