When a trace recorded on a 32-bit device is processed with a 64-bit
binary, the higher 32-bits of the address need to ignored
The lack of this results in the output of the 64-bit pointer
value to the trace as the 32-bit address lookup fails in find_printk.
Before:
burn-1778 [003] 548.600305: bputs: 0xc0046db2s: 2cec5c058d98c
After:
burn-1778 [003] 548.600305: bputs: 0xc0046db2s: RT throttling activated
The problem occurs in PRINT_FEILD when the field is recognized as a pointer
to a string (of the type const char *)
Heterogeneous architectures cases below can arise and should be handled:
* Traces recorded using 32-bit addresses processed on a 64-bit machine
* Traces recorded using 64-bit addresses processed on a 32-bit machine
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Javi Merino <javi.mer...@arm.com>
Cc: David Ahern <dsah...@gmail.com>
Cc: Jiri Olsa <jo...@kernel.org>
Reported-by: Juri Lelli <juri.le...@arm.com>
Signed-off-by: Kapileshwar Singh <kapileshwar.si...@arm.com>
---
tools/lib/traceevent/event-parse.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/tools/lib/traceevent/event-parse.c
b/tools/lib/traceevent/event-parse.c
index cc25f059ab3d..bb554e2ae70d 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -3721,7 +3721,7 @@ static void print_str_arg(struct trace_seq *s, void
*data, int size,
struct format_field *field;
struct printk_map *printk;
long long val, fval;
- unsigned long addr;
+ uint64_t addr;
char *str;
unsigned char *hex;
int print;
@@ -3754,7 +3754,24 @@ static void print_str_arg(struct trace_seq *s, void
*data, int size,
*/
if (!(field->flags & FIELD_IS_ARRAY) &&
field->size == pevent->long_size) {
- addr = *(unsigned long *)(data + field->offset);
+
+ /* Handle heterogeneous recording and processing
+ * architectures
+ *
+ * CASE I:
+ * Traces recorded on 32-bit devices (32-bit
+ * addressing) and processed on 64-bit devices:
+ * In this case, the higher 32-bits of the address
+ * need to be ignored.
+ *
+ * CASE II:
+ * Traces recorded on 64 bit devices and processed
+ * on 32-bit devices.
+ * In this case the pointer must be 64-bit long
+ */
+ addr = *(uint64_t *)(data + field->offset) &
+ ((1ULL << pevent->long_size * 8) - 1);
+
/* Check if it matches a print format */
printk = find_printk(pevent, addr);
if (printk)
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
