Messages in this thread Patch in this message | | | From | Kapileshwar Singh <> | Subject | [PATCH v2] tools lib traceevent: str addresses in heterogeneous arch environments | Date | Fri, 18 Sep 2015 11:57:29 +0100 |
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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 <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Javi Merino <javi.merino@arm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Reported-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Kapileshwar Singh <kapileshwar.singh@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
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