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 <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Javi Merino <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Reported-by: Juri Lelli <[email protected]> Signed-off-by: Kapileshwar Singh <[email protected]> --- tools/lib/traceevent/event-parse.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index cc25f059ab3d..9916e84e12a5 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; + unsigned long long addr; char *str; unsigned char *hex; int print; @@ -3754,13 +3754,31 @@ 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 64 bits must be + * read. + */ + addr = (pevent->long_size == 8) ? + *(unsigned long long *)(data + field->offset) : + (unsigned long long)*(unsigned int *)(data + field->offset); + /* Check if it matches a print format */ printk = find_printk(pevent, addr); if (printk) trace_seq_puts(s, printk->printk); else - trace_seq_printf(s, "%lx", addr); + trace_seq_printf(s, "%llx", addr); break; } str = malloc(len + 1); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
