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tools lib traceevent: Fix string handling in heterogeneous arch environments 

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_FIELD 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

Reported-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Kapileshwar Singh <kapileshwar.singh@arm.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Javi Merino <javi.merino@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1442928123-13824-1-git-send-email-kapileshwar.singh@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Kapileshwar Singh 2015-09-22 14:22:03 +01:00 committed by Arnaldo Carvalho de Melo
parent 381c02f6d8
commit c2e4b24ff8
1 changed files with 20 additions and 3 deletions
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23
tools/lib/traceevent/event-parse.c
View File

@ -3795,7 +3795,7 @@ 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;
@ -3828,13 +3828,30 @@ 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, only 32 bits should be read.
*
* 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);