Re: [PATCH] perf - ensure offset provided during probe addition isnot greater than function length

From: Prashanth Nageshappa
Date: Fri Feb 24 2012 - 06:33:20 EST


Can you please pick up this patch?

On 02/24/2012 04:02 PM, Masami Hiramatsu wrote:

> (2012/02/24 16:41), Prashanth Nageshappa wrote:
>> perf probe allows kprobe to be inserted at any offset from a function
>> start, which results in adding kprobes to unintended location.
>> (example: perf probe do_fork+10000 is allowed even though size of
>> do_fork is ~904)
>>
>> This patch will ensure probe addition fails when the offset specified
>> is greater than size of the function.
>>
>>
>> Signed-off-by: Prashanth Nageshappa <prashanth@xxxxxxxxxxxxxxxxxx>
>
> This seems good to me.
>
> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
>
> Thank you,
>
>> ---
>>
>> tools/perf/util/probe-finder.c | 12 +++++++++++-
>> 1 files changed, 11 insertions(+), 1 deletions(-)
>>
>> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
>> index 5d73262..d298f94 100644
>> --- a/tools/perf/util/probe-finder.c
>> +++ b/tools/perf/util/probe-finder.c
>> @@ -672,7 +672,7 @@ static int find_variable(Dwarf_Die *sc_die, struct probe_finder *pf)
>> static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
>> bool retprobe, struct probe_trace_point *tp)
>> {
>> - Dwarf_Addr eaddr;
>> + Dwarf_Addr eaddr, highaddr;
>> const char *name;
>>
>> /* Copy the name of probe point */
>> @@ -683,6 +683,16 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwarf_Addr paddr,
>> dwarf_diename(sp_die));
>> return -ENOENT;
>> }
>> + if (dwarf_highpc(sp_die, &highaddr) != 0) {
>> + pr_warning("Failed to get end address of %s\n",
>> + dwarf_diename(sp_die));
>> + return -ENOENT;
>> + }
>> + if (paddr > highaddr) {
>> + pr_warning("Offset specified is greater than size of %s\n",
>> + dwarf_diename(sp_die));
>> + return -EINVAL;
>> + }
>> tp->symbol = strdup(name);
>> if (tp->symbol == NULL)
>> return -ENOMEM;
>>
>
>


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