2012-02-24 07:41:54

by Prashanth Nageshappa

Subject: [PATCH] perf - ensure offset provided during probe addition is not greater than function length

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 <[email protected]>
---

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;

2012-02-24 10:32:38

by 平松雅巳 / HIRAMATU，MASAMI

Subject: Re: [PATCH] perf - ensure offset provided during probe addition is not greater than function length

(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 <[email protected]>

This seems good to me.

Acked-by: Masami Hiramatsu <[email protected]>

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;
>


--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: [email protected]

2012-02-24 11:33:22

by Prashanth Nageshappa

Subject: Re: [PATCH] perf - ensure offset provided during probe addition is not greater than function length

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 <[email protected]>
>
> This seems good to me.
>
> Acked-by: Masami Hiramatsu <[email protected]>
>
> 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;
>>
>
>

2012-02-24 19:17:01

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH] perf - ensure offset provided during probe addition is not greater than function length

Em Fri, Feb 24, 2012 at 05:03:03PM +0530, Prashanth Nageshappa escreveu:
> Can you please pick up this patch?

I'll do it, thanks,

- Arnaldo

> 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 <[email protected]>
> >
> > This seems good to me.
> >
> > Acked-by: Masami Hiramatsu <[email protected]>
> >
> > 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;
> >>
> >
> >
>