* Intel PT: Address filtering not working. (cc me)
@ 2016-10-13 1:11 Muhammad Usman Nadeem
2016-10-17 6:50 ` Adrian Hunter
0 siblings, 1 reply; 3+ messages in thread
From: Muhammad Usman Nadeem @ 2016-10-13 1:11 UTC (permalink / raw)
To: linux-kernel
[-- Attachment #1: Type: text/plain, Size: 535 bytes --]
Usage: sudo perf record -e intel_pt//u --filter='filter 0x400000 /
0x1000 @./a.out' ./a.out 123
a.out is my program (for loop, call using function pointer and use of
longjump) and 123 is the argument.
Output: [ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.171 MB perf.data ]
Output contains mostly MTC packets and no TNT or TIP packets.
I am on the latest mainline version of kernel (b67be92) and perf
version perf version 4.8.gb67be9.
What could be the problem?
I am using it wrong?
Thanks
[-- Attachment #2: test.c --]
[-- Type: text/x-csrc, Size: 538 bytes --]
#include <iostream>
#include <setjmp.h>
jmp_buf go;
int foo()
{
return 5;
}
int bar()
{
longjmp(go,1);
return 6;
}
int main(int argc, char* argv[])
{
bool jumped = false;
int (*ptr) ();
// if arg then long jump
if (argc != 2)
{
ptr = foo;
} else {
ptr = bar;
}
for (int i = 0; i < 50000000; ++i)
{
++i;
--i;
}
setjmp(go);
if (!jumped)
{
jumped = true;
ptr();
} else {
std::cout << "AFTER long jump." << std::endl;
}
return 0;
}
[-- Attachment #3: a.out --]
[-- Type: application/octet-stream, Size: 9408 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Intel PT: Address filtering not working. (cc me)
2016-10-13 1:11 Intel PT: Address filtering not working. (cc me) Muhammad Usman Nadeem
@ 2016-10-17 6:50 ` Adrian Hunter
2016-10-17 23:12 ` Muhammad Usman Nadeem
0 siblings, 1 reply; 3+ messages in thread
From: Adrian Hunter @ 2016-10-17 6:50 UTC (permalink / raw)
To: Muhammad Usman Nadeem, linux-kernel; +Cc: Andi Kleen, Alexander Shishkin
On 13/10/16 04:11, Muhammad Usman Nadeem wrote:
> Usage: sudo perf record -e intel_pt//u --filter='filter 0x400000 /
> 0x1000 @./a.out' ./a.out 123
>
> a.out is my program (for loop, call using function pointer and use of
> longjump) and 123 is the argument.
>
> Output: [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 1.171 MB perf.data ]
>
>
> Output contains mostly MTC packets and no TNT or TIP packets.
>
> I am on the latest mainline version of kernel (b67be92) and perf
> version perf version 4.8.gb67be9.
>
> What could be the problem?
> I am using it wrong?
Yes. The perf-record documentation says: "<file name> is the name of the
object file, <start> is the offset to the code to trace in that file"
So 0x400000 is well off the end of the file. Try:
--filter='filter 0 / 0x1000 @./a.out'
Also note:
"The kernel may not be able to configure a trace region if it is not
within a single mapping. MMAP events (or /proc/<pid>/maps) can be
examined to determine if that is a possibility."
You can see mmap events in using perf script with the --show-mmap-events option.
>
> Thanks
>
>
> test.c
>
>
> #include <iostream>
> #include <setjmp.h>
> jmp_buf go;
> int foo()
> {
> return 5;
> }
> int bar()
> {
> longjmp(go,1);
> return 6;
> }
>
> int main(int argc, char* argv[])
> {
> bool jumped = false;
> int (*ptr) ();
> // if arg then long jump
> if (argc != 2)
> {
> ptr = foo;
> } else {
> ptr = bar;
> }
>
> for (int i = 0; i < 50000000; ++i)
> {
> ++i;
> --i;
> }
> setjmp(go);
>
> if (!jumped)
> {
> jumped = true;
> ptr();
> } else {
> std::cout << "AFTER long jump." << std::endl;
> }
> return 0;
> }
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Intel PT: Address filtering not working. (cc me)
2016-10-17 6:50 ` Adrian Hunter
@ 2016-10-17 23:12 ` Muhammad Usman Nadeem
0 siblings, 0 replies; 3+ messages in thread
From: Muhammad Usman Nadeem @ 2016-10-17 23:12 UTC (permalink / raw)
To: Adrian Hunter; +Cc: linux-kernel, Andi Kleen, Alexander Shishkin
I was providing it the Virtual Memory Address instead of offset in the
file. It is working now.
Thanks.
On Mon, Oct 17, 2016 at 2:50 AM, Adrian Hunter <adrian.hunter@intel.com> wrote:
> On 13/10/16 04:11, Muhammad Usman Nadeem wrote:
>> Usage: sudo perf record -e intel_pt//u --filter='filter 0x400000 /
>> 0x1000 @./a.out' ./a.out 123
>>
>> a.out is my program (for loop, call using function pointer and use of
>> longjump) and 123 is the argument.
>>
>> Output: [ perf record: Woken up 1 times to write data ]
>> [ perf record: Captured and wrote 1.171 MB perf.data ]
>>
>>
>> Output contains mostly MTC packets and no TNT or TIP packets.
>>
>> I am on the latest mainline version of kernel (b67be92) and perf
>> version perf version 4.8.gb67be9.
>>
>> What could be the problem?
>> I am using it wrong?
>
> Yes. The perf-record documentation says: "<file name> is the name of the
> object file, <start> is the offset to the code to trace in that file"
>
> So 0x400000 is well off the end of the file. Try:
>
> --filter='filter 0 / 0x1000 @./a.out'
>
> Also note:
>
> "The kernel may not be able to configure a trace region if it is not
> within a single mapping. MMAP events (or /proc/<pid>/maps) can be
> examined to determine if that is a possibility."
>
> You can see mmap events in using perf script with the --show-mmap-events option.
>
>>
>> Thanks
>>
>>
>> test.c
>>
>>
>> #include <iostream>
>> #include <setjmp.h>
>> jmp_buf go;
>> int foo()
>> {
>> return 5;
>> }
>> int bar()
>> {
>> longjmp(go,1);
>> return 6;
>> }
>>
>> int main(int argc, char* argv[])
>> {
>> bool jumped = false;
>> int (*ptr) ();
>> // if arg then long jump
>> if (argc != 2)
>> {
>> ptr = foo;
>> } else {
>> ptr = bar;
>> }
>>
>> for (int i = 0; i < 50000000; ++i)
>> {
>> ++i;
>> --i;
>> }
>> setjmp(go);
>>
>> if (!jumped)
>> {
>> jumped = true;
>> ptr();
>> } else {
>> std::cout << "AFTER long jump." << std::endl;
>> }
>> return 0;
>> }
>>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-10-13 1:11 Intel PT: Address filtering not working. (cc me) Muhammad Usman Nadeem
2016-10-17 6:50 ` Adrian Hunter
2016-10-17 23:12 ` Muhammad Usman Nadeem
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