Add support for Python3.7 (#151)

[henryzhangsta]

Fixes #151

[CLAassistant]

All committers have signed the CLA.

[rpodgorny]

...can you, please, merge? thanks!

[tavianator]

I get an unending spew of

Unexpected ptrace(2) exception: waitpid() indicated a WIFSTOPPED process, but got unexpected signal 11

with this branch.

[henryzhangsta]

@tavianator What kernel/distribution are you using?

[tavianator]

Arch Linux, kernel 4.18.14-arch1-1-ARCH

[henryzhangsta]

@tavianator Can you verify that SELinux is not denying the ptrace call?

[tavianator]

@henryzhangsta No SELinux here. The relevant part of strace is:

ptrace(PTRACE_POKEDATA, 27855, 0x7fb56897e000, 0xccd0ff) = 0
ptrace(PTRACE_GETREGS, 27855, NULL, 0x7ffd34d418f0) = 0
ptrace(PTRACE_SETREGS, 27855, NULL, 0x7ffd34d41730) = 0
ptrace(PTRACE_CONT, 27855, NULL, SIG_0) = 0
wait4(27855, [{WIFSTOPPED(s) && WSTOPSIG(s) == SIGSEGV}], 0, NULL) = 27855

[ghost]

I just used it on Arch Linux with kernel 4.19.8-arch1-1-ARCH and did not get any errors, maybe there was something fixed related to this bug.

[tavianator]

@metafex Hmm, maybe something I'm doing wrong then, still reproduces for me. What's your ./configure line, etc.?

[ghost]

@tavianator I ran configure without any parameters, it perfectly detects python 3.7 for me. I attached pyflame to a uwsgi process in a container though, how are you running it?

[tavianator]

$ ./src/pyflame -t python3 -c 'import time; time.sleep(5); print("Hello world")'
Unexpected ptrace(2) exception: waitpid() indicated a WIFSTOPPED process, but got unexpected signal 11
Unexpected ptrace(2) exception: waitpid() indicated a WIFSTOPPED process, but got unexpected signal 11
Unexpected ptrace(2) exception: waitpid() indicated a WIFSTOPPED process, but got unexpected signal 11
...

The crash happens in the Python process when doing PtraceCallFunction(pid, addrs.tstate_get_addr);

[tavianator]

Turns out that this is fixed by #155, sorry for the noise!

[rpodgorny]

bump ;-)

[toabctl]

friendly ping - any reason why this is not merged yet? Having py37 support would be really helpful...

[henryzhangsta]

The person that originally wrote pyflame no longer works at Uber. I have not been able to get an Uber open source contact, so if anyone knows of one, let me know.

[hound672]

Hi, is anybody trying to build this with python 3.7 installed by pyenv? I cannot get how to pass path to Python3.7 for build pyflame. Can help me?
UPDATE: should use env var:
export PKG_CONFIG_PATH=~/.pyenv/versions/3.7.3/lib/pkgconfig/

[tavianator]

@hound672 I think people have switched to https://github.com/benfred/py-spy these days