On 2/03/2021 11:55 pm, Silas wrote:
On Mon, Mar 01, 2021 at 10:42:56AM +1100, MJ wrote:
On 1/03/2021 10:35 am, RVP wrote:
On FreeBSD-12.2 and OpenBSD-6.8 (both having Clang 10.0.1 as the native
compiler), the program segfaults even when not linked with any external
shared libs.
It looks like profiling on the *BSDs needs static binaries (the
profile libraries, /usr/lib/*_p.a, are all static anyway).
-RVP
That's correct and as expected. Gprof does not profile shared libraries.
I expected it to not produce the call graph for the shared libraries, but
segfaulting is rather strange, no? I didn't find others reporting this, so I
Well yes, segfault is not a desired or expected outcome. My hunch is gprof
neither likes shared libraries or threads.
Perhaps it is just too old and broken for modern profiling?
started to think there is a problem with my environment, although I'm not using
LD* environment variable or anything related. Should I file a PR?
Curious fact: I can profile (generate binary, run the program and use gprof) the
same program normally in NetBSD 8.0 armv7hf (Raspberry Pi 2).
Maybe dl_iterate_phdr() passes it's arguments back via %eax/%rax on x32/amd64
but uses the stack otherwise (I think SPARC does)? The former is more efficient
but perhaps it's whatever gcc is hooking into with the profile (-pg) flags
that's causing segmentation faults? I don't know.
Perhaps a PR is in order?
Mark.
