[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

--- Comment #1 from Matthias Klose <doko at gcc dot gnu.org> ---
correction: reverting the changes from PR65787 only helps for the 5.1.0
release, not the gcc-5-branch.

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |5.2

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

--- Comment #2 from Matthias Klose <doko at gcc dot gnu.org> ---
maybe the changes from PR65787 are unrelated.

Building a compiler which has -fstack-protector strong enabled by default. The
crash goes away when I add -fno-stack-protector to AM_CFLAGS in libgo.  So it
should be reproducible by adding -fstack-protector strong to AM_CFLAGS in
libgo.

Don't know why this shows up only now, and on powerpc-linux-gnu only.

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[boger at us dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

boger at us dot ibm.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |boger at us dot ibm.com

--- Comment #3 from boger at us dot ibm.com ---
Let's get the obvious set up questions out of the way first...

If you are building on Ubuntu, I assume you must be trying to build
powerpc64le-linux-gnu, and not powerpc-linux-gnu.

Is your LD_LIBRARY_PATH being set to the correct path for the libgo that
corresponds to the go and gccgo you are using?  That is, you aren't using libgo
from a gcc trunk build but go and gccgo from a gcc5 build?

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[adconrad at 0c3 dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

Adam Conrad <adconrad at 0c3 dot net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |adconrad at 0c3 dot net

--- Comment #4 from Adam Conrad <adconrad at 0c3 dot net> ---
No, this is specifically about powerpc-linux-gnu.  powerpc64le works fine.

As for the library path questions, this first came up in runtime bug reports,
and has been confirmed by many on clean chroots, so no, there aren't random
libraries kicking around from other builds.

doko's stack-protector discovery makes perfect sense as to why this works fine
on Debian but not Ubuntu, as that's really the only difference between our two
toolchains.  Now, the question is *why*, and why only on ppc32?  (Or maybe only
on big-endian PPC, neither of us has tested a powerpc64-linux-gnu build yet).

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

--- Comment #5 from Matthias Klose <doko at gcc dot gnu.org> ---
building trunk libgo with -fstack-protector-strong yields:

$ go version
fatal error: unexpected signal during runtime execution
[signal 0xb code=0x1 addr=0x3]

goroutine 16 [running]:

        :0

        :0

        :0

        :0
[...]

building libgo and libbacktrace with -fstack-protector-strong yields:

fatal error: unexpected signal during runtime execution
[signal 0xb code=0x1 addr=0x3]

goroutine 16 [running]:
runtime_dopanic
        ../../../src/libgo/runtime/panic.c:131
runtime_throw
        ../../../src/libgo/runtime/panic.c:193
sig_panic_leadin
        ../../../src/libgo/runtime/go-signal.c:247
sig_panic_info_handler
        ../../../src/libgo/runtime/go-signal.c:281

        :0
__go_go
        ../../../src/libgo/runtime/proc.c:2328
runtime_main
        ../../../src/libgo/runtime/proc.c:598

goroutine 0 [idle]:
panic during panic
goroutine 0 [idle]:
runtime_dopanic
        ../../../src/libgo/runtime/panic.c:131
runtime_startpanic
        ../../../src/libgo/runtime/panic.c:100
runtime_throw
        ../../../src/libgo/runtime/panic.c:191
runtime_gogo
        ../../../src/libgo/runtime/proc.c:251
runtime_tracebackothers
        ../../../src/libgo/runtime/proc.c:767
runtime_dopanic
        ../../../src/libgo/runtime/panic.c:139
runtime_throw
        ../../../src/libgo/runtime/panic.c:193
sig_panic_leadin
        ../../../src/libgo/runtime/go-signal.c:247
sig_panic_info_handler
        ../../../src/libgo/runtime/go-signal.c:281

        :0
__go_go
        ../../../src/libgo/runtime/proc.c:2328
runtime_main
        ../../../src/libgo/runtime/proc.c:598

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[boger at us dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

--- Comment #6 from boger at us dot ibm.com ---
I think you've said the problem only occurs when using -fstack-protector-strong
and when building with glibc-2.21.

Have you tried using gdb to see where the segv actually occurs?

>gdb go
.....


>run version
(Once it hits the segv)
>x/20ni $pc-24
>bt

The panic stacktrace is showing a line in proc.c:2328 which is making a call to
__builtin_return_address according to my source.  Does that match your source?

If that is the case then I have a feeling this isn't go specific, but a problem
with calling __builtin_return_address on ppc32 when using
-fstack-protector-strong and possibly glibc-2.21 has some affect.

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|5.2                         |5.3

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 5.2 is being released, adjusting target milestone to 5.3.

[Bug go/66368] [5 Regression] go tool crashes on powerpc-linux-gnu

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66368

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|---                         |WORKSFORME

--- Comment #12 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
No feedback in over 6 years so closing.