[Bug ada/89493] New: Stack smashing on armv7hl

[pavel at zhukoff dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89493

            Bug ID: 89493
           Summary: Stack smashing on armv7hl
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pavel at zhukoff dot net
  Target Milestone: ---

Created attachment 45816
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45816&action=edit
reproducer

Reporting this for ada as reproducer is part of gprbuild (gprinstall) code.

In some cases (return from exception handler) stack pointer is set to weird
value and either stack smashing protection or storage error occurs.

it's easy and 100% reproducible in Fedora linux distribution 
https://bugzilla.redhat.com/show_bug.cgi?id=1677173

gcc-9.0.1-0.4.fc30.armv7hl
gprbuild-2018-12.fc30.armv7hl

All other architectures (x86, s390x, ppc64le and aarch64 work fine)

We were able to strip reproducer to ~200 LOC (attached) 

# gprbuild -v -cargs:Ada -O2 -g


# valgrind ./exe/process
==29563== Memcheck, a memory error detector
==29563== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==29563== Using Valgrind-3.14.0 and LibVEX; rerun with -h for copyright info
==29563== Command: ./exe/process
==29563== 
warning: file does not exist '/tmp/a/satrace.log'
==29563== Warning: client switching stacks?  SP change: 0xbdef07c0 --> 0x68818
==29563==          to suppress, use: --max-stackframe=1108836440 or greater
aaa
==29563== Invalid write of size 4
==29563==    at 0x40C04: system__secondary_stack__ss_release (in
/tmp/test/exe/process)
==29563==  Address 0x68754 is 12 bytes inside data symbol
"ada_main__sec_default_sized_stacks"
==29563== 
==29563== Invalid read of size 4
==29563==    at 0x1A09C: _ada_process (process.adb:119)
==29563==  Address 0x687ec is 164 bytes inside data symbol
"ada_main__sec_default_sized_stacks"
==29563== 
==29563== Invalid read of size 4
==29563==    at 0x1A0A4: _ada_process (process.adb:119)
==29563==  Address 0xe1a02026 is not stack'd, malloc'd or (recently) free'd