Does the output of valgrind still reliable when it reports the 'impossible' happened: LibVEX called failure_exit()

Question

Here is the brief log:

# valgrind --error-limit=no --leak-check=full --tool=memcheck /mnt/aarch64/ld-linux-aarch64.so.1 ./program 
==12104== Memcheck, a memory error detector
==12104== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==12104== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==12104== Command: /mnt/aarch64/ld-linux-aarch64.so.1 ./program 
==12104== 



vex: priv/host_arm64_defs.c:2796 (genSpill_ARM64): Assertion `offsetB < 4096' failed.
vex storage: T total 4207069920 bytes allocated
vex storage: P total 0 bytes allocated

valgrind: the 'impossible' happened:
   LibVEX called failure_exit().

host stacktrace:
==12104==    at 0x5803F488: show_sched_status_wrk (m_libcassert.c:406)
==12104==    by 0x5803F5C7: report_and_quit (m_libcassert.c:477)
==12104==    by 0x5803F7FB: panic (m_libcassert.c:553)
==12104==    by 0x5803F7FB: vgPlain_core_panic_at (m_libcassert.c:558)
==12104==    by 0x5803F81F: vgPlain_core_panic (m_libcassert.c:563)
==12104==    by 0x5805481B: failure_exit (m_translate.c:761)
==12104==    by 0x5811E043: vex_assert_fail (main_util.c:245)
==12104==    by 0x5817A897: genSpill_ARM64 (host_arm64_defs.c:2796)
==12104==    by 0x58172217: spill_vreg (host_generic_reg_alloc3.c:338)
==12104==    by 0x5817324F: doRegisterAllocation_v3 (host_generic_reg_alloc3.c:1280)
==12104==    by 0x5811CD97: libvex_BackEnd (main_main.c:1133)
==12104==    by 0x5811CD97: LibVEX_Translate (main_main.c:1236)
==12104==    by 0x58056FCB: vgPlain_translate (m_translate.c:1830)
==12104==    by 0x58092A27: handle_chain_me (scheduler.c:1169)
==12104==    by 0x580954A7: vgPlain_scheduler (scheduler.c:1514)
==12104==    by 0x580D8E8F: thread_wrapper (syswrap-linux.c:101)
==12104==    by 0x580D8E8F: run_a_thread_NORETURN (syswrap-linux.c:154)
==12104==    by 0x580D916F: vgModuleLocal_start_thread_NORETURN (syswrap-linux.c:328)
==12104==    by 0x580A68D3: ??? (in /mnt/aarch64/lib/valgrind/memcheck-arm64-linux)

sched status:
  running_tid=3

I want to known whether the reset output of valgrind is still meaningful for pointing out the memory leak in the program when it reports the said error(ie the 'impossible' happened: LibVEX called failure_exit() )

Updated: The program does run, I can see many stack strace,eg:

Thread 1: status = VgTs_WaitSys syscall 98 (lwpid 12168)
==12168==    at 0x6E85274: syscall (in /lib/libc-2.31.so)
==12168==    by 0x6B99FF3: std::__atomic_futex_unsigned_base
...

Thread 2:
...

Answer 1

In general, if Valgrind reports some errors and then encounters an internal error, those initial reports should be valid.

In the case of the message that you show, the first report is an internal error related to the virtualization of the ARM aarch64 CPU. That's only useful for Valgrind developers.

Try running Valgrind with -d -v. There will be a lot of output, but you should see

• syswrap- run_a_thread_NORETURN(tid=1): pre-thread_wrapper that is the guest executable starting
• a load of gdbsrv messages
• a mix of REDIR and mallocrf/hashtbl messages as the guest startup code invokes ld.so to load shared libraries

I can't tell where you get the subsequent traces from - could be trace options, more likely from the assert.