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Diffstat (limited to 'results/classifier/118/none/1701971')
| -rw-r--r-- | results/classifier/118/none/1701971 | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/results/classifier/118/none/1701971 b/results/classifier/118/none/1701971 new file mode 100644 index 000000000..c410bb0f9 --- /dev/null +++ b/results/classifier/118/none/1701971 @@ -0,0 +1,115 @@ +KVM: 0.631 +peripherals: 0.629 +TCG: 0.617 +hypervisor: 0.609 +virtual: 0.600 +user-level: 0.570 +VMM: 0.568 +graphic: 0.566 +risc-v: 0.560 +ppc: 0.557 +vnc: 0.552 +x86: 0.536 +performance: 0.521 +debug: 0.503 +register: 0.499 +arm: 0.476 +permissions: 0.474 +device: 0.459 +architecture: 0.452 +mistranslation: 0.407 +semantic: 0.396 +kernel: 0.391 +network: 0.375 +i386: 0.372 +files: 0.366 +assembly: 0.365 +PID: 0.360 +boot: 0.358 +socket: 0.292 + +multithreading not working right under qemu user mode for sh4 + +In a multithreaded program running under qemu-sh4 (version 2.9.0), thread termination and/or pthread_join is not working right. + +The attached program works natively on all kinds of platforms, and under qemu user mode emulation for at least alpha, armelhf, aarch64, powerpc64le. + +How to reproduce: +- Compile the program: sh4-linux-gnu-gcc-5 -O -Wall -lpthread -o test-tls test-tls.c +- Set environment variables for running qemu-sh4. +- ~/inst-qemu/2.9.0/bin/qemu-sh4 test-tls + +Expected behaviour: After the "Worker xxxxx dying" line, the main() function prints "OK", and the program terminates. + +Actual behaviour (only on sh4): After the "Worker xxxxx dying" line, it hangs. Attaching gdb to qemu shows 15 threads with a stack trace like +#0 safe_syscall_base () at /build/qemu-2.9.0/linux-user/host/x86_64/safe-syscall.inc.S:75 +#1 0x00005584f86f4c48 in safe_futex (uaddr=<optimized out>, op=op@entry=128, val=val@entry=2, timeout=<optimized out>, uaddr2=uaddr2@entry=0x0, + val3=val3@entry=-161181992) at /build/qemu-2.9.0/linux-user/syscall.c:921 +#2 0x00005584f870353b in do_futex (val3=-161181992, uaddr2=4134624624, timeout=0, val=<optimized out>, op=<optimized out>, uaddr=<optimized out>) + at /build/qemu-2.9.0/linux-user/syscall.c:7147 +#3 do_syscall (cpu_env=<optimized out>, num=240, arg1=<optimized out>, arg2=<optimized out>, arg3=<optimized out>, arg4=0, arg5=-160342672, + arg6=-161181992, arg7=0, arg8=0) at /build/qemu-2.9.0/linux-user/syscall.c:11692 +#4 0x00005584f86f454a in cpu_loop (env=env@entry=0x5584fb3d04f8) at /build/qemu-2.9.0/linux-user/main.c:2676 +#5 0x00005584f86f5dd5 in clone_func (arg=0x7fff4d485c20) at /build/qemu-2.9.0/linux-user/syscall.c:6234 +#6 0x00007f08f05a46ba in start_thread (arg=0x7f08f1368700) at pthread_create.c:333 +#7 0x00007f08f02da3dd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 + +and 1 thread with a stack trace like +#0 safe_syscall_base () at /build/qemu-2.9.0/linux-user/host/x86_64/safe-syscall.inc.S:75 +#1 0x00005584f86f4c48 in safe_futex (uaddr=<optimized out>, op=op@entry=0, val=val@entry=18875, timeout=<optimized out>, uaddr2=uaddr2@entry=0x0, + val3=val3@entry=-161180376) at /build/qemu-2.9.0/linux-user/syscall.c:921 +#2 0x00005584f870353b in do_futex (val3=-161180376, uaddr2=4135101768, timeout=0, val=<optimized out>, op=<optimized out>, uaddr=<optimized out>) + at /build/qemu-2.9.0/linux-user/syscall.c:7147 +#3 do_syscall (cpu_env=<optimized out>, num=240, arg1=<optimized out>, arg2=<optimized out>, arg3=<optimized out>, arg4=0, arg5=-159865528, + arg6=-161180376, arg7=0, arg8=0) at /build/qemu-2.9.0/linux-user/syscall.c:11692 +#4 0x00005584f86f454a in cpu_loop (env=0x5584fb3b99a8) at /build/qemu-2.9.0/linux-user/main.c:2676 +#5 0x00005584f86c12d3 in main (argc=<optimized out>, argv=0x7fff4d4878b8, envp=<optimized out>) + at /build/qemu-2.9.0/linux-user/main.c:4860 + +and 1 thread with a stack trace like +#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38 +#1 0x00005584f876eab5 in qemu_futex_wait (val=<optimized out>, f=<optimized out>) at /build/qemu-2.9.0/include/qemu/futex.h:26 +#2 qemu_event_wait (ev=ev@entry=0x5584faa43d84 <rcu_call_ready_event>) at /build/qemu-2.9.0/util/qemu-thread-posix.c:399 +#3 0x00005584f87748ce in call_rcu_thread (opaque=<optimized out>) at /build/qemu-2.9.0/util/rcu.c:249 +#4 0x00007f08f05a46ba in start_thread (arg=0x7f08eff62700) at pthread_create.c:333 +#5 0x00007f08f02da3dd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 + + + + + +Another gnulib test (test-lock) fails with an assertion inside glibc: +test-lock: pthread_mutex_lock.c:81: __pthread_mutex_lock: Assertion `mutex->__data.__owner == 0' failed. +qemu: uncaught target signal 6 (Aborted) - core dumped + +Based on this, I would speculate that the problem is in the qemu emulation of the Linux system calls that glibc uses for multithreading or in the implementation of the primitives used by qemu_event_wait(). + +On 07/02/2017 12:53 PM, Bruno Haible wrote: +> In a multithreaded program running under qemu-sh4 (version 2.9.0), +> thread termination and/or pthread_join is not working right. + +QEMU does not support the roll-back atomic sequences used by linux on most +uniprocessor SH. + +Nor do we support the ll/sc form used by SH4A, although fixing that should be +trivial. + + +r~ + + +A patch for this has apparently been included in QEMU v2.10: +https://git.qemu.org/?p=qemu.git;a=commitdiff;h=4bfa602bc2227f5b5a506a4 +Is this issue now completely fixed (so that we can close this ticket), or is there something left to do? + +This works fine in qemu-2.10: +$ ~/inst-qemu/2.10.0/bin/qemu-sh4 test-tls +... +Worker 0xecdff4c0 doing value swapping +Worker 0xecdff4c0 doing value swapping +Worker 0xecdff4c0 before final verify +Worker 0xecdff4c0 after final verify +Worker 0xecdff4c0 dying. + OK + + |