Re: [Qemu-devel] [PATCH] cpus: fix TCG timer leak

[Alex Bennée]

Marc-André Lureau <address@hidden> writes:

> Spotted by ASAN:
>
> QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64 tests/bios-tables-test  
> -p /x86_64/acpi/piix4/cpuhp
> /x86_64/acpi/piix4/cpuhp: Could not access KVM kernel module: No such file or 
> directory
> qemu-system-x86_64: failed to initialize KVM: No such file or directory
> qemu-system-x86_64: Back to tcg accelerator
> ==21216==WARNING: ASan doesn't fully support makecontext/swapcontext 
> functions and may produce false positives in some cases!
>
> =================================================================
> ==21216==ERROR: LeakSanitizer: detected memory leaks
>
> Direct leak of 48 byte(s) in 1 object(s) allocated from:
>     #0 0x7f77c0668e50 in calloc (/lib64/libasan.so.5+0xeee50)
>     #1 0x7f77beb7b41d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5241d)
>     #2 0x557f756df5bd in timer_new 
> /home/elmarco/src/qemu/include/qemu/timer.h:561
>     #3 0x557f756df5ee in timer_new_ns 
> /home/elmarco/src/qemu/include/qemu/timer.h:584
>     #4 0x557f756e4690 in start_tcg_kick_timer 
> /home/elmarco/src/qemu/cpus.c:965
>     #5 0x557f756e64d7 in qemu_tcg_rr_wait_io_event 
> /home/elmarco/src/qemu/cpus.c:1210
>     #6 0x557f756e90ad in qemu_tcg_rr_cpu_thread_fn 
> /home/elmarco/src/qemu/cpus.c:1536
>     #7 0x557f76e9f233 in qemu_thread_start 
> /home/elmarco/src/qemu/util/qemu-thread-posix.c:504
>     #8 0x7f77b4a11593 in start_thread (/lib64/libpthread.so.0+0x7593)

I'm trying to reproduce to try the alternate approach but I can't get
the full object backtraces:

14:56:08 address@hidden:~/l/q/qemu.git] misc/tcg-timer-fix(1) 2 + env 
QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64 tests/bios-tables-test  -p 
/x86_64/acpi/piix4/cpuhp
/x86_64/acpi/piix4/cpuhp: ==30510==WARNING: ASan doesn't fully support 
makecontext/swapcontext functions and may produce false positives in some cases!
/home/alex/lsrc/qemu/qemu.git/include/qemu/rcu.h:78:21: runtime error: member 
access within null pointer of type 'struct rcu_reader_data'
/home/alex/lsrc/qemu/qemu.git/include/qemu/rcu.h:93:5: runtime error: member 
access within null pointer of type 'struct rcu_reader_data'
/home/alex/lsrc/qemu/qemu.git/include/qemu/rcu.h:94:8: runtime error: member 
access within null pointer of type 'struct rcu_reader_data'
/home/alex/lsrc/qemu/qemu.git/include/qemu/rcu.h:93:5: runtime error: member 
access within null pointer of type 'struct rcu_reader_data'
OK

What is your configure setup?

--
Alex Bennée