[Qemu-devel] [PULL for-2.9 0/1] Tracing patches

[Qemu-devel] [PULL for-2.9 0/1] Tracing patches

[Stefan Hajnoczi]

The following changes since commit ecc1f5adeec4e3324d1b695a7c54e3967c526949:

  maintainers: Add myself as linux-user reviewer (2017-05-11 13:31:11 -0400)

are available in the git repository at:

  git://github.com/stefanha/qemu.git tags/tracing-pull-request

for you to fetch changes up to 5651743c908d8c3b1ff0192ce9543a502ec7a206:

  trace: add sanity check (2017-05-12 10:37:40 -0400)

----------------------------------------------------------------

----------------------------------------------------------------

Anthony Xu (1):
  trace: add sanity check

 qom/cpu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

-- 
2.9.3

[Qemu-devel] [PULL for-2.9 1/1] trace: add sanity check

[Stefan Hajnoczi]

From: Anthony Xu <anthony.xu@intel.com>

If trace backend is set to TRACE_NOP, trace_get_vcpu_event_count
returns 0, cause bitmap_new call abort.

The abort can be triggered as follows:

  $ ./configure --enable-trace-backend=nop --target-list=x86_64-softmmu
  $ gdb ./x86_64-softmmu/qemu-system-x86_64 -M q35,accel=kvm -m 1G
  (gdb) bt
  #0  0x00007ffff04e25f7 in raise () from /lib64/libc.so.6
  #1  0x00007ffff04e3ce8 in abort () from /lib64/libc.so.6
  #2  0x00005555559de905 in bitmap_new (nbits=<optimized out>)
      at /home/root/git/qemu2.git/include/qemu/bitmap.h:96
  #3  cpu_common_initfn (obj=0x555556621d30) at qom/cpu.c:399
  #4  0x0000555555a11869 in object_init_with_type (obj=0x555556621d30, ti=0x55555656bbb0) at qom/object.c:341
  #5  0x0000555555a11869 in object_init_with_type (obj=0x555556621d30, ti=0x55555656bd30) at qom/object.c:341
  #6  0x0000555555a11efc in object_initialize_with_type (data=data@entry=0x555556621d30, size=76560,
      type=type@entry=0x55555656bd30) at qom/object.c:376
  #7  0x0000555555a12061 in object_new_with_type (type=0x55555656bd30) at qom/object.c:484
  #8  0x0000555555a121c5 in object_new (typename=typename@entry=0x555556550340 "qemu64-x86_64-cpu")
      at qom/object.c:494
  #9  0x00005555557f6e3d in pc_new_cpu (typename=typename@entry=0x555556550340 "qemu64-x86_64-cpu", apic_id=0,
      errp=errp@entry=0x5555565391b0 <error_fatal>) at /home/root/git/qemu2.git/hw/i386/pc.c:1101
  #10 0x00005555557fa33e in pc_cpus_init (pcms=pcms@entry=0x5555565f9690)
      at /home/root/git/qemu2.git/hw/i386/pc.c:1184
  #11 0x00005555557fe0f6 in pc_q35_init (machine=0x5555565f9690) at /home/root/git/qemu2.git/hw/i386/pc_q35.c:121
  #12 0x000055555574fbad in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4562

Signed-off-by: Anthony Xu <anthony.xu@intel.com>
Message-id: 1494369432-15418-1-git-send-email-anthony.xu@intel.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qom/cpu.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/qom/cpu.c b/qom/cpu.c
index f02e9c0..f9111a0 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -382,6 +382,7 @@ static void cpu_common_unrealizefn(DeviceState *dev, Error **errp)
 
 static void cpu_common_initfn(Object *obj)
 {
+    uint32_t count;
     CPUState *cpu = CPU(obj);
     CPUClass *cc = CPU_GET_CLASS(obj);
 
@@ -396,7 +397,10 @@ static void cpu_common_initfn(Object *obj)
     QTAILQ_INIT(&cpu->breakpoints);
     QTAILQ_INIT(&cpu->watchpoints);
 
-    cpu->trace_dstate = bitmap_new(trace_get_vcpu_event_count());
+    count = trace_get_vcpu_event_count();
+    if (count) {
+        cpu->trace_dstate = bitmap_new(count);
+    }
 
     cpu_exec_initfn(cpu);
 }
-- 
2.9.3

Re: [Qemu-devel] [PULL for-2.9 0/1] Tracing patches

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 889 bytes --]

On Fri, May 12, 2017 at 10:38:11AM -0400, Stefan Hajnoczi wrote:
> The following changes since commit ecc1f5adeec4e3324d1b695a7c54e3967c526949:
> 
>   maintainers: Add myself as linux-user reviewer (2017-05-11 13:31:11 -0400)
> 
> are available in the git repository at:
> 
>   git://github.com/stefanha/qemu.git tags/tracing-pull-request
> 
> for you to fetch changes up to 5651743c908d8c3b1ff0192ce9543a502ec7a206:
> 
>   trace: add sanity check (2017-05-12 10:37:40 -0400)
> 
> ----------------------------------------------------------------
> 
> ----------------------------------------------------------------
> 
> Anthony Xu (1):
>   trace: add sanity check
> 
>  qom/cpu.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> -- 
> 2.9.3
> 
> 

Thanks, applied to my master tree:
https://github.com/stefanha/qemu/commits/master

Stefan

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 455 bytes --]