On 07/29/12 13:42, Avi Kivity wrote:
On 07/27/2012 10:04 PM, Chris Clayton wrote:
On 07/27/12 19:08, Eric Northup wrote:
Could you include the output of "info registers" at the point where it
crashed?
Here you go:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb6a78b40 (LWP 13249)]
__strcmp_sse4_2 () at ../sysdeps/i386/i686/multiarch/strcmp-sse4.S:217
217 movdqu (%edx), %xmm2
(gdb) bt
#0 __strcmp_sse4_2 () at ../sysdeps/i386/i686/multiarch/strcmp-sse4.S:217
#1 0xb7e82cb4 in g_str_equal (v1=0x8a0cd58, v2=0x8319b82) at ghash.c:1704
#2 0xb7e8137a in g_hash_table_lookup_node (hash_table=0x89fe800,
key=0x8319b82, hash_return=0xb6a78178)
at ghash.c:422
#3 0xb7e821e5 in g_hash_table_lookup (hash_table=0x89fe800,
key=key@entry=0x8319b82) at ghash.c:1074
#4 0x0815c9cb in type_table_lookup (name=0x8319b82 "apic-common") at
qom/object.c:94
#5 type_get_by_name (name=name@entry=0x8319b82 "apic-common") at
qom/object.c:149
#6 0x0815cf93 in object_dynamic_cast (obj=obj@entry=0x8a313e0,
typename=typename@entry=0x8319b82 "apic-common")
at qom/object.c:416
#7 0x0815cf2d in object_dynamic_cast_assert (obj=obj@entry=0x8a313e0,
typename=typename@entry=0x8319b82 "apic-common") at qom/object.c:478
#8 0x08192c1b in cpu_set_apic_tpr (d=0x8a313e0, val=13 '\r')
at /home/chris/rpm/BUILD/qemu-kvm-1.1.1/hw/apic_common.c:60
#9 0x081cb86c in kvm_arch_post_run (env=env@entry=0x8a29370,
run=run@entry=0xb6274000)
at /home/chris/rpm/BUILD/qemu-kvm-1.1.1/target-i386/kvm.c:1695
#10 0x081c686f in kvm_cpu_exec (env=env@entry=0x8a29370) at
/home/chris/rpm/BUILD/qemu-kvm-1.1.1/kvm-all.c:1269
#11 0x08198c72 in qemu_kvm_cpu_thread_fn (arg=0x8a29370) at
/home/chris/rpm/BUILD/qemu-kvm-1.1.1/cpus.c:752
#12 0xb7a3ed9e in start_thread () from /lib/libpthread.so.0
#13 0xb77e45ee in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:132
(gdb) info registers
eax 0x8319b82 137468802
ecx 0xd58 3416
edx 0x8a0cd58 144756056
ebx 0xb7f7f2c4 -1208487228
esp 0xb6a780ec 0xb6a780ec
ebp 0xb6a78118 0xb6a78118
esi 0x8a313e0 144905184
edi 0xc513 50451
eip 0xb7824f77 0xb7824f77 <__strcmp_sse4_2+23>
eflags 0x10283 [ CF SF IF RF ]
cs 0x73 115
ss 0x7b 123
ds 0x0 0
es 0x0 0
fs 0x0 0
gs 0x33 51
ds shouldn't be zero for a 32-bit process.
But that should have crashed *much* earlier, ds is accessed all the time.
Please add the following snippet to the beginning of kvm_arch_post_run():
{
unsigned short ds;
asm("mov %%ds, %0" : "=rm"(ds));
assert(ds != 0);
}
if the assert triggers, then kvm corrupted the segment registers. If
not, corruption happens somewhere above.
Thanks, Avi.
The assert didn't trigger - I got:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb60ffb40 (LWP 2134)]
__strcmp_sse4_2 () at ../sysdeps/i386/i686/multiarch/strcmp-sse4.S:217
217 movdqu (%edx), %xmm2
(gdb) info registers
eax 0x8319ba2 137468834
ecx 0xd58 3416
edx 0x8a0cd58 144756056
ebx 0xb7f7f2c4 -1208487228
esp 0xb60ff0ec 0xb60ff0ec
ebp 0xb60ff118 0xb60ff118
esi 0x8a44818 144984088
edi 0xc513 50451
eip 0xb7820f77 0xb7820f77 <__strcmp_sse4_2+23>
eflags 0x10283 [ CF SF IF RF ]
cs 0x73 115
ss 0x7b 123
ds 0x0 0
es 0x0 0
fs 0x0 0
gs 0x33 51
(gdb) list
212 #endif
213 mov %dx, %cx
214 and $0xfff, %cx
215 cmp $0xff0, %cx
216 ja L(first4bytes)
217 movdqu (%edx), %xmm2
218 mov %eax, %ecx
219 and $0xfff, %ecx
220 cmp $0xff0, %ecx
221 ja L(first4bytes)
(gdb) bt
#0 __strcmp_sse4_2 () at ../sysdeps/i386/i686/multiarch/strcmp-sse4.S:217
#1 0xb7e82cb4 in g_str_equal (v1=0x8a0cd58, v2=0x8319ba2) at ghash.c:1704
#2 0xb7e8137a in g_hash_table_lookup_node (hash_table=0x89fe800,
key=0x8319ba2, hash_return=0xb60ff178)
at ghash.c:422
#3 0xb7e821e5 in g_hash_table_lookup (hash_table=0x89fe800,
key=key@entry=0x8319ba2) at ghash.c:1074
#4 0x0815c9cb in type_table_lookup (name=0x8319ba2 "apic-common") at
qom/object.c:94
#5 type_get_by_name (name=name@entry=0x8319ba2 "apic-common") at
qom/object.c:149
#6 0x0815cf93 in object_dynamic_cast (obj=obj@entry=0x8a44818,
typename=typename@entry=0x8319ba2 "apic-common")
at qom/object.c:416
#7 0x0815cf2d in object_dynamic_cast_assert (obj=obj@entry=0x8a44818,
typename=typename@entry=0x8319ba2 "apic-common") at qom/object.c:478
#8 0x08192c1b in cpu_set_apic_tpr (d=0x8a44818, val=7 '\a')
at /home/chris/rpm/BUILD/qemu-kvm-1.1.1/hw/apic_common.c:60
#9 0x081cb874 in kvm_arch_post_run (env=env@entry=0x8a3ca60,
run=run@entry=0xb626d000)
at /home/chris/rpm/BUILD/qemu-kvm-1.1.1/target-i386/kvm.c:1702
#10 0x081c686f in kvm_cpu_exec (env=env@entry=0x8a3ca60) at
/home/chris/rpm/BUILD/qemu-kvm-1.1.1/kvm-all.c:1269
#11 0x08198c72 in qemu_kvm_cpu_thread_fn (arg=0x8a3ca60) at
/home/chris/rpm/BUILD/qemu-kvm-1.1.1/cpus.c:752
#12 0xb7a3ad9e in start_thread () from /lib/libpthread.so.0
#13 0xb77e05ee in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:132
I think you are saying that the problem isn't in kvm, so where would you
recommend I continue investigations. I'm not seeing a crash with any
other applications.
Thanks again.
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