[fedora-arm] unaligned access of memory(Broken bluetooth a2dp profile)
Hi All,
I found weird bug when I have a bluetooth a2dp test.
The bug has been reported to Bugzilla[1] but I wonder why it was not
reported since fedora 23.
Is there any guys to have a a2dp test on arm since fedora 23?
I think the bug seems to be from gcc or gcc build option since gcc-5.x.
I've tried several approach to avoid SIGSEGV of pulseaudio process.
Base platform is fedora 24 arm.
1. Use fedora24's sbc-1.3-4.fc24.armv7hl -> SIGSEGV
2. Install fedora23's sbc-1.3-3.fc23.armv7hl -> SIGSEGV
3. Install fedora22's sbc-1.3-2.fc22.armv7hl -> Success
4. Build sbc-1.3-2.fc22 on fedora 22 -> SIGSEGV
The sbc-1.3-2 has been never built again since it was released from fedora22.
As I know, gcc version was changed from gcc-4.9 to gcc-5.3 after
released fedora22. I think it could affect the operation of sbc.
Below is GDB debug information of SIGSEGV error of pulseaudio.
Thread 4 "bluetooth" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb0899300 (LWP 3814)]
0xb08a7a58 in sbc_analyze_eight_armv6 () at sbc/sbc_primitives_armv6.c:115
115 __asm__ volatile (
(gdb) bt
#0 0xb08a7a58 in sbc_analyze_eight_armv6 () at sbc/sbc_primitives_armv6.c:115
#1 0x0000fffe in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb) disassemble
Dump of assembler code for function sbc_analyze_eight_armv6:
<snip>
0xb08a7a40 <+440>: smlad r4, lr, r8, r4
0xb08a7a44 <+444>: smlad r5, lr, r9, r5
0xb08a7a48 <+448>: ldrd r8, [r2, #40] ; 0x28
0xb08a7a4c <+452>: smlad r6, lr, r10, r6
0xb08a7a50 <+456>: smlad r7, lr, r11, r7
0xb08a7a54 <+460>: ldrd r10, [r2, #48] ; 0x30
=> 0xb08a7a58 <+464>: stmia r1!, {r4, r5}
0xb08a7a5c <+468>: smuad r4, r3, r8
0xb08a7a60 <+472>: smuad r5, r3, r9
---Type <return> to continue, or q <return> to quit---
0xb08a7a64 <+476>: ldrd r8, [r2, #72] ; 0x48
0xb08a7a68 <+480>: stmia r1!, {r6, r7}
0xb08a7a6c <+484>: smuad r6, r3, r10
0xb08a7a70 <+488>: smuad r7, r3, r11
0xb08a7a74 <+492>: ldrd r10, [r2, #80] ; 0x50
0xb08a7a78 <+496>: smlad r4, r12, r8, r4
(gdb) info registers
r0 0xfffc0001 4294705153
r1 0xb705a4af 3070600367
r2 0xb08a8c08 2961869832
r3 0x1ffff 131071
r4 0x201b 8219
r5 0x15467 87143
r6 0xffff5f4d 4294926157
r7 0xfffe8306 4294869766
r8 0x1d4d206f 491593839
r9 0x33badf91 867884945
r10 0xa4adf91 172679057
r11 0xd426206f 3559268463
r12 0x20003 131075
sp 0xb0898bf8 0xb0898bf8
lr 0xffff 65535
pc 0xb08a7a58 0xb08a7a58 <sbc_analyze_eight_armv6+464>
cpsr 0x80000010 -2147483632
It seems alignment error of stmia instruction.
[1]: https://bugzilla.redhat.com/show_bug.cgi?id=1350490
--
Best Regards,
Chanho Park