Hi All,
ISSUE : "Info threads" hangs in KGDBOE
Kernel : Linux-2.6.29
Bug found in Architectures: PowerPC (ppc32), x86
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While trying to run kernel Linux-2.6.29 on PowerPC Xilinx target with KGDBOE enabled. Further issues arise when I run "info threads" after connecting to the target. following is the error:
(gdb) target remote udp:10.161.2.35:6443
warning: The remote protocol may be unreliable over UDP.
Some events may be lost, rendering further debugging impossible.
Remote debugging using udp:10.161.2.35:6443
kgdb_breakpoint () at kernel/kgdb.c:1803
1803 arch_kgdb_breakpoint();
(gdb) info threads
[New Thread -2]
[New Thread 2]
[New Thread 3]
[New Thread 4]
[New Thread 5]
[New Thread 6]
[New Thread 59]
[New Thread 67]
[New Thread 101]
[New Thread 102]
[New Thread 103]
[New Thread 104]
[New Thread 105]
14 Thread 105 (nfsiod) __switch_to (prev=<value optimized out>, new=0xcf89c100) at arch/powerpc/kernel/process.c:411
13 Thread 104 (aio/0) __switch_to (prev=<value optimized out>, new=0xcf82f4e0) at arch/powerpc/kernel/process.c:411
12 Thread 103 (kswapd0) __switch_to (prev=<value optimized out>, new=0xcf82f4e0) at arch/powerpc/kernel/process.c:411
11 Thread 102 (pdflush) __switch_to (prev=<value optimized out>, new=0xcf82e880) at arch/powerpc/kernel/process.c:411
10 Thread 101 (pdflush) Ignoring packet error, continuing...
Ignoring packet error, continuing...
Ignoring packet error, continuing...
Ignoring packet error, continuing...
Ignoring packet error, continuing...
Finally kernel dies, after these error messages. This issue is not found till Linux-2.6.28.10 kernel version, KGDBOE works fine in x86 & PowerPC. Now the bug is seen in x86 (32bit) and PowerPC from kernel version Linux-2.6.29
Hope this should not be raw_smp_processor_id issue ! The CPU ID returned in both arch's is 0. Which patch in netpoll* or any net device has caused this issue.
One more thing to notice in x86 or PowerPC the kernel dies exactly after reply of four threads/packets.
Thanks,
Srikanth Krishnakar