Hi,
 
Two problems
 
First one,
when building kernel and LKMs,
WARNING: vmlinux - Section mismatch: reference to .init.text: from .plt after '' (at offset 0x8347e44)
WARNING: vmlinux - Section mismatch: reference to .init: from .plt after '' (at offset 0x8347e64)
WARNING: vmlinux - Section mismatch: reference to .init.setup: from .plt after '' (at offset 0x8347ea4)
WARNING: vmlinux - Section mismatch: reference to .init.text:nosmp from .plt after '' (at offset 0x8347f20)
WARNING: vmlinux - Section mismatch: reference to .init.setup:__setup_nosmp from .plt after '' (at offset 0x8347f28)
WARNING: vmlinux - Section mismatch: reference to .init.text:maxcpus from .plt after '' (at offset 0x8347f2c)
...
...
 
So when gdb loads LKM symbols, it seems .init.text and .exit.text sections overlapped with .text section.
 
 
Second one,
 
when run uml compiled with "-g" and without "-O2",
uml crashed
 
VFS: Mounted root (ext2 filesystem).
Stub registers -
        0 - 0
        1 - 0
        2 - 0
        3 - 0
        4 - 0
        5 - bffffd1c
        6 - e
        7 - 7b
        8 - 7b
        9 - 0
        10 - 0
        11 - ffffffff
        12 - bfdb8f9a
        13 - 73
        14 - 10282
        15 - bffffd04
        16 - 7b
Kernel panic - not syncing: get_skas_faultinfo : failed to wait for SIGUSR1/SIGTRAP, pid = 7760, n = 7760, errno = 0, status = 0xb7f
 
 
EIP: 0073:[<400007b0>] CPU: 0 Not tainted ESP: 007b:bf9fa530 EFLAGS: 00010246
    Not tainted
EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: 00000000
ESI: 00000000 EDI: 00000000 EBP: 00000000 DS: 007b ES: 007b
088a7b18:  [<08082abb>] show_regs+0x123/0x125
088a7b34:  [<08066441>] panic_exit+0x3e/0x60
088a7b4c:  [<080a5bed>] notifier_call_chain+0x3c/0x64
088a7b6c:  [<080a5ca9>] atomic_notifier_call_chain+0x1f/0x27
088a7b84:  [<0808cf37>] panic+0x7d/0x126
088a7ba8:  [<0807c293>] wait_stub_done+0x1e4/0x1e6
088a7c28:  [<0807c321>] get_skas_faultinfo+0x8c/0xaa
088a7c44:  [<0807d646>] user_signal+0x57/0x81
088a7c60:  [<0807cae7>] userspace+0x211/0x2c2
088a7cc8:  [<08066deb>] new_thread_handler+0x1aa/0x1b8
088a7d20:  [<006c2a48>] 0x6c2a48