Hi,
I am really interested in libmtcp.so, but now I get trouble with it.

According to the comments from mtcp.c,
--"We must also keep the new vdso segment, provided by mtcp_restart.",
but what if a restored library want to occupy this memory region?

Unfortunately, on my Ubuntu 10.04 32bit, mtcp_restart always maps [vdso]
into 0x110000 (btw, how do you disable ASLR here?) , where confliction
occurs very frequently and cause segmentation error.

I think it is a bug of mtcp. Can you fix it? or give comments so I can do it?

thank you.

Guanglin


I'd love to give 2 memory maps here:
garin@ubuntu:~/workspace/testmtcpsimple_pthread/Release$ cat /proc/`pidof
testmtcp3`/maps
00110000-00263000 r-xp 00000000 07:00 1569891   
/lib/tls/i686/cmov/libc-2.11.1.so
00263000-00265000 r--p 00153000 07:00 1569891   
/lib/tls/i686/cmov/libc-2.11.1.so
00265000-00266000 rw-p 00155000 07:00 1569891   
/lib/tls/i686/cmov/libc-2.11.1.so
00266000-00269000 rw-p 00000000 00:00 0
00269000-0028d000 r-xp 00000000 07:00 1569902   
/lib/tls/i686/cmov/libm-2.11.1.so
0028d000-0028e000 r--p 00023000 07:00 1569902   
/lib/tls/i686/cmov/libm-2.11.1.so
0028e000-0028f000 rw-p 00024000 07:00 1569902   
/lib/tls/i686/cmov/libm-2.11.1.so
00297000-00298000 r-xp 00000000 00:00 0          [vdso]
005f9000-0060e000 r-xp 00000000 07:00 1569842   
/lib/tls/i686/cmov/libpthread-2.11.1.so
0060e000-0060f000 r--p 00014000 07:00 1569842   
/lib/tls/i686/cmov/libpthread-2.11.1.so
0060f000-00610000 rw-p 00015000 07:00 1569842   
/lib/tls/i686/cmov/libpthread-2.11.1.so
00610000-00612000 rw-p 00000000 00:00 0
00a39000-00a54000 r-xp 00000000 07:00 1580341    /lib/ld-2.11.1.so
00a54000-00a55000 r--p 0001a000 07:00 1580341    /lib/ld-2.11.1.so
00a55000-00a56000 rw-p 0001b000 07:00 1580341    /lib/ld-2.11.1.so
00b6d000-00b86000 r-xp 00000000 07:00 1448440   
/home/garin/testground/dmtcp-1.2.5/mtcp/libmtcp.so.1.0.0
00b86000-00b87000 r--p 00018000 07:00 1448440   
/home/garin/testground/dmtcp-1.2.5/mtcp/libmtcp.so.1.0.0
00b87000-00b88000 rw-p 00019000 07:00 1448440   
/home/garin/testground/dmtcp-1.2.5/mtcp/libmtcp.so.1.0.0
00b88000-00b95000 rw-p 00000000 00:00 0
00dac000-00dae000 r-xp 00000000 07:00 1569825   
/lib/tls/i686/cmov/libdl-2.11.1.so
00dae000-00daf000 r--p 00001000 07:00 1569825   
/lib/tls/i686/cmov/libdl-2.11.1.so
00daf000-00db0000 rw-p 00002000 07:00 1569825   
/lib/tls/i686/cmov/libdl-2.11.1.so
08048000-08049000 r-xp 00000000 07:00 1446125   
/home/garin/testground/dmtcp-1.2.5/mtcp/testmtcp3
08049000-0804a000 r--p 00000000 07:00 1446125   
/home/garin/testground/dmtcp-1.2.5/mtcp/testmtcp3
0804a000-0804b000 rw-p 00001000 07:00 1446125   
/home/garin/testground/dmtcp-1.2.5/mtcp/testmtcp3
0804b000-0804c000 rw-p 00000000 00:00 0
08936000-08957000 rw-p 00000000 00:00 0          [heap]
b576c000-b576d000 ---p 00000000 00:00 0
b576d000-b5f6d000 rw-p 00000000 00:00 0
b5f6d000-b5f6e000 ---p 00000000 00:00 0
b5f6e000-b676e000 rw-p 00000000 00:00 0
b676e000-b676f000 ---p 00000000 00:00 0
b676f000-b6f6f000 rw-p 00000000 00:00 0
b6f6f000-b6f70000 ---p 00000000 00:00 0
b6f70000-b7772000 rw-p 00000000 00:00 0
b7781000-b7783000 rw-p 00000000 00:00 0
bfed2000-bfee7000 rw-p 00000000 00:00 0          [stack]

garin@ubuntu:~/workspace/testmtcpsimple_pthread/Release$ cat /proc/`pidof
mtcp_restart`/maps
00110000-00263000 r-xp 00000000 07:00 1569891   
/lib/tls/i686/cmov/libc-2.11.1.so            ##before restores, here lies
[vdso] section. so conflicts now!
00263000-00265000 r--p 00153000 07:00 1569891   
/lib/tls/i686/cmov/libc-2.11.1.so
00265000-00266000 rw-p 00155000 07:00 1569891   
/lib/tls/i686/cmov/libc-2.11.1.so
00266000-00269000 rw-p 00000000 00:00 0
00269000-0028d000 r-xp 00000000 07:00 1569902   
/lib/tls/i686/cmov/libm-2.11.1.so
0028d000-0028e000 r--p 00023000 07:00 1569902   
/lib/tls/i686/cmov/libm-2.11.1.so
0028e000-0028f000 rw-p 00024000 07:00 1569902   
/lib/tls/i686/cmov/libm-2.11.1.so
00297000-00298000 r-xp 00000000 00:00 0
005f9000-0060e000 r-xp 00000000 07:00 1569842   
/lib/tls/i686/cmov/libpthread-2.11.1.so
0060e000-0060f000 r--p 00014000 07:00 1569842   
/lib/tls/i686/cmov/libpthread-2.11.1.so
0060f000-00610000 rw-p 00015000 07:00 1569842   
/lib/tls/i686/cmov/libpthread-2.11.1.so
00610000-00612000 rw-p 00000000 00:00 0
00a39000-00a54000 r-xp 00000000 07:00 1580341    /lib/ld-2.11.1.so
00a54000-00a55000 r--p 0001a000 07:00 1580341    /lib/ld-2.11.1.so
00a55000-00a56000 rw-p 0001b000 07:00 1580341    /lib/ld-2.11.1.so
00b6d000-00b95000 rwxp 00000000 00:00 0
00dac000-00dae000 r-xp 00000000 07:00 1569825   
/lib/tls/i686/cmov/libdl-2.11.1.so
00dae000-00daf000 r--p 00001000 07:00 1569825   
/lib/tls/i686/cmov/libdl-2.11.1.so
00daf000-00db0000 rw-p 00002000 07:00 1569825   
/lib/tls/i686/cmov/libdl-2.11.1.so
08048000-08049000 r-xp 00000000 07:00 1446125   
/home/garin/testground/dmtcp-1.2.5/mtcp/testmtcp3
08049000-0804a000 r--p 00000000 07:00 1446125   
/home/garin/testground/dmtcp-1.2.5/mtcp/testmtcp3
0804a000-0804b000 rw-p 00001000 07:00 1446125   
/home/garin/testground/dmtcp-1.2.5/mtcp/testmtcp3
0804b000-0804c000 rw-p 00000000 00:00 0
08936000-08957000 rw-p 00000000 00:00 0          [heap]
b576c000-b576d000 ---p 00000000 00:00 0
b576d000-b5f6d000 rw-p 00000000 00:00 0
b5f6d000-b5f6e000 ---p 00000000 00:00 0
b5f6e000-b676e000 rw-p 00000000 00:00 0
b676e000-b676f000 ---p 00000000 00:00 0
b676f000-b6f6f000 rw-p 00000000 00:00 0
b6f6f000-b6f70000 ---p 00000000 00:00 0
b6f70000-b7772000 rw-p 00000000 00:00 0
b7781000-b7783000 rw-p 00000000 00:00 0
bfce4000-bfee7000 rw-p 00000000 00:00 0

...
[7591] mtcp.c:2172 checkpointhread:
  everything resumed
[7591] mtcp.c:3511 stopthisthread:
  tid 7615 returning to 0x110400
[7591] mtcp.c:3488 stopthisthread:
  thread 7616 resuming
[Segmentation fault


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