Thanks Greg for the thorough explanation.
Cheers --Arindam Greg Price wrote: >These instructions are branches with prediction, i.e. SPARC v9 >instructions. I suspect the disassemblers only display instructions they >think are legitimate for the target code. In this case it's a 32-bit >program, hence it's not SPARC v9, and the disassembler has decided it >won't decode the v9 instructions. The reason why we have v9 instructions >is this is an optimized platform specific library that will only be >loaded for relevant platforms - in this case the 480R loads the Sun4u / >UltraSPARC III library as the system knows it has UltraSPARC processors. >SPARC v9 instructions are still legitimate instructions in a 32 bit >program when running on an UltraSPARC (It's really only the address mode >that changes when running "32 bit mode") > >That would be my guess. Make sense? > >Cheers, >Greg > > > >Arindam Sarkar - Sun Microsystems wrote: > > >>Hi, >> I was looking at a userland core, where the tar program dumps core >>when it calls mempcy() routine >> of libc_psr library. The call to memcpy() is from a while loop, and >>during an iteration tar dumps >> core when it calls memcpy(). >> While i was analysing the userland core, i found the following >>after dumping the instructions at >> libc_psr.so.1`memcpy+0x3d4. >> >> > libc_psr.so.1`memcpy+0x3d4::dis >>libc_psr.so.1`memcpy+0x3ac: 0x248001a >>libc_psr.so.1`memcpy+0x3b0: sub %o2, %o5, %o2 >>libc_psr.so.1`memcpy+0x3b4: ldd [%o1], %f2 >>libc_psr.so.1`memcpy+0x3b8: subcc %o5, 8, %o5 >>libc_psr.so.1`memcpy+0x3bc: 0x240000e >>libc_psr.so.1`memcpy+0x3c0: add %o1, 8, %o1 >>libc_psr.so.1`memcpy+0x3c4: 0x89b00902 >>libc_psr.so.1`memcpy+0x3c8: ldd [%o1], %f0 >>libc_psr.so.1`memcpy+0x3cc: subcc %o5, 8, %o5 >>libc_psr.so.1`memcpy+0x3d0: add %o1, 0x10, %o1 >>libc_psr.so.1`memcpy+0x3d4: std %f4, [%o0] >> >> > !uname -a >>SunOS line2-v480 5.10 Generic_120011-11 sun4u sparc SUNW,Sun-Fire-480R >> > !cat /etc/release >> Solaris 10 8/07 s10s_u4wos_10 SPARC >> Copyright 2007 Sun Microsystems, Inc. All Rights Reserved. >> Use is subject to license terms. >> Assembled 21 June 2007 >> > ::status >>debugging core file of tar (32-bit) from line2-v480 >>file: /usr/sbin/tar >>initial argv: tar -xpf 10g.tar >>threading model: multi-threaded >>status: process terminated by SIGSEGV (Segmentation Fault) >> >> >> I am not sure why do we see an address at libc_psr.so.1`memcpy+0x3bc, >>instead of the usual mnemonic. >> Note, this core dump is the result of reproducing a bug on a sparc >>machine having S10U4. Can someone >> pls tell me *why* we don't see the mnemonic for the 3 instructions in >>the above output ? Pls respond to >> me directly since i am not yet a member of this alias. >> >> >> >>TIA >>--Arindam >>_______________________________________________ >>mdb-discuss mailing list >>mdb-discuss at opensolaris.org >> >> >> >_______________________________________________ >mdb-discuss mailing list >mdb-discuss at opensolaris.org > >
