On Fri, 2011-06-24 at 17:21 +0800, Yong Zhang wrote: > Hi, > > When I use kprobe to do something, I found some wired thing. > > When CONFIG_FUNCTION_TRACER is disabled: > (gdb) disassemble do_fork > Dump of assembler code for function do_fork: > 0xc0037390 <+0>: mflr r0 > 0xc0037394 <+4>: stwu r1,-64(r1) > 0xc0037398 <+8>: mfcr r12 > 0xc003739c <+12>: stmw r27,44(r1) > > Then I: > modprobe kprobe_example func=do_fork offset=4 > ls > Things works well. > > But when CONFIG_FUNCTION_TRACER is enabled: > (gdb) disassemble do_fork > Dump of assembler code for function do_fork: > 0xc0040334 <+0>: mflr r0 > 0xc0040338 <+4>: stw r0,4(r1) > 0xc004033c <+8>: bl 0xc00109d4 <mcount> > 0xc0040340 <+12>: stwu r1,-80(r1) > 0xc0040344 <+16>: mflr r0 > 0xc0040348 <+20>: stw r0,84(r1) > 0xc004034c <+24>: mfcr r12 > Then I: > modprobe kprobe_example func=do_fork offset=12 > ls > 'ls' will never retrun. system freeze.
I'm not sure if x86 had a similar issue. Masami, have any ideas to why this happened? I don't have a PPC32 to test on, but I can try it out on my PPC64. -- Steve > > I'm using toolchain from:http://www.denx.de/wiki/ELDK-5/WebHome > powerpc-linux-gcc -v > Using built-in specs. > COLLECT_GCC=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/bin/powerpc-linux/powerpc-linux-gcc > COLLECT_LTO_WRAPPER=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/libexec/powerpc-linux/gcc/powerpc-linux/4.5.1/lto-wrapper > Target: powerpc-linux > Configured with: > /opt/poky/build/eldk-2011-05-20-5cde06e-powerpc/tmp/work/i686-nativesdk-oesdk-linux/gcc-cross-canadian-powerpc-4.5.1-r4/gcc-4.5.1/configure > --build=x86_64-linux --host=i686-oesdk-linux --target=powerpc-linux > --prefix=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr > --exec_prefix=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr > --bindir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/bin/powerpc-linux > --sbindir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/bin/powerpc-linux > --libexecdir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/libexec/powerpc-linux > --datadir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/share > --sysconfdir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/etc > --sharedstatedir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/com > --localstatedir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/var > --libdir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/lib/powerpc-linux > --includedir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/include > --oldincludedir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/include > --infodir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/share/info > --mandir=/opt/eldk-5.0/powerpc/sysroots/i686-oesdk-linux/usr/share/man > --with-libtool-sysroot=/opt/poky/build/eldk-2011-05-20-5cde06e-powerpc/tmp/sysroots/i686-oesdk-linux-nativesdk > --with-gnu-ld --enable-shared --enable-languages=c,c++ > --enable-threads=posix --disable-multilib --enable-c99 > --enable-long-long --enable-symvers=gnu --enable-libstdcxx-pch > --program-prefix=powerpc-linux- --enable-lto --enable-libssp > --disable-bootstrap --disable-libgomp --disable-libmudflap > --enable-cheaders=c_global > --with-local-prefix=/opt/eldk-5.0/powerpc/sysroots/powerpc-linux/usr > --with-gxx-include-dir=/usr/include/c++ > --with-build-time-tools=/opt/poky/build/eldk-2011-05-20-5cde06e-powerpc/tmp/sysroots/x86_64-linux/usr/powerpc-linux/bin > --with-sysroot=/opt/eldk-5.0/powerpc/sysroots/powerpc-linux > --with-build-sysroot=/opt/poky/build/eldk-2011-05-20-5cde06e-powerpc/tmp/sysroots/powerpc > --disable-libunwind-exceptions --disable-libssp --disable-libgomp > --disable-libmudflap > --with-mpfr=/opt/poky/build/eldk-2011-05-20-5cde06e-powerpc/tmp/sysroots/i686-oesdk-linux-nativesdk > --with-mpc=/opt/poky/build/eldk-2011-05-20-5cde06e-powerpc/tmp/sysroots/i686-oesdk-linux-nativesdk > --enable-__cxa_atexit > Thread model: posix > gcc version 4.5.1 (GCC) > > > And kernel config is attached. > > BTW, I have made a patch to make kprobe_example set breakpoint easily, > attached too. > > Thanks, > Yong > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
