Hi David, Thank you for your cooperation. I couldn't find this CR. I will vote it.
Thanks, Yasumasa On 2012/01/31 19:58, David Holmes wrote: > Hi, > > A bug was opened for this just a few days ago - 7133122. > > I'll add your patch to the CR. > > David Holmes > ------------ > > On 31/01/2012 8:32 PM, Yasumasa Suenaga wrote: >> Hi, >> >> I've tried attach a corefile with jstack. However, I couldn't. >> >> I guess that this problem is caused by incorrect address mapping of >> libsaproc.so . >> I've made a patch which is attached this email. And I've been able to get >> correct thread stack with jstack. >> >> So, I'd like to contribute this patch, and I'd like to backport to JDK6/7 . >> Could you help me? >> >> >> ------ details ------ >> >> I got these messages then I ran jstack with LIBSAPROC_DEBUG environment >> variable: >> >> /*************************/ >> >> : >> >> libsaproc DEBUG: reading library >> /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.1.x86_64/jre/lib/amd64/server/libjvm.so >> @ 0x7f53b455a000 [ 0x7f53b455a000 ] >> libsaproc DEBUG: ---- sorted virtual address map ---- >> >> : >> >> libsaproc DEBUG: base = 0x7f53b455a000 size = 9993772 >> libsaproc DEBUG: base = 0x7f53b455a000 size = 4096 >> >> : >> >> libsaproc DEBUG: can't locate map_info at 0x7f53b4dbe000 >> libsaproc DEBUG: core read failed for 4096 byte(s) @ 0x7f53b4dbe000 (4096 >> more bytes) >> >> : >> >> /*************************/ >> >> libsaproc.so tries to read libjvm.so library address, and it is duplicated. >> I read Linux kernel source code of function of core dump, and I found these >> comment: >> >> source code: kernel-3.2.1-3.fc16.src.rpm (Fedora16 x86_64) >> in fs/binfmt_elf.c: static unsigned long vma_dump_size(struct vm_area_struct >> *vma, unsigned long mm_flags) >> ---------------------- >> /* >> * If this looks like the beginning of a DSO or executable mapping, >> * check for an ELF header. If we find one, dump the first page to >> * aid in determining what was mapped here. >> */ >> ---------------------- >> >> In fact, core image has executable load section which size is 1 page(0x1000) >> ---------------------- >> LOAD 0x0000000005173000 0x00007f53b455a000 0x0000000000000000 >> 0x0000000000001000 0x0000000000988000 R E 1000 >> ---------------------- >> >> So, we must think these case when we attach core image. >> I modified "read_lib_segments()" in hotspot/agent/src/os/linux/ps_core.c to >> overwrite >> correct address in shared library . >> >> >> Please check it. >> >> Thanks, >> Yasumasa >>
