gdb and JNI SIGSEGV

gdb and JNI SIGSEGV.txt

Suppose we have a following stack trace:

Stack: [...,...],  sp=...,  free space=...
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
C  [libcpp_mem_i_40.so+0xAAAA]  _ZN3Mem10setCounterExii+0xBBB

--- Using the first offset (0xAAAA) -------

Open the gdb:

> /usr/local/gdb72/bin/gdb /.../libcpp_mem_i_40.so

See where it crashed:

> list *0xAAAA

--- Using the second offset (0xBBB) -------

Convert the second offset into decimals:

> perl -e 'print 0xBBB."\n"'
3003

And examine the given function (looking for the 3003th opcode):

> disassemble _ZN3Mem10setCounterExii
> disassemble /m _ZN3Mem10setCounterExii

To obtain the line number we might try:

> print _ZN3Mem10setCounterExii+3003

or

> x/i _ZN3Mem10setCounterExii+3003

then use the given address to learn the line

> info line *0xAAAA
> list *0xAAAA
Line ... of "..."

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If stack trace is not available (usually when "abort" was called), then
> /usr/local/gdb72/bin/gdb /usr/local/openjdk7/bin/java -c java.core
might help.

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Alternative, if stack trace is available, is to use
> objdump -S lib....so | less