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Diffstat (limited to 'README_DEVELOPERS')
| -rw-r--r-- | README_DEVELOPERS | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/README_DEVELOPERS b/README_DEVELOPERS index defce7859..a3e835e7f 100644 --- a/README_DEVELOPERS +++ b/README_DEVELOPERS @@ -35,20 +35,35 @@ file. Eg: Debugging Valgrind with GDB ~~~~~~~~~~~~~~~~~~~~~~~~~~~ -To debug stage 1 just run it under GDB in the normal way. +To debug the valgrind launcher program (<prefix>/bin/valgrind) just +run it under gdb in the normal way. -To debug Valgrind proper (stage 2) with GDB, start Valgrind like this: +Debugging the main body of the valgrind code (and/or the code for +a particular tool) requires a bit more trickery but can be achieved +without too much problem by following these steps: - valgrind --tool=none --wait-for-gdb=yes <prog> +(1) Set VALGRIND_LAUNCHER to <prefix>/bin/valgrind: -Then start gdb like this in another terminal: + export VALGRIND_LAUNCHER=/usr/local/bin/valgrind - gdb /usr/lib/valgrind/stage2 <pid> +(2) Run "gdb <prefix>/lib/valgrind/<platform>/<tool>": -Where <pid> is the pid valgrind printed. Then set whatever breakpoints -you want and do this in gdb: + gdb /usr/local/lib/valgrind/ppc32-linux/lackey - jump *$eip +(3) Do "handle SIGSEGV SIGILL nostop noprint" in GDB to prevent GDB from + stopping on a SIGSEGV or SIGILL: + + (gdb) handle SIGILL SIGSEGV nostop noprint + +(4) Set any breakpoints you want and proceed as normal for gdb. The + macro VG_(FUNC) is expanded to vgPlain_FUNC, so If you want to set + a breakpoint VG_(do_exec), you could do like this in GDB: + + (gdb) b vgPlain_do_exec + +(5) Run the tool with required options: + + (gdb) run pwd Self-hosting |