Give more info about seginfo dropping.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@4425

diff --git a/coregrind/m_signals.c b/coregrind/m_signals.c
index cc43ff28b349d7d15e1e043f175f7366a91f88c0..b806f421ac73d7f40eb2600130a3cd2a36bacc27 100644 (file)
--- a/coregrind/m_signals.c
+++ b/coregrind/m_signals.c
@@ -1831,6 +1831,16 @@ void sync_signalhandler ( Int sigNo, vki_siginfo_t *info, struct vki_ucontext *u
                      sigNo, signame(sigNo));
         VG_(message)(Vg_UserMsg, "  This may be because one of your programs has consumed your");
         VG_(message)(Vg_UserMsg, "  ration of siginfo structures.");
+         VG_(printf)(
+"  For more information, see:\n"
+"    http://kerneltrap.org/mailarchive/1/message/25599/thread\n"
+"  Basically, some program on your system is building up a large queue of\n"
+"  pending signals, and this causes the siginfo data for other signals to\n"
+"  be dropped because it's exceeding a system limit.  However, Valgrind\n"
+"  absolutely needs siginfo for SIGSEGV.  A workaround is to track down the\n"
+"  offending program and avoid running it while using Valgrind, but there\n"
+"  is no easy way to do this.  Apparently the problem was fixed in kernel\n"
+"  2.6.12.\n");
 
         /* It's a fatal signal, so we force the default handler. */
         VG_(set_default_handler)(sigNo);