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+[[!meta copyright="Copyright © 2010, 2011, 2012 Free Software Foundation,
+Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!meta title="SA_SIGINFO, SA_SIGACTION"]]
+
+[[!tag open_issue_glibc]]
+
+Note: SA_SIGINFO has now been implemented by Jérémie Koenig. It will be
+uploaded in Debian eglibc 2.13-19.
+
+IRC, #hurd, August / September 2010:
+
+ <giselher> Hy, I came across SA_SIGINFO in cherokee, I have the void sighandler(int num) prototype but how do I add the sa_handler field?
+ <pinotree> if SA_SIGACTION is not defined, then you use sa_handler instead of sa_sigaction, and not add SA_SIGINFO in the sa_flags
+ <giselher> SA_SIGINFO is not defined
+ <pinotree> s/SA_SIGACTION/SA_SIGINFO/ above, yes
+ <giselher> K
+ <giselher> I am not sure if I fully understand this, there is the line "act.sa_flags = SA_SIGINFO" and how do I have to change that >_>
+ <pinotree> can you paste the source in a pastebin?
+ <giselher> k
+ <giselher> http://archhurd.pastebin.com/N8BCnG6g at line 790
+ <pinotree> something along the lines of http://www.archhurd.pastebin.com/tdpcFD5G
+ <pinotree> note that in the handler the siginfo_t parameter is used, which cannot be done if SA_SIGINFO is not defined
+ <pinotree> (that code still won't compile, yet)
+ <giselher> btw: is there a reason why SA_SIGINFO is not implemented?
+ <giselher> the guildlines only say "It's not implemented"
+ <azeem> 09:43 < azeem> signal stuff is tricky :-/
+ <azeem> basically it was pending on a complete rewrite by Roland, which never occured
+ <youpi> I have an almost complete implementation, just not finished yet
+ <youpi> (only the siginfo part)
+ <azeem> nobody really groked that code for years until youpi showed up, but he added partial support AFAIK, not having much time on his hand
+ <azeem> ah, he's here
+ <azeem> :)
+ <giselher> oh, should I just wait ?
+ <youpi> no
+ <giselher> k
+ <youpi> there are OSes which don't have SA_SIGINFO
+ <youpi> just cope with them: use sa_handler instead of sa_sigaction, and don't set SA_SIGINFO
+ <youpi> (i.e. replace with 0 in your example)
+ <giselher> ok
+ <youpi> when SA_SIGINFO becomes available, it'll just be used
+
+IRC, freenode, #hurd, 2011-08-20:
+
+ < youpi> erf, tcpwrappers will need si_pid
+ < jkoenig> I could implement it not too far away in the future, we just
+ need a version of msg_sig_post() with a siginfo argument or something.
+ < youpi> I can also see a lot of packages using SA_SIGINFO for no reason...
+ < youpi> (probably copy/pasty code)
+ < youpi> sa.sa_flags = SA_SIGINFO;
+ < youpi> sa.sa_handler = parse_config;
+ < youpi> void parse_config(int)
+ < youpi> yay
+ < youpi> if(siginf->si_signo == SIGXCPU)
+ < youpi> fprintf(stderr, "Exceeded CPU usage.\n");
+ < youpi> ...
+ < youpi> jkoenig: actually most package don't actually use the SA_SIGINFO
+ they request...
+ < youpi> jkoenig: si_pid should get us almost all actually used coverage
+ < youpi> I've seen only one example using si_errno
+ < jkoenig> ok
+ < youpi> oh, it's actually supported by your patch
+ < youpi> (errno)
+ < jkoenig> but I guess since implementing si_pid will require a new RPC, we
+ might as well plan for the rest
+ < youpi> jkoenig: indeed
+ < jkoenig> youpi, hmm I doubt it's properly filled in in all circumstances?
+ < youpi> ok, well, we'll see
+ < pinotree> jkoenig: if it can be of help, boost::unit_test queries various
+ fields of siginfo_t depending on the signal
+ < pinotree> jkoenig: also, pulseaudio uses siginfo_t for remapping faulting
+ memory on SIGBUS
+ < jkoenig> pinotree, oh ok good to know
+ < pinotree> *faulty
+ < youpi> jkoenig: well, I guess you had checked that the si_addr field is
+ correct in a few simple testcase :)
+ < jkoenig> hmm I think so, yes
+ < jkoenig> I ran like, "* (char *) 0x12345678;" or something IIRC
+ < youpi> ok
+ < jkoenig> I seem to remember mach generated SIGBUS instead of SIGSEGV
+ depending on the upper bit, or something (I can't quite remember)
+ < jkoenig> but when sigsegv was generated si_addr was right.
+ < pinotree> jkoenig: (see boost/test/impl/execution_monitor.ipp in boost
+ sources)
+ < pinotree> maybe you can try the unit tests for boost::unit_tests, if any
+ :)
+ < pinotree> (while src/pulsecore/memtrap.c in PA)
+ * pinotree stops doing MrObvious™