[lxc-devel] [PATCH] exclude non-existing signals from the loop

[Serge Hallyn]

Quoting S.Çağlar Onur (caglar at 10ur.org):
> On Thu, Jan 16, 2014 at 4:24 PM, Serge Hallyn <serge.hallyn at ubuntu.com> wrote:
> > Quoting S.Çağlar Onur (caglar at 10ur.org):
> >> 32 and 33 are not defined and causing sigaction to fail. "kill -l" shows following
> >> on my system
> >>
> >>  1) SIGHUP       2) SIGINT       3) SIGQUIT      4) SIGILL       5) SIGTRAP
> >>  6) SIGABRT      7) SIGBUS       8) SIGFPE       9) SIGKILL     10) SIGUSR1
> >> 11) SIGSEGV     12) SIGUSR2     13) SIGPIPE     14) SIGALRM     15) SIGTERM
> >> 16) SIGSTKFLT   17) SIGCHLD     18) SIGCONT     19) SIGSTOP     20) SIGTSTP
> >> 21) SIGTTIN     22) SIGTTOU     23) SIGURG      24) SIGXCPU     25) SIGXFSZ
> >> 26) SIGVTALRM   27) SIGPROF     28) SIGWINCH    29) SIGIO       30) SIGPWR
> >> 31) SIGSYS      34) SIGRTMIN    35) SIGRTMIN+1  36) SIGRTMIN+2  37) SIGRTMIN+3
> >> 38) SIGRTMIN+4  39) SIGRTMIN+5  40) SIGRTMIN+6  41) SIGRTMIN+7  42) SIGRTMIN+8
> >> 43) SIGRTMIN+9  44) SIGRTMIN+10 45) SIGRTMIN+11 46) SIGRTMIN+12 47) SIGRTMIN+13
> >> 48) SIGRTMIN+14 49) SIGRTMIN+15 50) SIGRTMAX-14 51) SIGRTMAX-13 52) SIGRTMAX-12
> >> 53) SIGRTMAX-11 54) SIGRTMAX-10 55) SIGRTMAX-9  56) SIGRTMAX-8  57) SIGRTMAX-7
> >> 58) SIGRTMAX-6  59) SIGRTMAX-5  60) SIGRTMAX-4  61) SIGRTMAX-3  62) SIGRTMAX-2
> >> 63) SIGRTMAX-1  64) SIGRTMAX
> >>
> >> Signed-off-by: S.Çağlar Onur <caglar at 10ur.org>
> >
> > Odd...  on my system NSIG is 32, so these should never hit (since it is
> > in a while i<NSIG loop)
> 
> Printing NSIG via ERROR shows that its 64 on my system.

So a header file is #defining NSIG, which is already defined to 32
in kernel headers, to _NSIG, which is 64.

Looking around the current state of kernel headers, i wonder whether
we should imply use min(SIGRTMIN, NSIG).

> > Does 32 show up in /usr/include/asm-generic/signal.h or
> > /usr/include/`arch`-linux-gnu/asm/signal.h ?
> 
> [caglar at qp:~/Projects/lxc(master)] find /usr/include/ -name signal.h |
> xargs grep NSIG
> /usr/include/asm-generic/signal.h:#define _NSIG         64
> /usr/include/asm-generic/signal.h:#define _NSIG_BPW     __BITS_PER_LONG
> /usr/include/asm-generic/signal.h:#define _NSIG_WORDS   (_NSIG / _NSIG_BPW)
> /usr/include/asm-generic/signal.h:#define SIGRTMAX      _NSIG
> /usr/include/asm-generic/signal.h:#define MINSIGSTKSZ   2048
> /usr/include/asm-generic/signal.h:      unsigned long sig[_NSIG_WORDS];
> /usr/include/x86_64-linux-gnu/asm/signal.h:#define NSIG         32
> /usr/include/x86_64-linux-gnu/asm/signal.h:#define SIGRTMAX     _NSIG
> /usr/include/x86_64-linux-gnu/asm/signal.h:#define MINSIGSTKSZ  2048
> /usr/include/signal.h:# define NSIG     _NSIG
> /usr/include/signal.h:extern const char *const _sys_siglist[_NSIG];
> /usr/include/signal.h:extern const char *const sys_siglist[_NSIG];
> 
> >> ---
> >>  src/lxc/lxc_init.c | 3 ++-
> >>  1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/src/lxc/lxc_init.c b/src/lxc/lxc_init.c
> >> index a59dd9c..ae64af8 100644
> >> --- a/src/lxc/lxc_init.c
> >> +++ b/src/lxc/lxc_init.c
> >> @@ -143,7 +143,8 @@ int main(int argc, char *argv[])
> >>                   i == SIGSEGV ||
> >>                   i == SIGBUS ||
> >>                   i == SIGSTOP ||
> >> -                 i == SIGKILL)
> >> +                 i == SIGKILL ||
> >> +                 i == 32 || i == 33)
> >>                       continue;
> >>
> >>               if (sigfillset(&act.sa_mask) ||
> >> --
> >> 1.8.3.2
> >>
> >> _______________________________________________
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> >> lxc-devel at lists.linuxcontainers.org
> >> http://lists.linuxcontainers.org/listinfo/lxc-devel
> > _______________________________________________
> > lxc-devel mailing list
> > lxc-devel at lists.linuxcontainers.org
> > http://lists.linuxcontainers.org/listinfo/lxc-devel
> 
> 
> 
> -- 
> S.Çağlar Onur <caglar at 10ur.org>
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