On Tuesday, August 26, 2014 3:32:10 pm John-Mark Gurney wrote: > John Baldwin wrote this message on Tue, Aug 26, 2014 at 15:09 -0400: > > On Monday, August 25, 2014 6:30:34 pm John-Mark Gurney wrote: > > > John Baldwin wrote this message on Mon, Aug 25, 2014 at 13:35 -0400: > > > > On Monday, August 25, 2014 07:02:41 PM Mateusz Guzik wrote: > > > > > On Mon, Aug 25, 2014 at 10:23:19AM -0400, John Baldwin wrote: > > > > > > On Sunday, August 24, 2014 09:04:09 AM Mateusz Guzik wrote: > > > > > > > Author: mjg > > > > > > > Date: Sun Aug 24 09:04:09 2014 > > > > > > > New Revision: 270444 > > > > > > > URL: http://svnweb.freebsd.org/changeset/base/270444 > > > > > > > > > > > > > > Log: > > > > > > > Fix getppid for traced processes. > > > > > > > > > > > > > > Traced processes always have the tracer set as the parent. > > > > > > > Utilize proc_realparent to obtain the right process when needed. > > > > > > > > > > > > Are you sure this won't break things? I know of several > > > > > > applications that > > > > > > expect a debugger to be the parent when attached and change > > > > > > behavior as a > > > > > > result (e.g. inserting a breakpoint on an assertion failure rather > > > > > > than > > > > > > generating a core). > > > > > > > > > > Well, this is what linux and solaris do. > > > > > > > > Interesting. > > > > > > > > > I don't feel strongly about this change. If you really want I'm happy > > > > > to > > > > > revert. > > > > > > > > In general I'd like to someday have the debugger-debuggee relationship > > > > not > > > > override parent-child and this is a step in that direction. However, > > > > this > > > > will break existing applications, so this needs to be clearly > > > > documented in > > > > the release notes. In addition, we should probably advertise how a > > > > process > > > > can correctly determine if it is being run under a debugger (right now > > > > you can > > > > do 'getppid()' and use strcmp or strstr on the p_comm of that pid so > > > > you can > > > > do different things for "gdb" vs "gcore", etc. so just checking > > > > P_TRACED from > > > > kinfo_proc wouldn't be equivalent in functionality) > > > > > > But what about when you attach gdb to a running process... That > > > doesn't magicly make the now debugged process a child of gdb does it? > > > > % cat hello.c > > #include <stdio.h> > > > > int > > main() > > { > > printf("hello world\n"); > > (void)getchar(); > > return (0); > > } > > % cc -g hello.c -o hello > > % ./hello > > hello world > > load: 9.81 cmd: hello 42599 [ttyin] 1.67r 0.00u 0.00s 0% 1056k > > > > < different window > > > > > % ps -O ppid -p `pgrep hello` > > PID PPID TT STAT TIME COMMAND > > 42599 5340 16 I+ 0:00.00 ./hello > > % gdb hello `pgrep hello` > > GNU gdb 6.1.1 [FreeBSD] > > ... > > (gdb) <hit Ctrl-Z> > > Suspended > > % ps -O ppid -p `pgrep hello` > > PID PPID TT STAT TIME COMMAND > > 42599 45079 16 TX+ 0:00.00 ./hello > > Wow, learn something new every day... > > But doesn't that break apps that use getppid to signal their parent > that forked them?
Until mjg@'s commit, yes. It's been that way in FreeBSD at least for as long as I can remember. Certainly back to 4.x. -- John Baldwin _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
