* Stephen Hahn <sch at sun.com> [2009-01-22 00:54]: > * Stephen Hahn <sch at sun.com> [2009-01-21 23:58]: > > * Stephen Hahn <sch at sun.com> [2009-01-21 23:28]: > > > * David Powell <David.Powell at sun.com> [2009-01-21 22:47]: > > > > Casper.Dik at sun.com wrote: > > > >>> * Nicolas Williams <Nicolas.Williams at sun.com> [2009-01-21 00:14]: > > > >>>> Perhaps we need a new system call, or proc(4) extension, or perhaps > > > >>>> we > > > >>>> could use proc(4) as is, via the agent LWP (to open the new logfile > > > >>>> in > > > >>>> each victim process and dup2() it into place as fildes 1 and 2). > > > >>> There's an old /proc-based tool in someone's home directory that does > > > >>> this; I've asked that someone to see if we can examine the source. > > > >> > > > >> > > > >> Argh. (We really should not create tools which change attributes > > > >> through > > > >> the agent LWP; and those we have should be scrapped) > > > > > > > > Agreed. > > > > > > > > More generally, the agent LWP is a debugging tool. It shouldn't play > > > > a role in our administrative infrastructure. > > > > > > Both of you must have sent your messages prematurely, as neither > > > contains a suggestion for solving the actual problem. > > > > Ignore me. I'm bothered about other things. Apologies to you and to > > Casper. > > > > (In the meantime, using the left side of my brain, I've looked at the > > write(2) implementation for tmpfs, ufs, and zfs, and for fprintf(3C), > > and don't see why logadm -c doesn't work--O_APPEND is correctly > > handled (or not overridden) throughout. A test program seems due.) > > For the non-stdio case, logadm -c is sufficient. > > It appears that stdio doesn't respect the O_APPEND on stdout or stderr > during initialization (see lib/libc/port/stdio/data.c), nor does > fdopen(3C) allow one to divine the presence of O_APPEND on an existing > file descriptor. > > I suppose we could fix the first case--standards permitting--by doing > 2 stat(2) calls in libc_init()...
Apparently, even that's not enough because stdio doesn't distinguish enough between "w" and "a" in the flush path. What a mess. -- sch at sun.com http://blogs.sun.com/sch/
