Date: Thu, 6 Nov 2014 12:13:58 +0100 From: Mateusz Guzik <mjguzik@gmail.com> To: Tiwei Bie <btw@mail.ustc.edu.cn> Cc: Konstantin Belousov <kostikbel@gmail.com>, freebsd-hackers@freebsd.org Subject: Re: [PATCH] Finish the task 'sysctl reporting current working directory' Message-ID: <20141106111358.GF12284@dft-labs.eu> In-Reply-To: <20141106100032.GA80996@freebsd> References: <1414987325-23280-1-git-send-email-btw@mail.ustc.edu.cn> <20141103051908.GC29497@dft-labs.eu> <20141103064052.GA1739@freebsd> <20141103080526.GE29497@dft-labs.eu> <20141103085235.GA85851@freebsd> <20141106081330.GA12284@dft-labs.eu> <20141106085750.GA52132@freebsd> <20141106092134.GL53947@kib.kiev.ua> <20141106100032.GA80996@freebsd>
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On Thu, Nov 06, 2014 at 06:00:32PM +0800, Tiwei Bie wrote: > On Thu, Nov 06, 2014 at 11:21:34AM +0200, Konstantin Belousov wrote: > > On Thu, Nov 06, 2014 at 04:57:50PM +0800, Tiwei Bie wrote: > > > On Thu, Nov 06, 2014 at 09:13:31AM +0100, Mateusz Guzik wrote: > > > > On Mon, Nov 03, 2014 at 04:52:35PM +0800, Tiwei Bie wrote: > > > > > > > > kernel changes got in in r274167 > > > > > > > > Please submit tmux patch to bugzilla. > > > > > > > > > > Thanks! I have submitted the tmux patch to bugzilla [1]. > > > > > > [1] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=194858 > > > > This is incorrect way to use kern_proc_cwd. You should try the new > > sysctl, and on ENOENT fall back to the kern_proc_file. Expecting > > that the binary is run on the same machine where it was build is > > wrong. > > > > Yeah, you are right. Following is my new patch, maybe it needs some > style improvements. > > diff --git a/osdep-freebsd.c b/osdep-freebsd.c > index d596eab..673ca98 100644 > --- a/osdep-freebsd.c > +++ b/osdep-freebsd.c > @@ -133,7 +133,7 @@ error: > } > > char * > -osdep_get_cwd(int fd) > +osdep_get_cwd_fallback(int fd) > { > static char wd[PATH_MAX]; > struct kinfo_file *info = NULL; > @@ -158,6 +158,31 @@ osdep_get_cwd(int fd) > return (NULL); > } > > +#ifdef KERN_PROC_CWD > +char * > +osdep_get_cwd(int fd) > +{ > + static struct kinfo_file info; > + int name[] = { CTL_KERN, KERN_PROC, KERN_PROC_CWD, 0 }; > + size_t len = sizeof info; > + > + if ((name[3] = tcgetpgrp(fd)) == -1) > + return (NULL); > + if (sysctl(name, 4, &info, &len, NULL, 0) == -1) { > + if (errno == ENOENT) > + return (osdep_get_cwd_fallback(fd)); > + return (NULL); > + } > + return (info.kf_path); tmux calls this quite often and trying out this sysctl just to see it fail each time is a waste. have a static var to indicate the failure and to know when to fallback immediately. Also this probably should be reworked to obtain tcgetpgrp once and then decide which sysctl to use, but that's largely a perference matter. > +} > +#else /* !KERN_PROC_CWD */ > +char * > +osdep_get_cwd(int fd) > +{ > + return (osdep_get_cwd_fallback(fd)); > +} > +#endif /* KERN_PROC_CWD */ > + > struct event_base * > osdep_event_init(void) > { > -- > 2.1.0 > > -- Mateusz Guzik <mjguzik gmail.com>
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