* Agenda for next release? @ 2012-12-31 19:11 Rich Felker 2012-12-31 21:37 ` Brad Conroy 2013-01-01 4:06 ` Rob Landley 0 siblings, 2 replies; 6+ messages in thread From: Rich Felker @ 2012-12-31 19:11 UTC (permalink / raw) To: musl Hi, I don't have any immediate plan for the next release, but I'd like to start thinking about what we'd like to go into it. A few things I know are still pending that should be possible to include are: - strverscmp - zoneinfo - inet_makeaddr - scanf %m modifier - getifaddrs - cpuset/affinity interfaces - ether.h interfaces I know there's also interest in exposing sigreturn and setcontext for libunwind use, but it's difficult to do right and I'm really skeptical of the whole thing. Their use of sigreturn seems completely incorrect (and thus probably untested); sigreturn expects a struct sigcontext on the stack, not a pointer to a sigcontext in the first function argument slot. I would rather have a conversation with their developers first to determine if that code is even working/valid, and defer the corresponding additions to musl until we eventually add all the ucontext.h interfaces in working form. Another port (perhaps x32, like originally proposed) is also definitely an option if anybody's up for doing it. I had considered doing it myself in this release cycle, but I'm a bit busy with some other projects for at least a couple weeks so I'd rather not get bogged down in a big time-eater right away, and instead spend my time with musl on small isolated feature additions and bug fixes. Anything else I missed? Rich ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Agenda for next release? 2012-12-31 19:11 Agenda for next release? Rich Felker @ 2012-12-31 21:37 ` Brad Conroy 2013-01-01 2:38 ` Rich Felker 2013-01-01 4:06 ` Rob Landley 1 sibling, 1 reply; 6+ messages in thread From: Brad Conroy @ 2012-12-31 21:37 UTC (permalink / raw) To: musl [-- Attachment #1: Type: text/plain, Size: 3257 bytes --] Not functionally necessary for the release, but nice for future compatibility reasons, a few paths are hard-coded into the c files rather than defining them in the (non-)"standard" location Ex.src/network/getaddrinfo.c has "/etc/hosts", "/etc/resolve.conf" and "/etc/services" hard-coded rather than defining them in netdb.h #define _PATH_HOSTS "/etc/hosts"#define _PATH_NSSWITCH_CONF "/etc/nsswitch.conf"#define _PATH_SERVICES "/etc/services" also defined in netdb.h for other uses #define _PATH_HEQUIV "/etc/hosts.equiv"#define _PATH_NETWORKS "/etc/networks"#define _PATH_PROTOCOLS "/etc/protocols" resolv.h does have #define _PATH_RESCONF "/etc/resolve.conf" however src/network/__dns.c still has the hard-coded path also I'm sure there are others that grep could find (fstab.h,paths.h,ttyent.h xtables.h,???) also android has etc in /system, so the actual path is /system/etc/hosts (though /etc is typically a symlink to /system/etc), but other strange layouts exist and it would be a lot easier/cleaner for work arounds to have the ifdefs confined to one location in the header files and use those definitions in the .c files so that port patches only hit a few headers without polluting the .c files with a lot of ifdef nests I ran into this while building a static wget-like downloader that would use an alternate hosts file to complement a custom local server that locally hosts some problematic CDNs (to work around problems such as: waiting for ajax.googleapis.com, platform.twitter.com etc...) but this is an obvious hack, not the typical use case for a standard library... but then again part of the charm of musl is its "hackability" --- On Mon, 12/31/12, Rich Felker <dalias@aerifal.cx> wrote: From: Rich Felker <dalias@aerifal.cx> Subject: [musl] Agenda for next release? To: musl@lists.openwall.com Date: Monday, December 31, 2012, 2:11 PM Hi, I don't have any immediate plan for the next release, but I'd like to start thinking about what we'd like to go into it. A few things I know are still pending that should be possible to include are: - strverscmp - zoneinfo - inet_makeaddr - scanf %m modifier - getifaddrs - cpuset/affinity interfaces - ether.h interfaces I know there's also interest in exposing sigreturn and setcontext for libunwind use, but it's difficult to do right and I'm really skeptical of the whole thing. Their use of sigreturn seems completely incorrect (and thus probably untested); sigreturn expects a struct sigcontext on the stack, not a pointer to a sigcontext in the first function argument slot. I would rather have a conversation with their developers first to determine if that code is even working/valid, and defer the corresponding additions to musl until we eventually add all the ucontext.h interfaces in working form. Another port (perhaps x32, like originally proposed) is also definitely an option if anybody's up for doing it. I had considered doing it myself in this release cycle, but I'm a bit busy with some other projects for at least a couple weeks so I'd rather not get bogged down in a big time-eater right away, and instead spend my time with musl on small isolated feature additions and bug fixes. Anything else I missed? Rich [-- Attachment #2: Type: text/html, Size: 5532 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Agenda for next release? 2012-12-31 21:37 ` Brad Conroy @ 2013-01-01 2:38 ` Rich Felker 0 siblings, 0 replies; 6+ messages in thread From: Rich Felker @ 2013-01-01 2:38 UTC (permalink / raw) To: musl On Mon, Dec 31, 2012 at 01:37:39PM -0800, Brad Conroy wrote: > Not functionally necessary for the release, but nice for future > compatibility reasons, a few paths are hard-coded into the c files > rather than defining them in the (non-)"standard" location > Ex.src/network/getaddrinfo.c has "/etc/hosts", "/etc/resolve.conf" > and "/etc/services" hard-coded rather than defining them in netdb.h The following should be read with the understanding that I have been convinced to change my mind on issues of similar scope in the past. However, basically the way it is right now is intentional: Unlike glibc, musl is intended to be useful for static linking, for making binaries you can just drop onto an arbitrary system and have them work. As such, I've aimed to eliminate most usages of any external files in the filesystem; for example, even iconv uses builtin tables rather than loading character table files. But in some cases where there's a need for configurability or reading system-specific information (like the user/group databases or dns servers), some minimum amount of filesystem policy needs to be encoded into libc (and thus, with static linking, into the application as well). To my knowledge, so far all such hard-coded paths correspond to universal (at least on Linux, and for the most part on ALL historical unices) so that only intentional gratuitous breakage could break them. Anyone who gets musl has access to the source, and can of course go changing all the hard-coded paths to whatever they like. There's nothing you or I can do to stop that. But there's also no reason to encourage it or make it easier than it needs to be. As for paths.h, it's purely there to make certain legacy programs which expect it to exist easier to build. Many of the macros defined in it are utter nonsense, or at least not policies I wish to impose on anybody. Perhaps this should be better-documented. Speaking of documentation, the actual documentation for musl, which I hope to have ready as part of the 1.0 release, will document all assumptions it makes about the layout of the filesystem, including which functionality depends on the existence of certain files/devices/mountpoints in the filesystem (for example, shm_open and sem_open depending on /dev/shm, or fexecve depending on /proc, or system and popen depending on /bin/sh). > also android has etc in /system, so the actual path > is /system/etc/hosts (though /etc is typically a symlink to > /system/etc), but other strange layouts exist and it would be a lot > easier/cleaner for work arounds to have the ifdefs confined to one > location in the header files and use those definitions in the .c > files so that port patches only hit a few headers without polluting > the .c files with a lot of ifdef nests The problem with making your binaries for alternate layouts like this is that then they won't work on any system that lacks the alternate layout. Now, let N people come up with their own N brilliant ideas of how the FS layout should be, and every system needs N different symlinks and fake directories all over the place in order to be able to run arbitrary binaries... This approach does not scale. On the other hand, if you want to use an alternate layout locally with symlinks in the standard locations, then your nonstandard layout just needs 1 set of symlinks (not N sets), and systems with standard layouts don't need any hackery at all. > I ran into this while building a static wget-like downloader that > would use an alternate hosts file to complement a custom local > server that locally hosts some problematic CDNs (to work around > problems such as: waiting for ajax.googleapis.com, > platform.twitter.com etc...) but this is an obvious hack, not the > typical use case for a standard library... but then again part of > the charm of musl is its "hackability" Using a custom hosts file or resolv.conf file via environment vars is actually an interesting idea we could explore at some point, but it would have to be secured so as not to affect suid programs or programs with other sorts of elevated privileges. Rich ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Agenda for next release? 2012-12-31 19:11 Agenda for next release? Rich Felker 2012-12-31 21:37 ` Brad Conroy @ 2013-01-01 4:06 ` Rob Landley 2013-01-01 4:51 ` Rich Felker 1 sibling, 1 reply; 6+ messages in thread From: Rob Landley @ 2013-01-01 4:06 UTC (permalink / raw) To: musl; +Cc: musl On 12/31/2012 01:11:31 PM, Rich Felker wrote: > Another port (perhaps x32, like originally proposed) is also > definitely an option if anybody's up for doing it. I had considered > doing it myself in this release cycle, but I'm a bit busy with some > other projects for at least a couple weeks so I'd rather not get > bogged down in a big time-eater right away, and instead spend my time > with musl on small isolated feature additions and bug fixes. > > Anything else I missed? From my point of view sh4, sparc32 support are interesting because switching aboriginal to musl would either have to drop support for those two platforms or support two libcs in parallel. (m68k and s390x are of secondary interest becauase those are the platforms I've been trying to add. In theory mips64 is currently supported but in practice it's deeply flaky at the kernel and possibly qemu level; not widely used.) Not priorities, just thought I'd chip in... Rob ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Agenda for next release? 2013-01-01 4:06 ` Rob Landley @ 2013-01-01 4:51 ` Rich Felker 2013-01-04 7:22 ` Rob Landley 0 siblings, 1 reply; 6+ messages in thread From: Rich Felker @ 2013-01-01 4:51 UTC (permalink / raw) To: musl On Mon, Dec 31, 2012 at 10:06:12PM -0600, Rob Landley wrote: > On 12/31/2012 01:11:31 PM, Rich Felker wrote: > >Another port (perhaps x32, like originally proposed) is also > >definitely an option if anybody's up for doing it. I had considered > >doing it myself in this release cycle, but I'm a bit busy with some > >other projects for at least a couple weeks so I'd rather not get > >bogged down in a big time-eater right away, and instead spend my time > >with musl on small isolated feature additions and bug fixes. > > > >Anything else I missed? > > From my point of view sh4, sparc32 support are interesting because > switching aboriginal to musl would either have to drop support for > those two platforms or support two libcs in parallel. (m68k and > s390x are of secondary interest becauase those are the platforms > I've been trying to add. In theory mips64 is currently supported but > in practice it's deeply flaky at the kernel and possibly qemu level; > not widely used.) > > Not priorities, just thought I'd chip in... Thanks! And good to see you again! I'd be interested in seeing these ports too, but like I said above now is not the best time for me to start doing a new port myself. So unless somebody else wants to try a shot at it, these will probably have to wait a bit. Rich ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Agenda for next release? 2013-01-01 4:51 ` Rich Felker @ 2013-01-04 7:22 ` Rob Landley 0 siblings, 0 replies; 6+ messages in thread From: Rob Landley @ 2013-01-04 7:22 UTC (permalink / raw) To: musl; +Cc: musl On 12/31/2012 10:51:07 PM, Rich Felker wrote: > > Not priorities, just thought I'd chip in... > > Thanks! And good to see you again! I'd be interested in seeing these > ports too, but like I said above now is not the best time for me to > start doing a new port myself. So unless somebody else wants to try a > shot at it, these will probably have to wait a bit. Yeah, I know. Part of the reason I was pestering you for port docs is that I might do one myself if it's not too much work, although there are still 15 other things competing for my attention. Speaking of which, today is the last day to submit a presentation proposal for CELF: http://events.linuxfoundation.org/events/embedded-linux-conference/cfp (Which used to be a good conference. I haven't been since the Linux Foundation annexed it, but in theory they sometimes provide travel expenses and there's still a checkbox to apply. Tim Bird's at least still involved, if not running the thing...) I submitted a couple off the top of my head and may submit more. No idea if they'll take 'em, in your case "writing a new Linux C library from scratch" would be a pretty AWESOME panel for the audience... Rob ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-01-04 7:22 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2012-12-31 19:11 Agenda for next release? Rich Felker 2012-12-31 21:37 ` Brad Conroy 2013-01-01 2:38 ` Rich Felker 2013-01-01 4:06 ` Rob Landley 2013-01-01 4:51 ` Rich Felker 2013-01-04 7:22 ` Rob Landley
Code repositories for project(s) associated with this public inbox https://git.vuxu.org/mirror/musl/ This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).