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authorThomas Schwinge <thomas@codesourcery.com>2014-02-26 12:32:06 +0100
committerThomas Schwinge <thomas@codesourcery.com>2014-02-26 12:32:06 +0100
commitc4ad3f73033c7e0511c3e7df961e1232cc503478 (patch)
tree16ddfd3348bfeec014a4d8bb8c1701023c63678f /open_issues/glibc
parentd9079faac8940c4654912b0e085e1583358631fe (diff)
IRC.
Diffstat (limited to 'open_issues/glibc')
-rw-r--r--open_issues/glibc/0.4.mdwn44
-rw-r--r--open_issues/glibc/debian/experimental.mdwn156
2 files changed, 198 insertions, 2 deletions
diff --git a/open_issues/glibc/0.4.mdwn b/open_issues/glibc/0.4.mdwn
index 8991d4c0..33ef8f3a 100644
--- a/open_issues/glibc/0.4.mdwn
+++ b/open_issues/glibc/0.4.mdwn
@@ -1,4 +1,5 @@
-[[!meta copyright="Copyright © 2012, 2013 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2012, 2013, 2014 Free Software Foundation,
+Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -15,6 +16,8 @@ Things to consider doing when bumping the glibc SONAME.
There are some comments in the sources, for example `hurd/geteuids.c`: `XXX
Remove this alias when we bump the libc soname.`
+[[!toc]]
+
# IRC, freenode, #hurd, 2012-12-14
@@ -33,3 +36,42 @@ In context of [[packaging_libpthread]]/[[libpthread]].
[[!GNU_Savannah_bug 28934]], [[user/pochu]], [[!message-id
"4BFA500A.7030502@gmail.com"]].
+
+
+# `time_t` -- Unix Epoch vs. 2038
+
+## IRC, freenode, #hurd, 2013-12-12
+
+ <azeem> because it gets discussed in #debian-devel for the Linux i386
+ architecture right now: what's the deal with hurd-i386 and the 32bit
+ epoch overflow in 2038?
+ <braunr> what do you mean ?
+ <azeem> braunr: http://lwn.net/Articles/563285/
+ <braunr> ok but what do you mean ?
+ <braunr> i don't think there is anything special with the hurd about that
+ <azeem> well, time_t is 64bit on amd64 AIUI
+ <braunr> it's a signed long
+ <azeem> so maybe the Hurd guys were clever from the start
+ <azeem> k, k
+ <braunr> our big advantage is that we can afford to break things a little
+ without too much trouble
+ <braunr> in a system at work, we use unsigned 32-bit words
+ <braunr> which overflows in 2106
+ <braunr> and we already include funny comments that predict our successors,
+ if any, will probably fail to deal with the problem until short before
+ the overflow :>
+ <azeem> luckily, no nuclear reactors are running the Hurd sofar
+ <braunr> i wonder how the problem will be dealt with though
+ <braunr> ah, openbsd decided to break their abi
+ <azeem> yeah
+ <braunr> that's probably the simplest solution
+ <azeem> "just recompile"
+ <braunr> and they can afford it too
+ <azeem> yeah
+ <braunr> good to see people actually worry about it
+ <azeem> I guess people are getting worried about where Linux embedded is
+ being put into
+ <braunr> they're right about that
+ <azeem> "Please, don't fix the 2038 year issue. I also want to have some
+ job security :)"
+ <braunr> haha
diff --git a/open_issues/glibc/debian/experimental.mdwn b/open_issues/glibc/debian/experimental.mdwn
index 5168479d..273f02fd 100644
--- a/open_issues/glibc/debian/experimental.mdwn
+++ b/open_issues/glibc/debian/experimental.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2013 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2013, 2014 Free Software Foundation, Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -130,6 +130,101 @@ Now in unstable.
<pinotree> btw i saw too the segmentation fault when generating locales
+## IRC, freenode, #hurd, 2014-02-04
+
+ <bu^> hello
+ <bu^> I just updated
+ <bu^> Setting up locales (2.17-98~0) ...
+ <bu^> Generating locales (this might take a while)...
+ <bu^> en_US.UTF-8...Segmentation fault
+ <bu^> done
+ <gnu_srs> bu^: That's known, it still seems to work, though. If you have
+ the time please debug. I've tried but not found the solution yet:-(
+ <bu^> ok, just wanted to notify
+
+
+## IRC, freenode, #hurd, 2014-02-19
+
+ <braunr> for info, the localedef segfault has been fixed upstream
+ <braunr> or rather, upstream has been written in a way that won't trigger
+ the segfault
+ <braunr> it is caused by the locale archive code that maps the locale
+ archive file in the address space, enlarging the mapping as needed, but
+ unmaps the complete reserved size of 512M on close
+ <braunr> munmap is implemented through vm_deallocate, but it looks like the
+ latter doesn't allow deallocating unmapped regions of the address space
+ <braunr> (to be confirmed)
+ <braunr> upstream code tracks the mapping size so vm_deallocate won't whine
+ <braunr> i expect we'll have that in eglibc 2.18
+ <braunr> hm actually, posix says munmap must refer to memory obtained with
+ mmap :)
+ <braunr> (or actually, that the behaviour is undefined, which most unix
+ systems allow anyway, but not us)
+
+ <braunr> also, before i leave, i have partially traced the localedef
+ segfault
+ <youpi> ah, cool
+ <braunr> localedef maps the locale archive, and enlarges the mapping as
+ needed
+ <braunr> but munmaps the complete 512m reserved area
+ <braunr> and i strongly suspect it unmaps something it shouldn't on the
+ hurd
+ <braunr> since linux mmap has different boundaries depending on the mapping
+ use
+ <braunr> while our glibc will happily maps stacks below text
+ <braunr> the good news is that it looks fixed upstream
+ <youpi> ah :)
+ <braunr>
+ https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=17db6e8d6b12f55e312fcab46faf5d332c806fb6
+ <braunr> see the change about close_archive
+ <braunr> i haven't tested it though
+
+
+## IRC, freenode, #hurd, 2014-02-21
+
+ <gg0> just upgraded to 2.18, locales still segfaults
+ <braunr> ok
+
+
+## IRC, freenode, #hurd, 2014-02-23
+
+ <braunr> ok, as expected, the localdef bug is because of some mmap issue
+
+[[glibc/mmap]].
+
+ <braunr> looks like our mmap doesn't like mapping files with PROT_NONE
+ <braunr> shouldn't be too hard to fix
+ <braunr> gg0: i should have a fix ready soon for localedef
+
+ <braunr> youpi: i have a patch for glibc about the localedef segfault
+ <youpi> is that the backport we talked about, or something else?
+ <braunr> something else
+ <braunr> in short
+ <braunr> mmap() PROT_NONE on files return 0
+ <youpi> ok
+ <youpi> seems like fixable indeed
+ <braunr> nothing is mapped, and the localdef code doesn't consider this an
+ error
+ <braunr> my current fix is to handle PROT_NONE like PROT_READ
+ <youpi> doesn't vm_protect allow to map something without giving read
+ right?
+ <braunr> it probably does
+ <braunr> the problem is in glibc
+ <youpi> ok
+ <braunr> when i say like PROT_READ, i mean a memory object gets a reference
+ <braunr> on the read port returned by io_map
+ <braunr> since it's not accessible anyway, it shouldn't make a difference
+ <braunr> but i preferred to have the memory object referenced anyway to
+ match what i expect is done by other systems
+
+
+## IRC, freenode, #hurd, 2014-02-24
+
+ <youpi> braunr: ah ok
+
+ <braunr> ok that mmap fix looks fine, i'll add comments and commit it soon
+
+
# IRC, OFTC, #debian-hurd, 2013-06-20
<youpi> damn
@@ -173,3 +268,62 @@ Now in unstable.
<youpi> I'd warmly welcome a way to detect whether being the / translator
process btw
<youpi> it seems far from trivial
+
+
+# glibc 2.18 vs. GCC 4.8
+
+## IRC, freenode, #hurd, 2013-11-25
+
+ <youpi> grmbl, installing a glibc 2.18 rebuilt with gcc-4.8 brings an
+ unbootable system
+
+
+## IRC, freenode, #hurd, 2013-11-29
+
+ <teythoon> so, what do I do? rebuild the glibc 2.18 package with gcc4.8 and
+ see what breaks ?
+ <teythoon> when I boot a system with that libc that is ?
+ <teythoon> I wish youpi would have been more specific, I've never built the
+ libc before...
+ <braunr> debian/rules build in the debian package
+ <braunr> ctrl-c when you see gcc invocations
+ <braunr> cd buildir; make lib others
+ <braunr> although hm
+ <braunr> what breaks is at boot time right ?
+ <teythoon> yes
+ <braunr> heh ..
+ <braunr> then dpkg-buildpackage
+ <braunr> DEB_BUILD_OPTIONS=nocheck speeds things up
+ <braunr> just answer on the mailing list and ask him
+ <braunr> he usually answers quickly
+
+
+## IRC, freenode, #hurd, 2013-12-18
+
+ <gnu_srs> teythoon: k!, any luck with eglibc-2.18?
+ <teythoon> tbh i didn't look into this after two unsuccessful attempts at
+ building the libc package
+ <teythoon> there was a post over at the libc-alpha list that sounded
+ familiar
+ <teythoon> http://www.cygwin.com/ml/libc-alpha/2013-12/msg00281.html
+ <braunr> wow
+ <teythoon> ?
+ <braunr> this looks tricky
+ <braunr> and why ia64 only
+ <teythoon> indeed
+ <braunr> it's rare to see aurel32 ask such questions
+
+
+## IRC, freenode, #hurd, 2014-01-22
+
+ <youpi> btw, did anybody investigate the glibc-built-with-gcc-4.8 issue?
+ <youpi> oddly enough, a subhurd boots completely fine with it
+ <braunr> i didn't
+ <teythoon> no, sorry
+ <youpi> I was wondering whether the bogus deallocation at boot might have
+ something to do
+ <braunr> which one ?
+ <braunr> ah
+ <braunr> yes
+ <braunr> maybe
+ <youpi> quoted earlier here