summaryrefslogtreecommitdiff
path: root/hurd/translator/procfs/jkoenig/discussion.mdwn
diff options
context:
space:
mode:
authorSamuel Thibault <samuel.thibault@ens-lyon.org>2013-09-28 16:22:08 +0200
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2013-09-28 16:22:08 +0200
commitca39ad0592e9b99dac9d99c68bb36ef1d27f72df (patch)
tree5ad12783d506039cd440ccfacbac264085137075 /hurd/translator/procfs/jkoenig/discussion.mdwn
parentbe2307c1bf9aef3e22984dd298827d8e1ca18b2c (diff)
parent264b066cd313b23f6748711c6f9b4d3336e03136 (diff)
Merge branch 'master' of braunbox:~hurd-web/hurd-web
Diffstat (limited to 'hurd/translator/procfs/jkoenig/discussion.mdwn')
-rw-r--r--hurd/translator/procfs/jkoenig/discussion.mdwn176
1 files changed, 142 insertions, 34 deletions
diff --git a/hurd/translator/procfs/jkoenig/discussion.mdwn b/hurd/translator/procfs/jkoenig/discussion.mdwn
index d26f05f9..fc071337 100644
--- a/hurd/translator/procfs/jkoenig/discussion.mdwn
+++ b/hurd/translator/procfs/jkoenig/discussion.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2010, 2011, 2012 Free Software Foundation,
+[[!meta copyright="Copyright © 2010, 2011, 2012, 2013 Free Software Foundation,
Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
@@ -14,12 +14,13 @@ License|/fdl]]."]]"""]]
[[!toc]]
-# Miscellaneous
+# `/proc/version`
-IRC, #hurd, around September 2010
+[[!taglink open_issue_documentation]]: edit and move to [[FAQ]].
+
+
+## IRC, freenode, #hurd, around 2010-09
- <youpi> jkoenig: is it not possible to provide a /proc/self which points at
- the client's pid?
<pinotree> (also, shouldn't /proc/version say something else than "Linux"?)
<youpi> to make linux tools work, no :/
<youpi> kfreebsd does that too
@@ -33,10 +34,103 @@ IRC, #hurd, around September 2010
<youpi> Linux version 2.6.16 (des@freebsd.org) (gcc version 4.3.5) #4 Sun
Dec 18 04:30:00 CET 1977
<pinotree> k
- <giselher> I had some problems with killall5 to read the pid from /proc, Is
- this now more reliable?
- <youpi> I haven't tested with jkoenig's implementation
- [...]
+
+
+## IRC, freenode, #hurd, 2013-06-04
+
+ <safinaskar> ?@?#@?$?@#???!?!?!?!??!?!?!?! why /proc/version on gnu system
+ reports "Linux version 2.6.1 (GNU 0.3...)"?
+ <braunr> safinaskar: because /proc/version is a linux thing
+ <braunr> applications using it don't expect to see anything else than linux
+ when parsing
+ <braunr> think of it as your web brower allowing you to set the user-agent
+ <safinaskar> braunr: yes, i just thought about user-agent, too
+ <safinaskar> braunr: but freebsd doesn't report it is linux (as well as i
+ know)
+ <braunr> their choice
+ <braunr> we could change it, but frankly, we don't care
+ <safinaskar> so why "uname" says "GNU" and not "Linux"?
+ <braunr> uname is posix
+ <braunr> note that /proc/version also includes GNU and GNU Mach/Hurd
+ versions
+ <safinaskar> if some program read the word "Linux" from /proc/version, it
+ will assume it is linux. so, i think it is bad idea
+ <braunr> why ?
+ <safinaskar> there is no standard /proc across unixen
+ <braunr> if a program reads /proc/version, it expects to be run on linux
+ <safinaskar> every unix implement his own /proc
+ <safinaskar> so, we don't need to create /proc which is fully compatible
+ with linux
+ <braunr> procfs doesn't by default
+ <safinaskar> instead, we can make /proc, which is partially compatible with
+ linux
+ <braunr> debiansets the -c compatibility flag
+ <braunr> that's what we did
+ <safinaskar> but /proc/version should really report kernel name and its
+ version
+ <braunr> why ?
+ <braunr> (and again, it does)
+ <safinaskar> because this is why /proc/version created
+ <pinotree> no?
+ <braunr> on linux, yes
+ <braunr> pinotree: hm ?
+ <safinaskar> and /proc/version should not contain the "Linux" word, because
+ this is not Linux
+ <braunr> pinotree: no to what ? :)
+ <braunr> safinaskar: *sigh*
+ <braunr> i explained the choice to you
+ <pinotree> safinaskar: if you are using /proc/version to get the kernel
+ name and version, you're doing bad already
+ <braunr> disagree if you want
+ <braunr> but there is a point to using the word Linux there
+ <pinotree> safinaskar: there's the proper aposix api for that, which is
+ uname
+ <safinaskar> pinotree: okey. so why we ever implement /proc/version?
+ <braunr> it's a linux thing
+ <braunr> they probably wanted more than what the posix api was intended to
+ do
+ <safinaskar> okey, so why we need this linux thing? there is a lot of
+ linux thing which is useful in hurd. but not this thing. because this
+ is not linux. if we support /proc/version, we should not write "Linux"
+ to it
+ <pinotree> and even on freebsd their linprocfs (mounted on /proc) is not
+ mounted by default
+ <braunr> 10:37 < braunr> applications using it don't expect to see anything
+ else than linux when parsing
+ <braunr> 10:37 < braunr> think of it as your web brower allowing you to set
+ the user-agent
+ <braunr> safinaskar: the answer hasn't changed
+ <safinaskar> pinotree: but they don't export /proc/version with "Linux"
+ word in it anyway
+ <pinotree> safinaskar: they do
+ <safinaskar> pinotree: ??? their /proc/version contain Linux?
+ <pinotree> Linux version 2.6.16 (des@freebsd.org) (gcc version 4.6.3) #4
+ Sun Dec 18 04:30:00 CET 1977
+ <kilobug> safinaskar: it's like all web browsers reporting "mozilla" in
+ their UA, it may be silly, but it's how it is for
+ compatibility/historical reasons, and it's just not worth the trouble of
+ changing it
+ <pinotree> that's on a debian gnu/kfreebsd machine
+ <pinotree> and on a freebsd machine it is the same
+ <braunr> safinaskar: you should understand that parsing this string allows
+ correctly walking the rest of the /proc tree
+ <pinotree> and given such filesystem on freebsd is called "linprocfs", you
+ can already have a guess what it is for
+ <kilobug> safinaskar: saying "Linux version 2.6.1" just means "I'm
+ compatible with Linux 2.6.1 interfaces", like saying "Mozilla/5.0 (like
+ Gecko)" in the UA means "I'm a modern browser"
+ <safinaskar> so, is there really a lot of programs which expect "Linux"
+ word in /proc/version even on non-linux platforms?
+ <braunr> no
+ <braunr> but when they do, they do
+
+
+# `/proc/self`
+
+## IRC, freenode, #hurd, around 2010-09
+
+ <youpi> jkoenig: is it not possible to provide a /proc/self which points at
+ the client's pid?
<pinotree> looks like he did 'self' too, see rootdir_entries[] in rootdir.c
<youpi> but it doesn't point at self
<antrik> youpi: there is no way to provide /proc/self, because the server
@@ -56,10 +150,12 @@ IRC, #hurd, around September 2010
<youpi> it "just" needs to be commited :)
<antrik> in either case, it can't hurt to bring this up again :-)
+[[mtab/discussion]], *IRC, freenode, #hurd, 2013-09-07*.
+
# root group
-IRC, #hurd, around October 2010
+## IRC, freenode, #hurd, around October 2010
<pinotree> the only glitch is that files/dirs have the right user as
owner, but always with root group
@@ -67,7 +163,7 @@ IRC, #hurd, around October 2010
# `/proc/[PID]/stat` being 400 and not 444, and some more
-IRC, freenode, #hurd, 2011-03-27
+## IRC, freenode, #hurd, 2011-03-27
<pochu> is there a reason for /proc/$pid/stat to be 400 and not 444 like on
Linux?
@@ -112,7 +208,8 @@ IRC, freenode, #hurd, 2011-03-27
/proc uses rather than rely on CLK_TCK
<jkoenig> (so we can choose whatever reasonable value we want)
-IRC, freenode, #hurd, 2011-03-28
+
+## IRC, freenode, #hurd, 2011-03-28
<antrik> jkoenig: does procfs expose any information that is not available
to everyone through the proc server?...
@@ -165,7 +262,8 @@ IRC, freenode, #hurd, 2011-03-28
<antrik> (though I never got around to look at his buggy code...)
<jkoenig> ok
-IRC, freenode, #hurd, 2011-07-22
+
+## IRC, freenode, #hurd, 2011-07-22
<pinotree> hm, why /proc/$pid/stat is 600 instead of 644 of linux?
<jkoenig> pinotree, it reveals information which, while not that sensitive,
@@ -186,7 +284,7 @@ IRC, freenode, #hurd, 2011-07-22
# `/proc/mounts`, `/proc/[PID]/mounts`
-IRC, freenode, #hurd, 2011-07-25
+## IRC, freenode, #hurd, 2011-07-25
< pinotree> jkoenig: btw, what do you think about providing empty
/proc/mounts and /proc/$pid/mounts files?
@@ -206,17 +304,34 @@ IRC, freenode, #hurd, 2011-07-25
i don't remember)
< pinotree> not a strict need
+A [[mtab]] translator now exists.
+
-# `/proc/[PID]/auxv`, `/proc/[PID]/exe`, `/proc/[PID]/mem`
+## IRC, freenode, #hurd, 2013-09-20
+
+ <pinotree> teythoon: should procfs now have $pid/mounts files pointing to
+ ../mounts?
+ <teythoon> pinotree: probably yes
+
+
+# `/proc/[PID]/auxv`
Needed by glibc's `pldd` tool (commit
11988f8f9656042c3dfd9002ac85dff33173b9bd).
-# `/proc/self/exe`
+# `/proc/[PID]/exe`
+
+Needed by glibc's `pldd` tool (commit
+11988f8f9656042c3dfd9002ac85dff33173b9bd).
+
+
+## `/proc/self/exe`
[[!message-id "alpine.LFD.2.02.1110111111260.2016@akari"]]. Needed by glibc's
`stdlib/tst-secure-getenv.c`.
+`HAVE_PROC_SELF_EXE` in `[GCC]/libjava/configure.ac`.
+Also used in `[GCC]/libgfortran/runtime/main.c`:`store_exe_path`.
Is it generally possible to use something like the following instead?
Disadvantage is that every program using this needs to be patched.
@@ -314,32 +429,25 @@ This is used in `[LLVM]/lib/Support/Unix/Path.inc`.
report why the test suite failed
-# `/proc/[PID]/cwd`
+## `/proc/self/maps`
-## IRC, freenode, #hurd, 2012-06-30
-
- * pinotree has a local work to add the /proc/$pid/cwd symlink, but relying
- on "internal" (but exported) glibc functions
+`HAVE_PROC_SELF_MAPS` in `[GCC]/libjava/configure.ac`.
+Also used in `[GCC]/intl/relocatable.c`:`find_shared_library_fullname` for
+`#ifdef __linux__`.
-# "Unusual" PIDs
+# `/proc/[PID]/mem`
-Not actually related to procfs, but here seems to be a convenient place for
-filing these:
-
-
-## IRC, freenode, #hurd, 2012-08-10
+Needed by glibc's `pldd` tool (commit
+11988f8f9656042c3dfd9002ac85dff33173b9bd).
- <braunr> too bad the proc server has pid 0
- <braunr> top & co won't show it
+# `/proc/[PID]/cwd`
-## IRC, OFTC, #debian-hurd, 2012-09-18
+## IRC, freenode, #hurd, 2012-06-30
- <pinotree> youpi: did you see
- https://enc.com.au/2012/09/careful-with-pids/'
- <pinotree> ?
- <youpi> nope
+ * pinotree has a local work to add the /proc/$pid/cwd symlink, but relying
+ on "internal" (but exported) glibc functions
# CPU Usage