diff options
| author | William Hubbs <williamh@gentoo.org> | 2011-03-24 18:27:35 -0500 |
|---|---|---|
| committer | William Hubbs <williamh@gentoo.org> | 2011-03-24 19:14:16 -0500 |
| commit | 1d63e85794ad850752eec95fa077e5895295f3b7 (patch) | |
| tree | 0ee4d9210c5be13783ddd957e56f1cb4eaf75c07 /sh | |
| parent | 25049d3e80aeb17d4d62a653cfa8223fae56ddd0 (diff) | |
rework test for mounted /proc
The previous test assumed that we could always rely on the minor fault
counter to change between reads of /proc/self/stat, but we found that
this is not the case.
The new test compares two reads of /proc/self/environ for which we have
set the same environment variable to two different values.
If the comparison shows the two reads have the same contents, we know
that /proc is not working.
I would like to thank Robin Johnson and Mike Frysinger for their input
for this patch.
X-Gentoo-Bug: 348416
X-Gentoo-Bug-URL: http://bugs.gentoo.org/show_bug.cgi?id=348416
Diffstat (limited to 'sh')
| -rw-r--r-- | sh/init.sh.Linux.in | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/sh/init.sh.Linux.in b/sh/init.sh.Linux.in index 9b045570..361de0bc 100644 --- a/sh/init.sh.Linux.in +++ b/sh/init.sh.Linux.in @@ -65,27 +65,21 @@ mount_svcdir() # By default VServer already has /proc mounted, but OpenVZ does not! # However, some of our users have an old proc image in /proc # NFC how they managed that, but the end result means we have to test if -# /proc actually works or not. We to this by comparing two reads of -# /proc/self/stat. They will not match, because at least the minor fault count -# field (field 10) should have changed. -# -# We can use any file here that fills the following requirements: -# - changes between sequential reads -# - is world-readable (not blocked in hardened kernel) -# - Is only a single line (ergo entire check is doable with no forks) +# /proc actually works or not. We do this by comparing two reads of +# /proc/self/environ for which we have set the variable VAR to two +# different values. If the comparison comes back equal, we know that +# /proc is not working. mountproc=true -f=/proc/self/stat +f=/proc/self/environ if [ -e $f ]; then - exec 9<$f ; read a <&9 ; exec 9<&- - exec 9<$f ; read b <&9 ; exec 9<&- - if [ "$a" = "$b" ]; then + if [ "$(VAR=a cat $f)" = "$(VAR=b cat $f)" ]; then eerror "You have cruft in /proc that should be deleted" else einfo "/proc is already mounted, skipping" mountproc=false fi fi -unset a b f +unset f if $mountproc; then procfs="proc" |