Hi,
I have recently got a bug report about Linux::Smaps. The poster said it'd
report 2 [vdso] areas and that it can be cured if /proc/self/smaps is opened
with '<:stdio'. Later on he also found the behavior depends on the kernel
version, 2.6.25.3 shows 2 vdsos 2.6.23.1-21 only one.
Since I don't have any of these kernels I am asking for help. To all of my
knowledge multiple vdsos is nonsense. But is it a kernel bug or a bug in the
perlio layer?
Could you please run the following command on various combinations of linux
kernel and perlio?
PERLIO="stdio" perl -pe 'BEGIN {my $smaps="/proc/$$/smaps";
open STDIN, "<", $smaps or die "$!\n"; system "cat -n $smaps"}
$_="$.\t$_"' | grep vdso
It should print 2 almost identical lines. If there are more please report.
Here an example:
$ PERLIO="stdio" perl -pe 'BEGIN {my $smaps="/proc/$$/smaps"; open STDIN, "<",
$smaps or die "$!\n"; system "cat -n $smaps"} $_="$.\t$_"'|grep vdso
321 ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
321 ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
Keep in mind that /proc/$$/smaps exists only for kernels >=2.6.14.
Thanks,
Torsten
