[ofa-general] Question about registering the [vdso] memory section in user level

[Dotan Barak]

Hi.

In our regression, there is a test case in which we register the last 
VMA of a process that has a read permission.
Only in kernel 2.6.20-rc5 i get a failure.

Here is the last line that i got from executing "cat /proc/1873/maps":


In kernel 2.6.16.21-0.8-smp:
2b42d103f000-2b42d1116000 r--p 00000000 08:07 647899                     
/usr/lib/locale/en_US.utf8/LC_COLLATE
2b42d1116000-2b42d1117000 r--p 00000000 08:07 633217                     
/usr/lib/locale/en_US.utf8/LC_TIME
2b42d1117000-2b42d1118000 r--p 00000000 08:07 647880                     
/usr/lib/locale/en_US.utf8/LC_NUMERIC
2b42d1118000-2b42d114b000 r--p 00000000 08:07 647898                     
/usr/lib/locale/en_US.utf8/LC_CTYPE
2b42d114b000-2b42d114c000 rw-p 2b42d114b000 00:00 0
7fffda251000-7fffda267000 rw-p 7fffda251000 00:00 0                      
[stack]
ffffffffff600000-ffffffffffe00000 ---p 00000000 00:00 0                  
[vdso]

In kernel 2.6.20-rc5:
2ba22fd99000-2ba22fd9b000 rw-p 0000a000 08:03 309500                     
/lib64/libnss_files-2.3.4.so
2ba22fd9b000-2ba232be6000 r--p 00000000 08:03 68735                      
/usr/lib/locale/locale-archive
2ba232be6000-2ba232bec000 r--s 00000000 08:03 97940                      
/usr/lib64/gconv/gconv-modules.cache
2ba232bec000-2ba232bee000 rw-p 2ba232bec000 00:00 0
7fff7ae2d000-7fff7ae43000 rw-p 7fff7ae2d000 00:00 0                      
[stack]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  
[vdso]

It seems that in kernel 2.6.20-rc5 the last VMA which has a read 
permission is the [vdso] section but when i try
to register it i get a failure.

Is it wrong to register this section?


thanks
Dotan