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problem with /proc/self/mem ... can i read it?
Hello,
I am trying to learn about vdso and about what is sysenter ...
I am using :
Linux 2.6.17-1.2157_FC5 i686 athlon i386 GNU/Linux
Ok, If i do
># cat /proc/self/maps
00800000-00801000 r-xp 00800000 00:00 0 [vdso]
00801000-0081a000 r-xp 00000000 22:05 2387467 /lib/ld-2.4.so
... // no interesting
b7fa2000-b7fa4000 rw-p b7fa2000 00:00 0
bfc36000-bfc4b000 rw-p bfc36000 00:00 0 [stack]
It shows my [vdso] block . Ok ...Is it the right address?.. then
># ldd /bin/ls that is shows:
linux-gate.so.1 => (0x00800000)
librt.so.1 => /lib/librt.so.1 (0x00dea000)
libacl.so.1 => /lib/libacl.so.1 (0x00111000)
Ok, i wanna see insde linux-gate .. how many bytes?
># cat /proc/self/smaps
00800000-00801000 r-xp 00800000 00:00 0 [vdso]
Size: 4 kB
Rss: 4 kB
Shared_Clean: 4 kB
ok, then:
># dd if=/proc/self/mem of=/tmp/linux-gate.dso bs=4096 skip=8388608 count=1
dd: reading `/proc/self/mem': Input/output error
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.001729 seconds, 0.0 kB/s
what? i/o error? ... i am using <root> ... so strange ...
how about rights ? ... lets me see ...
-r--r--r-- 1 root root 0 Aug 7 11:58 mem
what am i doing wrong ?
thank you
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