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blockio tapset problem
- From: "Frank Ch. Eigler" <fche at redhat dot com>
- To: systemtap at sources dot redhat dot com
- Date: Sat, 12 Aug 2006 00:59:13 -0400
- Subject: blockio tapset problem
Hi -
While running the unified dejagnu bucket (which I'm about to commit
btw), I ran into one failure associated with the recent ioblock
tapset. In particular, this kernel panic occurred (just once) on a
busy vmware box running the RHEL4U4 kernel:
EIP: 0060:[<d5b24433>] Tainted: P VLI
EFLAGS: 00010082 (2.6.9-42.EL)
EIP is at function___bio_ino+0x3e/0x4c [stap_13844]
eax: 001d244b ebx: 00000000 ecx: 00000000 edx: c18fa2c4
esi: c18fa000 edi: c18fa01c ebp: d48e0d88 esp: d48e0cec
ds: 007b es: 007b ss: 0068
Process kswapd0 (pid: 38, threadinfo=d48e0000 task=d48ce0b0)
Stack: d5b248c5 c18fa000 d5b26494 00000046 d5b24d71 d5b68720 d48e0d88 c025870c
c0405f20 c011bf04 00000000 c036b7e0 d48e0d88 00000002 00000001 c011c1cd
00000000 c036b7e0 d48e0d54 00000002 00000001 c01348a1 d48e0d88 00000000
Call Trace:
[<d5b248c5>] probe_805+0x1d4/0x5ff [stap_13844]
[<d5b24d71>] enter_probe_805+0x35/0x45 [stap_13844]
[<c025870c>] generic_make_request+0x2/0x1a0
[<c011bf04>] kprobe_handler+0x1c9/0x20b
[<c011c1cd>] kprobe_exceptions_notify+0x54/0x19b
[<c01348a1>] notifier_call_chain+0x17/0x2e
It looks like the __bio_ino embedded-C function is not performing any
safety checks on the pointer chains it is chasing. A basic first step
would be to use the deref() macro from runtime/oc2c-runtime.h.
- FChE