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Re: registration error (rc -84) and -DSTP_OVERLOAD_THRESHOLD
- From: "Richard W.M. Jones" <rjones at redhat dot com>
- To: "Frank Ch. Eigler" <fche at redhat dot com>
- Cc: mglt dot biz at gmail dot com, systemtap at sourceware dot org
- Date: Tue, 14 Jun 2011 14:29:43 +0100
- Subject: Re: registration error (rc -84) and -DSTP_OVERLOAD_THRESHOLD
- References: <4DE5EEEA.7070400@gmail.com> <y0mhb8965b8.fsf@fche.csb>
On Wed, Jun 01, 2011 at 09:37:31AM -0400, Frank Ch. Eigler wrote:
>
> mglt.biz wrote:
>
> > [...] While running my tap script, I receive WARNINGs and would
> > like to knwo how to consider them. [...]
>
> > WARNING: probe
> > kernel.function("tcp_new_space@net/ipv4/tcp_input.c:4885") (address
> > 0xffffffff814064f0) registration error (rc -84)
>
> This is an error (-EILSEQ) that comes from the kernel, most likely
> arch/x86/kernel/kprobes.c. It may be a somehow blacklisted function,
> or perhaps a problem with the 'optimized kprobes' widget. It may help
> to get a vmlinux disassembly around that 0xffffffff814064f0 address.
I'm also receiving these warnings. My script attempts to add a probe
at every line in a module (yes, there's a good reason for it):
probe module("ext2").statement ("*@*.c:*") {
printf ("%s\n", pp());
}
and I get maybe about 100 warnings like this:
WARNING: probe module("ext2").statement("ext2_try_to_allocate_with_rsv@fs/ext2/balloc.c:1162") (address 0xffffffffa055f982) registration error (rc -84)
WARNING: probe module("ext2").statement("ext2_new_blocks@fs/ext2/balloc.c:1270") (address 0xffffffffa055ff3b) registration error (rc -84)
WARNING: probe module("ext2").statement("ext2_new_blocks@fs/ext2/balloc.c:1272") (address 0xffffffffa055ff3e) registration error (rc -84)
WARNING: probe module("ext2").statement("ext2_new_blocks@fs/ext2/balloc.c:1277") (address 0xffffffffa055ffd4) registration error (rc -84)
WARNING: probe module("ext2").statement("ext2_readdir@fs/ext2/dir.c:342") (address 0xffffffffa056098f) registration error (rc -84)
WARNING: probe module("ext2").statement("ext2_find_entry@fs/ext2/dir.c:426") (address 0xffffffffa0560b28) registration error (rc -84)
Apart from the warnings, systemtap functions correctly.
Because these addresses are in a module, I couldn't work out the right
invocation of gdb / objdump to get it to disassemble those addresses.
But if you tell me how, I'll be glad to provide that information.
Fedora 15, 2.6.38.7-30.fc15.x86_64
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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