Messages in this thread | | | Date | Thu, 7 Jun 2007 11:12:32 +1200 | From | "Ian McDonald" <> | Subject | Re: [BUG] Fwd: segfault : modprobe dccp_probe/tcp_probe |
| |
On 6/7/07, Chuck Ebbert <cebbert@redhat.com> wrote: > On 06/06/2007 04:47 PM, Ian McDonald wrote: > > Hi there, > > > > We've seen a report of a problem with dccp_probe as shown below. The > > user has also verified that it occurs in tcp_probe as well. This is on > > Dave Miller's tree but that currently tracks Linus' tree quite > > closely. I do note that it is around 2.6.22-rc2 timeframe so there is > > a possibility fixes may have gone in since. > > > > It faulted when it tried to write the breakpoint instruction into the > running kernel's executable code. Apparently the kernel code is now marked > read-only? > > Yes it would appear to be the case as user has CONFIG_DEBUG_RODATA set. Patrick - can you turn this off and retest? It's under Kernel Hacking, Write protect kernel read only data structures.
The list of commits that I see around this are at: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git&a=search&h=HEAD&st=commit&s=DEBUG_RODATA
I suspect it's probably one of the latter ones giving the timing.
I guess there are a couple of solutions here - either make kprobes conflict with CONFIG_DEBUG_RODATA so you can do one or the other, or look into more detail what access kprobes need.
Ian -- Web: http://wand.net.nz/~iam4/ Blog: http://iansblog.jandi.co.nz WAND Network Research Group - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |