Re: ptrace problem on ia64 with kernel 2.4.26
From: Marcelo Tosatti (marcelo.tosatti_at_cyclades.com)
Date: 08/10/04
- Previous message: Alan Cox: "Re: [PATCH 2.6] Remove spaces from PCI IDE pci_driver.name field"
- In reply to: Mike Becher: "ptrace problem on ia64 with kernel 2.4.26"
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Date: Mon, 9 Aug 2004 21:28:08 -0300 To: Mike Becher <Mike.Becher@lrz-muenchen.de>
Woh, I've got no clue, but I believe the check you are hitting is:
ia64/kernel/ptrace.c sys_ptrace():
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
unsigned long tmp;
ret = -EIO;
if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
***********************************
tmp = 0; /* Default return condition */
if(addr < FRAME_SIZE*sizeof(long))
tmp = getreg(child, addr);
if(addr >= (long) &dummy->u_debugreg[0] &&
addr <= (long) &dummy->u_debugreg[7]){
addr -= (long) &dummy->u_debugreg[0];
addr = addr >> 2;
tmp = child->thread.debugreg[addr];
}
ret = put_user(tmp,(unsigned long *) data);
break;
}
Can you show us the address which is being passed to successful ptrace's
and to the failed ones?
Bjorn, David?
On Thu, Aug 05, 2004 at 12:06:08PM +0200, Mike Becher wrote:
> Hi,
>
> on our Linux IA64 cluster we got the problem that tools like strace, gdb,
> ddd, and other debugging tools, which depend on ptrace system call, don't
> work after some days of uptime of a node. I have searched already in the
> web about information relating to that problem but haven't found any answer.
>
> description:
> ------------
> On a node that got the problem (when it runs longer than 3 days) strace
> produce this output:
> [mibe@lxsrv154]# strace /bin/true
> execve("/bin/true", ["/bin/true"], [/* 38 vars */]) = 0
> upeek: ptrace(PTRACE_PEEKUSER, ... ): Input/output error
> Instead on a `younger' node or fresh booted node strace works fine.
>
> To find out what is differnt I have used also the `utrace' tool
> (http://www.gelato.unsw.edu.au/IA64wiki/utrace) with a small
> modification to peek info about register r4.
>
> diff utrace.c.orig utrace.c
> 62c62
> < long scnum, result, error, val;
> ---
> > long scnum, result, result_r4, error, val;
> 74a75
> > result_r4 = ptrace (PTRACE_PEEKUSER, child_pid, PT_R4, 0);
>
> With this register starts the critical area of ptrace for debuggers
> when problem exists. They all don't do their work because they cannot
> gather information about some registers like r4, r5, r6, r7.
> Also it doesn't work for user `root'.
> Whether in messages files nor in /proc filesystem nor with dmesg I
> have found any info that can give me a hint what has changed.
>
> configuration:
> --------------
> We use the following configuration:
> * kernel 2.4.26 (vanilla kernel) with
> - official linux-2.4.26-ia64-040510.diff.bz2 (11-May-2004 11:18)
> - EXPORT_SYMBOL_NOVERS(iosapic_fixup_pci_interrupt) in
> linux-2.4.26/arch/ia64/kernel/ia64_ksyms.c
> - commented out
> printk(KERN_WARNING "%s(%d): floating-point assist...)
> in linux-2.4.26/arch/ia64/kernel/traps.c
> - BitKeeper patch which fixes x86 "clear_cpu()" macro.
> on line 34 to >>> asm volatile("fnclex ; fwait");
> * openafs 1.2.11
> * Myrinet driver GM build ID is "1.6.4_Linux_and_AIX
> * PVFS 1.6.2 with pvfs-1.6.2-01292004.patch
> * following modules are loaded:
> [mibe@lxsrv154 ia64]# lsmod
> Module Size Used by Tainted: PF
> pvfs 147336 7
> imb 43024 0
> gm 620176 1 (autoclean)
> libafs-2.4.26.mp 1296528 2
> e1000 170976 1
> nls_iso8859-1 6000 1 (autoclean)
> nls_cp437 7680 1 (autoclean)
> usbkbd 9040 0 (unused)
> ehci-hcd 54872 0 (unused)
> usb-uhci 66888 0 (unused)
> usbcore 182800 1 [usbkbd ehci-hcd usb-uhci]
> aacraid 95512 7
> sd_mod 33856 14
>
> Hope someone can help me to solve this problem.
>
> best regards,
> Mike
> -
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- Previous message: Alan Cox: "Re: [PATCH 2.6] Remove spaces from PCI IDE pci_driver.name field"
- In reply to: Mike Becher: "ptrace problem on ia64 with kernel 2.4.26"
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