This is the mail archive of the mailing list for the systemtap project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [RFC -mm][PATCH 5/6] prepare kprobes code for x86 unification

Masami Hiramatsu wrote:
Hi Srinivasa,

Thank you for reporting.

Srinivasa Ds wrote:
Hi Masami
I was testing your patch on x86_64 by executing systemtap tests. I got this oops message.

I ran systemtap testsuite on x86-64. But I could not reproduce it yet. Would you apply all of these patches or just first 5 patches?

Yes, I applied all patches and then tested it.

Sure, I also tested it (stap -e 'probe kernel.function("init_sched_debug_procfs"){}') but it could not cause oops.

By the way, as far as I can see, the current.stp does not probe "init_sched_debug_procfs".
So it could be caused by incorrect debuginfo...

I verified the debuginfo and then ran the test, but still I could able to reproduce the problem.

Unable to handle kernel paging request at ffffffff8086ccb3 RIP: [<ffffffff804739c5>] arch_prepare_kprobe+0x22/0x217 PGD 203067 PUD 207063 PMD 7e0da163 PTE 86c000 Oops: 0000 [1] SMP last sysfs file: /sys/module/stap_35adaae6e718a71673316d7b16a93286_356228/sections/.bss CPU 1 Modules linked in: stap_35adaae6e718a71673316d7b16a93286_356228 systemtap_test_module1 systemtap_test_module2 ipv6 autofs4 hidp rfcomm l2cap bluetooth sunrpc dm_multipath video output sbs sbshc battery acpi_memhotplug ac power_supply lp sg tg3 ide_cd cdrom floppy serio_raw parport_pc button e752x_edac parport edac_core i2c_i801 shpchp i2c_core pcspkr dm_snapshot dm_zero dm_mirror dm_mod ata_piix libata aic79xx scsi_transport_spi sd_mod scsi_mod ext3 jbd ehci_hcd ohci_hcd uhci_hcd Pid: 28478, comm: stapio Tainted: GF 2.6.24-rc4-mm1 #4 RIP: 0010:[<ffffffff804739c5>] [<ffffffff804739c5>] arch_prepare_kprobe+0x22/0x217 RSP: 0018:ffff810067055e48 EFLAGS: 00010286 RAX: ffffffff8086ccb3 RBX: ffffffff88464130 RCX: ffffffff8842af30 RDX: 0000000000000f30 RSI: 6600000000000000 RDI: ffffffff88464130 RBP: ffffffff88464130 R08: ffff81000d4d6000 R09: ffff81007f834000 R10: ffffffff8024bf9c R11: 0000000000000000 R12: 00000000000036b0 R13: 0000000000000000 R14: ffffffff8843b3b2 R15: 0000000000000000 FS: 00002aebec1e2b00(0000) GS:ffff81007fbac840(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b

[root@llm42 ~]# cat /proc/kallsyms | grep ffffffff8086ccb3
ffffffff8086ccb3 T migration_init
[root@llm42 ~]# cat /root/linux-2.6.24-rc4/ | grep ffffffff8086ccb3
ffffffff8086ccb3 T migration_init

This time it was probing "__init migration_init" function in kernel/sched.c,I saw systemtap code blacklisting all .init and .exit functions but still it failed.
I replaced all __init function in kernel/sched.c to __kprobes then executed the tests successfully.

So may be problem is in naming the section of vmlinux properly.

Thanks Srinivasa DS

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]