On 23/05/13 13:39, zhangwei(Jovi) wrote:
On 2013/5/23 17:36, Oded Gabbay wrote:On 23/05/13 12:13, zhangwei(Jovi) wrote:On 2013/5/23 16:48, Oded Gabbay wrote:Hi Jovi, I read today about the ktap release in LWN and tried to give it a go on my custom board, which contains a powerpc processor from Freescale called P2020 (e500v2 core). I have two comments and a question: 1. I needed to enable CONFIG_RELAY in the kernel configuration, although this is not mentioned in the requirements. Maybe you should add it.Involve ktap mailing list :) Thanks, you are right, I will add it.2. I needed to add #include <linux/vmalloc.h> to ktap.c for compilationwhich kernel version of the board? currently ktap can support kernel 3.1 or later, older kernel need some patch to run ktap. I haven't compile ktap in powerpc, so might you are right.My kernel version is 3.4.41.I now arrived to a situation where I insmod the ktapvm.ko on my board, but when I run: ./ktap scripts/syscalls.kp I get the following error: open /sys/kernel/debug/ktap/ktapvm failed: No such file or directory I checked and indeed there is no /sys/kernel/debug/ktap folder (debug folder is empty).I guess you are missing mount debugfs? mount -t debugfs none /sys/kernel/debug/ Also I will add this into ktap doc.Yes, I was missing the mount. Thanks :)Note that currently ktap is not stable enough to running in production system, but I'm trying to make it more stable :)I'm aware of that and I'm not putting it in production, but thanks for the warning. After I fixed the mount issue, I was able to run the syscalls script but the kernel immediately crashed... I will try to look into it. This was the message from the kernel: [cj:/usr/local/ktap] # ./ktap scripts/syscalls.kp Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xf1eb5dcc Oops: Kernel access of bad area, sig: 11 [#1] PREEMPT SMP NR_CPUS=2 P2020 FSP150 Modules linked in: ktapvm(O) mdio(O) hardware_version(PO) clipresent(PO) monotonic(O) restartcause(PO) panic_buffer(O) [last unloaded: ktapvm] NIP: f1eb5dcc LR: f1eb5d90 CTR: c0265f04 REGS: eedd5c90 TRAP: 0300 Tainted: P O (3.4.41-dev_ogabbay-105684*) MSR: 00029000 <CE,EE,ME> CR: 44000482 XER: 20000000 DEAR: 00000000, ESR: 00000000 TASK = ef0c6820[2097] 'ktap' THREAD: eedd4000 CPU: 1 GPR00: 00000000 eedd5d40 ef0c6820 eedd5d4c f1eb801c 00000016 eedd5d6a 0000003a GPR08: eedd5d54 00000000 00000000 f1eb801d c0265f04 1002cacc 00000005 00000003 GPR16: 00000001 eede9628 00000001 eede9600 00000000 eee6e640 00000000 00000000 GPR24: 00000000 eedd5d4c f1ec0000 eede9200 ffffffff eede8600 eedd5d4c eedd5db8 NIP [f1eb5dcc] ftrace_on_event_call.clone.6+0xb4/0x1fc [ktapvm] LR [f1eb5d90] ftrace_on_event_call.clone.6+0x78/0x1fc [ktapvm] Call Trace: [eedd5d40] [f1eb0824] kp_tstring_newlstr+0xdc/0x164 [ktapvm] (unreliable) [eedd5db0] [f1eb5ff4] ktap_lib_probe+0xe0/0x198 [ktapvm] [eedd5de0] [f1eb2a90] precall+0x1e4/0x318 [ktapvm] [eedd5e00] [f1eb3244] kp_call+0x680/0x1180 [ktapvm] [eedd5e60] [f1eaf2c0] ktap_ioctl+0x20c/0x30c [ktapvm] [eedd5ea0] [c010d4f4] do_vfs_ioctl+0xa0/0x754 [eedd5f10] [c010dc44] sys_ioctl+0x9c/0xa4 [eedd5f40] [c000f3a0] ret_from_syscall+0x0/0x3c --- Exception: c01 at 0xff1e254 LR = 0xffb2c0c Instruction dump: 419e0024 88030000 2f800000 409e0148 88180000 2f800000 409e011c 3b200000 3b000000 3f40f1ec 3ac00000 813a93a0 <83c90000> 7f89f000 419e00c0 3b5a93a0 ---[ end trace b87e7dec14e55ffe ]--- cannot lookup ftrace_events in kallsyms Kernel panic - not syncing: Fatal exception Rebooting in 5 seconds..Please pull latest ktap from github, I just figure out I missed function return value check. Then there will have no panic, I assume.
Yes, now there is no panic
CONFIG_KALLSYMS is enabled. CONFIG_EVENT_TRACING is also enabled. But, when I do:But I'm still curious on why your kernel didn't exported "ftrace_events", CONFIG_KALLSYMS not enabled?
grep ftrace_events /proc/kallsyms I don't get any results.When I look at kernel/trace/trace_events.c, I don't see that "ftrace_events" is exported...
Thanks.I thought maybe you would have any idea how to fix this and save me time. -- Best regards, Oded Gabbay Principal Engineer Advanced Packet Technologies ADVA Optical Networking Israel Ltd. P.O. Box 2552 2 Hatidhar St. Raanana 43665, Israel Tel: +(972)-9-7750130 Fax: +(972)-9-7462092 Mobile: +(972)-54-6543998 E-mail: ogabbay@xxxxxxxxxxxxxxx <mailto:ogabbay@xxxxxxxxxxxxxxx> www.advaoptical.com <http://www.advaoptical.com> *Let's ADVANCE* ADVA Optical Networking SE is a European stock corporation ("Societas Europaea") with registered offices at Maerzenquelle 1-3, D-98617 Meiningen, Germany * CEO: Brian L. Protiva, Chief Officers: Dr. Christoph Glingener, Christian Unterberger, Jaswir Singh * Chairman of the Supervisory Board: Anthony Maher * AG Jena HRB 508155 * VAT No. DE 175 446 349.