* Debug Kernel Modules With KGDB @ 2014-12-01 9:56 Freeman Zhang 2014-12-01 9:53 ` Raghavendra 0 siblings, 1 reply; 5+ messages in thread From: Freeman Zhang @ 2014-12-01 9:56 UTC (permalink / raw) To: kernelnewbies Hi list, I've been trying to setup a debug environment for linux kernel(v3.4,Android,ARM) with kgdb. It worked fine untill I tried to use it to debug a module. Under the instruction from LDD, I add module debug info in gdb with command: add-symbol-file test-module.ko address LDD uses `cat /sys/module/test-module/sections/.text` to get the address where the module has been loaded. However, I got: 0x00000000 When I use `lsmod`, I got: test-module 15278 0 - Live 0x00000000 (O) Why nothing but 0x00000000 ?? So I have to do some research in kernel/module.c, and find out that struct module -> module_core = 0xbf000000. But when I try these in gdb: add-symbol-file test-module.ko 0xbf000000 break one_of_my_function I got: Cannot access memory at address 0xbf002350 :( Could somebody help? All the best! Freeman Zhang -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: OpenPGP digital signature Url : http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20141201/0c8874e6/attachment.bin ^ permalink raw reply [flat|nested] 5+ messages in thread
* Debug Kernel Modules With KGDB 2014-12-01 9:56 Debug Kernel Modules With KGDB Freeman Zhang @ 2014-12-01 9:53 ` Raghavendra 2014-12-01 11:02 ` Freeman Zhang 0 siblings, 1 reply; 5+ messages in thread From: Raghavendra @ 2014-12-01 9:53 UTC (permalink / raw) To: kernelnewbies On Monday 01 December 2014 03:26 PM, Freeman Zhang wrote: > Hi list, > > I've been trying to setup a debug environment for linux > kernel(v3.4,Android,ARM) with kgdb. It worked fine untill I tried to use > it to debug a module. Under the instruction from LDD, I add module debug > info in gdb with command: > > add-symbol-file test-module.ko address > > LDD uses `cat /sys/module/test-module/sections/.text` to get the address > where the module has been loaded. However, I got: > > 0x00000000 Try reading the file as a root. $ sudo cat /sys/module/test-module/sections/.text > > When I use `lsmod`, I got: > > test-module 15278 0 - Live 0x00000000 (O) > > Why nothing but 0x00000000 ?? > > So I have to do some research in kernel/module.c, and find out that > struct module -> module_core = 0xbf000000. But when I try these in gdb: > > add-symbol-file test-module.ko 0xbf000000 > break one_of_my_function > > I got: > > Cannot access memory at address 0xbf002350 > > :( > Could somebody help? > > > All the best! > Freeman Zhang > > > > > > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies at kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies ------------------------------------------------------------------------------------------------------------------------------- [ C-DAC is on Social-Media too. Kindly follow us at: Facebook: https://www.facebook.com/CDACINDIA & Twitter: @cdacindia ] This e-mail is for the sole use of the intended recipient(s) and may contain confidential and privileged information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies and the original message. Any unauthorized review, use, disclosure, dissemination, forwarding, printing or copying of this email is strictly prohibited and appropriate legal action will be taken. ------------------------------------------------------------------------------------------------------------------------------- -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20141201/bed63263/attachment-0001.html ^ permalink raw reply [flat|nested] 5+ messages in thread
* Debug Kernel Modules With KGDB 2014-12-01 9:53 ` Raghavendra @ 2014-12-01 11:02 ` Freeman Zhang 2014-12-01 11:17 ` Raghavendra 0 siblings, 1 reply; 5+ messages in thread From: Freeman Zhang @ 2014-12-01 11:02 UTC (permalink / raw) To: kernelnewbies Hi Raghavendra, Thanks for your reply, but `sudo` doesn't solve the problem :( All the best! Freeman Zhang -------- Original Message -------- > On Monday 01 December 2014 03:26 PM, Freeman Zhang wrote: >> Hi list, >> >> I've been trying to setup a debug environment for linux >> kernel(v3.4,Android,ARM) with kgdb. It worked fine untill I tried to use >> it to debug a module. Under the instruction from LDD, I add module debug >> info in gdb with command: >> >> add-symbol-file test-module.ko address >> >> LDD uses `cat /sys/module/test-module/sections/.text` to get the address >> where the module has been loaded. However, I got: >> >> 0x00000000 > Try reading the file as a root. > $ sudo cat /sys/module/test-module/sections/.text >> >> When I use `lsmod`, I got: >> >> test-module 15278 0 - Live 0x00000000 (O) >> >> Why nothing but 0x00000000 ?? >> >> So I have to do some research in kernel/module.c, and find out that >> struct module -> module_core = 0xbf000000. But when I try these in gdb: >> >> add-symbol-file test-module.ko 0xbf000000 >> break one_of_my_function >> >> I got: >> >> Cannot access memory at address 0xbf002350 >> >> :( >> Could somebody help? >> >> >> All the best! >> Freeman Zhang >> >> >> >> >> >> >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies at kernelnewbies.org >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > ------------------------------------------------------------------------------------------------------------------------------- > > [ C-DAC is on Social-Media too. Kindly follow us at: > Facebook: https://www.facebook.com/CDACINDIA & Twitter: @cdacindia ] > > This e-mail is for the sole use of the intended recipient(s) and may > contain confidential and privileged information. If you are not the > intended recipient, please contact the sender by reply e-mail and destroy > all copies and the original message. Any unauthorized review, use, > disclosure, dissemination, forwarding, printing or copying of this email > is strictly prohibited and appropriate legal action will be taken. > ------------------------------------------------------------------------------------------------------------------------------- > > > > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies at kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: OpenPGP digital signature Url : http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20141201/0b502f4d/attachment.bin ^ permalink raw reply [flat|nested] 5+ messages in thread
* Debug Kernel Modules With KGDB 2014-12-01 11:02 ` Freeman Zhang @ 2014-12-01 11:17 ` Raghavendra 2014-12-01 11:30 ` Freeman Zhang 0 siblings, 1 reply; 5+ messages in thread From: Raghavendra @ 2014-12-01 11:17 UTC (permalink / raw) To: kernelnewbies Hi Zhang, On Monday 01 December 2014 04:32 PM, Freeman Zhang wrote: > Hi Raghavendra, > > Thanks for your reply, but `sudo` doesn't solve the problem :( Well then I guess 'sudo' isn't implemented in android. Any way, ultimately you may wan't to login as root and then try reading the file in order to get the address. Regards, Raghavendra > > All the best! > > Freeman Zhang > > -------- Original Message -------- >> On Monday 01 December 2014 03:26 PM, Freeman Zhang wrote: >>> Hi list, >>> >>> I've been trying to setup a debug environment for linux >>> kernel(v3.4,Android,ARM) with kgdb. It worked fine untill I tried to use >>> it to debug a module. Under the instruction from LDD, I add module debug >>> info in gdb with command: >>> >>> add-symbol-file test-module.ko address >>> >>> LDD uses `cat /sys/module/test-module/sections/.text` to get the address >>> where the module has been loaded. However, I got: >>> >>> 0x00000000 >> Try reading the file as a root. >> $ sudo cat /sys/module/test-module/sections/.text >>> When I use `lsmod`, I got: >>> >>> test-module 15278 0 - Live 0x00000000 (O) >>> >>> Why nothing but 0x00000000 ?? >>> >>> So I have to do some research in kernel/module.c, and find out that >>> struct module -> module_core = 0xbf000000. But when I try these in gdb: >>> >>> add-symbol-file test-module.ko 0xbf000000 >>> break one_of_my_function >>> >>> I got: >>> >>> Cannot access memory at address 0xbf002350 >>> >>> :( >>> Could somebody help? >>> >>> >>> All the best! >>> Freeman Zhang >>> >>> >>> >>> >>> >>> >>> >>> _______________________________________________ >>> Kernelnewbies mailing list >>> Kernelnewbies at kernelnewbies.org >>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> >> ------------------------------------------------------------------------------------------------------------------------------- >> >> [ C-DAC is on Social-Media too. Kindly follow us at: >> Facebook: https://www.facebook.com/CDACINDIA & Twitter: @cdacindia ] >> >> This e-mail is for the sole use of the intended recipient(s) and may >> contain confidential and privileged information. If you are not the >> intended recipient, please contact the sender by reply e-mail and destroy >> all copies and the original message. Any unauthorized review, use, >> disclosure, dissemination, forwarding, printing or copying of this email >> is strictly prohibited and appropriate legal action will be taken. >> ------------------------------------------------------------------------------------------------------------------------------- >> >> >> >> >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies at kernelnewbies.org >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> ------------------------------------------------------------------------------------------------------------------------------- [ C-DAC is on Social-Media too. Kindly follow us at: Facebook: https://www.facebook.com/CDACINDIA & Twitter: @cdacindia ] This e-mail is for the sole use of the intended recipient(s) and may contain confidential and privileged information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies and the original message. Any unauthorized review, use, disclosure, dissemination, forwarding, printing or copying of this email is strictly prohibited and appropriate legal action will be taken. ------------------------------------------------------------------------------------------------------------------------------- ^ permalink raw reply [flat|nested] 5+ messages in thread
* Debug Kernel Modules With KGDB 2014-12-01 11:17 ` Raghavendra @ 2014-12-01 11:30 ` Freeman Zhang 0 siblings, 0 replies; 5+ messages in thread From: Freeman Zhang @ 2014-12-01 11:30 UTC (permalink / raw) To: kernelnewbies Hi Raghavendra, Yes, you are right, 'sudo' isn't implemented in android. However, `su` enable me to read the .text as root. It's the same, 0x00000000. So I guess something else should be wrong. Thanks anyway! Freeman Zhang -------- Original Message -------- > Hi Zhang, > > On Monday 01 December 2014 04:32 PM, Freeman Zhang wrote: >> Hi Raghavendra, >> >> Thanks for your reply, but `sudo` doesn't solve the problem :( > Well then I guess 'sudo' isn't implemented in android. Any way, > ultimately you may wan't to login as root and then try reading the file > in order to get the address. > Regards, > Raghavendra >> >> All the best! >> >> Freeman Zhang >> >> -------- Original Message -------- >>> On Monday 01 December 2014 03:26 PM, Freeman Zhang wrote: >>>> Hi list, >>>> >>>> I've been trying to setup a debug environment for linux >>>> kernel(v3.4,Android,ARM) with kgdb. It worked fine untill I tried to >>>> use >>>> it to debug a module. Under the instruction from LDD, I add module >>>> debug >>>> info in gdb with command: >>>> >>>> add-symbol-file test-module.ko address >>>> >>>> LDD uses `cat /sys/module/test-module/sections/.text` to get the >>>> address >>>> where the module has been loaded. However, I got: >>>> 0x00000000 >>> Try reading the file as a root. >>> $ sudo cat /sys/module/test-module/sections/.text >>>> When I use `lsmod`, I got: >>>> >>>> test-module 15278 0 - Live 0x00000000 (O) >>>> >>>> Why nothing but 0x00000000 ?? >>>> >>>> So I have to do some research in kernel/module.c, and find out that >>>> struct module -> module_core = 0xbf000000. But when I try these in gdb: >>>> >>>> add-symbol-file test-module.ko 0xbf000000 >>>> break one_of_my_function >>>> >>>> I got: >>>> >>>> Cannot access memory at address 0xbf002350 >>>> >>>> :( >>>> Could somebody help? >>>> >>>> >>>> All the best! >>>> Freeman Zhang >>>> >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> Kernelnewbies mailing list >>>> Kernelnewbies at kernelnewbies.org >>>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>> >>> ------------------------------------------------------------------------------------------------------------------------------- >>> >>> >>> [ C-DAC is on Social-Media too. Kindly follow us at: >>> Facebook: https://www.facebook.com/CDACINDIA & Twitter: @cdacindia ] >>> >>> This e-mail is for the sole use of the intended recipient(s) and may >>> contain confidential and privileged information. If you are not the >>> intended recipient, please contact the sender by reply e-mail and >>> destroy >>> all copies and the original message. Any unauthorized review, use, >>> disclosure, dissemination, forwarding, printing or copying of this email >>> is strictly prohibited and appropriate legal action will be taken. >>> ------------------------------------------------------------------------------------------------------------------------------- >>> >>> >>> >>> >>> >>> >>> _______________________________________________ >>> Kernelnewbies mailing list >>> Kernelnewbies at kernelnewbies.org >>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>> > > > ------------------------------------------------------------------------------------------------------------------------------- > > [ C-DAC is on Social-Media too. Kindly follow us at: > Facebook: https://www.facebook.com/CDACINDIA & Twitter: @cdacindia ] > > This e-mail is for the sole use of the intended recipient(s) and may > contain confidential and privileged information. If you are not the > intended recipient, please contact the sender by reply e-mail and destroy > all copies and the original message. Any unauthorized review, use, > disclosure, dissemination, forwarding, printing or copying of this email > is strictly prohibited and appropriate legal action will be taken. > ------------------------------------------------------------------------------------------------------------------------------- > > -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: OpenPGP digital signature Url : http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20141201/be2301f2/attachment.bin ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2014-12-01 11:30 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2014-12-01 9:56 Debug Kernel Modules With KGDB Freeman Zhang 2014-12-01 9:53 ` Raghavendra 2014-12-01 11:02 ` Freeman Zhang 2014-12-01 11:17 ` Raghavendra 2014-12-01 11:30 ` Freeman Zhang
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