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
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
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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
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-------------------------------------------------------------------------------------------------------------------------------
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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@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
-------------------------------------------------------------------------------------------------------------------------------
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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@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
-------------------------------------------------------------------------------------------------------------------------------
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participants (2)
-
Freeman Zhang -
Raghavendra