使用dump_stack查看内核函数调用

使用dump_stack在driver开发期间清晰查看内核中函数调用流程

void dump_stack(void)
{
    __backtrace();
}

arch/arm/lib/backtrace.S|25| ENTRY(__backtrace)

在 int wlan_init_fw(wlan_private * priv)函数中加入dump_stack();函数,这样我们可以查看执行到我们加在wlan_init_fw()函数中的dump_stack();函数中所有栈中引发入栈动作的层层上级函数们[luther.gliethttp].

luther@gliethttp:~$ insmod sd8688.ko

会打出如下log：
可以看出函数调用的栈视图是这样的[luther.gliethttp]：
dump_stack
<= wlan_init_fw 
<= wlan_add_card
<= wlan_probe
<= sdio_bus_probe
<= driver_probe_device
<= __device_attach
<= bus_for_each_drv
<= device_attach
<= bus_attach_device
<= device_add
<= sdio_add_func
<= mmc_attach_sdio
<= mmc_rescan
<= run_workqueue
<= worker_thread
<= kthread
<= do_exit


[  189.648865] [<c0031514>] (dump_stack+0x0/0x14) from [<bf05b76c>] (wlan_init_fw+0x78/0x364 [sd8688])
[  189.649170] [<bf05b6f4>] (wlan_init_fw+0x0/0x364 [sd8688]) from [<bf05b0b8>] (wlan_add_card+0x1c0/0x4a0 [sd8688])
[  189.649292]  r8:c40e7208 r7:c5684600 r6:c6962000 r5:c539b000 r4:c539b360
[  189.649323] [<bf05aef8>] (wlan_add_card+0x0/0x4a0 [sd8688]) from [<bf088ed8>] (wlan_probe+0x54/0x128 [sd8688])
[  189.649536] [<bf088e84>] (wlan_probe+0x0/0x128 [sd8688]) from [<c020157c>] (sdio_bus_probe+0x70/0x7c)
[  189.649719]  r6:bf0a0aac r5:00000000 r4:c5778400
[  189.649719] [<c020150c>] (sdio_bus_probe+0x0/0x7c) from [<c01ae2bc>] (driver_probe_device+0xac/0x1b0)
[  189.649780]  r7:c01ae3c0 r6:c5778408 r5:bf0a0ac4 r4:c5778408
[  189.649811] [<c01ae210>] (driver_probe_device+0x0/0x1b0) from [<c01ae3d0>] (__device_attach+0x10/0x14)
[  189.649841]  r8:c6962000 r7:c01ae3c0 r6:c5778408 r5:c6963e7c r4:00000000
[  189.649872] [<c01ae3c0>] (__device_attach+0x0/0x14) from [<c01ad33c>] (bus_for_each_drv+0x68/0x94)
[  189.649903] [<c01ad2d4>] (bus_for_each_drv+0x0/0x94) from [<c01ae494>] (device_attach+0x94/0x9c)
[  189.649933]  r7:00000000 r6:00000000 r5:c57784b0 r4:c5778408
[  189.649964] [<c01ae400>] (device_attach+0x0/0x9c) from [<c01ad2a4>] (bus_attach_device+0x4c/0x7c)
[  189.649994]  r5:c5778408 r4:c03bad34
[  189.649994] [<c01ad258>] (bus_attach_device+0x0/0x7c) from [<c01abca4>] (device_add+0x3b4/0x55c)
[  189.650025]  r5:c5778494 r4:c5778408
[  189.650055] [<c01ab8f0>] (device_add+0x0/0x55c) from [<c02013d0>] (sdio_add_func+0x3c/0x58)
[  189.650086] [<c0201394>] (sdio_add_func+0x0/0x58) from [<c0200bdc>] (mmc_attach_sdio+0xf0/0x170)
[  189.650116]  r4:c6de2c00
[  189.650116] [<c0200aec>] (mmc_attach_sdio+0x0/0x170) from [<c01fd294>] (mmc_rescan+0x208/0x28c)
[  189.650147]  r6:00000000 r5:c6963f5c r4:c6de2c00
[  189.650177] [<c01fd08c>] (mmc_rescan+0x0/0x28c) from [<c006c70c>] (run_workqueue+0x15c/0x2c4)
[  189.650208]  r7:c690d808 r6:c01fd08c r5:c690d800 r4:c6de2d74
[  189.650238] [<c006c5b0>] (run_workqueue+0x0/0x2c4) from [<c006d464>] (worker_thread+0xa0/0x124)
[  189.650269]  r8:00000000 r7:c6963fac r6:c690d800 r5:c690db3c r4:c6962000
[  189.650299] [<c006d3c4>] (worker_thread+0x0/0x124) from [<c007046c>] (kthread+0x50/0x7c)
[  189.650330]  r7:00000000 r6:00000000 r5:c006d3c4 r4:c690d800
[  189.650360] [<c007041c>] (kthread+0x0/0x7c) from [<c005eb2c>] (do_exit+0x0/0x704)
[  189.650391]  r5:00000000 r4:00000000