[microblaze-uclinux] Kernel module driver crash

Hi all,

I am writing a module driver and have run into a problem and just wanted to check I’m not doing anything stupid!

I am not currently using the latest SVN version I am using an export from the 25/2/09 – I am in the process of updating to the latest version.

I have made an example which on my system causes an illegal instruction Oops:

---------------------------------------

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/module.h>

MODULE_AUTHOR("Ian Whitmore");

MODULE_DESCRIPTION("Discovery communications example");

MODULE_LICENSE("Dual BSD/GPL");

static void test1(void);

static void test2(void);

static int __init startGoing(void)

{

printk("I'm in startGoing\n");

test1();

return 0;

}

static void __exit stopGoing(void)

{

printk("I'm in stopGoing\n");

test1();

return;

}

static void test1(void)

{

printk("I'm in test1\n");

test2();

test2(); //If this call is commented out the module does not crash!

return;

}

static void test2(void)

{

printk("I'm in test2\n");

return;

}

module_init(startGoing);

module_exit(stopGoing);

This is the error message I get:

# insmod discovery-module.ko

I'm in startGoing

Oops: Exception in kernel mode, sig: 4

Registers dump: mode=8816FEC0

r1=88038130, r2=8809408C, r3=00000015, r4=FFFFFFFF

r5=881605A4, r6=00000001, r7=FFFFFFFF, r8=00000000

r9=23410000, r10=00000049, r11=00000000, r12=84000000

r13=8F023B10, r14=88096654, r15=8F5881B0, r16=881788F8

r17=881787DC, r18=00000000, r19=8802651C, r20=881788E0

r21=00000001, r22=881788F8, r23=00000001, r24=00000004

r25=00000001, r26=88004598, r27=8818172C, r28=8813F808

r29=88178904, r30=00000000, r31=00000000, rPC=88175968

msr=00000000, ear=00000000, esr=880020B4, fsr=00000A33

Illegal instruction

---------------------------------------

If I comment out the 2^nd call to test2() the module does not crash:

---------------------------------------

# insmod discovery-module.ko

I'm in startGoing

I'm in test1

I'm in test2

I'm in test1

I'm in test2

Has anyone got any ideas?

Ian.

PS. sorry about the footer to this email – It’s a work address and I can’t get rid of it!!!

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