Hi, I'm trying to port linux-2.4.21 to mpc852t custom board. The bootloader (u-boot) works fine and the kernel boots. The kernel is _VERY_ unstable, in that it gives sig 11 ( Oops: kernel access of bad area, sig: 11 ) at random intervals. I've created this short test program :
int *testmem; g = atoi(argv[1]); if(( testmem =(int*)malloc(1024*g)) == NULL ) { printf("mem test failed at iteration : %d",i); exit(0); } bzero(testmem,1024*g); printf("mem test at 0x%08x \t i = %d\n",testmem,i); We have 32MB RAM.The above code never returns cleanly, it always gives panic with sig 11. I've added a printk to arch/ppc/mm/fault.c kernel for debugging purpose if (!(vma->vm_flags & VM_GROWSDOWN)){ printk("\nerror : vm_start = 0x%08x Address = 0x%08x\n ",vma->vm_start,address); goto bad_area; } Sample output: [root]$ ./b0memtest 64 mem test at 0x10010c60 i = 0 mem test at 0x10020c68 i = 1 .... mem test at 0x10140cf8 i = 19 mem test at 0x10150d00 i = 20 mem test at 0x10160d08 i = 21 <comment> The following is my printk from arch/ppc/mm/fault.c </comment> vm_start = 0x10000000 vm_end = 0x10001000 Address = 0x00000024 <===== Why is it trying to access 0x00000024 Oops: kernel access of bad area, sig: 11 NIP: C000B80C XER: 00000000 LR: C000B7F4 SP: C1D59F00 REGS: c1d59e50 TRAP: 0300 Not tainted MSR: 00009032 EE: 1 PR: 0 FP: 0 ME: 1 IR/DR: 11 DAR: 00000024, DSISR: 0000000B TASK = c1d58000[32] 'b0memtest' Last syscall: 4 last math 00000000 last altivec 00000000 GPR00: 00000005 C1D59F00 C1D58000 00009032 C1F22C3C C1D59EA0 C0138258 00000000 GPR08: C1D58000 00000006 C0136050 00000000 44004082 00000000 00000000 00000000 GPR16: 00000000 00000000 00000000 00000000 C0160000 C0140000 C0130000 C0140000 GPR24: C00025C0 10000A00 7FFFFB40 00000020 C1D58000 C0144940 00000000 C1D59F00 Call backtrace: 10000A00 C000286C 3003B55E 30068BF8 3006954C 300690F8 3006CA50 30068024 10000788 300593A4 00000000 [root]$ ./b0memtest 128 mem test at 0x10010c60 i = 0 mem test at 0x10030c68 i = 1 .... mem test at 0x10190cc0 i = 12 mem test at 0x101b0cc8 i = 13 <comment> Again the same address </comment> vm_start = 0x10000000 vm_end = 0x10001000 Address = 0x00000024 <===== Oops: kernel access of bad area, sig: 11 NIP: C000B80C XER: 00000000 LR: C000B7F4 SP: C1DE1F00 REGS: c1de1e50 TRAP: 0300 Not tainted MSR: 00009032 EE: 1 PR: 0 FP: 0 ME: 1 IR/DR: 11 DAR: 00000024, DSISR: 0000000B TASK = c1de0000[24] 'b0memtest' Last syscall: 45 last math 00000000 last altivec 00000000 GPR00: 00000005 C1DE1F00 C1DE0000 00009032 00001032 000000E4 C0138258 00000000 GPR08: C1DE0000 00000006 C0136050 00000000 04000084 00000000 00000000 00000000 GPR16: 00000000 00000000 00000000 00000000 C0160000 C0140000 C0130000 C0140000 GPR24: C0003F78 10000A00 00000002 100004D8 C1DE0000 C0144940 00000000 C1DE1F00 Call backtrace: C000402C C000286C 30074024 10000728 300593A4 00000000 Thanks in advance.