On Mon, 2012-07-09 at 20:14 +0530, AYAN KUMAR HALDER wrote: > Hi Amit, > > Thanks for the prompt and detailed explanation. > > I had the same understanding, but now I have experienced a different > behavior with Pandaboard ES (OMAP- 4460). > > I have declared a global static variable as (in my project) :- > static char utcb[THREADS_TOTAL * ( 13 )] L4_ALIGN(UTCB_SIZE); > With this, my program got executed successfully. > > The logs were as follows:- > code0: Mapping 0x3000 bytes as RX from 0x84000000 physical to > 0xc0000000 virtual for project0 > code0: Mapping 0x2000 bytes as RW from 0x84003000 physical to > 0xc0003000 virtual for project0 > In __l4_threadlib_init > c0003100 = address of utcb ( starting address of array ) > c0004e28 = address of &utcb + 1 ( last address of array ) > > Thus as we can see address accessed was 0xc0004e28 which is within the > permissible range of ( 0xc0003000 + 0x2000 = 0xc0005000 ) > > When I modified it as follows:- > static char utcb[THREADS_TOTAL * ( 14 )] L4_ALIGN(UTCB_SIZE); > > The logs were as follows:- > code0: Mapping 0x3000 bytes as RX from 0x84000000 physical to > 0xc0000000 virtual for project0 > code0: Mapping 0x2000 bytes as RW from 0x84003000 physical to > 0xc0003000 virtual for project0 > In __l4_threadlib_init > c0003100 = address of utcb ( starting address of array ) > c0004f28 = address of &utcb + 1 ( last address of array ) > > Thus as we can see address accessed was 0xc0004f28 which is within the > permissible range of ( 0xc0003000 + 0x2000 = 0xc0005000 ) > > But When I modified it as follows:- > static char utcb[THREADS_TOTAL * ( 15 )] L4_ALIGN(UTCB_SIZE); > It caused kernel panic > > The logs were as follows:- > code0: Mapping 0x3000 bytes as RX from 0x84000000 physical to > 0xc0000000 virtual for project0 > code0: Mapping 0x2000 bytes as RW from 0x84003000 physical to > 0xc0003000 virtual for project0 > fault_ipc_to_pager: Sending ipc from 1 to 1, > faulty_address=0xc0005060, faulty pc=0xc00016a8 > tid=0x00000001 > Unhandled kernel data abort at address 0x00000008 > FAR:0x00000008 > PC:0xf000e380 > Unhandled kernel abort. > Kernel panic. > Halting system... > > Here, the array had an address range of 0xc0003100 till 0xc0005028 > ( 0xc0004f28 + 100 ) which lies beyond the permissible range > 0xc0003000 to 0xc0005000 ( 0xc0003000 + 0x2000 - as seen from kernel > logs). > Ok you need to check 2 things here:
1. Check the elf file of the hello world container and do a readelf on it to make sure it is having correct number of RX and RW pages. It should not have any RWX section. 2. If 1. looks fine, then the problem is in Codezero's reading of elf sections at load time. These manipulations are done in some python script under codezero/config. Find this script and add some prints in it so see if it is manipulating container's section properly. -- Thanks, Amit Mahajan _______________________________________________ codezero-devel mailing list codezero-devel@lists.l4dev.org http://lists.l4dev.org/mailman/listinfo/codezero-devel_lists.l4dev.org
