Hi
I was debugging kprobes-test for BE8 and noticed that some data fields are stored in LE instead of BE. It happens because these data fields get interpreted as instructions.
Is it a known issue?
For example: test_align_fail_data: bx lr .byte 0xaa .align .word 0x12345678
I would expect to see something like this: 00000000 <test_align_fail_data>: 0: e12fff1e bx lr 4: aa .byte 0xaa 5: 00 .byte 0x00 6: 0000 .short 0x0000 8: 12345678 .word 0x12345678
But instead I have: 00000000 <test_align_fail_data>: 0: e12fff1e bx lr 4: aa .byte 0xaa 5: 00 .byte 0x00 6: 0000 .short 0x0000 8: 12345678 eorsne r5, r4, #120, 12 ; 0x7800000
As a result the word 0x12345678 will be stored in LE.
I've run several tests and here are my observations: - Double ".align" fixes the issue :) - Behavior is the same for LE/BE, ARM/Thumb, GCC 4.4.1/4.6.x/4.8.2 - Size of alignment doesn't matter. - Issue happens only if previous data is not instruction-aligned and 0's are added before NOPs. - Explicit filling with 0's (.align , 0) fixes the issue, but as a side effect data @0x4 is interpreted as a single ".word 0xaa000000" instead of ".byte .byte .short". I'm not sure if there can be any functional difference because of this. - Issue doesn't happen if there is no instructions before data (no "bx lr" in the example). - Issue doesn't happen if data after .align is defined as ".type <symbol>,%object".