Messages in this thread | | | From | Robert Jarzmik <> | Subject | Follow-up to remaining issue with alignment of __log_buf in printk.c | Date | Thu, 14 Jun 2012 21:19:31 +0200 |
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Hi Stephen and others,
I have a XScale PXA based board with has the alignement issue which makes the kernel trap during its early stage.
I wonder what is the status now, is there a fix available ?
I have tracked what happens on PXA. The pxa is an ARM v5TE chip. The new printk version you submitted is translated to the following assembly on the line : msg->ts_nsec = local_clock(); Into: => 0xc001bbe0 <log_store+496>: strd r0, [r4, r5]
In ARMv5, the "strd" assembly opcode expects the address to be 64bits aligned, hence the bug.
Now the solutions I have seen so far in the mailing lists : - #define LOG_ALIGN (__alignof__(u64)) Does always work. - #define LOG_ALIGN (__alignof__(struct log)) Doesn't work with my toolchain, as __alignof__(struct log) is 4, not 8
What are you intending to do to solve the ARMv5 issue ? Are you waiting for someone to submit a patch ?
Cheers.
-- Robert
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