![]() The self-modifying code that updates the TLB handler at start-up has a subtle ordering requirement: the DTLB handler must be the last thing changed. What I was seeing was the following: i) The DTLB handler was updated ii) The following printk caused a TLB miss and the look-up resulted in the page containing itlb_vector (0xc0000a00) being bounced from the TLB. iii) The subsequent access to itlb_vector caused a TLB miss and reload of the page containing itlb_vector from the page tables. iv) But this reload of the page in iii) was being done by the "new" DTLB-miss handler which resulted (correctly) in the page flags being set to read-only; the subsequent write-access to itlb_vector thus resulted in a page (access) fault. This is easily remedied if we ensure that the boot-time DTLB-miss handler continues running until the very last bit of self-modifying code has been executed. This patch should ensure that the very last thing updated is the DTLB-handler itself. Signed-off-by: Jonas Bonn <jonas@southpole.se> Acked-by: Julius Baxter <juliusbaxter@gmail.com> Tested-by: Sebastian Macke <sebastian@macke.de> |
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fault.c | ||
init.c | ||
ioremap.c | ||
Makefile | ||
tlb.c |