On 10 October 2013 17:12, Dave Martin Dave.Martin@arm.com wrote:
On Wed, Oct 09, 2013 at 11:57:03PM +0300, Taras Kondratiuk wrote:
In Thumb2 kernel (CONFIG_THUMB2_KERNEL) kexec's relocate code is assembled in Thumb2 mode, but cpu_v7_reset() jumps to this code in ARM state, because its address is page aligned and has 0 in LSB.
Assemble this code in ARM mode to fix the issue.
I think the actual issue here is that relocate_new_kernel is not properly annotated as a function symbol.
Can you remove the explicit label declaration and try the following:
#include <linux/linkage.h> ENTRY(relocate_new_kernel) /* body of relocate_new_kernel */ ENDPROC(relocate_new_kernel)Without this, the linker will treat it as a random pointer to data and never set the Thumb bit.
This fails in precisely the same was as an ordinary function call would fail if the destination function doesn't have the needed annotation.
There should be no need to switch to ARM if the kernel is just jumping to itself...
I think it won't help, because here is no direct jump to this label. This code gets copied to a new page and jump is done to the beginning of that page.