The hyp-stub is loaded by the kernel's early startup code at EL2 during boot, before KVM takes ownership later. The hyp-stub's text is part of the regular kernel text, meaning it can be kprobed.
A breakpoint in the hyp-stub causes the CPU to spin in el2_sync_invalid. Add it to the __hyp_text. Signed-off-by: James Morse <[email protected]> Cc: [email protected] --- This has been a problem since kprobes was merged, it should probably have been covered in 888b3c8720e0. I'm not sure __hyp_text is the right place. Its not idmaped, and as it contains a set of vectors, adding it to the host/hyp idmap sections could grow them beyond a page... but it does run with the MMU off, so does need to be cleaned to PoC when anything wacky, like hibernate happens. With this patch, hibernate should clean the __hyp_text to PoC too. --- arch/arm64/kernel/hyp-stub.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index e1261fbaa374..17f325ba831e 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -28,6 +28,8 @@ #include <asm/virt.h> .text + .pushsection .hyp.text, "ax" + .align 11 ENTRY(__hyp_stub_vectors) -- 2.20.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
