On Thu, Jan 24, 2019 at 04:32:56PM +0000, James Morse wrote: > 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 <james.mo...@arm.com> > Cc: sta...@vger.kernel.org > --- > > 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.
How did this code get cleaned before? Is there a problem you can identify with putting it in __hyp_text? Seems to me we should just stick it there if it has no negative side-effects and otherwise we have to make up a separate section with a specialized meaning. Thanks, Christoffer > --- > 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 kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm