arm64: kprobe: Always blacklist the KVM world-switch code

On systems with VHE the kernel and KVM's world-switch code run at the
same exception level. Code that is only used on a VHE system does not
need to be annotated as __hyp_text as it can reside anywhere in the
 kernel text.

__hyp_text was also used to prevent kprobes from patching breakpoint
instructions into this region, as this code runs at a different
exception level. While this is no longer true with VHE, KVM still
switches VBAR_EL1, meaning a kprobe's breakpoint executed in the
world-switch code will cause a hyp-panic.

Move the __hyp_text check in the kprobes blacklist so it applies on
VHE systems too, to cover the common code and guest enter/exit
assembly.

Fixes: 888b3c8720e0 ("arm64: Treat all entry code as non-kprobe-able")
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 2a5b338b254240c8af9d552632214df144a1215a..f17afb99890c7241f1c035140d5d24ab10a7c79e 100644 (file)
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -478,13 +478,13 @@ bool arch_within_kprobe_blacklist(unsigned long addr)
            addr < (unsigned long)__entry_text_end) ||
            (addr >= (unsigned long)__idmap_text_start &&
            addr < (unsigned long)__idmap_text_end) ||
+           (addr >= (unsigned long)__hyp_text_start &&
+           addr < (unsigned long)__hyp_text_end) ||
            !!search_exception_tables(addr))
                return true;
 
        if (!is_kernel_in_hyp_mode()) {
-               if ((addr >= (unsigned long)__hyp_text_start &&
-                   addr < (unsigned long)__hyp_text_end) ||
-                   (addr >= (unsigned long)__hyp_idmap_text_start &&
+               if ((addr >= (unsigned long)__hyp_idmap_text_start &&
                    addr < (unsigned long)__hyp_idmap_text_end))
                        return true;
        }