From: James Morse Date: Thu, 24 Jan 2019 16:32:55 +0000 (+0000) Subject: arm64: kprobe: Always blacklist the KVM world-switch code X-Git-Tag: v4.9.163~38 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=32d14df09a909fb333734e63c2f2e4facaead26b;p=platform%2Fkernel%2Flinux-amlogic.git arm64: kprobe: Always blacklist the KVM world-switch code [ Upstream commit f2b3d8566d81deaca31f4e3163def0bea7746e11 ] 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 Signed-off-by: James Morse Acked-by: Masami Hiramatsu Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index 30bcae0..d2b1b62 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -546,13 +546,13 @@ 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; }