From: James Morse <james.morse@arm.com>
Date: Thu, 24 Jan 2019 16:32:55 +0000
Subject: arm64: kprobe: Always blacklist the KVM world-switch code
Git-commit: f2b3d8566d81deaca31f4e3163def0bea7746e11
Patch-mainline: v5.0-rc5
References: git-fixes
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>
Acked-by: Ivan T. Ivanov <iivanov@suse.de>
---
arch/arm64/kernel/probes/kprobes.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -541,13 +541,13 @@ bool arch_within_kprobe_blacklist(unsign
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;
}