5.10-stable review patch. If anyone has any objections, please let me know.
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From: Sami Tolvanen samitolvanen@google.com
commit dbaee836d60a8e1b03e7d53a37893235662ba124 upstream.
allmodconfig + CONFIG_LTO_CLANG_THIN=y fails to build due to following linker errors:
ld.lld: error: irqbypass.c:(function __guest_enter: .text+0x21CC): relocation R_AARCH64_CONDBR19 out of range: 2031220 is not in [-1048576, 1048575]; references hyp_panic
defined in vmlinux.o
ld.lld: error: irqbypass.c:(function __guest_enter: .text+0x21E0): relocation R_AARCH64_ADR_PREL_LO21 out of range: 2031200 is not in [-1048576, 1048575]; references hyp_panic
defined in vmlinux.o
This is because with LTO, the compiler ends up placing hyp_panic() more than 1MB away from __guest_enter(). Use an unconditional branch and adr_l instead to fix the issue.
Link: https://github.com/ClangBuiltLinux/linux/issues/1317 Reported-by: Nathan Chancellor nathan@kernel.org Suggested-by: Marc Zyngier maz@kernel.org Suggested-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Sami Tolvanen samitolvanen@google.com Reviewed-by: Kees Cook keescook@chromium.org Acked-by: Will Deacon will@kernel.org Tested-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20210305202124.3768527-1-samitolvanen@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kvm/hyp/entry.S | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -85,8 +85,10 @@ SYM_INNER_LABEL(__guest_exit_panic, SYM_
// If the hyp context is loaded, go straight to hyp_panic get_loaded_vcpu x0, x1 - cbz x0, hyp_panic + cbnz x0, 1f + b hyp_panic
+1: // The hyp context is saved so make sure it is restored to allow // hyp_panic to run at hyp and, subsequently, panic to run in the host. // This makes use of __guest_exit to avoid duplication but sets the @@ -94,7 +96,7 @@ SYM_INNER_LABEL(__guest_exit_panic, SYM_ // current state is saved to the guest context but it will only be // accurate if the guest had been completely restored. adr_this_cpu x0, kvm_hyp_ctxt, x1 - adr x1, hyp_panic + adr_l x1, hyp_panic str x1, [x0, #CPU_XREG_OFFSET(30)]
get_vcpu_ptr x1, x0