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| author | Sami Tolvanen <samitolvanen@google.com> | 2021-03-05 23:21:24 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-03-09 11:48:24 +0300 |
| commit | dbaee836d60a8e1b03e7d53a37893235662ba124 (patch) | |
| tree | 9b54253bb7d87bd65da08980876668f986bfa457 | |
| parent | 357ad203d45c0f9d76a8feadbd5a1c5d460c638b (diff) | |
| download | linux-dbaee836d60a8e1b03e7d53a37893235662ba124.tar.xz | |
KVM: arm64: Don't use cbz/adr with external symbols
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
| -rw-r--r-- | arch/arm64/kvm/hyp/entry.S | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index 0c66a1d408fd..e831d3dfd50d 100644 --- 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_L_GLOBAL) // 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_L_GLOBAL) // 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 |