From: Sami Tolvanen <samitolvanen@google.com>
To: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>
Cc: Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Ard Biesheuvel <ardb@kernel.org>,
Kees Cook <keescook@chromium.org>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH] KVM: arm64: Don't use cbz/adr with external symbols
Date: Fri, 5 Mar 2021 12:21:24 -0800 [thread overview]
Message-ID: <20210305202124.3768527-1-samitolvanen@google.com> (raw)
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>
---
arch/arm64/kvm/hyp/entry.S | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index b0afad7a99c6..c62265951467 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
base-commit: 280d542f6ffac0e6d65dc267f92191d509b13b64
--
2.30.1.766.gb4fecdf3b7-goog
WARNING: multiple messages have this Message-ID (diff)
From: Sami Tolvanen <samitolvanen@google.com>
To: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Nick Desaulniers <ndesaulniers@google.com>,
linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
Nathan Chancellor <nathan@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Sami Tolvanen <samitolvanen@google.com>,
Will Deacon <will@kernel.org>
Subject: [PATCH] KVM: arm64: Don't use cbz/adr with external symbols
Date: Fri, 5 Mar 2021 12:21:24 -0800 [thread overview]
Message-ID: <20210305202124.3768527-1-samitolvanen@google.com> (raw)
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>
---
arch/arm64/kvm/hyp/entry.S | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index b0afad7a99c6..c62265951467 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
base-commit: 280d542f6ffac0e6d65dc267f92191d509b13b64
--
2.30.1.766.gb4fecdf3b7-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Sami Tolvanen <samitolvanen@google.com>
To: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>
Cc: Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Ard Biesheuvel <ardb@kernel.org>,
Kees Cook <keescook@chromium.org>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH] KVM: arm64: Don't use cbz/adr with external symbols
Date: Fri, 5 Mar 2021 12:21:24 -0800 [thread overview]
Message-ID: <20210305202124.3768527-1-samitolvanen@google.com> (raw)
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>
---
arch/arm64/kvm/hyp/entry.S | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index b0afad7a99c6..c62265951467 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
base-commit: 280d542f6ffac0e6d65dc267f92191d509b13b64
--
2.30.1.766.gb4fecdf3b7-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2021-03-05 20:22 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 20:21 Sami Tolvanen [this message]
2021-03-05 20:21 ` [PATCH] KVM: arm64: Don't use cbz/adr with external symbols Sami Tolvanen
2021-03-05 20:21 ` Sami Tolvanen
2021-03-05 20:22 ` Kees Cook
2021-03-05 20:22 ` Kees Cook
2021-03-05 20:22 ` Kees Cook
2021-03-07 4:35 ` Nathan Chancellor
2021-03-07 4:35 ` Nathan Chancellor
2021-03-07 4:35 ` Nathan Chancellor
2021-03-08 14:38 ` Will Deacon
2021-03-08 14:38 ` Will Deacon
2021-03-08 14:38 ` Will Deacon
2021-03-09 8:49 ` Marc Zyngier
2021-03-09 8:49 ` Marc Zyngier
2021-03-09 8:49 ` Marc Zyngier
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