Add some stub implementations of protected nVHE stack unwinder, for
building. These are implemented later in this series.
Signed-off-by: Kalesh Singh <[email protected]>
---
arch/arm64/include/asm/stacktrace/nvhe.h | 57 ++++++++++++++++++++++++
arch/arm64/kvm/hyp/nvhe/stacktrace.c | 3 +-
2 files changed, 58 insertions(+), 2 deletions(-)
create mode 100644 arch/arm64/include/asm/stacktrace/nvhe.h
diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h
new file mode 100644
index 000000000000..1eac4e57f2ae
--- /dev/null
+++ b/arch/arm64/include/asm/stacktrace/nvhe.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * KVM nVHE hypervisor stack tracing support.
+ *
+ * The unwinder implementation depends on the nVHE mode:
+ *
+ * 1) pKVM (protected nVHE) mode - the host cannot directly access
+ * the HYP memory. The stack is unwinded in EL2 and dumped to a shared
+ * buffer where the host can read and print the stacktrace.
+ *
+ * Copyright (C) 2022 Google LLC
+ */
+#ifndef __ASM_STACKTRACE_NVHE_H
+#define __ASM_STACKTRACE_NVHE_H
+
+#include <asm/stacktrace/common.h>
+
+static inline bool on_accessible_stack(const struct task_struct *tsk,
+ unsigned long sp, unsigned long size,
+ struct stack_info *info)
+{
+ return false;
+}
+
+/*
+ * Protected nVHE HYP stack unwinder
+ */
+#ifdef __KVM_NVHE_HYPERVISOR__
+
+#ifdef CONFIG_PROTECTED_NVHE_STACKTRACE
+static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
+ struct stack_info *info)
+{
+ return false;
+}
+
+static int notrace unwind_next(struct unwind_state *state)
+{
+ return 0;
+}
+NOKPROBE_SYMBOL(unwind_next);
+#else /* !CONFIG_PROTECTED_NVHE_STACKTRACE */
+static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
+ struct stack_info *info)
+{
+ return false;
+}
+
+static int notrace unwind_next(struct unwind_state *state)
+{
+ return 0;
+}
+NOKPROBE_SYMBOL(unwind_next);
+#endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */
+
+#endif /* __KVM_NVHE_HYPERVISOR__ */
+#endif /* __ASM_STACKTRACE_NVHE_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/stacktrace.c b/arch/arm64/kvm/hyp/nvhe/stacktrace.c
index 69e65b457f1c..96c8b93320eb 100644
--- a/arch/arm64/kvm/hyp/nvhe/stacktrace.c
+++ b/arch/arm64/kvm/hyp/nvhe/stacktrace.c
@@ -4,8 +4,7 @@
*
* Copyright (C) 2022 Google LLC
*/
-#include <asm/memory.h>
-#include <asm/percpu.h>
+#include <asm/stacktrace/nvhe.h>
DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack)
__aligned(16);
--
2.37.0.170.g444d1eabd0-goog
On Fri, 15 Jul 2022 07:10:19 +0100,
Kalesh Singh <[email protected]> wrote:
>
> Add some stub implementations of protected nVHE stack unwinder, for
> building. These are implemented later in this series.
>
> Signed-off-by: Kalesh Singh <[email protected]>
> ---
> arch/arm64/include/asm/stacktrace/nvhe.h | 57 ++++++++++++++++++++++++
> arch/arm64/kvm/hyp/nvhe/stacktrace.c | 3 +-
> 2 files changed, 58 insertions(+), 2 deletions(-)
> create mode 100644 arch/arm64/include/asm/stacktrace/nvhe.h
>
> diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h
> new file mode 100644
> index 000000000000..1eac4e57f2ae
> --- /dev/null
> +++ b/arch/arm64/include/asm/stacktrace/nvhe.h
> @@ -0,0 +1,57 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * KVM nVHE hypervisor stack tracing support.
> + *
> + * The unwinder implementation depends on the nVHE mode:
> + *
> + * 1) pKVM (protected nVHE) mode - the host cannot directly access
> + * the HYP memory. The stack is unwinded in EL2 and dumped to a shared
> + * buffer where the host can read and print the stacktrace.
> + *
> + * Copyright (C) 2022 Google LLC
> + */
> +#ifndef __ASM_STACKTRACE_NVHE_H
> +#define __ASM_STACKTRACE_NVHE_H
> +
> +#include <asm/stacktrace/common.h>
> +
> +static inline bool on_accessible_stack(const struct task_struct *tsk,
> + unsigned long sp, unsigned long size,
> + struct stack_info *info)
> +{
> + return false;
> +}
> +
> +/*
> + * Protected nVHE HYP stack unwinder
> + */
> +#ifdef __KVM_NVHE_HYPERVISOR__
> +
> +#ifdef CONFIG_PROTECTED_NVHE_STACKTRACE
> +static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
> + struct stack_info *info)
> +{
> + return false;
> +}
> +
> +static int notrace unwind_next(struct unwind_state *state)
> +{
> + return 0;
> +}
> +NOKPROBE_SYMBOL(unwind_next);
I find this rather dodgy. It means that every compilation unit that
(indirectly) drags this include file may end-up with an 'unwind_next'
function. At best this will be eliminated at compilation time, but it
may also generate a warning.
Why can't this me made an 'inline' function? At the very least, it
should have a __maybe_unused attribute.
> +#else /* !CONFIG_PROTECTED_NVHE_STACKTRACE */
> +static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
> + struct stack_info *info)
> +{
> + return false;
> +}
> +
> +static int notrace unwind_next(struct unwind_state *state)
> +{
> + return 0;
> +}
> +NOKPROBE_SYMBOL(unwind_next);
Same thing here.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.