From: Fuad Tabba <tabba@google.com>
To: Kalesh Singh <kaleshsingh@google.com>
Cc: maz@kernel.org, mark.rutland@arm.com, broonie@kernel.org,
madvenka@linux.microsoft.com, will@kernel.org,
qperret@google.com, james.morse@arm.com,
alexandru.elisei@arm.com, suzuki.poulose@arm.com,
catalin.marinas@arm.com, andreyknvl@gmail.com,
vincenzo.frascino@arm.com, mhiramat@kernel.org, ast@kernel.org,
wangkefeng.wang@huawei.com, elver@google.com, keirf@google.com,
yuzenghui@huawei.com, ardb@kernel.org, oupton@google.com,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
kernel-team@android.com
Subject: Re: [PATCH v5 14/17] KVM: arm64: Implement protected nVHE hyp stack unwinder
Date: Thu, 21 Jul 2022 10:58:40 +0100 [thread overview]
Message-ID: <CA+EHjTzyK+bhtbC3xU5zCnsTDHpAKFqP3sp3LYFXjkHfPn8o-Q@mail.gmail.com> (raw)
In-Reply-To: <20220721055728.718573-15-kaleshsingh@google.com>
Hi Kalesh,
On Thu, Jul 21, 2022 at 6:58 AM Kalesh Singh <kaleshsingh@google.com> wrote:
>
> Implements the common framework necessary for unwind() to work in
> the protected nVHE context:
> - on_accessible_stack()
> - on_overflow_stack()
> - unwind_next()
>
> Protected nVHE unwind() is used to unwind and save the hyp stack
> addresses to the shared stacktrace buffer. The host reads the
> entries in this buffer, symbolizes and dumps the stacktrace (later
> patch in the series).
>
> Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
> ---
Reviewed-by: Fuad Tabba <tabba@google.com>
Cheers,
/fuad
> arch/arm64/include/asm/stacktrace/common.h | 2 ++
> arch/arm64/include/asm/stacktrace/nvhe.h | 34 ++++++++++++++++++++--
> 2 files changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h
> index be7920ba70b0..73fd9e143c4a 100644
> --- a/arch/arm64/include/asm/stacktrace/common.h
> +++ b/arch/arm64/include/asm/stacktrace/common.h
> @@ -34,6 +34,7 @@ enum stack_type {
> STACK_TYPE_OVERFLOW,
> STACK_TYPE_SDEI_NORMAL,
> STACK_TYPE_SDEI_CRITICAL,
> + STACK_TYPE_HYP,
> __NR_STACK_TYPES
> };
>
> @@ -186,6 +187,7 @@ static inline int unwind_next_common(struct unwind_state *state,
> *
> * TASK -> IRQ -> OVERFLOW -> SDEI_NORMAL
> * TASK -> SDEI_NORMAL -> SDEI_CRITICAL -> OVERFLOW
> + * HYP -> OVERFLOW
> *
> * ... but the nesting itself is strict. Once we transition from one
> * stack to another, it's never valid to unwind back to that first
> diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h
> index 8f02803a005f..c3688e717136 100644
> --- a/arch/arm64/include/asm/stacktrace/nvhe.h
> +++ b/arch/arm64/include/asm/stacktrace/nvhe.h
> @@ -39,10 +39,19 @@ static inline void kvm_nvhe_unwind_init(struct unwind_state *state,
> state->pc = pc;
> }
>
> +static inline bool on_hyp_stack(unsigned long sp, unsigned long size,
> + struct stack_info *info);
> +
> static inline bool on_accessible_stack(const struct task_struct *tsk,
> unsigned long sp, unsigned long size,
> struct stack_info *info)
> {
> + if (on_accessible_stack_common(tsk, sp, size, info))
> + return true;
> +
> + if (on_hyp_stack(sp, size, info))
> + return true;
> +
> return false;
> }
>
> @@ -60,12 +69,27 @@ DECLARE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
> static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
> struct stack_info *info)
> {
> - return false;
> + unsigned long low = (unsigned long)this_cpu_ptr(overflow_stack);
> + unsigned long high = low + OVERFLOW_STACK_SIZE;
> +
> + return on_stack(sp, size, low, high, STACK_TYPE_OVERFLOW, info);
> +}
> +
> +static inline bool on_hyp_stack(unsigned long sp, unsigned long size,
> + struct stack_info *info)
> +{
> + struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params);
> + unsigned long high = params->stack_hyp_va;
> + unsigned long low = high - PAGE_SIZE;
> +
> + return on_stack(sp, size, low, high, STACK_TYPE_HYP, info);
> }
>
> static inline int notrace unwind_next(struct unwind_state *state)
> {
> - return 0;
> + struct stack_info info;
> +
> + return unwind_next_common(state, &info, NULL);
> }
> NOKPROBE_SYMBOL(unwind_next);
> #else /* !CONFIG_PROTECTED_NVHE_STACKTRACE */
> @@ -75,6 +99,12 @@ static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
> return false;
> }
>
> +static inline bool on_hyp_stack(unsigned long sp, unsigned long size,
> + struct stack_info *info)
> +{
> + return false;
> +}
> +
> static inline int notrace unwind_next(struct unwind_state *state)
> {
> return 0;
> --
> 2.37.0.170.g444d1eabd0-goog
>
next prev parent reply other threads:[~2022-07-21 9:59 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-21 5:57 [PATCH v5 00/17] KVM nVHE Hypervisor stack unwinder Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 01/17] arm64: stacktrace: Add shared header for common stack unwinding code Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 02/17] arm64: stacktrace: Factor out on_accessible_stack_common() Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 03/17] arm64: stacktrace: Factor out unwind_next_common() Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 04/17] arm64: stacktrace: Handle frame pointer from different address spaces Kalesh Singh
2022-07-21 9:57 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 05/17] arm64: stacktrace: Factor out common unwind() Kalesh Singh
2022-07-25 14:05 ` Mark Brown
2022-07-21 5:57 ` [PATCH v5 06/17] arm64: stacktrace: Add description of stacktrace/common.h Kalesh Singh
2022-07-21 9:57 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 07/17] KVM: arm64: On stack overflow switch to hyp overflow_stack Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 08/17] KVM: arm64: Add PROTECTED_NVHE_STACKTRACE Kconfig Kalesh Singh
2022-07-21 9:57 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 09/17] KVM: arm64: Allocate shared pKVM hyp stacktrace buffers Kalesh Singh
2022-07-21 9:57 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 10/17] KVM: arm64: Stub implementation of pKVM HYP stack unwinder Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 11/17] KVM: arm64: Stub implementation of non-protected nVHE " Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 12/17] KVM: arm64: Save protected-nVHE (pKVM) hyp stacktrace Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-22 15:33 ` Oliver Upton
2022-07-22 17:28 ` Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 13/17] KVM: arm64: Prepare non-protected nVHE hypervisor stacktrace Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 14/17] KVM: arm64: Implement protected nVHE hyp stack unwinder Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba [this message]
2022-07-21 5:57 ` [PATCH v5 15/17] KVM: arm64: Implement non-protected " Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 16/17] KVM: arm64: Introduce pkvm_dump_backtrace() Kalesh Singh
2022-07-21 9:59 ` Fuad Tabba
2022-07-22 11:16 ` Oliver Upton
2022-07-22 17:25 ` Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 17/17] KVM: arm64: Introduce hyp_dump_backtrace() Kalesh Singh
2022-07-21 9:59 ` Fuad Tabba
2022-07-21 20:35 ` Oliver Upton
2022-07-22 0:01 ` Kalesh Singh
2022-07-21 9:55 ` [PATCH v5 00/17] KVM nVHE Hypervisor stack unwinder Fuad Tabba
2022-07-21 16:06 ` Kalesh Singh
2022-07-22 10:48 ` Oliver Upton
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