diff mbox series

[v2,2/5] KVM: arm64: Compile stacktrace.nvhe.o

Message ID 20220502191222.4192768-3-kaleshsingh@google.com (mailing list archive)
State New, archived
Headers show
Series KVM nVHE Hypervisor stack unwinder | expand

Commit Message

Kalesh Singh May 2, 2022, 7:12 p.m. UTC 
Recompile stack unwinding code for use with the nVHE hypervisor. This is
a preparatory patch that will allow reusing most of the kernel unwinding
logic in the nVHE hypervisor.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---

Changes in v2:
  - Split out refactoring of common unwinding logic into a separate patch,
    per Mark Brown

 arch/arm64/include/asm/stacktrace.h | 18 +++++++++-----
 arch/arm64/kernel/stacktrace.c      | 37 ++++++++++++++++-------------
 arch/arm64/kvm/hyp/nvhe/Makefile    |  3 ++-
 3 files changed, 35 insertions(+), 23 deletions(-)

Comments

Mark Brown May 4, 2022, 2:16 p.m. UTC | #1 
On Mon, May 02, 2022 at 12:12:02PM -0700, Kalesh Singh wrote:

> Recompile stack unwinding code for use with the nVHE hypervisor. This is
> a preparatory patch that will allow reusing most of the kernel unwinding
> logic in the nVHE hypervisor.

>  enum stack_type {
> -	STACK_TYPE_UNKNOWN,
> +#ifndef __KVM_NVHE_HYPERVISOR__
>  	STACK_TYPE_TASK,
>  	STACK_TYPE_IRQ,
>  	STACK_TYPE_OVERFLOW,
>  	STACK_TYPE_SDEI_NORMAL,
>  	STACK_TYPE_SDEI_CRITICAL,
> +#endif /* !__KVM_NVHE_HYPERVISOR__ */
> +	STACK_TYPE_UNKNOWN,
>  	__NR_STACK_TYPES
>  };

I don't immediately see a problem with it but I'm curious as to why
STACK_TYPE_UNKNOWN got moved to the end of the list here?  It does mean
that zeroed memory will default to STACK_TYPE_TASK but we're not
actually relying on that.  Otherwise

Reviwed-by: Mark Brown <broonie@kernel.org>
Kalesh Singh May 4, 2022, 4:02 p.m. UTC | #2 
On Wed, May 4, 2022 at 7:17 AM Mark Brown <broonie@kernel.org> wrote:
>
> On Mon, May 02, 2022 at 12:12:02PM -0700, Kalesh Singh wrote:
>
> > Recompile stack unwinding code for use with the nVHE hypervisor. This is
> > a preparatory patch that will allow reusing most of the kernel unwinding
> > logic in the nVHE hypervisor.
>
> >  enum stack_type {
> > -     STACK_TYPE_UNKNOWN,
> > +#ifndef __KVM_NVHE_HYPERVISOR__
> >       STACK_TYPE_TASK,
> >       STACK_TYPE_IRQ,
> >       STACK_TYPE_OVERFLOW,
> >       STACK_TYPE_SDEI_NORMAL,
> >       STACK_TYPE_SDEI_CRITICAL,
> > +#endif /* !__KVM_NVHE_HYPERVISOR__ */
> > +     STACK_TYPE_UNKNOWN,
> >       __NR_STACK_TYPES
> >  };
>
> I don't immediately see a problem with it but I'm curious as to why
> STACK_TYPE_UNKNOWN got moved to the end of the list here?  It does mean
> that zeroed memory will default to STACK_TYPE_TASK but we're not
> actually relying on that.  Otherwise

Hi Mark. Thanks for the reviews.

STACK_TYPE_UNKNOWN was moved to the end purely to group the common
enum values. Not a functionality change as we don't reply on an
uninitialized stack_type

Thanks,
Kalesh

>
> Reviwed-by: Mark Brown <broonie@kernel.org>
>
> --
> To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com.
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index aec9315bf156..f5af9a94c5a6 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -16,12 +16,14 @@ 
 #include <asm/sdei.h>
 
 enum stack_type {
-	STACK_TYPE_UNKNOWN,
+#ifndef __KVM_NVHE_HYPERVISOR__
 	STACK_TYPE_TASK,
 	STACK_TYPE_IRQ,
 	STACK_TYPE_OVERFLOW,
 	STACK_TYPE_SDEI_NORMAL,
 	STACK_TYPE_SDEI_CRITICAL,
+#endif /* !__KVM_NVHE_HYPERVISOR__ */
+	STACK_TYPE_UNKNOWN,
 	__NR_STACK_TYPES
 };
 
@@ -31,11 +33,6 @@  struct stack_info {
 	enum stack_type type;
 };
 
-extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
-			   const char *loglvl);
-
-DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
-
 static inline bool on_stack(unsigned long sp, unsigned long size,
 			    unsigned long low, unsigned long high,
 			    enum stack_type type, struct stack_info *info)
@@ -54,6 +51,12 @@  static inline bool on_stack(unsigned long sp, unsigned long size,
 	return true;
 }
 
+#ifndef __KVM_NVHE_HYPERVISOR__
+extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
+			   const char *loglvl);
+
+DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
+
 static inline bool on_irq_stack(unsigned long sp, unsigned long size,
 				struct stack_info *info)
 {
@@ -88,6 +91,7 @@  static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
 static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
 			struct stack_info *info) { return false; }
 #endif
+#endif /* !__KVM_NVHE_HYPERVISOR__ */
 
 
 /*
@@ -101,6 +105,7 @@  static inline bool on_accessible_stack(const struct task_struct *tsk,
 	if (info)
 		info->type = STACK_TYPE_UNKNOWN;
 
+#ifndef __KVM_NVHE_HYPERVISOR__
 	if (on_task_stack(tsk, sp, size, info))
 		return true;
 	if (tsk != current || preemptible())
@@ -111,6 +116,7 @@  static inline bool on_accessible_stack(const struct task_struct *tsk,
 		return true;
 	if (on_sdei_stack(sp, size, info))
 		return true;
+#endif /* !__KVM_NVHE_HYPERVISOR__ */
 
 	return false;
 }
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index ee60c279511c..a84e38d41d38 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -129,6 +129,26 @@  static int notrace __unwind_next(struct task_struct *tsk,
 }
 NOKPROBE_SYMBOL(__unwind_next);
 
+static int notrace unwind_next(struct task_struct *tsk,
+			       struct unwind_state *state);
+
+static void notrace unwind(struct task_struct *tsk,
+			   struct unwind_state *state,
+			   stack_trace_consume_fn consume_entry, void *cookie)
+{
+	while (1) {
+		int ret;
+
+		if (!consume_entry(cookie, state->pc))
+			break;
+		ret = unwind_next(tsk, state);
+		if (ret < 0)
+			break;
+	}
+}
+NOKPROBE_SYMBOL(unwind);
+
+#ifndef __KVM_NVHE_HYPERVISOR__
 static int notrace unwind_next(struct task_struct *tsk,
 			       struct unwind_state *state)
 {
@@ -171,22 +191,6 @@  static int notrace unwind_next(struct task_struct *tsk,
 }
 NOKPROBE_SYMBOL(unwind_next);
 
-static void notrace unwind(struct task_struct *tsk,
-			   struct unwind_state *state,
-			   stack_trace_consume_fn consume_entry, void *cookie)
-{
-	while (1) {
-		int ret;
-
-		if (!consume_entry(cookie, state->pc))
-			break;
-		ret = unwind_next(tsk, state);
-		if (ret < 0)
-			break;
-	}
-}
-NOKPROBE_SYMBOL(unwind);
-
 static bool dump_backtrace_entry(void *arg, unsigned long where)
 {
 	char *loglvl = arg;
@@ -238,3 +242,4 @@  noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
 
 	unwind(task, &state, consume_entry, cookie);
 }
+#endif /* !__KVM_NVHE_HYPERVISOR__ */
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index f9fe4dc21b1f..c0ff0d6fc403 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -14,7 +14,8 @@  lib-objs := $(addprefix ../../../lib/, $(lib-objs))
 
 obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \
 	 hyp-main.o hyp-smp.o psci-relay.o early_alloc.o page_alloc.o \
-	 cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o
+	 cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o \
+	 ../../../kernel/stacktrace.o
 obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
 	 ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o
 obj-$(CONFIG_DEBUG_LIST) += list_debug.o