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-rw-r--r--arch/arm64/include/asm/stacktrace/common.h74
-rw-r--r--arch/arm64/include/asm/stacktrace/frame.h48
-rw-r--r--arch/arm64/include/asm/stacktrace/nvhe.h2
3 files changed, 92 insertions, 32 deletions
diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h
index f63dc654e545..821a8fdd31af 100644
--- a/arch/arm64/include/asm/stacktrace/common.h
+++ b/arch/arm64/include/asm/stacktrace/common.h
@@ -60,13 +60,27 @@ static inline void unwind_init_common(struct unwind_state *state)
state->stack = stackinfo_get_unknown();
}
-static struct stack_info *unwind_find_next_stack(const struct unwind_state *state,
- unsigned long sp,
- unsigned long size)
+/**
+ * unwind_find_stack() - Find the accessible stack which entirely contains an
+ * object.
+ *
+ * @state: the current unwind state.
+ * @sp: the base address of the object.
+ * @size: the size of the object.
+ *
+ * Return: a pointer to the relevant stack_info if found; NULL otherwise.
+ */
+static struct stack_info *unwind_find_stack(struct unwind_state *state,
+ unsigned long sp,
+ unsigned long size)
{
- for (int i = 0; i < state->nr_stacks; i++) {
- struct stack_info *info = &state->stacks[i];
+ struct stack_info *info = &state->stack;
+ if (stackinfo_on_stack(info, sp, size))
+ return info;
+
+ for (int i = 0; i < state->nr_stacks; i++) {
+ info = &state->stacks[i];
if (stackinfo_on_stack(info, sp, size))
return info;
}
@@ -75,36 +89,31 @@ static struct stack_info *unwind_find_next_stack(const struct unwind_state *stat
}
/**
- * unwind_consume_stack() - Check if an object is on an accessible stack,
- * updating stack boundaries so that future unwind steps cannot consume this
- * object again.
+ * unwind_consume_stack() - Update stack boundaries so that future unwind steps
+ * cannot consume this object again.
*
* @state: the current unwind state.
+ * @info: the stack_info of the stack containing the object.
* @sp: the base address of the object.
* @size: the size of the object.
*
* Return: 0 upon success, an error code otherwise.
*/
-static inline int unwind_consume_stack(struct unwind_state *state,
- unsigned long sp,
- unsigned long size)
+static inline void unwind_consume_stack(struct unwind_state *state,
+ struct stack_info *info,
+ unsigned long sp,
+ unsigned long size)
{
- struct stack_info *next;
-
- if (stackinfo_on_stack(&state->stack, sp, size))
- goto found;
-
- next = unwind_find_next_stack(state, sp, size);
- if (!next)
- return -EINVAL;
+ struct stack_info tmp;
/*
* Stack transitions are strictly one-way, and once we've
* transitioned from one stack to another, it's never valid to
* unwind back to the old stack.
*
- * Remove the current stack from the list of stacks so that it cannot
- * be found on a subsequent transition.
+ * Destroy the old stack info so that it cannot be found upon a
+ * subsequent transition. If the stack has not changed, we'll
+ * immediately restore the current stack info.
*
* Note that stacks can nest in several valid orders, e.g.
*
@@ -115,16 +124,15 @@ static inline int unwind_consume_stack(struct unwind_state *state,
* ... so we do not check the specific order of stack
* transitions.
*/
- state->stack = *next;
- *next = stackinfo_get_unknown();
+ tmp = *info;
+ *info = stackinfo_get_unknown();
+ state->stack = tmp;
-found:
/*
* Future unwind steps can only consume stack above this frame record.
* Update the current stack to start immediately above it.
*/
state->stack.low = sp + size;
- return 0;
}
/**
@@ -137,21 +145,25 @@ found:
static inline int
unwind_next_frame_record(struct unwind_state *state)
{
+ struct stack_info *info;
+ struct frame_record *record;
unsigned long fp = state->fp;
- int err;
if (fp & 0x7)
return -EINVAL;
- err = unwind_consume_stack(state, fp, 16);
- if (err)
- return err;
+ info = unwind_find_stack(state, fp, sizeof(*record));
+ if (!info)
+ return -EINVAL;
+
+ unwind_consume_stack(state, info, fp, sizeof(*record));
/*
* Record this frame record's values.
*/
- state->fp = READ_ONCE(*(unsigned long *)(fp));
- state->pc = READ_ONCE(*(unsigned long *)(fp + 8));
+ record = (struct frame_record *)fp;
+ state->fp = READ_ONCE(record->fp);
+ state->pc = READ_ONCE(record->lr);
return 0;
}
diff --git a/arch/arm64/include/asm/stacktrace/frame.h b/arch/arm64/include/asm/stacktrace/frame.h
new file mode 100644
index 000000000000..0ee0f6ba0fd8
--- /dev/null
+++ b/arch/arm64/include/asm/stacktrace/frame.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_STACKTRACE_FRAME_H
+#define __ASM_STACKTRACE_FRAME_H
+
+/*
+ * - FRAME_META_TYPE_NONE
+ *
+ * This value is reserved.
+ *
+ * - FRAME_META_TYPE_FINAL
+ *
+ * The record is the last entry on the stack.
+ * Unwinding should terminate successfully.
+ *
+ * - FRAME_META_TYPE_PT_REGS
+ *
+ * The record is embedded within a struct pt_regs, recording the registers at
+ * an arbitrary point in time.
+ * Unwinding should consume pt_regs::pc, followed by pt_regs::lr.
+ *
+ * Note: all other values are reserved and should result in unwinding
+ * terminating with an error.
+ */
+#define FRAME_META_TYPE_NONE 0
+#define FRAME_META_TYPE_FINAL 1
+#define FRAME_META_TYPE_PT_REGS 2
+
+#ifndef __ASSEMBLY__
+/*
+ * A standard AAPCS64 frame record.
+ */
+struct frame_record {
+ u64 fp;
+ u64 lr;
+};
+
+/*
+ * A metadata frame record indicating a special unwind.
+ * The record::{fp,lr} fields must be zero to indicate the presence of
+ * metadata.
+ */
+struct frame_record_meta {
+ struct frame_record record;
+ u64 type;
+};
+#endif /* __ASSEMBLY */
+
+#endif /* __ASM_STACKTRACE_FRAME_H */
diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h
index 44759281d0d4..171f9edef49f 100644
--- a/arch/arm64/include/asm/stacktrace/nvhe.h
+++ b/arch/arm64/include/asm/stacktrace/nvhe.h
@@ -47,7 +47,7 @@ static inline void kvm_nvhe_unwind_init(struct unwind_state *state,
DECLARE_KVM_NVHE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_stacktrace_info, kvm_stacktrace_info);
-DECLARE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
+DECLARE_PER_CPU(unsigned long, kvm_arm_hyp_stack_base);
void kvm_nvhe_dump_backtrace(unsigned long hyp_offset);