1 files changed, 42 insertions, 0 deletions
diff --git a/arch/powerpc/perf/callchain.h b/arch/powerpc/perf/callchain.h
new file mode 100644
index 000000000..ae24d4a00
--- /dev/null
+++ b/arch/powerpc/perf/callchain.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _POWERPC_PERF_CALLCHAIN_H
+#define _POWERPC_PERF_CALLCHAIN_H
+
+int read_user_stack_slow(const void __user *ptr, void *buf, int nb);
+void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
+			    struct pt_regs *regs);
+void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
+			    struct pt_regs *regs);
+
+static inline bool invalid_user_sp(unsigned long sp)
+{
+	unsigned long mask = is_32bit_task() ? 3 : 7;
+	unsigned long top = STACK_TOP - (is_32bit_task() ? 16 : 32);
+
+	return (!sp || (sp & mask) || (sp > top));
+}
+
+/*
+ * On 32-bit we just access the address and let hash_page create a
+ * HPTE if necessary, so there is no need to fall back to reading
+ * the page tables.  Since this is called at interrupt level,
+ * do_page_fault() won't treat a DSI as a page fault.
+ */
+static inline int __read_user_stack(const void __user *ptr, void *ret,
+				    size_t size)
+{
+	unsigned long addr = (unsigned long)ptr;
+	int rc;
+
+	if (addr > TASK_SIZE - size || (addr & (size - 1)))
+		return -EFAULT;
+
+	rc = copy_from_user_nofault(ret, ptr, size);
+
+	if (IS_ENABLED(CONFIG_PPC64) && rc)
+		return read_user_stack_slow(ptr, ret, size);
+
+	return rc;
+}
+
+#endif /* _POWERPC_PERF_CALLCHAIN_H */