1/* SPDX-License-Identifier: GPL-2.0-or-later */
2#ifndef _POWERPC_PERF_CALLCHAIN_H
3#define _POWERPC_PERF_CALLCHAIN_H
4
5int read_user_stack_slow(const void __user *ptr, void *buf, int nb);
6void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
7			    struct pt_regs *regs);
8void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
9			    struct pt_regs *regs);
10
11static inline bool invalid_user_sp(unsigned long sp)
12{
13	unsigned long mask = is_32bit_task() ? 3 : 7;
14	unsigned long top = STACK_TOP - (is_32bit_task() ? 16 : 32);
15
16	return (!sp || (sp & mask) || (sp > top));
17}
18
19/*
20 * On 32-bit we just access the address and let hash_page create a
21 * HPTE if necessary, so there is no need to fall back to reading
22 * the page tables.  Since this is called at interrupt level,
23 * do_page_fault() won't treat a DSI as a page fault.
24 */
25static inline int __read_user_stack(const void __user *ptr, void *ret,
26				    size_t size)
27{
28	unsigned long addr = (unsigned long)ptr;
29	int rc;
30
31	if (addr > TASK_SIZE - size || (addr & (size - 1)))
32		return -EFAULT;
33
34	rc = copy_from_user_nofault(ret, ptr, size);
35
36	if (IS_ENABLED(CONFIG_PPC64) && rc)
37		return read_user_stack_slow(ptr, ret, size);
38
39	return rc;
40}
41
42#endif /* _POWERPC_PERF_CALLCHAIN_H */
43