arch/powerpc/perf/callchain.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 #ifndef _POWERPC_PERF_CALLCHAIN_H
   3 #define _POWERPC_PERF_CALLCHAIN_H
   4
   5 int read_user_stack_slow(const void __user *ptr, void *buf, int nb);
   6 void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
   7                             struct pt_regs *regs);
   8 void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
   9                             struct pt_regs *regs);
  10
  11 static 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  */
  25 static 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) && !radix_enabled() && rc)
  37                 return read_user_stack_slow(ptr, ret, size);
  38
  39         return rc;
  40 }
  41
  42 #endif /* _POWERPC_PERF_CALLCHAIN_H */