arch/arm64/kernel/perf_regs.c

   1 #include <linux/errno.h>
   2 #include <linux/kernel.h>
   3 #include <linux/perf_event.h>
   4 #include <linux/bug.h>
   5
   6 #include <asm/compat.h>
   7 #include <asm/perf_regs.h>
   8 #include <asm/ptrace.h>
   9
  10 u64 perf_reg_value(struct pt_regs *regs, int idx)
  11 {
  12         if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM64_MAX))
  13                 return 0;
  14
  15         /*
  16          * Compat (i.e. 32 bit) mode:
  17          * - PC has been set in the pt_regs struct in kernel_entry,
  18          * - Handle SP and LR here.
  19          */
  20         if (compat_user_mode(regs)) {
  21                 if ((u32)idx == PERF_REG_ARM64_SP)
  22                         return regs->compat_sp;
  23                 if ((u32)idx == PERF_REG_ARM64_LR)
  24                         return regs->compat_lr;
  25         }
  26
  27         if ((u32)idx == PERF_REG_ARM64_SP)
  28                 return regs->sp;
  29
  30         if ((u32)idx == PERF_REG_ARM64_PC)
  31                 return regs->pc;
  32
  33         return regs->regs[idx];
  34 }
  35
  36 #define REG_RESERVED (~((1ULL << PERF_REG_ARM64_MAX) - 1))
  37
  38 int perf_reg_validate(u64 mask)
  39 {
  40         if (!mask || mask & REG_RESERVED)
  41                 return -EINVAL;
  42
  43         return 0;
  44 }
  45
  46 u64 perf_reg_abi(struct task_struct *task)
  47 {
  48         if (is_compat_thread(task_thread_info(task)))
  49                 return PERF_SAMPLE_REGS_ABI_32;
  50         else
  51                 return PERF_SAMPLE_REGS_ABI_64;
  52 }
  53
  54 void perf_get_regs_user(struct perf_regs *regs_user,
  55                         struct pt_regs *regs,
  56                         struct pt_regs *regs_user_copy)
  57 {
  58         regs_user->regs = task_pt_regs(current);
  59         regs_user->abi = perf_reg_abi(current);
  60 }