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 #include <linux/sched/task_stack.h>
   6
   7 #include <asm/compat.h>
   8 #include <asm/perf_regs.h>
   9 #include <asm/ptrace.h>
  10
  11 u64 perf_reg_value(struct pt_regs *regs, int idx)
  12 {
  13         if (WARN_ON_ONCE((u32)idx >= PERF_REG_ARM64_MAX))
  14                 return 0;
  15
  16         /*
  17          * Compat (i.e. 32 bit) mode:
  18          * - PC has been set in the pt_regs struct in kernel_entry,
  19          * - Handle SP and LR here.
  20          */
  21         if (compat_user_mode(regs)) {
  22                 if ((u32)idx == PERF_REG_ARM64_SP)
  23                         return regs->compat_sp;
  24                 if ((u32)idx == PERF_REG_ARM64_LR)
  25                         return regs->compat_lr;
  26         }
  27
  28         if ((u32)idx == PERF_REG_ARM64_SP)
  29                 return regs->sp;
  30
  31         if ((u32)idx == PERF_REG_ARM64_PC)
  32                 return regs->pc;
  33
  34         return regs->regs[idx];
  35 }
  36
  37 #define REG_RESERVED (~((1ULL << PERF_REG_ARM64_MAX) - 1))
  38
  39 int perf_reg_validate(u64 mask)
  40 {
  41         if (!mask || mask & REG_RESERVED)
  42                 return -EINVAL;
  43
  44         return 0;
  45 }
  46
  47 u64 perf_reg_abi(struct task_struct *task)
  48 {
  49         if (is_compat_thread(task_thread_info(task)))
  50                 return PERF_SAMPLE_REGS_ABI_32;
  51         else
  52                 return PERF_SAMPLE_REGS_ABI_64;
  53 }
  54
  55 void perf_get_regs_user(struct perf_regs *regs_user,
  56                         struct pt_regs *regs,
  57                         struct pt_regs *regs_user_copy)
  58 {
  59         regs_user->regs = task_pt_regs(current);
  60         regs_user->abi = perf_reg_abi(current);
  61 }