arch/x86/kernel/perf_regs.c

   1 #include <linux/errno.h>
   2 #include <linux/kernel.h>
   3 #include <linux/sched.h>
   4 #include <linux/perf_event.h>
   5 #include <linux/bug.h>
   6 #include <linux/stddef.h>
   7 #include <asm/perf_regs.h>
   8 #include <asm/ptrace.h>
   9
  10 #ifdef CONFIG_X86_32
  11 #define PERF_REG_X86_MAX PERF_REG_X86_32_MAX
  12 #else
  13 #define PERF_REG_X86_MAX PERF_REG_X86_64_MAX
  14 #endif
  15
  16 #define PT_REGS_OFFSET(id, r) [id] = offsetof(struct pt_regs, r)
  17
  18 static unsigned int pt_regs_offset[PERF_REG_X86_MAX] = {
  19         PT_REGS_OFFSET(PERF_REG_X86_AX, ax),
  20         PT_REGS_OFFSET(PERF_REG_X86_BX, bx),
  21         PT_REGS_OFFSET(PERF_REG_X86_CX, cx),
  22         PT_REGS_OFFSET(PERF_REG_X86_DX, dx),
  23         PT_REGS_OFFSET(PERF_REG_X86_SI, si),
  24         PT_REGS_OFFSET(PERF_REG_X86_DI, di),
  25         PT_REGS_OFFSET(PERF_REG_X86_BP, bp),
  26         PT_REGS_OFFSET(PERF_REG_X86_SP, sp),
  27         PT_REGS_OFFSET(PERF_REG_X86_IP, ip),
  28         PT_REGS_OFFSET(PERF_REG_X86_FLAGS, flags),
  29         PT_REGS_OFFSET(PERF_REG_X86_CS, cs),
  30         PT_REGS_OFFSET(PERF_REG_X86_SS, ss),
  31 #ifdef CONFIG_X86_32
  32         PT_REGS_OFFSET(PERF_REG_X86_DS, ds),
  33         PT_REGS_OFFSET(PERF_REG_X86_ES, es),
  34         PT_REGS_OFFSET(PERF_REG_X86_FS, fs),
  35         PT_REGS_OFFSET(PERF_REG_X86_GS, gs),
  36 #else
  37         /*
  38          * The pt_regs struct does not store
  39          * ds, es, fs, gs in 64 bit mode.
  40          */
  41         (unsigned int) -1,
  42         (unsigned int) -1,
  43         (unsigned int) -1,
  44         (unsigned int) -1,
  45 #endif
  46 #ifdef CONFIG_X86_64
  47         PT_REGS_OFFSET(PERF_REG_X86_R8, r8),
  48         PT_REGS_OFFSET(PERF_REG_X86_R9, r9),
  49         PT_REGS_OFFSET(PERF_REG_X86_R10, r10),
  50         PT_REGS_OFFSET(PERF_REG_X86_R11, r11),
  51         PT_REGS_OFFSET(PERF_REG_X86_R12, r12),
  52         PT_REGS_OFFSET(PERF_REG_X86_R13, r13),
  53         PT_REGS_OFFSET(PERF_REG_X86_R14, r14),
  54         PT_REGS_OFFSET(PERF_REG_X86_R15, r15),
  55 #endif
  56 };
  57
  58 u64 perf_reg_value(struct pt_regs *regs, int idx)
  59 {
  60         if (WARN_ON_ONCE(idx >= ARRAY_SIZE(pt_regs_offset)))
  61                 return 0;
  62
  63         return regs_get_register(regs, pt_regs_offset[idx]);
  64 }
  65
  66 #define REG_RESERVED (~((1ULL << PERF_REG_X86_MAX) - 1ULL))
  67
  68 #ifdef CONFIG_X86_32
  69 int perf_reg_validate(u64 mask)
  70 {
  71         if (!mask || mask & REG_RESERVED)
  72                 return -EINVAL;
  73
  74         return 0;
  75 }
  76
  77 u64 perf_reg_abi(struct task_struct *task)
  78 {
  79         return PERF_SAMPLE_REGS_ABI_32;
  80 }
  81 #else /* CONFIG_X86_64 */
  82 #define REG_NOSUPPORT ((1ULL << PERF_REG_X86_DS) | \
  83                        (1ULL << PERF_REG_X86_ES) | \
  84                        (1ULL << PERF_REG_X86_FS) | \
  85                        (1ULL << PERF_REG_X86_GS))
  86
  87 int perf_reg_validate(u64 mask)
  88 {
  89         if (!mask || mask & REG_RESERVED)
  90                 return -EINVAL;
  91
  92         if (mask & REG_NOSUPPORT)
  93                 return -EINVAL;
  94
  95         return 0;
  96 }
  97
  98 u64 perf_reg_abi(struct task_struct *task)
  99 {
 100         if (test_tsk_thread_flag(task, TIF_IA32))
 101                 return PERF_SAMPLE_REGS_ABI_32;
 102         else
 103                 return PERF_SAMPLE_REGS_ABI_64;
 104 }
 105 #endif /* CONFIG_X86_32 */