mcount.S 4.1 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * Copyright IBM Corp. 2008, 2009
  4. *
  5. */
  6. #include <linux/linkage.h>
  7. #include <asm/asm-offsets.h>
  8. #include <asm/ftrace.h>
  9. #include <asm/nospec-insn.h>
  10. #include <asm/ptrace.h>
  11. #include <asm/export.h>
  12. #define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE)
  13. #define STACK_PTREGS (STACK_FRAME_OVERHEAD)
  14. #define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
  15. #define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
  16. #define STACK_PTREGS_ORIG_GPR2 (STACK_PTREGS + __PT_ORIG_GPR2)
  17. #define STACK_PTREGS_FLAGS (STACK_PTREGS + __PT_FLAGS)
  18. /* packed stack: allocate just enough for r14, r15 and backchain */
  19. #define TRACED_FUNC_FRAME_SIZE 24
  20. #ifdef CONFIG_FUNCTION_TRACER
  21. GEN_BR_THUNK %r1
  22. GEN_BR_THUNK %r14
  23. .section .kprobes.text, "ax"
  24. ENTRY(ftrace_stub)
  25. BR_EX %r14
  26. ENDPROC(ftrace_stub)
  27. .macro ftrace_regs_entry, allregs=0
  28. stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
  29. .if \allregs == 1
  30. # save psw mask
  31. # don't put any instructions clobbering CC before this point
  32. epsw %r1,%r14
  33. risbg %r14,%r1,0,31,32
  34. .endif
  35. lgr %r1,%r15
  36. # allocate stack frame for ftrace_caller to contain traced function
  37. aghi %r15,-TRACED_FUNC_FRAME_SIZE
  38. stg %r1,__SF_BACKCHAIN(%r15)
  39. stg %r0,(__SF_GPRS+8*8)(%r15)
  40. stg %r15,(__SF_GPRS+9*8)(%r15)
  41. # allocate pt_regs and stack frame for ftrace_trace_function
  42. aghi %r15,-STACK_FRAME_SIZE
  43. stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
  44. xc STACK_PTREGS_ORIG_GPR2(8,%r15),STACK_PTREGS_ORIG_GPR2(%r15)
  45. .if \allregs == 1
  46. stg %r14,(STACK_PTREGS_PSW)(%r15)
  47. mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
  48. .else
  49. xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15)
  50. .endif
  51. lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
  52. aghi %r1,-TRACED_FUNC_FRAME_SIZE
  53. stg %r1,__SF_BACKCHAIN(%r15)
  54. stg %r0,(STACK_PTREGS_PSW+8)(%r15)
  55. stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
  56. .endm
  57. SYM_CODE_START(ftrace_regs_caller)
  58. ftrace_regs_entry 1
  59. j ftrace_common
  60. SYM_CODE_END(ftrace_regs_caller)
  61. SYM_CODE_START(ftrace_caller)
  62. ftrace_regs_entry 0
  63. j ftrace_common
  64. SYM_CODE_END(ftrace_caller)
  65. SYM_CODE_START(ftrace_common)
  66. #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  67. aghik %r2,%r0,-MCOUNT_INSN_SIZE
  68. lgrl %r4,function_trace_op
  69. lgrl %r1,ftrace_func
  70. #else
  71. lgr %r2,%r0
  72. aghi %r2,-MCOUNT_INSN_SIZE
  73. larl %r4,function_trace_op
  74. lg %r4,0(%r4)
  75. larl %r1,ftrace_func
  76. lg %r1,0(%r1)
  77. #endif
  78. lgr %r3,%r14
  79. la %r5,STACK_PTREGS(%r15)
  80. BASR_EX %r14,%r1
  81. #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  82. # The j instruction gets runtime patched to a nop instruction.
  83. # See ftrace_enable_ftrace_graph_caller.
  84. SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL)
  85. j .Lftrace_graph_caller_end
  86. lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15)
  87. lg %r4,(STACK_PTREGS_PSW+8)(%r15)
  88. brasl %r14,prepare_ftrace_return
  89. stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
  90. .Lftrace_graph_caller_end:
  91. #endif
  92. lg %r0,(STACK_PTREGS_PSW+8)(%r15)
  93. #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  94. ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
  95. locgrz %r1,%r0
  96. #else
  97. lg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
  98. ltgr %r1,%r1
  99. jnz 0f
  100. lgr %r1,%r0
  101. #endif
  102. 0: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
  103. BR_EX %r1
  104. SYM_CODE_END(ftrace_common)
  105. #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  106. SYM_FUNC_START(return_to_handler)
  107. stmg %r2,%r5,32(%r15)
  108. lgr %r1,%r15
  109. aghi %r15,-STACK_FRAME_OVERHEAD
  110. stg %r1,__SF_BACKCHAIN(%r15)
  111. brasl %r14,ftrace_return_to_handler
  112. aghi %r15,STACK_FRAME_OVERHEAD
  113. lgr %r14,%r2
  114. lmg %r2,%r5,32(%r15)
  115. BR_EX %r14
  116. SYM_FUNC_END(return_to_handler)
  117. #endif
  118. #endif /* CONFIG_FUNCTION_TRACER */
  119. #ifdef CONFIG_KPROBES
  120. SYM_FUNC_START(__kretprobe_trampoline)
  121. stg %r14,(__SF_GPRS+8*8)(%r15)
  122. lay %r15,-STACK_FRAME_SIZE(%r15)
  123. stmg %r0,%r14,STACK_PTREGS_GPRS(%r15)
  124. # store original stack pointer in backchain and pt_regs
  125. lay %r7,STACK_FRAME_SIZE(%r15)
  126. stg %r7,__SF_BACKCHAIN(%r15)
  127. stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15)
  128. # store full psw
  129. epsw %r2,%r3
  130. risbg %r3,%r2,0,31,32
  131. stg %r3,STACK_PTREGS_PSW(%r15)
  132. larl %r1,__kretprobe_trampoline
  133. stg %r1,STACK_PTREGS_PSW+8(%r15)
  134. lay %r2,STACK_PTREGS(%r15)
  135. brasl %r14,trampoline_probe_handler
  136. mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15)
  137. lmg %r0,%r15,STACK_PTREGS_GPRS(%r15)
  138. lpswe __SF_EMPTY(%r15)
  139. SYM_FUNC_END(__kretprobe_trampoline)
  140. #endif /* CONFIG_KPROBES */