arch/s390/kernel/mcount.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright IBM Corp. 2008, 2009
   4  *
   5  *   Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
   6  *
   7  */
   8
   9 #include <linux/linkage.h>
  10 #include <asm/asm-offsets.h>
  11 #include <asm/ftrace.h>
  12 #include <asm/ptrace.h>
  13 #include <asm/export.h>
  14
  15         .section .kprobes.text, "ax"
  16
  17 ENTRY(ftrace_stub)
  18         br      %r14
  19
  20 #define STACK_FRAME_SIZE  (STACK_FRAME_OVERHEAD + __PT_SIZE)
  21 #define STACK_PTREGS      (STACK_FRAME_OVERHEAD)
  22 #define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
  23 #define STACK_PTREGS_PSW  (STACK_PTREGS + __PT_PSW)
  24
  25 ENTRY(_mcount)
  26         br      %r14
  27
  28 EXPORT_SYMBOL(_mcount)
  29
  30 ENTRY(ftrace_caller)
  31         .globl  ftrace_regs_caller
  32         .set    ftrace_regs_caller,ftrace_caller
  33         lgr     %r1,%r15
  34 #ifndef CC_USING_HOTPATCH
  35         aghi    %r0,MCOUNT_RETURN_FIXUP
  36 #endif
  37         aghi    %r15,-STACK_FRAME_SIZE
  38         stg     %r1,__SF_BACKCHAIN(%r15)
  39         stg     %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
  40         stg     %r0,(STACK_PTREGS_PSW+8)(%r15)
  41         stmg    %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
  42 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  43         aghik   %r2,%r0,-MCOUNT_INSN_SIZE
  44         lgrl    %r4,function_trace_op
  45         lgrl    %r1,ftrace_trace_function
  46 #else
  47         lgr     %r2,%r0
  48         aghi    %r2,-MCOUNT_INSN_SIZE
  49         larl    %r4,function_trace_op
  50         lg      %r4,0(%r4)
  51         larl    %r1,ftrace_trace_function
  52         lg      %r1,0(%r1)
  53 #endif
  54         lgr     %r3,%r14
  55         la      %r5,STACK_PTREGS(%r15)
  56         basr    %r14,%r1
  57 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  58 # The j instruction gets runtime patched to a nop instruction.
  59 # See ftrace_enable_ftrace_graph_caller.
  60 ENTRY(ftrace_graph_caller)
  61         j       ftrace_graph_caller_end
  62         lg      %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
  63         lg      %r3,(STACK_PTREGS_PSW+8)(%r15)
  64         brasl   %r14,prepare_ftrace_return
  65         stg     %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
  66 ftrace_graph_caller_end:
  67         .globl  ftrace_graph_caller_end
  68 #endif
  69         lg      %r1,(STACK_PTREGS_PSW+8)(%r15)
  70         lmg     %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
  71         br      %r1
  72
  73 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  74
  75 ENTRY(return_to_handler)
  76         stmg    %r2,%r5,32(%r15)
  77         lgr     %r1,%r15
  78         aghi    %r15,-STACK_FRAME_OVERHEAD
  79         stg     %r1,__SF_BACKCHAIN(%r15)
  80         brasl   %r14,ftrace_return_to_handler
  81         aghi    %r15,STACK_FRAME_OVERHEAD
  82         lgr     %r14,%r2
  83         lmg     %r2,%r5,32(%r15)
  84         br      %r14
  85
  86 #endif