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-rw-r--r--arch/s390/kernel/mcount.S167
1 files changed, 167 insertions, 0 deletions
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
new file mode 100644
index 000000000..4786bfe02
--- /dev/null
+++ b/arch/s390/kernel/mcount.S
@@ -0,0 +1,167 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright IBM Corp. 2008, 2009
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/ftrace.h>
+#include <asm/nospec-insn.h>
+#include <asm/ptrace.h>
+#include <asm/export.h>
+
+
+#define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE)
+#define STACK_PTREGS (STACK_FRAME_OVERHEAD)
+#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
+#define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW)
+#define STACK_PTREGS_ORIG_GPR2 (STACK_PTREGS + __PT_ORIG_GPR2)
+#define STACK_PTREGS_FLAGS (STACK_PTREGS + __PT_FLAGS)
+/* packed stack: allocate just enough for r14, r15 and backchain */
+#define TRACED_FUNC_FRAME_SIZE 24
+
+#ifdef CONFIG_FUNCTION_TRACER
+
+ GEN_BR_THUNK %r1
+ GEN_BR_THUNK %r14
+
+ .section .kprobes.text, "ax"
+
+ENTRY(ftrace_stub)
+ BR_EX %r14
+ENDPROC(ftrace_stub)
+
+ .macro ftrace_regs_entry, allregs=0
+ stg %r14,(__SF_GPRS+8*8)(%r15) # save traced function caller
+
+ .if \allregs == 1
+ # save psw mask
+ # don't put any instructions clobbering CC before this point
+ epsw %r1,%r14
+ risbg %r14,%r1,0,31,32
+ .endif
+
+ lgr %r1,%r15
+ # allocate stack frame for ftrace_caller to contain traced function
+ aghi %r15,-TRACED_FUNC_FRAME_SIZE
+ stg %r1,__SF_BACKCHAIN(%r15)
+ stg %r0,(__SF_GPRS+8*8)(%r15)
+ stg %r15,(__SF_GPRS+9*8)(%r15)
+ # allocate pt_regs and stack frame for ftrace_trace_function
+ aghi %r15,-STACK_FRAME_SIZE
+ stg %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
+ xc STACK_PTREGS_ORIG_GPR2(8,%r15),STACK_PTREGS_ORIG_GPR2(%r15)
+
+ .if \allregs == 1
+ stg %r14,(STACK_PTREGS_PSW)(%r15)
+ mvghi STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
+ .else
+ xc STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15)
+ .endif
+
+ lg %r14,(__SF_GPRS+8*8)(%r1) # restore original return address
+ aghi %r1,-TRACED_FUNC_FRAME_SIZE
+ stg %r1,__SF_BACKCHAIN(%r15)
+ stg %r0,(STACK_PTREGS_PSW+8)(%r15)
+ stmg %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
+ .endm
+
+SYM_CODE_START(ftrace_regs_caller)
+ ftrace_regs_entry 1
+ j ftrace_common
+SYM_CODE_END(ftrace_regs_caller)
+
+SYM_CODE_START(ftrace_caller)
+ ftrace_regs_entry 0
+ j ftrace_common
+SYM_CODE_END(ftrace_caller)
+
+SYM_CODE_START(ftrace_common)
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+ aghik %r2,%r0,-MCOUNT_INSN_SIZE
+ lgrl %r4,function_trace_op
+ lgrl %r1,ftrace_func
+#else
+ lgr %r2,%r0
+ aghi %r2,-MCOUNT_INSN_SIZE
+ larl %r4,function_trace_op
+ lg %r4,0(%r4)
+ larl %r1,ftrace_func
+ lg %r1,0(%r1)
+#endif
+ lgr %r3,%r14
+ la %r5,STACK_PTREGS(%r15)
+ BASR_EX %r14,%r1
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+# The j instruction gets runtime patched to a nop instruction.
+# See ftrace_enable_ftrace_graph_caller.
+SYM_INNER_LABEL(ftrace_graph_caller, SYM_L_GLOBAL)
+ j .Lftrace_graph_caller_end
+ lmg %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15)
+ lg %r4,(STACK_PTREGS_PSW+8)(%r15)
+ brasl %r14,prepare_ftrace_return
+ stg %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
+.Lftrace_graph_caller_end:
+#endif
+ lg %r0,(STACK_PTREGS_PSW+8)(%r15)
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+ ltg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
+ locgrz %r1,%r0
+#else
+ lg %r1,STACK_PTREGS_ORIG_GPR2(%r15)
+ ltgr %r1,%r1
+ jnz 0f
+ lgr %r1,%r0
+#endif
+0: lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
+ BR_EX %r1
+SYM_CODE_END(ftrace_common)
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+SYM_FUNC_START(return_to_handler)
+ stmg %r2,%r5,32(%r15)
+ lgr %r1,%r15
+ aghi %r15,-STACK_FRAME_OVERHEAD
+ stg %r1,__SF_BACKCHAIN(%r15)
+ brasl %r14,ftrace_return_to_handler
+ aghi %r15,STACK_FRAME_OVERHEAD
+ lgr %r14,%r2
+ lmg %r2,%r5,32(%r15)
+ BR_EX %r14
+SYM_FUNC_END(return_to_handler)
+
+#endif
+#endif /* CONFIG_FUNCTION_TRACER */
+
+#ifdef CONFIG_KPROBES
+
+SYM_FUNC_START(__kretprobe_trampoline)
+
+ stg %r14,(__SF_GPRS+8*8)(%r15)
+ lay %r15,-STACK_FRAME_SIZE(%r15)
+ stmg %r0,%r14,STACK_PTREGS_GPRS(%r15)
+
+ # store original stack pointer in backchain and pt_regs
+ lay %r7,STACK_FRAME_SIZE(%r15)
+ stg %r7,__SF_BACKCHAIN(%r15)
+ stg %r7,STACK_PTREGS_GPRS+(15*8)(%r15)
+
+ # store full psw
+ epsw %r2,%r3
+ risbg %r3,%r2,0,31,32
+ stg %r3,STACK_PTREGS_PSW(%r15)
+ larl %r1,__kretprobe_trampoline
+ stg %r1,STACK_PTREGS_PSW+8(%r15)
+
+ lay %r2,STACK_PTREGS(%r15)
+ brasl %r14,trampoline_probe_handler
+
+ mvc __SF_EMPTY(16,%r7),STACK_PTREGS_PSW(%r15)
+ lmg %r0,%r15,STACK_PTREGS_GPRS(%r15)
+ lpswe __SF_EMPTY(%r15)
+
+SYM_FUNC_END(__kretprobe_trampoline)
+
+#endif /* CONFIG_KPROBES */