8 files changed, 56 insertions, 216 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 608adfb65dd3..95174d2cc4fb 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -117,11 +117,11 @@ config S390
         select HAVE_CMPXCHG_LOCAL
         select HAVE_C_RECORDMCOUNT
         select HAVE_DEBUG_KMEMLEAK
-        select HAVE_DYNAMIC_FTRACE
+        select HAVE_DYNAMIC_FTRACE if 64BIT
         select HAVE_DYNAMIC_FTRACE_WITH_REGS if 64BIT
         select HAVE_FTRACE_MCOUNT_RECORD
-        select HAVE_FUNCTION_GRAPH_TRACER
-        select HAVE_FUNCTION_TRACER
+        select HAVE_FUNCTION_GRAPH_TRACER if 64BIT
+        select HAVE_FUNCTION_TRACER if 64BIT
         select HAVE_FUTEX_CMPXCHG if FUTEX
         select HAVE_KERNEL_BZIP2
         select HAVE_KERNEL_GZIP
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index d419362dc231..3aef8afec336 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h
@@ -18,14 +18,8 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
 
 #endif /* __ASSEMBLY__ */
 
-#ifdef CONFIG_64BIT
 #define MCOUNT_INSN_SIZE  18
-#else
-#define MCOUNT_INSN_SIZE  22
-#endif
 
-#ifdef CONFIG_64BIT
 #define ARCH_SUPPORTS_FTRACE_OPS 1
-#endif
 
 #endif /* _ASM_S390_FTRACE_H */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index c249785669f3..204c43a4c245 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -52,8 +52,7 @@ obj-$(CONFIG_COMPAT)		+= compat_wrapper.o $(compat-obj-y)
 
 obj-$(CONFIG_STACKTRACE)        += stacktrace.o
 obj-$(CONFIG_KPROBES)           += kprobes.o
-obj-$(CONFIG_FUNCTION_TRACER)   += $(if $(CONFIG_64BIT),mcount64.o,mcount.o)
-obj-$(CONFIG_FUNCTION_TRACER)   += ftrace.o
+obj-$(CONFIG_FUNCTION_TRACER)   += mcount.o ftrace.o
 obj-$(CONFIG_CRASH_DUMP)        += crash_dump.o
 obj-$(CONFIG_UPROBES)           += uprobes.o
 
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index fcb009d3edde..f0072125926c 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -21,9 +21,8 @@ void mcount_replace_code(void);
 void ftrace_disable_code(void);
 void ftrace_enable_insn(void);
 
-#ifdef CONFIG_64BIT
 /*
- * The 64-bit mcount code looks like this:
+ * The mcount code looks like this:
  *      stg     %r14,8(%r15)            # offset 0
  *      larl    %r1,<&counter>          # offset 6
  *      brasl   %r14,_mcount            # offset 12
@@ -34,7 +33,7 @@ void ftrace_enable_insn(void);
  * Note: we do not patch the first instruction to an unconditional branch,
  * since that would break kprobes/jprobes. It is easier to leave the larl
  * instruction in and only modify the second instruction.
- * The 64-bit enabled ftrace code block looks like this:
+ * The enabled ftrace code block looks like this:
  *      larl    %r0,.+24                # offset 0
  * >    lg      %r1,__LC_FTRACE_FUNC    # offset 6
  *      br      %r1                     # offset 12
@@ -71,65 +70,15 @@ asm(
 #define MCOUNT_INSN_OFFSET      6
 #define FTRACE_INSN_SIZE        6
 
-#else /* CONFIG_64BIT */
-/*
- * The 31-bit mcount code looks like this:
- *      st      %r14,4(%r15)            # offset 0
- * >    bras    %r1,0f                  # offset 4
- * >    .long   _mcount                 # offset 8
- * >    .long   <&counter>              # offset 12
- * > 0: l       %r14,0(%r1)             # offset 16
- * >    l       %r1,4(%r1)              # offset 20
- *      basr    %r14,%r14               # offset 24
- *      l       %r14,4(%r15)            # offset 26
- * Total length is 30 bytes. The twenty bytes starting from offset 4
- * to offset 24 get overwritten by ftrace_make_nop / ftrace_make_call.
- * The 31-bit enabled ftrace code block looks like this:
- *      st      %r14,4(%r15)            # offset 0
- * >    l       %r14,__LC_FTRACE_FUNC   # offset 4
- * >    j       0f                      # offset 8
- * >    .fill   12,1,0x07               # offset 12
- *   0: basr    %r14,%r14               # offset 24
- *      l       %r14,4(%r14)            # offset 26
- * The return points of the mcount/ftrace function have the same offset 26.
- * The 31-bit disabled ftrace code block looks like this:
- *      st      %r14,4(%r15)            # offset 0
- * >    j       .+26                    # offset 4
- * >    j       0f                      # offset 8
- * >    .fill   12,1,0x07               # offset 12
- *   0: basr    %r14,%r14               # offset 24
- *      l       %r14,4(%r14)            # offset 26
- * The j instruction branches to offset 30 to skip as many instructions
- * as possible.
- */
-asm(
-        "       .align  4\n"
-        "ftrace_disable_code:\n"
-        "       j       1f\n"
-        "       j       0f\n"
-        "       .fill   12,1,0x07\n"
-        "0:     basr    %r14,%r14\n"
-        "1:\n"
-        "       .align  4\n"
-        "ftrace_enable_insn:\n"
-        "       l       %r14,"__stringify(__LC_FTRACE_FUNC)"\n");
-
-#define FTRACE_INSN_SIZE        4
-
-#endif /* CONFIG_64BIT */
-
-#ifdef CONFIG_64BIT
 int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
                        unsigned long addr)
 {
         return 0;
 }
-#endif
 
 int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
                     unsigned long addr)
 {
-#ifdef CONFIG_64BIT
         /* Initial replacement of the whole mcount block */
         if (addr == MCOUNT_ADDR) {
                 if (probe_kernel_write((void *) rec->ip - MCOUNT_INSN_OFFSET,
@@ -138,7 +87,6 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
                         return -EPERM;
                 return 0;
         }
-#endif
         if (probe_kernel_write((void *) rec->ip, ftrace_disable_code,
                                MCOUNT_INSN_SIZE))
                 return -EPERM;
@@ -196,8 +144,6 @@ out:
  * the original offset to prepare_ftrace_return and put it back.
  */
 
-#ifdef CONFIG_64BIT
-
 int ftrace_enable_ftrace_graph_caller(void)
 {
         static unsigned short offset = 0x0002;
@@ -216,25 +162,4 @@ int ftrace_disable_ftrace_graph_caller(void)
                                   &offset, sizeof(offset));
 }
 
-#else /* CONFIG_64BIT */
-
-int ftrace_enable_ftrace_graph_caller(void)
-{
-        unsigned short offset;
-
-        offset = ((void *) prepare_ftrace_return -
-                  (void *) ftrace_graph_caller) / 2;
-        return probe_kernel_write((void *) ftrace_graph_caller + 2,
-                                  &offset, sizeof(offset));
-}
-
-int ftrace_disable_ftrace_graph_caller(void)
-{
-        static unsigned short offset = 0x0002;
-
-        return probe_kernel_write((void *) ftrace_graph_caller + 2,
-                                  &offset, sizeof(offset));
-}
-
-#endif /* CONFIG_64BIT */
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index be6dbd9a81a7..07abe8d464d4 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -8,60 +8,73 @@
 #include <linux/linkage.h>
 #include <asm/asm-offsets.h>
 #include <asm/ftrace.h>
+#include <asm/ptrace.h>
 
         .section .kprobes.text, "ax"
 
 ENTRY(ftrace_stub)
         br      %r14
 
+#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)
+
 ENTRY(_mcount)
         br      %r14
 
 ENTRY(ftrace_caller)
-        stm     %r2,%r5,16(%r15)
-        bras    %r1,1f
-0:      .long   ftrace_trace_function
-1:      st      %r14,56(%r15)
-        lr      %r0,%r15
-        ahi     %r15,-96
-        l       %r3,100(%r15)
-        la      %r2,0(%r14)
-        st      %r0,__SF_BACKCHAIN(%r15)
-        la      %r3,0(%r3)
-        ahi     %r2,-MCOUNT_INSN_SIZE
-        l       %r14,0b-0b(%r1)
-        l       %r14,0(%r14)
-        basr    %r14,%r14
+        .globl  ftrace_regs_caller
+        .set    ftrace_regs_caller,ftrace_caller
+        lgr     %r1,%r15
+        aghi    %r15,-STACK_FRAME_SIZE
+        stg     %r1,__SF_BACKCHAIN(%r15)
+        stg     %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
+        stg     %r0,(STACK_PTREGS_PSW+8)(%r15)
+        stmg    %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+        aghik   %r2,%r0,-MCOUNT_INSN_SIZE
+        lgrl    %r4,function_trace_op
+        lgrl    %r1,ftrace_trace_function
+#else
+        lgr     %r2,%r0
+        aghi    %r2,-MCOUNT_INSN_SIZE
+        larl    %r4,function_trace_op
+        lg      %r4,0(%r4)
+        larl    %r1,ftrace_trace_function
+        lg      %r1,0(%r1)
+#endif
+        lgr     %r3,%r14
+        la      %r5,STACK_PTREGS(%r15)
+        basr    %r14,%r1
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-        l       %r2,100(%r15)
-        l       %r3,152(%r15)
-ENTRY(ftrace_graph_caller)
-# The bras instruction gets runtime patched to call prepare_ftrace_return.
+# The j instruction gets runtime patched to a nop instruction.
 # See ftrace_enable_ftrace_graph_caller. The patched instruction is:
-#       bras    %r14,prepare_ftrace_return
-        bras    %r14,0f
-0:      st      %r2,100(%r15)
+#       j       .+4
+ENTRY(ftrace_graph_caller)
+        j       ftrace_graph_caller_end
+        lg      %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
+        lg      %r3,(STACK_PTREGS_PSW+8)(%r15)
+        brasl   %r14,prepare_ftrace_return
+        stg     %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
+ftrace_graph_caller_end:
+        .globl  ftrace_graph_caller_end
 #endif
-        ahi     %r15,96
-        l       %r14,56(%r15)
-        lm      %r2,%r5,16(%r15)
-        br      %r14
+        lg      %r1,(STACK_PTREGS_PSW+8)(%r15)
+        lmg     %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
+        br      %r1
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
 ENTRY(return_to_handler)
-        stm     %r2,%r5,16(%r15)
-        st      %r14,56(%r15)
-        lr      %r0,%r15
-        ahi     %r15,-96
-        st      %r0,__SF_BACKCHAIN(%r15)
-        bras    %r1,0f
-        .long   ftrace_return_to_handler
-0:      l       %r2,0b-0b(%r1)
-        basr    %r14,%r2
-        lr      %r14,%r2
-        ahi     %r15,96
-        lm      %r2,%r5,16(%r15)
+        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      %r14
 
 #endif
diff --git a/arch/s390/kernel/mcount64.S b/arch/s390/kernel/mcount64.S
deleted file mode 100644
index 07abe8d464d4..000000000000
--- a/arch/s390/kernel/mcount64.S
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * Copyright IBM Corp. 2008, 2009
- *
- *   Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
- *
- */
-
-#include <linux/linkage.h>
-#include <asm/asm-offsets.h>
-#include <asm/ftrace.h>
-#include <asm/ptrace.h>
-
-        .section .kprobes.text, "ax"
-
-ENTRY(ftrace_stub)
-        br      %r14
-
-#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)
-
-ENTRY(_mcount)
-        br      %r14
-
-ENTRY(ftrace_caller)
-        .globl  ftrace_regs_caller
-        .set    ftrace_regs_caller,ftrace_caller
-        lgr     %r1,%r15
-        aghi    %r15,-STACK_FRAME_SIZE
-        stg     %r1,__SF_BACKCHAIN(%r15)
-        stg     %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
-        stg     %r0,(STACK_PTREGS_PSW+8)(%r15)
-        stmg    %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
-#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
-        aghik   %r2,%r0,-MCOUNT_INSN_SIZE
-        lgrl    %r4,function_trace_op
-        lgrl    %r1,ftrace_trace_function
-#else
-        lgr     %r2,%r0
-        aghi    %r2,-MCOUNT_INSN_SIZE
-        larl    %r4,function_trace_op
-        lg      %r4,0(%r4)
-        larl    %r1,ftrace_trace_function
-        lg      %r1,0(%r1)
-#endif
-        lgr     %r3,%r14
-        la      %r5,STACK_PTREGS(%r15)
-        basr    %r14,%r1
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-# The j instruction gets runtime patched to a nop instruction.
-# See ftrace_enable_ftrace_graph_caller. The patched instruction is:
-#       j       .+4
-ENTRY(ftrace_graph_caller)
-        j       ftrace_graph_caller_end
-        lg      %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
-        lg      %r3,(STACK_PTREGS_PSW+8)(%r15)
-        brasl   %r14,prepare_ftrace_return
-        stg     %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
-ftrace_graph_caller_end:
-        .globl  ftrace_graph_caller_end
-#endif
-        lg      %r1,(STACK_PTREGS_PSW+8)(%r15)
-        lmg     %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
-        br      %r1
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-
-ENTRY(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      %r14
-
-#endif
diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
index 650ecc83d7d7..001facfa5b74 100644
--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -388,10 +388,6 @@ do_file(char const *const fname)
                                 "unrecognized ET_REL file: %s\n", fname);
                         fail_file();
                 }
-                if (w2(ehdr->e_machine) == EM_S390) {
-                        reltype = R_390_32;
-                        mcount_adjust_32 = -4;
-                }
                 if (w2(ehdr->e_machine) == EM_MIPS) {
                         reltype = R_MIPS_32;
                         is_fake_mcount32 = MIPS32_is_fake_mcount;
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 397b6b84e8c5..d4b665610d67 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -241,13 +241,6 @@ if ($arch eq "x86_64") {
     $objcopy .= " -O elf32-i386";
     $cc .= " -m32";
 
-} elsif ($arch eq "s390" && $bits == 32) {
-    $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_390_32\\s+_mcount\$";
-    $mcount_adjust = -4;
-    $alignment = 4;
-    $ld .= " -m elf_s390";
-    $cc .= " -m31";
-
 } elsif ($arch eq "s390" && $bits == 64) {
     $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_390_(PC|PLT)32DBL\\s+_mcount\\+0x2\$";
     $mcount_adjust = -8;