[S390] ftrace: add dynamic ftrace support
Dynamic ftrace support for s390.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 1094787..b674e79 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -82,6 +82,8 @@
select USE_GENERIC_SMP_HELPERS if SMP
select HAVE_SYSCALL_WRAPPERS
select HAVE_FUNCTION_TRACER
+ select HAVE_FTRACE_MCOUNT_RECORD
+ select HAVE_DYNAMIC_FTRACE
select HAVE_DEFAULT_NO_SPIN_MUTEXES
select HAVE_OPROFILE
select HAVE_KPROBES
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index 5a5bc75..ba23d8f 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h
@@ -2,7 +2,26 @@
#define _ASM_S390_FTRACE_H
#ifndef __ASSEMBLY__
+
extern void _mcount(void);
+extern unsigned long ftrace_dyn_func;
+
+struct dyn_arch_ftrace { };
+
+#define MCOUNT_ADDR ((long)_mcount)
+
+#ifdef CONFIG_64BIT
+#define MCOUNT_INSN_SIZE 24
+#define MCOUNT_OFFSET 14
+#else
+#define MCOUNT_INSN_SIZE 30
+#define MCOUNT_OFFSET 8
#endif
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+ return addr - MCOUNT_OFFSET;
+}
+
+#endif /* __ASSEMBLY__ */
#endif /* _ASM_S390_FTRACE_H */
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index 713fe9f..5046ad6 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -68,6 +68,7 @@
#define __LC_CPUID 0x02b0
#define __LC_INT_CLOCK 0x02c8
#define __LC_MACHINE_FLAGS 0x02d8
+#define __LC_FTRACE_FUNC 0x02dc
#define __LC_IRB 0x0300
#define __LC_PFAULT_INTPARM 0x0080
#define __LC_CPU_TIMER_SAVE_AREA 0x00d8
@@ -113,6 +114,7 @@
#define __LC_INT_CLOCK 0x0340
#define __LC_VDSO_PER_CPU 0x0350
#define __LC_MACHINE_FLAGS 0x0358
+#define __LC_FTRACE_FUNC 0x0360
#define __LC_IRB 0x0380
#define __LC_PASTE 0x03c0
#define __LC_PFAULT_INTPARM 0x11b8
@@ -281,7 +283,8 @@
__u64 int_clock; /* 0x02c8 */
__u64 clock_comparator; /* 0x02d0 */
__u32 machine_flags; /* 0x02d8 */
- __u8 pad_0x02dc[0x0300-0x02dc]; /* 0x02dc */
+ __u32 ftrace_func; /* 0x02dc */
+ __u8 pad_0x02f0[0x0300-0x02f0]; /* 0x02f0 */
/* Interrupt response block */
__u8 irb[64]; /* 0x0300 */
@@ -386,7 +389,8 @@
__u64 clock_comparator; /* 0x0348 */
__u64 vdso_per_cpu_data; /* 0x0350 */
__u64 machine_flags; /* 0x0358 */
- __u8 pad_0x0360[0x0380-0x0360]; /* 0x0360 */
+ __u64 ftrace_func; /* 0x0360 */
+ __u8 pad_0x0368[0x0380-0x0368]; /* 0x0368 */
/* Interrupt response block. */
__u8 irb[64]; /* 0x0380 */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 0657de7..ce172bf 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -7,6 +7,10 @@
CFLAGS_REMOVE_early.o = -pg
endif
+ifdef CONFIG_DYNAMIC_FTRACE
+CFLAGS_REMOVE_ftrace.o = -pg
+endif
+
#
# Passing null pointers is ok for smp code, since we access the lowcore here.
#
@@ -41,6 +45,7 @@
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o
+obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
# Kexec part
S390_KEXEC_OBJS := machine_kexec.o crash.o
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index cf09948..fb26373 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -11,6 +11,7 @@
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/ctype.h>
+#include <linux/ftrace.h>
#include <linux/lockdep.h>
#include <linux/module.h>
#include <linux/pfn.h>
@@ -410,5 +411,8 @@
sclp_facilities_detect();
detect_memory_layout(memory_chunk);
S390_lowcore.machine_flags = machine_flags;
+#ifdef CONFIG_DYNAMIC_FTRACE
+ S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
+#endif
lockdep_on();
}
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
new file mode 100644
index 0000000..0b81a78
--- /dev/null
+++ b/arch/s390/kernel/ftrace.c
@@ -0,0 +1,132 @@
+/*
+ * Dynamic function tracer architecture backend.
+ *
+ * Copyright IBM Corp. 2009
+ *
+ * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
+ *
+ */
+
+#include <linux/uaccess.h>
+#include <linux/ftrace.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <asm/lowcore.h>
+
+void ftrace_disable_code(void);
+void ftrace_call_code(void);
+void ftrace_nop_code(void);
+
+#define FTRACE_INSN_SIZE 4
+
+#ifdef CONFIG_64BIT
+
+asm(
+ " .align 4\n"
+ "ftrace_disable_code:\n"
+ " j 0f\n"
+ " .word 0x0024\n"
+ " lg %r1,"__stringify(__LC_FTRACE_FUNC)"\n"
+ " basr %r14,%r1\n"
+ " lg %r14,8(15)\n"
+ " lgr %r0,%r0\n"
+ "0:\n");
+
+asm(
+ " .align 4\n"
+ "ftrace_nop_code:\n"
+ " j .+"__stringify(MCOUNT_INSN_SIZE)"\n");
+
+asm(
+ " .align 4\n"
+ "ftrace_call_code:\n"
+ " stg %r14,8(%r15)\n");
+
+#else /* CONFIG_64BIT */
+
+asm(
+ " .align 4\n"
+ "ftrace_disable_code:\n"
+ " j 0f\n"
+ " l %r1,"__stringify(__LC_FTRACE_FUNC)"\n"
+ " basr %r14,%r1\n"
+ " l %r14,4(%r15)\n"
+ " j 0f\n"
+ " bcr 0,%r7\n"
+ " bcr 0,%r7\n"
+ " bcr 0,%r7\n"
+ " bcr 0,%r7\n"
+ " bcr 0,%r7\n"
+ " bcr 0,%r7\n"
+ "0:\n");
+
+asm(
+ " .align 4\n"
+ "ftrace_nop_code:\n"
+ " j .+"__stringify(MCOUNT_INSN_SIZE)"\n");
+
+asm(
+ " .align 4\n"
+ "ftrace_call_code:\n"
+ " st %r14,4(%r15)\n");
+
+#endif /* CONFIG_64BIT */
+
+static int ftrace_modify_code(unsigned long ip,
+ void *old_code, int old_size,
+ void *new_code, int new_size)
+{
+ unsigned char replaced[MCOUNT_INSN_SIZE];
+
+ /*
+ * Note: Due to modules code can disappear and change.
+ * We need to protect against faulting as well as code
+ * changing. We do this by using the probe_kernel_*
+ * functions.
+ * This however is just a simple sanity check.
+ */
+ if (probe_kernel_read(replaced, (void *)ip, old_size))
+ return -EFAULT;
+ if (memcmp(replaced, old_code, old_size) != 0)
+ return -EINVAL;
+ if (probe_kernel_write((void *)ip, new_code, new_size))
+ return -EPERM;
+ return 0;
+}
+
+static int ftrace_make_initial_nop(struct module *mod, struct dyn_ftrace *rec,
+ unsigned long addr)
+{
+ return ftrace_modify_code(rec->ip,
+ ftrace_call_code, FTRACE_INSN_SIZE,
+ ftrace_disable_code, MCOUNT_INSN_SIZE);
+}
+
+int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
+ unsigned long addr)
+{
+ if (addr == MCOUNT_ADDR)
+ return ftrace_make_initial_nop(mod, rec, addr);
+ return ftrace_modify_code(rec->ip,
+ ftrace_call_code, FTRACE_INSN_SIZE,
+ ftrace_nop_code, FTRACE_INSN_SIZE);
+}
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ return ftrace_modify_code(rec->ip,
+ ftrace_nop_code, FTRACE_INSN_SIZE,
+ ftrace_call_code, FTRACE_INSN_SIZE);
+}
+
+int ftrace_update_ftrace_func(ftrace_func_t func)
+{
+ ftrace_dyn_func = (unsigned long)func;
+ return 0;
+}
+
+int __init ftrace_dyn_arch_init(void *data)
+{
+ *(unsigned long *)data = 0;
+ return 0;
+}
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index 8064122..de27499 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -1,5 +1,5 @@
/*
- * Copyright IBM Corp. 2008
+ * Copyright IBM Corp. 2008,2009
*
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
*
@@ -7,10 +7,101 @@
#include <asm/asm-offsets.h>
-#ifndef CONFIG_64BIT
-.globl _mcount
+ .globl ftrace_stub
+ftrace_stub:
+ br %r14
+
+#ifdef CONFIG_64BIT
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+ .globl _mcount
_mcount:
- stm %r0,%r5,8(%r15)
+ br %r14
+
+ .globl ftrace_caller
+ftrace_caller:
+ stmg %r2,%r5,32(%r15)
+ stg %r14,112(%r15)
+ lgr %r1,%r15
+ aghi %r15,-160
+ stg %r1,__SF_BACKCHAIN(%r15)
+ lgr %r2,%r14
+ lg %r3,168(%r15)
+ larl %r14,ftrace_dyn_func
+ lg %r14,0(%r14)
+ basr %r14,%r14
+ aghi %r15,160
+ lmg %r2,%r5,32(%r15)
+ lg %r14,112(%r15)
+ br %r14
+
+ .data
+ .globl ftrace_dyn_func
+ftrace_dyn_func:
+ .quad ftrace_stub
+ .previous
+
+#else /* CONFIG_DYNAMIC_FTRACE */
+
+ .globl _mcount
+_mcount:
+ stmg %r2,%r5,32(%r15)
+ stg %r14,112(%r15)
+ lgr %r1,%r15
+ aghi %r15,-160
+ stg %r1,__SF_BACKCHAIN(%r15)
+ lgr %r2,%r14
+ lg %r3,168(%r15)
+ larl %r14,ftrace_trace_function
+ lg %r14,0(%r14)
+ basr %r14,%r14
+ aghi %r15,160
+ lmg %r2,%r5,32(%r15)
+ lg %r14,112(%r15)
+ br %r14
+
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#else /* CONFIG_64BIT */
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+ .globl _mcount
+_mcount:
+ br %r14
+
+ .globl ftrace_caller
+ftrace_caller:
+ stm %r2,%r5,16(%r15)
+ st %r14,56(%r15)
+ lr %r1,%r15
+ ahi %r15,-96
+ l %r3,100(%r15)
+ la %r2,0(%r14)
+ st %r1,__SF_BACKCHAIN(%r15)
+ la %r3,0(%r3)
+ bras %r14,0f
+ .long ftrace_dyn_func
+0: l %r14,0(%r14)
+ l %r14,0(%r14)
+ basr %r14,%r14
+ ahi %r15,96
+ lm %r2,%r5,16(%r15)
+ l %r14,56(%r15)
+ br %r14
+
+ .data
+ .globl ftrace_dyn_func
+ftrace_dyn_func:
+ .long ftrace_stub
+ .previous
+
+#else /* CONFIG_DYNAMIC_FTRACE */
+
+ .globl _mcount
+_mcount:
+ stm %r2,%r5,16(%r15)
st %r14,56(%r15)
lr %r1,%r15
ahi %r15,-96
@@ -24,35 +115,9 @@
l %r14,0(%r14)
basr %r14,%r14
ahi %r15,96
- lm %r0,%r5,8(%r15)
+ lm %r2,%r5,16(%r15)
l %r14,56(%r15)
br %r14
-.globl ftrace_stub
-ftrace_stub:
- br %r14
-
-#else /* CONFIG_64BIT */
-
-.globl _mcount
-_mcount:
- stmg %r0,%r5,16(%r15)
- stg %r14,112(%r15)
- lgr %r1,%r15
- aghi %r15,-160
- stg %r1,__SF_BACKCHAIN(%r15)
- lgr %r2,%r14
- lg %r3,168(%r15)
- larl %r14,ftrace_trace_function
- lg %r14,0(%r14)
- basr %r14,%r14
- aghi %r15,160
- lmg %r0,%r5,16(%r15)
- lg %r14,112(%r15)
- br %r14
-
-.globl ftrace_stub
-ftrace_stub:
- br %r14
-
+#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* CONFIG_64BIT */
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 7402b6a..9717717 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -42,6 +42,7 @@
#include <linux/ctype.h>
#include <linux/reboot.h>
#include <linux/topology.h>
+#include <linux/ftrace.h>
#include <asm/ipl.h>
#include <asm/uaccess.h>
@@ -442,6 +443,7 @@
lc->steal_timer = S390_lowcore.steal_timer;
lc->last_update_timer = S390_lowcore.last_update_timer;
lc->last_update_clock = S390_lowcore.last_update_clock;
+ lc->ftrace_func = S390_lowcore.ftrace_func;
set_prefix((u32)(unsigned long) lc);
lowcore_ptr[0] = lc;
}
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 0af302c..cc8c484 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -572,6 +572,7 @@
cpu_lowcore->cpu_nr = cpu;
cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
+ cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
eieio();
while (signal_processor(cpu, sigp_restart) == sigp_busy)
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 0fae7da..91033e6 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -185,6 +185,19 @@
$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\$";
+ $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\$";
+ $alignment = 8;
+ $type = ".quad";
+ $ld .= " -m elf64_s390";
+ $cc .= " -m64";
+
} elsif ($arch eq "sh") {
$alignment = 2;
