aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--Makefile4
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/kernel/entry_32.S27
-rw-r--r--arch/x86/kernel/entry_64.S37
-rw-r--r--include/linux/ftrace.h38
-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/trace/Kconfig5
-rw-r--r--kernel/trace/Makefile3
-rw-r--r--kernel/trace/ftrace.c138
-rw-r--r--lib/Kconfig.debug2
10 files changed, 256 insertions, 0 deletions
diff --git a/Makefile b/Makefile
index 20b32351906..b4a273f19b5 100644
--- a/Makefile
+++ b/Makefile
@@ -528,6 +528,10 @@ KBUILD_CFLAGS += -g
KBUILD_AFLAGS += -gdwarf-2
endif
+ifdef CONFIG_FTRACE
+KBUILD_CFLAGS += -pg
+endif
+
# We trigger additional mismatches with less inlining
ifdef CONFIG_DEBUG_SECTION_MISMATCH
KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fe361ae7ef2..c742dfeb0db 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -23,6 +23,7 @@ config X86
select HAVE_OPROFILE
select HAVE_KPROBES
select HAVE_KRETPROBES
+ select HAVE_FTRACE
select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
select HAVE_ARCH_KGDB if !X86_VOYAGER
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 2a609dc3271..f47b9b5440d 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1109,6 +1109,33 @@ ENDPROC(xen_failsafe_callback)
#endif /* CONFIG_XEN */
+#ifdef CONFIG_FTRACE
+ENTRY(mcount)
+ cmpl $ftrace_stub, ftrace_trace_function
+ jnz trace
+
+.globl ftrace_stub
+ftrace_stub:
+ ret
+
+ /* taken from glibc */
+trace:
+ pushl %eax
+ pushl %ecx
+ pushl %edx
+ movl 0xc(%esp), %eax
+ movl 0x4(%ebp), %edx
+
+ call *ftrace_trace_function
+
+ popl %edx
+ popl %ecx
+ popl %eax
+
+ jmp ftrace_stub
+END(mcount)
+#endif
+
.section .rodata,"a"
#include "syscall_table_32.S"
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 556a8df522a..f046e0c6488 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -54,6 +54,43 @@
.code64
+#ifdef CONFIG_FTRACE
+ENTRY(mcount)
+ cmpq $ftrace_stub, ftrace_trace_function
+ jnz trace
+.globl ftrace_stub
+ftrace_stub:
+ retq
+
+trace:
+ /* taken from glibc */
+ subq $0x38, %rsp
+ movq %rax, (%rsp)
+ movq %rcx, 8(%rsp)
+ movq %rdx, 16(%rsp)
+ movq %rsi, 24(%rsp)
+ movq %rdi, 32(%rsp)
+ movq %r8, 40(%rsp)
+ movq %r9, 48(%rsp)
+
+ movq 0x38(%rsp), %rdi
+ movq 8(%rbp), %rsi
+
+ call *ftrace_trace_function
+
+ movq 48(%rsp), %r9
+ movq 40(%rsp), %r8
+ movq 32(%rsp), %rdi
+ movq 24(%rsp), %rsi
+ movq 16(%rsp), %rdx
+ movq 8(%rsp), %rcx
+ movq (%rsp), %rax
+ addq $0x38, %rsp
+
+ jmp ftrace_stub
+END(mcount)
+#endif
+
#ifndef CONFIG_PREEMPT
#define retint_kernel retint_restore_args
#endif
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
new file mode 100644
index 00000000000..b96ef14c249
--- /dev/null
+++ b/include/linux/ftrace.h
@@ -0,0 +1,38 @@
+#ifndef _LINUX_FTRACE_H
+#define _LINUX_FTRACE_H
+
+#ifdef CONFIG_FTRACE
+
+#include <linux/linkage.h>
+
+#define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
+#define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
+#define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
+
+typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
+
+struct ftrace_ops {
+ ftrace_func_t func;
+ struct ftrace_ops *next;
+};
+
+/*
+ * The ftrace_ops must be a static and should also
+ * be read_mostly. These functions do modify read_mostly variables
+ * so use them sparely. Never free an ftrace_op or modify the
+ * next pointer after it has been registered. Even after unregistering
+ * it, the next pointer may still be used internally.
+ */
+int register_ftrace_function(struct ftrace_ops *ops);
+int unregister_ftrace_function(struct ftrace_ops *ops);
+void clear_ftrace_function(void);
+
+extern void ftrace_stub(unsigned long a0, unsigned long a1);
+extern void mcount(void);
+
+#else /* !CONFIG_FTRACE */
+# define register_ftrace_function(ops) do { } while (0)
+# define unregister_ftrace_function(ops) do { } while (0)
+# define clear_ftrace_function(ops) do { } while (0)
+#endif /* CONFIG_FTRACE */
+#endif /* _LINUX_FTRACE_H */
diff --git a/kernel/Makefile b/kernel/Makefile
index 1c9938addb9..fa05f6d8bdb 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
obj-$(CONFIG_MARKERS) += marker.o
obj-$(CONFIG_LATENCYTOP) += latencytop.o
+obj-$(CONFIG_FTRACE) += trace/
ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
new file mode 100644
index 00000000000..8185c91417b
--- /dev/null
+++ b/kernel/trace/Kconfig
@@ -0,0 +1,5 @@
+#
+# Architectures that offer an FTRACE implementation should select HAVE_FTRACE:
+#
+config HAVE_FTRACE
+ bool
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
new file mode 100644
index 00000000000..bf4fd215a6a
--- /dev/null
+++ b/kernel/trace/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_FTRACE) += libftrace.o
+
+libftrace-y := ftrace.o
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
new file mode 100644
index 00000000000..b6a80b98a3f
--- /dev/null
+++ b/kernel/trace/ftrace.c
@@ -0,0 +1,138 @@
+/*
+ * Infrastructure for profiling code inserted by 'gcc -pg'.
+ *
+ * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
+ * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
+ *
+ * Originally ported from the -rt patch by:
+ * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
+ *
+ * Based on code in the latency_tracer, that is:
+ *
+ * Copyright (C) 2004-2006 Ingo Molnar
+ * Copyright (C) 2004 William Lee Irwin III
+ */
+
+#include <linux/module.h>
+#include <linux/ftrace.h>
+
+static DEFINE_SPINLOCK(ftrace_func_lock);
+static struct ftrace_ops ftrace_list_end __read_mostly =
+{
+ .func = ftrace_stub,
+};
+
+static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
+ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
+
+/* mcount is defined per arch in assembly */
+EXPORT_SYMBOL(mcount);
+
+notrace void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
+{
+ struct ftrace_ops *op = ftrace_list;
+
+ /* in case someone actually ports this to alpha! */
+ read_barrier_depends();
+
+ while (op != &ftrace_list_end) {
+ /* silly alpha */
+ read_barrier_depends();
+ op->func(ip, parent_ip);
+ op = op->next;
+ };
+}
+
+/**
+ * register_ftrace_function - register a function for profiling
+ * @ops - ops structure that holds the function for profiling.
+ *
+ * Register a function to be called by all functions in the
+ * kernel.
+ *
+ * Note: @ops->func and all the functions it calls must be labeled
+ * with "notrace", otherwise it will go into a
+ * recursive loop.
+ */
+int register_ftrace_function(struct ftrace_ops *ops)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ftrace_func_lock, flags);
+ ops->next = ftrace_list;
+ /*
+ * We are entering ops into the ftrace_list but another
+ * CPU might be walking that list. We need to make sure
+ * the ops->next pointer is valid before another CPU sees
+ * the ops pointer included into the ftrace_list.
+ */
+ smp_wmb();
+ ftrace_list = ops;
+ /*
+ * For one func, simply call it directly.
+ * For more than one func, call the chain.
+ */
+ if (ops->next == &ftrace_list_end)
+ ftrace_trace_function = ops->func;
+ else
+ ftrace_trace_function = ftrace_list_func;
+ spin_unlock_irqrestore(&ftrace_func_lock, flags);
+
+ return 0;
+}
+
+/**
+ * unregister_ftrace_function - unresgister a function for profiling.
+ * @ops - ops structure that holds the function to unregister
+ *
+ * Unregister a function that was added to be called by ftrace profiling.
+ */
+int unregister_ftrace_function(struct ftrace_ops *ops)
+{
+ unsigned long flags;
+ struct ftrace_ops **p;
+ int ret = 0;
+
+ spin_lock_irqsave(&ftrace_func_lock, flags);
+
+ /*
+ * If we are the only function, then the ftrace pointer is
+ * pointing directly to that function.
+ */
+ if (ftrace_list == ops && ops->next == &ftrace_list_end) {
+ ftrace_trace_function = ftrace_stub;
+ ftrace_list = &ftrace_list_end;
+ goto out;
+ }
+
+ for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next)
+ if (*p == ops)
+ break;
+
+ if (*p != ops) {
+ ret = -1;
+ goto out;
+ }
+
+ *p = (*p)->next;
+
+ /* If we only have one func left, then call that directly */
+ if (ftrace_list->next == &ftrace_list_end)
+ ftrace_trace_function = ftrace_list->func;
+
+ out:
+ spin_unlock_irqrestore(&ftrace_func_lock, flags);
+
+ return 0;
+}
+
+/**
+ * clear_ftrace_function - reset the ftrace function
+ *
+ * This NULLs the ftrace function and in essence stops
+ * tracing. There may be lag
+ */
+void clear_ftrace_function(void)
+{
+ ftrace_trace_function = ftrace_stub;
+}
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d2099f41aa1..d8b6279a9b4 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -634,6 +634,8 @@ config LATENCYTOP
Enable this option if you want to use the LatencyTOP tool
to find out which userspace is blocking on what kernel operations.
+source kernel/trace/Kconfig
+
config PROVIDE_OHCI1394_DMA_INIT
bool "Remote debugging over FireWire early on boot"
depends on PCI && X86