Merge branch 'ftrace' of git://github.com/rabinv/linux-2.6 into devel-stable

11 files changed, 273 insertions, 77 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c8fa1443e2c1..49778bb43782 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -14,6 +14,7 @@ config ARM
         select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
         select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
         select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL)
+        select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL)
         select HAVE_GENERIC_DMA_COHERENT
         select HAVE_KERNEL_GZIP
         select HAVE_KERNEL_LZO
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 2fd0b99afc4b..eac62085f5b2 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -23,7 +23,7 @@ config STRICT_DEVMEM
 config FRAME_POINTER
         bool
         depends on !THUMB2_KERNEL
-        default y if !ARM_UNWIND
+        default y if !ARM_UNWIND || FUNCTION_GRAPH_TRACER
         help
           If you say N here, the resulting kernel will be slightly smaller and
           faster. However, if neither FRAME_POINTER nor ARM_UNWIND are enabled,
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 1120f18a6b17..ec4327a4653d 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -63,6 +63,11 @@
 #include <asm/outercache.h>
 
 #define __exception     __attribute__((section(".exception.text")))
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#define __exception_irq_entry   __irq_entry
+#else
+#define __exception_irq_entry   __exception
+#endif
 
 struct thread_info;
 struct task_struct;
diff --git a/arch/arm/include/asm/traps.h b/arch/arm/include/asm/traps.h
index 491960bf4260..124475afb007 100644
--- a/arch/arm/include/asm/traps.h
+++ b/arch/arm/include/asm/traps.h
@@ -15,13 +15,32 @@ struct undef_hook {
 void register_undef_hook(struct undef_hook *hook);
 void unregister_undef_hook(struct undef_hook *hook);
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static inline int __in_irqentry_text(unsigned long ptr)
+{
+        extern char __irqentry_text_start[];
+        extern char __irqentry_text_end[];
+
+        return ptr >= (unsigned long)&__irqentry_text_start &&
+               ptr < (unsigned long)&__irqentry_text_end;
+}
+#else
+static inline int __in_irqentry_text(unsigned long ptr)
+{
+        return 0;
+}
+#endif
+
 static inline int in_exception_text(unsigned long ptr)
 {
         extern char __exception_text_start[];
         extern char __exception_text_end[];
+        int in;
+
+        in = ptr >= (unsigned long)&__exception_text_start &&
+             ptr < (unsigned long)&__exception_text_end;
 
-        return ptr >= (unsigned long)&__exception_text_start &&
-               ptr < (unsigned long)&__exception_text_end;
+        return in ? : __in_irqentry_text(ptr);
 }
 
 extern void __init early_trap_init(void);
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 5b9b268f4fbb..679851a9f589 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -5,7 +5,7 @@
 CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$(TEXT_OFFSET)
 AFLAGS_head.o        := -DTEXT_OFFSET=$(TEXT_OFFSET)
 
-ifdef CONFIG_DYNAMIC_FTRACE
+ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_ftrace.o = -pg
 endif
 
@@ -33,6 +33,7 @@ obj-$(CONFIG_SMP)		+= smp.o
 obj-$(CONFIG_HAVE_ARM_SCU)      += smp_scu.o
 obj-$(CONFIG_HAVE_ARM_TWD)      += smp_twd.o
 obj-$(CONFIG_DYNAMIC_FTRACE)    += ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER)     += ftrace.o
 obj-$(CONFIG_KEXEC)             += machine_kexec.o relocate_kernel.o
 obj-$(CONFIG_KPROBES)           += kprobes.o kprobes-decode.o
 obj-$(CONFIG_ATAGS_PROC)        += atags.o
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 8bfa98757cd2..aae802ee12f8 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -141,98 +141,170 @@ ENDPROC(ret_from_fork)
 #endif
 #endif
 
-#ifdef CONFIG_DYNAMIC_FTRACE
-ENTRY(__gnu_mcount_nc)
-        mov     ip, lr
-        ldmia   sp!, {lr}
-        mov     pc, ip
-ENDPROC(__gnu_mcount_nc)
+.macro __mcount suffix
+        mcount_enter
+        ldr     r0, =ftrace_trace_function
+        ldr     r2, [r0]
+        adr     r0, .Lftrace_stub
+        cmp     r0, r2
+        bne     1f
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+        ldr     r1, =ftrace_graph_return
+        ldr     r2, [r1]
+        cmp     r0, r2
+        bne     ftrace_graph_caller\suffix
+
+        ldr     r1, =ftrace_graph_entry
+        ldr     r2, [r1]
+        ldr     r0, =ftrace_graph_entry_stub
+        cmp     r0, r2
+        bne     ftrace_graph_caller\suffix
+#endif
 
-ENTRY(ftrace_caller)
-        stmdb   sp!, {r0-r3, lr}
-        mov     r0, lr
+        mcount_exit
+
+1:      mcount_get_lr   r1                      @ lr of instrumented func
+        mov     r0, lr                          @ instrumented function
+        sub     r0, r0, #MCOUNT_INSN_SIZE
+        adr     lr, BSYM(2f)
+        mov     pc, r2
+2:      mcount_exit
+.endm
+
+.macro __ftrace_caller suffix
+        mcount_enter
+
+        mcount_get_lr   r1                      @ lr of instrumented func
+        mov     r0, lr                          @ instrumented function
         sub     r0, r0, #MCOUNT_INSN_SIZE
-        ldr     r1, [sp, #20]
 
-        .global ftrace_call
-ftrace_call:
+        .globl ftrace_call\suffix
+ftrace_call\suffix:
         bl      ftrace_stub
-        ldmia   sp!, {r0-r3, ip, lr}
-        mov     pc, ip
-ENDPROC(ftrace_caller)
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+        .globl ftrace_graph_call\suffix
+ftrace_graph_call\suffix:
+        mov     r0, r0
+#endif
+
+        mcount_exit
+.endm
+
+.macro __ftrace_graph_caller
+        sub     r0, fp, #4              @ &lr of instrumented routine (&parent)
+#ifdef CONFIG_DYNAMIC_FTRACE
+        @ called from __ftrace_caller, saved in mcount_enter
+        ldr     r1, [sp, #16]           @ instrumented routine (func)
+#else
+        @ called from __mcount, untouched in lr
+        mov     r1, lr                  @ instrumented routine (func)
+#endif
+        sub     r1, r1, #MCOUNT_INSN_SIZE
+        mov     r2, fp                  @ frame pointer
+        bl      prepare_ftrace_return
+        mcount_exit
+.endm
 
 #ifdef CONFIG_OLD_MCOUNT
+/*
+ * mcount
+ */
+
+.macro mcount_enter
+        stmdb   sp!, {r0-r3, lr}
+.endm
+
+.macro mcount_get_lr reg
+        ldr     \reg, [fp, #-4]
+.endm
+
+.macro mcount_exit
+        ldr     lr, [fp, #-4]
+        ldmia   sp!, {r0-r3, pc}
+.endm
+
 ENTRY(mcount)
+#ifdef CONFIG_DYNAMIC_FTRACE
         stmdb   sp!, {lr}
         ldr     lr, [fp, #-4]
         ldmia   sp!, {pc}
+#else
+        __mcount _old
+#endif
 ENDPROC(mcount)
 
+#ifdef CONFIG_DYNAMIC_FTRACE
 ENTRY(ftrace_caller_old)
-        stmdb   sp!, {r0-r3, lr}
-        ldr     r1, [fp, #-4]
-        mov     r0, lr
-        sub     r0, r0, #MCOUNT_INSN_SIZE
-
-        .globl ftrace_call_old
-ftrace_call_old:
-        bl      ftrace_stub
-        ldr     lr, [fp, #-4]                   @ restore lr
-        ldmia   sp!, {r0-r3, pc}
+        __ftrace_caller _old
 ENDPROC(ftrace_caller_old)
 #endif
 
-#else
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller_old)
+        __ftrace_graph_caller
+ENDPROC(ftrace_graph_caller_old)
+#endif
 
-ENTRY(__gnu_mcount_nc)
+.purgem mcount_enter
+.purgem mcount_get_lr
+.purgem mcount_exit
+#endif
+
+/*
+ * __gnu_mcount_nc
+ */
+
+.macro mcount_enter
         stmdb   sp!, {r0-r3, lr}
-        ldr     r0, =ftrace_trace_function
-        ldr     r2, [r0]
-        adr     r0, .Lftrace_stub
-        cmp     r0, r2
-        bne     gnu_trace
+.endm
+
+.macro mcount_get_lr reg
+        ldr     \reg, [sp, #20]
+.endm
+
+.macro mcount_exit
         ldmia   sp!, {r0-r3, ip, lr}
         mov     pc, ip
+.endm
 
-gnu_trace:
-        ldr     r1, [sp, #20]                   @ lr of instrumented routine
-        mov     r0, lr
-        sub     r0, r0, #MCOUNT_INSN_SIZE
-        adr     lr, BSYM(1f)
-        mov     pc, r2
-1:
-        ldmia   sp!, {r0-r3, ip, lr}
+ENTRY(__gnu_mcount_nc)
+#ifdef CONFIG_DYNAMIC_FTRACE
+        mov     ip, lr
+        ldmia   sp!, {lr}
         mov     pc, ip
+#else
+        __mcount
+#endif
 ENDPROC(__gnu_mcount_nc)
 
-#ifdef CONFIG_OLD_MCOUNT
-/*
- * This is under an ifdef in order to force link-time errors for people trying
- * to build with !FRAME_POINTER with a GCC which doesn't use the new-style
- * mcount.
- */
-ENTRY(mcount)
-        stmdb   sp!, {r0-r3, lr}
-        ldr     r0, =ftrace_trace_function
-        ldr     r2, [r0]
-        adr     r0, ftrace_stub
-        cmp     r0, r2
-        bne     trace
-        ldr     lr, [fp, #-4]                   @ restore lr
-        ldmia   sp!, {r0-r3, pc}
+#ifdef CONFIG_DYNAMIC_FTRACE
+ENTRY(ftrace_caller)
+        __ftrace_caller
+ENDPROC(ftrace_caller)
+#endif
 
-trace:
-        ldr     r1, [fp, #-4]                   @ lr of instrumented routine
-        mov     r0, lr
-        sub     r0, r0, #MCOUNT_INSN_SIZE
-        mov     lr, pc
-        mov     pc, r2
-        ldr     lr, [fp, #-4]                   @ restore lr
-        ldmia   sp!, {r0-r3, pc}
-ENDPROC(mcount)
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+        __ftrace_graph_caller
+ENDPROC(ftrace_graph_caller)
 #endif
 
-#endif /* CONFIG_DYNAMIC_FTRACE */
+.purgem mcount_enter
+.purgem mcount_get_lr
+.purgem mcount_exit
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+        .globl return_to_handler
+return_to_handler:
+        stmdb   sp!, {r0-r3}
+        mov     r0, fp                  @ frame pointer
+        bl      ftrace_return_to_handler
+        mov     lr, r0                  @ r0 has real ret addr
+        ldmia   sp!, {r0-r3}
+        mov     pc, lr
+#endif
 
 ENTRY(ftrace_stub)
 .Lftrace_stub:
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index 971ac8c36ea7..c0062ad1e847 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -24,6 +24,7 @@
 #define NOP             0xe8bd4000      /* pop {lr} */
 #endif
 
+#ifdef CONFIG_DYNAMIC_FTRACE
 #ifdef CONFIG_OLD_MCOUNT
 #define OLD_MCOUNT_ADDR ((unsigned long) mcount)
 #define OLD_FTRACE_ADDR ((unsigned long) ftrace_caller_old)
@@ -59,9 +60,9 @@ static unsigned long adjust_address(struct dyn_ftrace *rec, unsigned long addr)
 }
 #endif
 
-/* construct a branch (BL) instruction to addr */
 #ifdef CONFIG_THUMB2_KERNEL
-static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
+static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
+                                       bool link)
 {
         unsigned long s, j1, j2, i1, i2, imm10, imm11;
         unsigned long first, second;
@@ -83,15 +84,22 @@ static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
         j2 = (!i2) ^ s;
 
         first = 0xf000 | (s << 10) | imm10;
-        second = 0xd000 | (j1 << 13) | (j2 << 11) | imm11;
+        second = 0x9000 | (j1 << 13) | (j2 << 11) | imm11;
+        if (link)
+                second |= 1 << 14;
 
         return (second << 16) | first;
 }
 #else
-static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
+static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
+                                       bool link)
 {
+        unsigned long opcode = 0xea000000;
         long offset;
 
+        if (link)
+                opcode |= 1 << 24;
+
         offset = (long)addr - (long)(pc + 8);
         if (unlikely(offset < -33554432 || offset > 33554428)) {
                 /* Can't generate branches that far (from ARM ARM). Ftrace
@@ -103,10 +111,15 @@ static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
 
         offset = (offset >> 2) & 0x00ffffff;
 
-        return 0xeb000000 | offset;
+        return opcode | offset;
 }
 #endif
 
+static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
+{
+        return ftrace_gen_branch(pc, addr, true);
+}
+
 static int ftrace_modify_code(unsigned long pc, unsigned long old,
                               unsigned long new)
 {
@@ -193,3 +206,83 @@ int __init ftrace_dyn_arch_init(void *data)
 
         return 0;
 }
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+                           unsigned long frame_pointer)
+{
+        unsigned long return_hooker = (unsigned long) &return_to_handler;
+        struct ftrace_graph_ent trace;
+        unsigned long old;
+        int err;
+
+        if (unlikely(atomic_read(&current->tracing_graph_pause)))
+                return;
+
+        old = *parent;
+        *parent = return_hooker;
+
+        err = ftrace_push_return_trace(old, self_addr, &trace.depth,
+                                       frame_pointer);
+        if (err == -EBUSY) {
+                *parent = old;
+                return;
+        }
+
+        trace.func = self_addr;
+
+        /* Only trace if the calling function expects to */
+        if (!ftrace_graph_entry(&trace)) {
+                current->curr_ret_stack--;
+                *parent = old;
+        }
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern unsigned long ftrace_graph_call;
+extern unsigned long ftrace_graph_call_old;
+extern void ftrace_graph_caller_old(void);
+
+static int __ftrace_modify_caller(unsigned long *callsite,
+                                  void (*func) (void), bool enable)
+{
+        unsigned long caller_fn = (unsigned long) func;
+        unsigned long pc = (unsigned long) callsite;
+        unsigned long branch = ftrace_gen_branch(pc, caller_fn, false);
+        unsigned long nop = 0xe1a00000; /* mov r0, r0 */
+        unsigned long old = enable ? nop : branch;
+        unsigned long new = enable ? branch : nop;
+
+        return ftrace_modify_code(pc, old, new);
+}
+
+static int ftrace_modify_graph_caller(bool enable)
+{
+        int ret;
+
+        ret = __ftrace_modify_caller(&ftrace_graph_call,
+                                     ftrace_graph_caller,
+                                     enable);
+
+#ifdef CONFIG_OLD_MCOUNT
+        if (!ret)
+                ret = __ftrace_modify_caller(&ftrace_graph_call_old,
+                                             ftrace_graph_caller_old,
+                                             enable);
+#endif
+
+        return ret;
+}
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+        return ftrace_modify_graph_caller(true);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+        return ftrace_modify_graph_caller(false);
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 36ad3be4692a..6d616333340f 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -35,6 +35,7 @@
 #include <linux/list.h>
 #include <linux/kallsyms.h>
 #include <linux/proc_fs.h>
+#include <linux/ftrace.h>
 
 #include <asm/system.h>
 #include <asm/mach/irq.h>
@@ -105,7 +106,8 @@ unlock:
  * come via this function.  Instead, they should provide their
  * own 'handler'
  */
-asmlinkage void __exception asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
+asmlinkage void __exception_irq_entry
+asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
 {
         struct pt_regs *old_regs = set_irq_regs(regs);
 
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 8c1959590252..bbca89872c18 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -16,6 +16,7 @@
 #include <linux/cache.h>
 #include <linux/profile.h>
 #include <linux/errno.h>
+#include <linux/ftrace.h>
 #include <linux/mm.h>
 #include <linux/err.h>
 #include <linux/cpu.h>
@@ -457,7 +458,7 @@ static void ipi_timer(void)
 }
 
 #ifdef CONFIG_LOCAL_TIMERS
-asmlinkage void __exception do_local_timer(struct pt_regs *regs)
+asmlinkage void __exception_irq_entry do_local_timer(struct pt_regs *regs)
 {
         struct pt_regs *old_regs = set_irq_regs(regs);
         int cpu = smp_processor_id();
@@ -544,7 +545,7 @@ static void ipi_cpu_stop(unsigned int cpu)
  *
  *  Bit 0 - Inter-processor function call
  */
-asmlinkage void __exception do_IPI(struct pt_regs *regs)
+asmlinkage void __exception_irq_entry do_IPI(struct pt_regs *regs)
 {
         unsigned int cpu = smp_processor_id();
         struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index cead8893b46b..897c1a8f1694 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -101,6 +101,7 @@ SECTIONS
                         __exception_text_start = .;
                         *(.exception.text)
                         __exception_text_end = .;
+                        IRQENTRY_TEXT
                         TEXT_TEXT
                         SCHED_TEXT
                         LOCK_TEXT
diff --git a/arch/arm/plat-versatile/sched-clock.c b/arch/arm/plat-versatile/sched-clock.c
index 9768cf7e83d7..9696ddc238c9 100644
--- a/arch/arm/plat-versatile/sched-clock.c
+++ b/arch/arm/plat-versatile/sched-clock.c
@@ -20,6 +20,7 @@
  */
 #include <linux/cnt32_to_63.h>
 #include <linux/io.h>
+#include <linux/sched.h>
 #include <asm/div64.h>
 
 #include <mach/hardware.h>