* [PATCH 2/6] ARM: place C irq handlers in IRQ_ENTRY for ftrace
2010-11-06 18:25 [PATCH 1/6] ARM: ensure sched_clock() and children are notrace Rabin Vincent
@ 2010-11-06 18:25 ` Rabin Vincent
2010-11-06 18:25 ` [PATCH 3/6] ARM: ftrace: use gas macros to avoid code duplication Rabin Vincent
` (4 subsequent siblings)
5 siblings, 0 replies; 13+ messages in thread
From: Rabin Vincent @ 2010-11-06 18:25 UTC (permalink / raw)
To: linux-arm-kernel
When FUNCTION_GRAPH_TRACER is enabled, place do_IRQ() and friends in the
IRQ_ENTRY section so that the irq-related features of the function graph
tracer work.
Signed-off-by: Rabin Vincent <rabin@rab.in>
---
arch/arm/include/asm/system.h | 5 +++++
arch/arm/include/asm/traps.h | 23 +++++++++++++++++++++--
arch/arm/kernel/irq.c | 4 +++-
arch/arm/kernel/smp.c | 5 +++--
arch/arm/kernel/vmlinux.lds.S | 1 +
5 files changed, 33 insertions(+), 5 deletions(-)
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 1120f18..ec4327a 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 af5d5d1..1b960d5 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/irq.c b/arch/arm/kernel/irq.c
index 36ad3be..6d61633 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 8c19595..bbca898 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 cead889..897c1a8 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
--
1.7.2.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 3/6] ARM: ftrace: use gas macros to avoid code duplication
2010-11-06 18:25 [PATCH 1/6] ARM: ensure sched_clock() and children are notrace Rabin Vincent
2010-11-06 18:25 ` [PATCH 2/6] ARM: place C irq handlers in IRQ_ENTRY for ftrace Rabin Vincent
@ 2010-11-06 18:25 ` Rabin Vincent
2010-11-06 18:25 ` [PATCH 4/6] ARM: ftrace: function graph tracer support Rabin Vincent
` (3 subsequent siblings)
5 siblings, 0 replies; 13+ messages in thread
From: Rabin Vincent @ 2010-11-06 18:25 UTC (permalink / raw)
To: linux-arm-kernel
Use assembler macros to avoid copy/pasting code between the
implementations of the two variants of the mcount call.
Signed-off-by: Rabin Vincent <rabin@rab.in>
---
arch/arm/kernel/entry-common.S | 146 ++++++++++++++++++++++------------------
1 files changed, 80 insertions(+), 66 deletions(-)
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 8bfa987..fe1d586 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -141,98 +141,112 @@ 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
+ mcount_exit
-ENTRY(ftrace_caller)
- stmdb sp!, {r0-r3, lr}
- mov r0, lr
+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)
+
+ 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
+.purgem mcount_enter
+.purgem mcount_get_lr
+.purgem mcount_exit
+#endif
-ENTRY(__gnu_mcount_nc)
+/*
+ * __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}
-
-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_DYNAMIC_FTRACE
+ENTRY(ftrace_caller)
+ __ftrace_caller
+ENDPROC(ftrace_caller)
#endif
-#endif /* CONFIG_DYNAMIC_FTRACE */
+.purgem mcount_enter
+.purgem mcount_get_lr
+.purgem mcount_exit
ENTRY(ftrace_stub)
.Lftrace_stub:
--
1.7.2.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 4/6] ARM: ftrace: function graph tracer support
2010-11-06 18:25 [PATCH 1/6] ARM: ensure sched_clock() and children are notrace Rabin Vincent
2010-11-06 18:25 ` [PATCH 2/6] ARM: place C irq handlers in IRQ_ENTRY for ftrace Rabin Vincent
2010-11-06 18:25 ` [PATCH 3/6] ARM: ftrace: use gas macros to avoid code duplication Rabin Vincent
@ 2010-11-06 18:25 ` Rabin Vincent
2010-11-06 18:25 ` [PATCH 5/6] ARM: ftrace: graph tracer + dynamic ftrace Rabin Vincent
` (2 subsequent siblings)
5 siblings, 0 replies; 13+ messages in thread
From: Rabin Vincent @ 2010-11-06 18:25 UTC (permalink / raw)
To: linux-arm-kernel
From: Tim Bird <tim.bird@am.sony.com>
Cc: Tim Bird <tim.bird@am.sony.com>
[rabin at rab.in: rebase on top of latest code,
keep code in ftrace.c instead of separate file,
check for ftrace_graph_entry also]
Signed-off-by: Rabin Vincent <rabin@rab.in>
---
arch/arm/kernel/Makefile | 3 +-
arch/arm/kernel/entry-common.S | 46 ++++++++++++++++++++++++++++++++++++++++
arch/arm/kernel/ftrace.c | 34 +++++++++++++++++++++++++++++
3 files changed, 82 insertions(+), 1 deletions(-)
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 078dd22..b3225d4 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 fe1d586..9f17662 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -148,6 +148,20 @@ ENDPROC(ret_from_fork)
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
+
mcount_exit
1: mcount_get_lr r1 @ lr of instrumented func
@@ -172,6 +186,15 @@ ftrace_call\suffix:
mcount_exit
.endm
+.macro __ftrace_graph_caller
+ sub r0, fp, #4 @ &lr of instrumented routine (&parent)
+ mov r1, lr @ instrumented routine (func)
+ sub r1, r1, #MCOUNT_INSN_SIZE
+ mov r2, fp @ frame pointer
+ bl prepare_ftrace_return
+ mcount_exit
+.endm
+
#ifdef CONFIG_OLD_MCOUNT
/*
* mcount
@@ -206,6 +229,12 @@ ENTRY(ftrace_caller_old)
ENDPROC(ftrace_caller_old)
#endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller_old)
+ __ftrace_graph_caller
+ENDPROC(ftrace_graph_caller_old)
+#endif
+
.purgem mcount_enter
.purgem mcount_get_lr
.purgem mcount_exit
@@ -244,10 +273,27 @@ ENTRY(ftrace_caller)
ENDPROC(ftrace_caller)
#endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+ __ftrace_graph_caller
+ENDPROC(ftrace_graph_caller)
+#endif
+
.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:
mov pc, lr
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index 971ac8c..7a702a5 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)
@@ -193,3 +194,36 @@ 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(¤t->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;
+ }
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
--
1.7.2.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 5/6] ARM: ftrace: graph tracer + dynamic ftrace
2010-11-06 18:25 [PATCH 1/6] ARM: ensure sched_clock() and children are notrace Rabin Vincent
` (2 preceding siblings ...)
2010-11-06 18:25 ` [PATCH 4/6] ARM: ftrace: function graph tracer support Rabin Vincent
@ 2010-11-06 18:25 ` Rabin Vincent
2010-11-06 18:25 ` [PATCH 6/6] ARM: ftrace: enable function graph tracer Rabin Vincent
2010-11-12 18:44 ` [PATCH 1/6] ARM: ensure sched_clock() and children are notrace Rabin Vincent
5 siblings, 0 replies; 13+ messages in thread
From: Rabin Vincent @ 2010-11-06 18:25 UTC (permalink / raw)
To: linux-arm-kernel
Support the graph tracer + dynamic ftrace combination on ARM.
Signed-off-by: Rabin Vincent <rabin@rab.in>
---
arch/arm/kernel/entry-common.S | 12 +++++++
arch/arm/kernel/ftrace.c | 69 +++++++++++++++++++++++++++++++++++++---
2 files changed, 76 insertions(+), 5 deletions(-)
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 9f17662..aae802e 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -183,12 +183,24 @@ ENDPROC(ret_from_fork)
ftrace_call\suffix:
bl ftrace_stub
+#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
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index 7a702a5..c0062ad 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -60,9 +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;
@@ -84,15 +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
@@ -104,10 +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)
{
@@ -226,4 +238,51 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
*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 */
--
1.7.2.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 6/6] ARM: ftrace: enable function graph tracer
2010-11-06 18:25 [PATCH 1/6] ARM: ensure sched_clock() and children are notrace Rabin Vincent
` (3 preceding siblings ...)
2010-11-06 18:25 ` [PATCH 5/6] ARM: ftrace: graph tracer + dynamic ftrace Rabin Vincent
@ 2010-11-06 18:25 ` Rabin Vincent
2010-11-06 19:06 ` Catalin Marinas
2010-11-12 18:44 ` [PATCH 1/6] ARM: ensure sched_clock() and children are notrace Rabin Vincent
5 siblings, 1 reply; 13+ messages in thread
From: Rabin Vincent @ 2010-11-06 18:25 UTC (permalink / raw)
To: linux-arm-kernel
Add the options to enable the function graph tracer on ARM. Function
graph tracer support requires frame pointers, so exclude Thumb-2 and
also explicitly select FRAME_POINTER in FUNCTION_GRAPH_TRACER since
FUNCTION_TRACER doesn't select FRAME_POINTER when ARM_UNWIND is used
Therefore, with GCC 4.4.0+, you get plain function tracing without frame
pointers, but you'll need them if you want function graph tracing.
Signed-off-by: Rabin Vincent <rabin@rab.in>
---
arch/arm/Kconfig | 1 +
kernel/trace/Kconfig | 1 +
2 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a19a526..c5e96ff 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/kernel/trace/Kconfig b/kernel/trace/Kconfig
index e04b8bc..ff23dcf 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -141,6 +141,7 @@ config FUNCTION_TRACER
config FUNCTION_GRAPH_TRACER
bool "Kernel Function Graph Tracer"
+ select FRAME_POINTER if ARM_UNWIND
depends on HAVE_FUNCTION_GRAPH_TRACER
depends on FUNCTION_TRACER
depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
--
1.7.2.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 6/6] ARM: ftrace: enable function graph tracer
2010-11-06 18:25 ` [PATCH 6/6] ARM: ftrace: enable function graph tracer Rabin Vincent
@ 2010-11-06 19:06 ` Catalin Marinas
2010-11-08 9:18 ` Uwe Kleine-König
0 siblings, 1 reply; 13+ messages in thread
From: Catalin Marinas @ 2010-11-06 19:06 UTC (permalink / raw)
To: linux-arm-kernel
On Saturday, November 6, 2010, Rabin Vincent <rabin@rab.in> wrote:
> Add the options to enable the function graph tracer on ARM. ?Function
> graph tracer support requires frame pointers, so exclude Thumb-2 and
> also explicitly select FRAME_POINTER in FUNCTION_GRAPH_TRACER since
> FUNCTION_TRACER doesn't select FRAME_POINTER when ARM_UNWIND is used
> Therefore, with GCC 4.4.0+, you get plain function tracing without frame
> pointers, but you'll need them if you want function graph tracing.
.....
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -141,6 +141,7 @@ config FUNCTION_TRACER
>
> ?config FUNCTION_GRAPH_TRACER
> ? ? ? ?bool "Kernel Function Graph Tracer"
> + ? ? ? select FRAME_POINTER if ARM_UNWIND
Would it be better to modify FRAME_POINTER definition in the ARM
Kconfig so that it is enabled automatically when FUNCTION_GRAPH_TRACER
is enabled?
--
Catalin
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 6/6] ARM: ftrace: enable function graph tracer
2010-11-06 19:06 ` Catalin Marinas
@ 2010-11-08 9:18 ` Uwe Kleine-König
2010-11-08 10:42 ` Catalin Marinas
0 siblings, 1 reply; 13+ messages in thread
From: Uwe Kleine-König @ 2010-11-08 9:18 UTC (permalink / raw)
To: linux-arm-kernel
On Sat, Nov 06, 2010 at 07:06:28PM +0000, Catalin Marinas wrote:
> On Saturday, November 6, 2010, Rabin Vincent <rabin@rab.in> wrote:
> > Add the options to enable the function graph tracer on ARM. ?Function
> > graph tracer support requires frame pointers, so exclude Thumb-2 and
> > also explicitly select FRAME_POINTER in FUNCTION_GRAPH_TRACER since
> > FUNCTION_TRACER doesn't select FRAME_POINTER when ARM_UNWIND is used
> > Therefore, with GCC 4.4.0+, you get plain function tracing without frame
> > pointers, but you'll need them if you want function graph tracing.
> .....
> > --- a/kernel/trace/Kconfig
> > +++ b/kernel/trace/Kconfig
> > @@ -141,6 +141,7 @@ config FUNCTION_TRACER
> >
> > ?config FUNCTION_GRAPH_TRACER
> > ? ? ? ?bool "Kernel Function Graph Tracer"
> > + ? ? ? select FRAME_POINTER if ARM_UNWIND
>
> Would it be better to modify FRAME_POINTER definition in the ARM
> Kconfig so that it is enabled automatically when FUNCTION_GRAPH_TRACER
> is enabled?
I don't like that suggestion much because it hides the dependency.
Moreover a "default y if FUNCTION_GRAPH_TRACER" doesn't work if a
precondition for FRAME_POINTER isn't true. Rabin's approach at least
generates a warning.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | http://www.pengutronix.de/ |
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 6/6] ARM: ftrace: enable function graph tracer
2010-11-08 9:18 ` Uwe Kleine-König
@ 2010-11-08 10:42 ` Catalin Marinas
2010-11-09 13:46 ` Rabin Vincent
0 siblings, 1 reply; 13+ messages in thread
From: Catalin Marinas @ 2010-11-08 10:42 UTC (permalink / raw)
To: linux-arm-kernel
2010/11/8 Uwe Kleine-K?nig <u.kleine-koenig@pengutronix.de>:
> On Sat, Nov 06, 2010 at 07:06:28PM +0000, Catalin Marinas wrote:
>> On Saturday, November 6, 2010, Rabin Vincent <rabin@rab.in> wrote:
>> > Add the options to enable the function graph tracer on ARM. ?Function
>> > graph tracer support requires frame pointers, so exclude Thumb-2 and
>> > also explicitly select FRAME_POINTER in FUNCTION_GRAPH_TRACER since
>> > FUNCTION_TRACER doesn't select FRAME_POINTER when ARM_UNWIND is used
>> > Therefore, with GCC 4.4.0+, you get plain function tracing without frame
>> > pointers, but you'll need them if you want function graph tracing.
>> .....
>> > --- a/kernel/trace/Kconfig
>> > +++ b/kernel/trace/Kconfig
>> > @@ -141,6 +141,7 @@ config FUNCTION_TRACER
>> >
>> > ?config FUNCTION_GRAPH_TRACER
>> > ?? ? ? ?bool "Kernel Function Graph Tracer"
>> > + ? ? ? select FRAME_POINTER if ARM_UNWIND
>>
>> Would it be better to modify FRAME_POINTER definition in the ARM
>> Kconfig so that it is enabled automatically when FUNCTION_GRAPH_TRACER
>> is enabled?
> I don't like that suggestion much because it hides the dependency.
> Moreover a "default y if FUNCTION_GRAPH_TRACER" doesn't work if a
> precondition for FRAME_POINTER isn't true. ?Rabin's approach at least
> generates a warning.
If a precondition for FRAME_POINTER isn't true, we should not force it
via 'select'. We try to get rid of such warnings in the kernel.
However, on ARM the FRAME_POINTER depends on !THUMB2_KERNEL but for
Thumb-2 kernels HAVE_FUNCTION_GRAPH_TRACER is also disabled, so there
isn't a dependency issue here. It's more like a personal preference to
keep the changes within the arch/arm tree.
--
Catalin
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 6/6] ARM: ftrace: enable function graph tracer
2010-11-08 10:42 ` Catalin Marinas
@ 2010-11-09 13:46 ` Rabin Vincent
2010-11-09 14:22 ` Catalin Marinas
0 siblings, 1 reply; 13+ messages in thread
From: Rabin Vincent @ 2010-11-09 13:46 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Nov 08, 2010 at 10:42:57AM +0000, Catalin Marinas wrote:
> 2010/11/8 Uwe Kleine-K?nig <u.kleine-koenig@pengutronix.de>:
> > On Sat, Nov 06, 2010 at 07:06:28PM +0000, Catalin Marinas wrote:
> >> On Saturday, November 6, 2010, Rabin Vincent <rabin@rab.in> wrote:
> >> > --- a/kernel/trace/Kconfig
> >> > +++ b/kernel/trace/Kconfig
> >> > @@ -141,6 +141,7 @@ config FUNCTION_TRACER
> >> >
> >> > ?config FUNCTION_GRAPH_TRACER
> >> > ?? ? ? ?bool "Kernel Function Graph Tracer"
> >> > + ? ? ? select FRAME_POINTER if ARM_UNWIND
> >>
> >> Would it be better to modify FRAME_POINTER definition in the ARM
> >> Kconfig so that it is enabled automatically when FUNCTION_GRAPH_TRACER
> >> is enabled?
> > I don't like that suggestion much because it hides the dependency.
> > Moreover a "default y if FUNCTION_GRAPH_TRACER" doesn't work if a
> > precondition for FRAME_POINTER isn't true. ?Rabin's approach at least
> > generates a warning.
>
> If a precondition for FRAME_POINTER isn't true, we should not force it
> via 'select'. We try to get rid of such warnings in the kernel.
>
> However, on ARM the FRAME_POINTER depends on !THUMB2_KERNEL but for
> Thumb-2 kernels HAVE_FUNCTION_GRAPH_TRACER is also disabled, so there
> isn't a dependency issue here. It's more like a personal preference to
> keep the changes within the arch/arm tree.
OK, new patch below.
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 6/6] ARM: ftrace: enable function graph tracer
2010-11-09 13:46 ` Rabin Vincent
@ 2010-11-09 14:22 ` Catalin Marinas
0 siblings, 0 replies; 13+ messages in thread
From: Catalin Marinas @ 2010-11-09 14:22 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, 2010-11-09 at 13:46 +0000, Rabin Vincent wrote:
> Subject: [PATCHv2] ARM: ftrace: enable function graph tracer
>
> Add the options to enable the function graph tracer on ARM. Function
> graph tracer support requires frame pointers, so exclude Thumb-2 and
> also make sure FRAME_POINTER gets enabled when FUNCTION_GRAPH_TRACER is
> used, since FUNCTION_TRACER doesn't "select FRAME_POINTER" when
> ARM_UNWIND is used. Therefore, with GCC 4.4.0+, you get plain function
> tracing without frame pointers, but you'll need them if you want
> function graph tracing.
>
> Signed-off-by: Rabin Vincent <rabin@rab.in>
Looks ok to me.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 1/6] ARM: ensure sched_clock() and children are notrace
2010-11-06 18:25 [PATCH 1/6] ARM: ensure sched_clock() and children are notrace Rabin Vincent
` (4 preceding siblings ...)
2010-11-06 18:25 ` [PATCH 6/6] ARM: ftrace: enable function graph tracer Rabin Vincent
@ 2010-11-12 18:44 ` Rabin Vincent
2010-11-19 16:09 ` Rabin Vincent
5 siblings, 1 reply; 13+ messages in thread
From: Rabin Vincent @ 2010-11-12 18:44 UTC (permalink / raw)
To: linux-arm-kernel
CC'd some mach maintainers. I can split this up if needed,
since these bits can be applied independently from the rest
of the patches in the series.
On Sat, Nov 6, 2010 at 11:55 PM, Rabin Vincent <rabin@rab.in> wrote:
> Include sched.h in the files implementing sched_clock() and ensure that
> any functions called from sched_clock() have the notrace annotation.
>
> Signed-off-by: Rabin Vincent <rabin@rab.in>
> ---
> ?arch/arm/mach-tegra/timer.c ? ? ? ? ? | ? ?3 ++-
> ?arch/arm/mach-u300/timer.c ? ? ? ? ? ?| ? ?1 +
> ?arch/arm/plat-iop/time.c ? ? ? ? ? ? ?| ? ?3 ++-
> ?arch/arm/plat-nomadik/timer.c ? ? ? ? | ? ?5 +++--
> ?arch/arm/plat-omap/counter_32k.c ? ? ?| ? 11 ++++++-----
> ?arch/arm/plat-versatile/sched-clock.c | ? ?1 +
> ?6 files changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c
> index 9057d6f..88ed925 100644
> --- a/arch/arm/mach-tegra/timer.c
> +++ b/arch/arm/mach-tegra/timer.c
> @@ -21,6 +21,7 @@
> ?#include <linux/time.h>
> ?#include <linux/interrupt.h>
> ?#include <linux/irq.h>
> +#include <linux/sched.h>
> ?#include <linux/clockchips.h>
> ?#include <linux/clocksource.h>
> ?#include <linux/clk.h>
> @@ -89,7 +90,7 @@ static void tegra_timer_set_mode(enum clock_event_mode mode,
> ? ? ? ?}
> ?}
>
> -static cycle_t tegra_clocksource_read(struct clocksource *cs)
> +static cycle_t notrace tegra_clocksource_read(struct clocksource *cs)
> ?{
> ? ? ? ?return cnt32_to_63(timer_readl(TIMERUS_CNTR_1US));
> ?}
> diff --git a/arch/arm/mach-u300/timer.c b/arch/arm/mach-u300/timer.c
> index 3fc4472..672b28a 100644
> --- a/arch/arm/mach-u300/timer.c
> +++ b/arch/arm/mach-u300/timer.c
> @@ -11,6 +11,7 @@
> ?#include <linux/interrupt.h>
> ?#include <linux/time.h>
> ?#include <linux/timex.h>
> +#include <linux/sched.h>
> ?#include <linux/clockchips.h>
> ?#include <linux/clocksource.h>
> ?#include <linux/types.h>
> diff --git a/arch/arm/plat-iop/time.c b/arch/arm/plat-iop/time.c
> index 85d3e55..558cdfa 100644
> --- a/arch/arm/plat-iop/time.c
> +++ b/arch/arm/plat-iop/time.c
> @@ -18,6 +18,7 @@
> ?#include <linux/time.h>
> ?#include <linux/init.h>
> ?#include <linux/timex.h>
> +#include <linux/sched.h>
> ?#include <linux/io.h>
> ?#include <linux/clocksource.h>
> ?#include <linux/clockchips.h>
> @@ -36,7 +37,7 @@
> ?/*
> ?* IOP clocksource (free-running timer 1).
> ?*/
> -static cycle_t iop_clocksource_read(struct clocksource *unused)
> +static cycle_t notrace iop_clocksource_read(struct clocksource *unused)
> ?{
> ? ? ? ?return 0xffffffffu - read_tcr1();
> ?}
> diff --git a/arch/arm/plat-nomadik/timer.c b/arch/arm/plat-nomadik/timer.c
> index aedf9c1..70969a7 100644
> --- a/arch/arm/plat-nomadik/timer.c
> +++ b/arch/arm/plat-nomadik/timer.c
> @@ -11,6 +11,7 @@
> ?#include <linux/init.h>
> ?#include <linux/interrupt.h>
> ?#include <linux/irq.h>
> +#include <linux/sched.h>
> ?#include <linux/io.h>
> ?#include <linux/clockchips.h>
> ?#include <linux/clk.h>
> @@ -26,13 +27,13 @@ void __iomem *mtu_base; /* ssigned by machine code */
> ?* Kernel assumes that sched_clock can be called early
> ?* but the MTU may not yet be initialized.
> ?*/
> -static cycle_t nmdk_read_timer_dummy(struct clocksource *cs)
> +static cycle_t notrace nmdk_read_timer_dummy(struct clocksource *cs)
> ?{
> ? ? ? ?return 0;
> ?}
>
> ?/* clocksource: MTU decrements, so we negate the value being read. */
> -static cycle_t nmdk_read_timer(struct clocksource *cs)
> +static cycle_t notrace nmdk_read_timer(struct clocksource *cs)
> ?{
> ? ? ? ?return -readl(mtu_base + MTU_VAL(0));
> ?}
> diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c
> index 155fe43..bc9bc6c 100644
> --- a/arch/arm/plat-omap/counter_32k.c
> +++ b/arch/arm/plat-omap/counter_32k.c
> @@ -13,6 +13,7 @@
> ?* NOTE: This timer is not the same timer as the old OMAP1 MPU timer.
> ?*/
> ?#include <linux/kernel.h>
> +#include <linux/sched.h>
> ?#include <linux/init.h>
> ?#include <linux/clk.h>
> ?#include <linux/io.h>
> @@ -44,7 +45,7 @@
> ?static u32 offset_32k __read_mostly;
>
> ?#ifdef CONFIG_ARCH_OMAP16XX
> -static cycle_t omap16xx_32k_read(struct clocksource *cs)
> +static cycle_t notrace omap16xx_32k_read(struct clocksource *cs)
> ?{
> ? ? ? ?return omap_readl(OMAP16XX_TIMER_32K_SYNCHRONIZED) - offset_32k;
> ?}
> @@ -53,7 +54,7 @@ static cycle_t omap16xx_32k_read(struct clocksource *cs)
> ?#endif
>
> ?#ifdef CONFIG_ARCH_OMAP2420
> -static cycle_t omap2420_32k_read(struct clocksource *cs)
> +static cycle_t notrace omap2420_32k_read(struct clocksource *cs)
> ?{
> ? ? ? ?return omap_readl(OMAP2420_32KSYNCT_BASE + 0x10) - offset_32k;
> ?}
> @@ -62,7 +63,7 @@ static cycle_t omap2420_32k_read(struct clocksource *cs)
> ?#endif
>
> ?#ifdef CONFIG_ARCH_OMAP2430
> -static cycle_t omap2430_32k_read(struct clocksource *cs)
> +static cycle_t notrace omap2430_32k_read(struct clocksource *cs)
> ?{
> ? ? ? ?return omap_readl(OMAP2430_32KSYNCT_BASE + 0x10) - offset_32k;
> ?}
> @@ -71,7 +72,7 @@ static cycle_t omap2430_32k_read(struct clocksource *cs)
> ?#endif
>
> ?#ifdef CONFIG_ARCH_OMAP3
> -static cycle_t omap34xx_32k_read(struct clocksource *cs)
> +static cycle_t notrace omap34xx_32k_read(struct clocksource *cs)
> ?{
> ? ? ? ?return omap_readl(OMAP3430_32KSYNCT_BASE + 0x10) - offset_32k;
> ?}
> @@ -80,7 +81,7 @@ static cycle_t omap34xx_32k_read(struct clocksource *cs)
> ?#endif
>
> ?#ifdef CONFIG_ARCH_OMAP4
> -static cycle_t omap44xx_32k_read(struct clocksource *cs)
> +static cycle_t notrace omap44xx_32k_read(struct clocksource *cs)
> ?{
> ? ? ? ?return omap_readl(OMAP4430_32KSYNCT_BASE + 0x10) - offset_32k;
> ?}
> diff --git a/arch/arm/plat-versatile/sched-clock.c b/arch/arm/plat-versatile/sched-clock.c
> index 9768cf7..9696ddc 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>
> --
> 1.7.2.3
>
>
^ permalink raw reply [flat|nested] 13+ messages in thread* [PATCH 1/6] ARM: ensure sched_clock() and children are notrace
2010-11-12 18:44 ` [PATCH 1/6] ARM: ensure sched_clock() and children are notrace Rabin Vincent
@ 2010-11-19 16:09 ` Rabin Vincent
0 siblings, 0 replies; 13+ messages in thread
From: Rabin Vincent @ 2010-11-19 16:09 UTC (permalink / raw)
To: linux-arm-kernel
> On Sat, Nov 6, 2010 at 11:55 PM, Rabin Vincent <rabin@rab.in> wrote:
> > Include sched.h in the files implementing sched_clock() and ensure that
> > any functions called from sched_clock() have the notrace annotation.
On Sat, Nov 13, 2010 at 12:14:51AM +0530, Rabin Vincent wrote:
> CC'd some mach maintainers. I can split this up if needed,
> since these bits can be applied independently from the rest
> of the patches in the series.
I've split it up anyway, since tegra and nomadik have since fixed it
themselves while reworking their sched_clock() implementations (and
there are probably others who need to do this), and I missed a couple of
functions in omap and u300 in the first patch.
^ permalink raw reply [flat|nested] 13+ messages in thread