* [Adeos-main] [PATCH] x86-2.6.27: Port I-pipe tracer over ftrace
@ 2008-12-16 18:04 Jan Kiszka
0 siblings, 0 replies; only message in thread
From: Jan Kiszka @ 2008-12-16 18:04 UTC (permalink / raw)
To: adeos-main
This is a port of the I-pipe trace over 2.6.27's new ftrace
infrastructure. It basically off-loads us from maintaining the mcount
stubs. But it also adds some small additional overhead when enabled, and
you should know that playing with /proc/sys/kernel/ftrace_enabled while
using the I-pipe trace may disable the function trace points. Besides
that, all seems to be fine again, ready to be used.
The patch also contains a bunch of tracer-related cleanups, so the patch
actually shrinks.
Signed-off-by: Jan Kiszka <jan.kiszka@domain.hid>
---
Makefile | 4 --
arch/x86/kernel/Makefile | 1
arch/x86/kernel/cpu/common_64.c | 4 +-
arch/x86/kernel/head64.c | 2 -
arch/x86/kernel/ipipe.c | 5 --
arch/x86/kernel/mcount_32.S | 27 ---------------
arch/x86/kernel/mcount_64.S | 41 -----------------------
arch/x86/kernel/smpboot.c | 2 -
include/linux/linkage.h | 4 --
kernel/ipipe/Kconfig.debug | 6 ---
kernel/ipipe/tracer.c | 69 +++++++++++++++++++++++++++++++++++++---
kernel/trace/Kconfig | 1
12 files changed, 71 insertions(+), 95 deletions(-)
Index: b/Makefile
===================================================================
--- a/Makefile
+++ b/Makefile
@@ -525,10 +525,6 @@ endif
# Arch Makefiles may override this setting
KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
-ifdef CONFIG_IPIPE_TRACE_MCOUNT
-KBUILD_CFLAGS += -pg
-endif
-
ifdef CONFIG_FRAME_POINTER
KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
else
Index: b/arch/x86/kernel/Makefile
===================================================================
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -79,7 +79,6 @@ obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_VM86) += vm86_32.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_IPIPE) += ipipe.o
-obj-$(CONFIG_IPIPE_TRACE_MCOUNT) += mcount_$(BITS).o
obj-$(CONFIG_HPET_TIMER) += hpet.o
Index: b/arch/x86/kernel/ipipe.c
===================================================================
--- a/arch/x86/kernel/ipipe.c
+++ b/arch/x86/kernel/ipipe.c
@@ -1009,8 +1009,3 @@ EXPORT_PER_CPU_SYMBOL_GPL(cpu_tlbstate);
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
EXPORT_SYMBOL(tasklist_lock);
#endif /* CONFIG_SMP || CONFIG_DEBUG_SPINLOCK */
-
-#ifdef CONFIG_IPIPE_TRACE_MCOUNT
-void notrace mcount(void);
-EXPORT_SYMBOL(mcount);
-#endif /* CONFIG_IPIPE_TRACE_MCOUNT */
Index: b/arch/x86/kernel/mcount_32.S
===================================================================
--- a/arch/x86/kernel/mcount_32.S
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * linux/arch/x86/mcount_32.S
- *
- * Copyright (C) 2005, 2007 Jan Kiszka
- */
-
-.globl mcount
-mcount:
- cmpl $0,ipipe_trace_enable
- je out
-
- pushl %eax
- pushl %ecx
- pushl %edx
-
- pushl $0 # no additional value (v)
- movl 4(%ebp),%ecx # __CALLER_ADDR1
- movl 16(%esp),%edx # __CALLER_ADDR0
- movl $0,%eax # IPIPE_TRACE_FUNC
- call __ipipe_trace
- popl %eax
-
- popl %edx
- popl %ecx
- popl %eax
-out:
- ret
Index: b/arch/x86/kernel/mcount_64.S
===================================================================
--- a/arch/x86/kernel/mcount_64.S
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * linux/arch/x86/kernel/mcount_64.S
- *
- * Copyright (C) 2002 Free Software Foundation, Inc.
- * Contributed by Andreas Jaeger <aj@domain.hid>.
- * Slightly adapted by Philippe Gerum for the I-pipe tracer.
- */
-
-#include <linux/linkage.h>
-
- .code64
-
-ENTRY(mcount)
- cmpl $0,ipipe_trace_enable
- jz out
- subq $56,%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 $0,%rcx /* No additional value. */
- movq 8(%rbp),%rdx /* Parent rip. */
- movq 56(%rsp),%rsi /* Caller rip. */
- movq $0,%rdi /* IPIPE_TRACE_FN */
- call __ipipe_trace
-
- 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 $56,%rsp
-out:
- ret
-END(mcount)
Index: b/kernel/ipipe/Kconfig.debug
===================================================================
--- a/kernel/ipipe/Kconfig.debug
+++ b/kernel/ipipe/Kconfig.debug
@@ -39,6 +39,7 @@ config IPIPE_TRACE_ENABLE
config IPIPE_TRACE_MCOUNT
bool "Instrument function entries"
default y
+ select FTRACE
---help---
When enabled, records every kernel function entry in the tracer
log. While this slows down the system noticeably, it provides
@@ -80,9 +81,4 @@ config IPIPE_TRACE_PANIC
as well as ordinary kernel oopses. You can control the number
of printed back trace points via /proc/ipipe/trace.
-config IPIPE_TRACE_ENABLE_VALUE
- int
- default 0 if !IPIPE_TRACE_ENABLE
- default 1 if IPIPE_TRACE_ENABLE
-
endif
Index: b/kernel/ipipe/tracer.c
===================================================================
--- a/kernel/ipipe/tracer.c
+++ b/kernel/ipipe/tracer.c
@@ -32,6 +32,7 @@
#include <linux/utsrelease.h>
#include <linux/sched.h>
#include <linux/ipipe.h>
+#include <linux/ftrace.h>
#include <asm/uaccess.h>
#define IPIPE_TRACE_PATHS 4 /* <!> Do not lower below 3 */
@@ -1292,9 +1293,57 @@ static int __ipipe_wr_trigger(struct fil
return count;
}
+#ifdef CONFIG_IPIPE_TRACE_MCOUNT
+static void notrace
+ipipe_trace_function(unsigned long ip, unsigned long parent_ip)
+{
+ if (!ipipe_trace_enable)
+ return;
+ __ipipe_trace(IPIPE_TRACE_FUNC, ip, parent_ip, 0);
+}
+
+static struct ftrace_ops ipipe_trace_ops = {
+ .func = ipipe_trace_function
+};
+
+static int __ipipe_wr_enable(struct file *file, const char __user *buffer,
+ unsigned long count, void *data)
+{
+ char *end, buf[16];
+ int val;
+ int n;
+
+ n = (count > sizeof(buf) - 1) ? sizeof(buf) - 1 : count;
+
+ if (copy_from_user(buf, buffer, n))
+ return -EFAULT;
+
+ buf[n] = '\0';
+ val = simple_strtol(buf, &end, 0);
+
+ if (((*end != '\0') && !isspace(*end)) || (val < 0))
+ return -EINVAL;
+
+ mutex_lock(&out_mutex);
+
+ if (ipipe_trace_enable) {
+ if (!val)
+ unregister_ftrace_function(&ipipe_trace_ops);
+ } else if (val) {
+ ftrace_enabled = 1;
+ register_ftrace_function(&ipipe_trace_ops);
+ }
+ ipipe_trace_enable = val;
+
+ mutex_unlock(&out_mutex);
+
+ return count;
+}
+#endif /* CONFIG_IPIPE_TRACE_MCOUNT */
+
extern struct proc_dir_entry *ipipe_proc_root;
-static void __init
+static struct proc_dir_entry * __init
__ipipe_create_trace_proc_val(struct proc_dir_entry *trace_dir,
const char *name, int *value_ptr)
{
@@ -1307,6 +1356,7 @@ __ipipe_create_trace_proc_val(struct pro
entry->write_proc = __ipipe_wr_proc_val;
entry->owner = THIS_MODULE;
}
+ return entry;
}
void __init __ipipe_init_tracer(void)
@@ -1337,7 +1387,6 @@ void __init __ipipe_init_tracer(void)
per_cpu(trace_path, cpu) = tp_buf;
}
#endif /* CONFIG_IPIPE_TRACE_VMALLOC */
- ipipe_trace_enable = CONFIG_IPIPE_TRACE_ENABLE_VALUE;
/* Calculate minimum overhead of __ipipe_trace() */
local_irq_disable_hw();
@@ -1354,6 +1403,14 @@ void __init __ipipe_init_tracer(void)
local_irq_enable_hw();
trace_overhead = ipipe_tsc2ns(min);
+#ifdef CONFIG_IPIPE_TRACE_ENABLE
+ ipipe_trace_enable = 1;
+#ifdef CONFIG_IPIPE_TRACE_MCOUNT
+ ftrace_enabled = 1;
+ register_ftrace_function(&ipipe_trace_ops);
+#endif /* CONFIG_IPIPE_TRACE_MCOUNT */
+#endif /* CONFIG_IPIPE_TRACE_ENABLE */
+
trace_dir = create_proc_entry("trace", S_IFDIR, ipipe_proc_root);
entry = create_proc_entry("max", 0644, trace_dir);
@@ -1379,6 +1436,10 @@ void __init __ipipe_init_tracer(void)
&back_trace);
__ipipe_create_trace_proc_val(trace_dir, "verbose",
&verbose_trace);
- __ipipe_create_trace_proc_val(trace_dir, "enable",
- &ipipe_trace_enable);
+ entry = __ipipe_create_trace_proc_val(trace_dir, "enable",
+ &ipipe_trace_enable);
+#ifdef CONFIG_IPIPE_TRACE_MCOUNT
+ if (entry)
+ entry->write_proc = __ipipe_wr_enable;
+#endif /* CONFIG_IPIPE_TRACE_MCOUNT */
}
Index: b/kernel/trace/Kconfig
===================================================================
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -107,6 +107,7 @@ config DYNAMIC_FTRACE
depends on BROKEN
depends on FTRACE
depends on HAVE_DYNAMIC_FTRACE
+ depends on !IPIPE_TRACE_MCOUNT
default y
help
This option will modify all the calls to ftrace dynamically
Index: b/arch/x86/kernel/cpu/common_64.c
===================================================================
--- a/arch/x86/kernel/cpu/common_64.c
+++ b/arch/x86/kernel/cpu/common_64.c
@@ -506,7 +506,7 @@ static int __init nonx32_setup(char *str
}
__setup("noexec32=", nonx32_setup);
-notrace void pda_init(int cpu)
+void pda_init(int cpu)
{
struct x8664_pda *pda = cpu_pda(cpu);
@@ -595,7 +595,7 @@ DEFINE_PER_CPU(struct orig_ist, orig_ist
* 'CPU state barrier', nothing should get across.
* A lot of state is already set up in PDA init.
*/
-notrace void __cpuinit cpu_init(void)
+void __cpuinit cpu_init(void)
{
int cpu = stack_smp_processor_id();
struct tss_struct *t = &per_cpu(init_tss, cpu);
Index: b/arch/x86/kernel/head64.c
===================================================================
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -72,7 +72,7 @@ static void __init copy_bootdata(char *r
}
}
-void __init notrace x86_64_start_kernel(char * real_mode_data)
+void __init x86_64_start_kernel(char * real_mode_data)
{
int i;
Index: b/arch/x86/kernel/smpboot.c
===================================================================
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -282,7 +282,7 @@ static void __cpuinit smp_callin(void)
/*
* Activate a secondary processor.
*/
-static void notrace __cpuinit start_secondary(void *unused)
+static void __cpuinit start_secondary(void *unused)
{
/*
* Don't put *anything* before cpu_init(), SMP booting is too
Index: b/include/linux/linkage.h
===================================================================
--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -95,8 +95,4 @@
#define ATTRIB_NORET __attribute__((noreturn))
#define NORET_AND noreturn,
-#ifndef notrace
-#define notrace __attribute__((no_instrument_function))
-#endif
-
#endif
--
Siemens AG, Corporate Technology, CT SE 26
Corporate Competence Center Embedded Linux
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2008-12-16 18:04 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-12-16 18:04 [Adeos-main] [PATCH] x86-2.6.27: Port I-pipe tracer over ftrace Jan Kiszka
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.