Merge branch 'tracing/function-return-tracer' into tracing/fastboot
This commit is contained in:
Коммит
60a011c736
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@ -29,6 +29,7 @@ config X86
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select HAVE_FTRACE_MCOUNT_RECORD
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select HAVE_DYNAMIC_FTRACE
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select HAVE_FUNCTION_TRACER
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select HAVE_FUNCTION_RET_TRACER if X86_32
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select HAVE_FUNCTION_TRACE_MCOUNT_TEST
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select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
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select HAVE_ARCH_KGDB if !X86_VOYAGER
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@ -20,4 +20,30 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
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#endif /* __ASSEMBLY__ */
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#endif /* CONFIG_FUNCTION_TRACER */
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#ifdef CONFIG_FUNCTION_RET_TRACER
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#define FTRACE_RET_STACK_SIZE 20
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#ifndef __ASSEMBLY__
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/*
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* Stack of return addresses for functions
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* of a thread.
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* Used in struct thread_info
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*/
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struct ftrace_ret_stack {
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unsigned long ret;
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unsigned long func;
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unsigned long long calltime;
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};
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/*
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* Primary handler of a function return.
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* It relays on ftrace_return_to_handler.
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* Defined in entry32.S
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*/
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extern void return_to_handler(void);
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#endif /* __ASSEMBLY__ */
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#endif /* CONFIG_FUNCTION_RET_TRACER */
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#endif /* _ASM_X86_FTRACE_H */
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@ -20,6 +20,7 @@
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struct task_struct;
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struct exec_domain;
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#include <asm/processor.h>
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#include <asm/ftrace.h>
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struct thread_info {
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struct task_struct *task; /* main task structure */
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@ -38,8 +39,30 @@ struct thread_info {
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*/
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__u8 supervisor_stack[0];
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#endif
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#ifdef CONFIG_FUNCTION_RET_TRACER
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/* Index of current stored adress in ret_stack */
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int curr_ret_stack;
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/* Stack of return addresses for return function tracing */
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struct ftrace_ret_stack ret_stack[FTRACE_RET_STACK_SIZE];
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#endif
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};
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#ifdef CONFIG_FUNCTION_RET_TRACER
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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.exec_domain = &default_exec_domain, \
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.flags = 0, \
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.cpu = 0, \
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.preempt_count = 1, \
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.addr_limit = KERNEL_DS, \
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.restart_block = { \
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.fn = do_no_restart_syscall, \
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}, \
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.curr_ret_stack = -1,\
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}
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#else
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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@ -52,6 +75,7 @@ struct thread_info {
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.fn = do_no_restart_syscall, \
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}, \
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}
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#endif
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#define init_thread_info (init_thread_union.thread_info)
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#define init_stack (init_thread_union.stack)
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|
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@ -14,6 +14,11 @@ CFLAGS_REMOVE_paravirt-spinlocks.o = -pg
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CFLAGS_REMOVE_ftrace.o = -pg
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endif
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ifdef CONFIG_FUNCTION_RET_TRACER
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# Don't trace __switch_to() but let it for function tracer
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CFLAGS_REMOVE_process_32.o = -pg
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endif
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#
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# vsyscalls (which work on the user stack) should have
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# no stack-protector checks:
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|
@ -65,6 +70,7 @@ obj-$(CONFIG_X86_LOCAL_APIC) += apic.o nmi.o
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obj-$(CONFIG_X86_IO_APIC) += io_apic.o
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obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups_32.o
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obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
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obj-$(CONFIG_FUNCTION_RET_TRACER) += ftrace.o
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obj-$(CONFIG_KEXEC) += machine_kexec_$(BITS).o
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obj-$(CONFIG_KEXEC) += relocate_kernel_$(BITS).o crash.o
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obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o
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|
|
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@ -1188,6 +1188,10 @@ ENTRY(mcount)
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cmpl $ftrace_stub, ftrace_trace_function
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jnz trace
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#ifdef CONFIG_FUNCTION_RET_TRACER
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cmpl $ftrace_stub, ftrace_function_return
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jnz trace_return
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#endif
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.globl ftrace_stub
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ftrace_stub:
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ret
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|
@ -1206,8 +1210,37 @@ trace:
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popl %edx
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popl %ecx
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popl %eax
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jmp ftrace_stub
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#ifdef CONFIG_FUNCTION_RET_TRACER
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trace_return:
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pushl %eax
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pushl %ecx
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pushl %edx
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movl 0xc(%esp), %eax
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pushl %eax
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lea 0x4(%ebp), %eax
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pushl %eax
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call prepare_ftrace_return
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addl $8, %esp
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popl %edx
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popl %ecx
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popl %eax
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jmp ftrace_stub
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.globl return_to_handler
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return_to_handler:
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pushl $0
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pushl %eax
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pushl %ecx
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pushl %edx
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call ftrace_return_to_handler
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movl %eax, 0xc(%esp)
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popl %edx
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popl %ecx
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popl %eax
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ret
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#endif /* CONFIG_FUNCTION_RET_TRACER */
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END(mcount)
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#endif /* CONFIG_DYNAMIC_FTRACE */
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#endif /* CONFIG_FUNCTION_TRACER */
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|
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@ -14,14 +14,178 @@
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#include <linux/uaccess.h>
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#include <linux/ftrace.h>
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#include <linux/percpu.h>
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#include <linux/sched.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <asm/ftrace.h>
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#include <linux/ftrace.h>
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#include <asm/nops.h>
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#include <asm/nmi.h>
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static unsigned char ftrace_nop[MCOUNT_INSN_SIZE];
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#ifdef CONFIG_FUNCTION_RET_TRACER
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/*
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* These functions are picked from those used on
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* this page for dynamic ftrace. They have been
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* simplified to ignore all traces in NMI context.
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*/
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static atomic_t in_nmi;
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void ftrace_nmi_enter(void)
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{
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atomic_inc(&in_nmi);
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}
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void ftrace_nmi_exit(void)
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{
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atomic_dec(&in_nmi);
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}
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/*
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* Synchronize accesses to return adresses stack with
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* interrupts.
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*/
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static raw_spinlock_t ret_stack_lock;
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/* Add a function return address to the trace stack on thread info.*/
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static int push_return_trace(unsigned long ret, unsigned long long time,
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unsigned long func)
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{
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int index;
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struct thread_info *ti;
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unsigned long flags;
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int err = 0;
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raw_local_irq_save(flags);
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__raw_spin_lock(&ret_stack_lock);
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ti = current_thread_info();
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/* The return trace stack is full */
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if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1) {
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err = -EBUSY;
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goto out;
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}
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index = ++ti->curr_ret_stack;
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ti->ret_stack[index].ret = ret;
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ti->ret_stack[index].func = func;
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ti->ret_stack[index].calltime = time;
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out:
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__raw_spin_unlock(&ret_stack_lock);
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raw_local_irq_restore(flags);
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return err;
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}
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/* Retrieve a function return address to the trace stack on thread info.*/
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static void pop_return_trace(unsigned long *ret, unsigned long long *time,
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unsigned long *func)
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{
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struct thread_info *ti;
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int index;
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unsigned long flags;
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raw_local_irq_save(flags);
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__raw_spin_lock(&ret_stack_lock);
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ti = current_thread_info();
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index = ti->curr_ret_stack;
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*ret = ti->ret_stack[index].ret;
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*func = ti->ret_stack[index].func;
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*time = ti->ret_stack[index].calltime;
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ti->curr_ret_stack--;
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__raw_spin_unlock(&ret_stack_lock);
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raw_local_irq_restore(flags);
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}
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/*
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* Send the trace to the ring-buffer.
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* @return the original return address.
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*/
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unsigned long ftrace_return_to_handler(void)
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{
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struct ftrace_retfunc trace;
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pop_return_trace(&trace.ret, &trace.calltime, &trace.func);
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trace.rettime = cpu_clock(raw_smp_processor_id());
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ftrace_function_return(&trace);
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return trace.ret;
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}
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/*
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* Hook the return address and push it in the stack of return addrs
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* in current thread info.
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*/
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asmlinkage
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void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
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{
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unsigned long old;
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unsigned long long calltime;
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int faulted;
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unsigned long return_hooker = (unsigned long)
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&return_to_handler;
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/* Nmi's are currently unsupported */
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if (atomic_read(&in_nmi))
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return;
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/*
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* Protect against fault, even if it shouldn't
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* happen. This tool is too much intrusive to
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* ignore such a protection.
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*/
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asm volatile(
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"1: movl (%[parent_old]), %[old]\n"
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"2: movl %[return_hooker], (%[parent_replaced])\n"
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" movl $0, %[faulted]\n"
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".section .fixup, \"ax\"\n"
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"3: movl $1, %[faulted]\n"
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".previous\n"
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".section __ex_table, \"a\"\n"
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" .long 1b, 3b\n"
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" .long 2b, 3b\n"
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".previous\n"
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: [parent_replaced] "=r" (parent), [old] "=r" (old),
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[faulted] "=r" (faulted)
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: [parent_old] "0" (parent), [return_hooker] "r" (return_hooker)
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: "memory"
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);
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|
||||
if (WARN_ON(faulted)) {
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unregister_ftrace_return();
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return;
|
||||
}
|
||||
|
||||
if (WARN_ON(!__kernel_text_address(old))) {
|
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unregister_ftrace_return();
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||||
*parent = old;
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||||
return;
|
||||
}
|
||||
|
||||
calltime = cpu_clock(raw_smp_processor_id());
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||||
|
||||
if (push_return_trace(old, calltime, self_addr) == -EBUSY)
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*parent = old;
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||||
}
|
||||
|
||||
static int __init init_ftrace_function_return(void)
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||||
{
|
||||
ret_stack_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
|
||||
return 0;
|
||||
}
|
||||
device_initcall(init_ftrace_function_return);
|
||||
|
||||
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
|
||||
union ftrace_code_union {
|
||||
char code[MCOUNT_INSN_SIZE];
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||||
|
@ -31,17 +195,11 @@ union ftrace_code_union {
|
|||
} __attribute__((packed));
|
||||
};
|
||||
|
||||
|
||||
static int ftrace_calc_offset(long ip, long addr)
|
||||
{
|
||||
return (int)(addr - ip);
|
||||
}
|
||||
|
||||
unsigned char *ftrace_nop_replace(void)
|
||||
{
|
||||
return ftrace_nop;
|
||||
}
|
||||
|
||||
unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
|
||||
{
|
||||
static union ftrace_code_union calc;
|
||||
|
@ -183,6 +341,15 @@ do_ftrace_mod_code(unsigned long ip, void *new_code)
|
|||
}
|
||||
|
||||
|
||||
|
||||
|
||||
static unsigned char ftrace_nop[MCOUNT_INSN_SIZE];
|
||||
|
||||
unsigned char *ftrace_nop_replace(void)
|
||||
{
|
||||
return ftrace_nop;
|
||||
}
|
||||
|
||||
int
|
||||
ftrace_modify_code(unsigned long ip, unsigned char *old_code,
|
||||
unsigned char *new_code)
|
||||
|
@ -292,3 +459,4 @@ int __init ftrace_dyn_arch_init(void *data)
|
|||
|
||||
return 0;
|
||||
}
|
||||
#endif
|
||||
|
|
|
@ -267,6 +267,26 @@ ftrace_init_module(unsigned long *start, unsigned long *end) { }
|
|||
#endif
|
||||
|
||||
|
||||
/*
|
||||
* Structure that defines a return function trace.
|
||||
*/
|
||||
struct ftrace_retfunc {
|
||||
unsigned long ret; /* Return address */
|
||||
unsigned long func; /* Current function */
|
||||
unsigned long long calltime;
|
||||
unsigned long long rettime;
|
||||
};
|
||||
|
||||
#ifdef CONFIG_FUNCTION_RET_TRACER
|
||||
/* Type of a callback handler of tracing return function */
|
||||
typedef void (*trace_function_return_t)(struct ftrace_retfunc *);
|
||||
|
||||
extern void register_ftrace_return(trace_function_return_t func);
|
||||
/* The current handler in use */
|
||||
extern trace_function_return_t ftrace_function_return;
|
||||
extern void unregister_ftrace_return(void);
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Structure which defines the trace of an initcall.
|
||||
* You don't have to fill the func field since it is
|
||||
|
|
|
@ -2,7 +2,7 @@
|
|||
#define _LINUX_FTRACE_IRQ_H
|
||||
|
||||
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_FUNCTION_RET_TRACER)
|
||||
extern void ftrace_nmi_enter(void);
|
||||
extern void ftrace_nmi_exit(void);
|
||||
#else
|
||||
|
|
|
@ -2006,6 +2006,17 @@ static inline void setup_thread_stack(struct task_struct *p, struct task_struct
|
|||
{
|
||||
*task_thread_info(p) = *task_thread_info(org);
|
||||
task_thread_info(p)->task = p;
|
||||
|
||||
#ifdef CONFIG_FUNCTION_RET_TRACER
|
||||
/*
|
||||
* When fork() creates a child process, this function is called.
|
||||
* But the child task may not inherit the return adresses traced
|
||||
* by the return function tracer because it will directly execute
|
||||
* in userspace and will not return to kernel functions its parent
|
||||
* used.
|
||||
*/
|
||||
task_thread_info(p)->curr_ret_stack = -1;
|
||||
#endif
|
||||
}
|
||||
|
||||
static inline unsigned long *end_of_stack(struct task_struct *p)
|
||||
|
|
|
@ -23,6 +23,10 @@ CFLAGS_REMOVE_cgroup-debug.o = -pg
|
|||
CFLAGS_REMOVE_sched_clock.o = -pg
|
||||
CFLAGS_REMOVE_sched.o = -mno-spe -pg
|
||||
endif
|
||||
ifdef CONFIG_FUNCTION_RET_TRACER
|
||||
CFLAGS_REMOVE_extable.o = -pg # For __kernel_text_address()
|
||||
CFLAGS_REMOVE_module.o = -pg # For __module_text_address()
|
||||
endif
|
||||
|
||||
obj-$(CONFIG_FREEZER) += freezer.o
|
||||
obj-$(CONFIG_PROFILING) += profile.o
|
||||
|
|
|
@ -9,6 +9,9 @@ config NOP_TRACER
|
|||
config HAVE_FUNCTION_TRACER
|
||||
bool
|
||||
|
||||
config HAVE_FUNCTION_RET_TRACER
|
||||
bool
|
||||
|
||||
config HAVE_FUNCTION_TRACE_MCOUNT_TEST
|
||||
bool
|
||||
help
|
||||
|
@ -54,6 +57,17 @@ config FUNCTION_TRACER
|
|||
(the bootup default), then the overhead of the instructions is very
|
||||
small and not measurable even in micro-benchmarks.
|
||||
|
||||
config FUNCTION_RET_TRACER
|
||||
bool "Kernel Function return Tracer"
|
||||
depends on !DYNAMIC_FTRACE
|
||||
depends on HAVE_FUNCTION_RET_TRACER
|
||||
depends on FUNCTION_TRACER
|
||||
help
|
||||
Enable the kernel to trace a function at its return.
|
||||
It's first purpose is to trace the duration of functions.
|
||||
This is done by setting the current return address on the thread
|
||||
info structure of the current task.
|
||||
|
||||
config IRQSOFF_TRACER
|
||||
bool "Interrupts-off Latency Tracer"
|
||||
default n
|
||||
|
|
|
@ -24,5 +24,6 @@ obj-$(CONFIG_NOP_TRACER) += trace_nop.o
|
|||
obj-$(CONFIG_STACK_TRACER) += trace_stack.o
|
||||
obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
|
||||
obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
|
||||
obj-$(CONFIG_FUNCTION_RET_TRACER) += trace_functions_return.o
|
||||
|
||||
libftrace-y := ftrace.o
|
||||
|
|
|
@ -1480,3 +1480,19 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
|
|||
return ret;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_FUNCTION_RET_TRACER
|
||||
trace_function_return_t ftrace_function_return =
|
||||
(trace_function_return_t)ftrace_stub;
|
||||
void register_ftrace_return(trace_function_return_t func)
|
||||
{
|
||||
ftrace_function_return = func;
|
||||
}
|
||||
|
||||
void unregister_ftrace_return(void)
|
||||
{
|
||||
ftrace_function_return = (trace_function_return_t)ftrace_stub;
|
||||
}
|
||||
#endif
|
||||
|
||||
|
||||
|
||||
|
|
|
@ -244,13 +244,6 @@ unsigned long nsecs_to_usecs(unsigned long nsecs)
|
|||
return nsecs / 1000;
|
||||
}
|
||||
|
||||
/*
|
||||
* TRACE_ITER_SYM_MASK masks the options in trace_flags that
|
||||
* control the output of kernel symbols.
|
||||
*/
|
||||
#define TRACE_ITER_SYM_MASK \
|
||||
(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
|
||||
|
||||
/* These must match the bit postions in trace_iterator_flags */
|
||||
static const char *trace_options[] = {
|
||||
"print-parent",
|
||||
|
@ -810,6 +803,35 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data,
|
|||
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_FUNCTION_RET_TRACER
|
||||
static void __trace_function_return(struct trace_array *tr,
|
||||
struct trace_array_cpu *data,
|
||||
struct ftrace_retfunc *trace,
|
||||
unsigned long flags,
|
||||
int pc)
|
||||
{
|
||||
struct ring_buffer_event *event;
|
||||
struct ftrace_ret_entry *entry;
|
||||
unsigned long irq_flags;
|
||||
|
||||
if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
|
||||
return;
|
||||
|
||||
event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
|
||||
&irq_flags);
|
||||
if (!event)
|
||||
return;
|
||||
entry = ring_buffer_event_data(event);
|
||||
tracing_generic_entry_update(&entry->ent, flags, pc);
|
||||
entry->ent.type = TRACE_FN_RET;
|
||||
entry->ip = trace->func;
|
||||
entry->parent_ip = trace->ret;
|
||||
entry->rettime = trace->rettime;
|
||||
entry->calltime = trace->calltime;
|
||||
ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
|
||||
}
|
||||
#endif
|
||||
|
||||
void
|
||||
ftrace(struct trace_array *tr, struct trace_array_cpu *data,
|
||||
unsigned long ip, unsigned long parent_ip, unsigned long flags,
|
||||
|
@ -1038,6 +1060,29 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
|
|||
raw_local_irq_restore(flags);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_FUNCTION_RET_TRACER
|
||||
void trace_function_return(struct ftrace_retfunc *trace)
|
||||
{
|
||||
struct trace_array *tr = &global_trace;
|
||||
struct trace_array_cpu *data;
|
||||
unsigned long flags;
|
||||
long disabled;
|
||||
int cpu;
|
||||
int pc;
|
||||
|
||||
raw_local_irq_save(flags);
|
||||
cpu = raw_smp_processor_id();
|
||||
data = tr->data[cpu];
|
||||
disabled = atomic_inc_return(&data->disabled);
|
||||
if (likely(disabled == 1)) {
|
||||
pc = preempt_count();
|
||||
__trace_function_return(tr, data, trace, flags, pc);
|
||||
}
|
||||
atomic_dec(&data->disabled);
|
||||
raw_local_irq_restore(flags);
|
||||
}
|
||||
#endif /* CONFIG_FUNCTION_RET_TRACER */
|
||||
|
||||
static struct ftrace_ops trace_ops __read_mostly =
|
||||
{
|
||||
.func = function_trace_call,
|
||||
|
@ -1285,7 +1330,7 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt,
|
|||
# define IP_FMT "%016lx"
|
||||
#endif
|
||||
|
||||
static int
|
||||
int
|
||||
seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
|
||||
{
|
||||
int ret;
|
||||
|
@ -1738,6 +1783,10 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
|
|||
trace_seq_print_cont(s, iter);
|
||||
break;
|
||||
}
|
||||
case TRACE_FN_RET: {
|
||||
return print_return_function(iter);
|
||||
break;
|
||||
}
|
||||
}
|
||||
return TRACE_TYPE_HANDLED;
|
||||
}
|
||||
|
|
|
@ -22,6 +22,7 @@ enum trace_type {
|
|||
TRACE_MMIO_RW,
|
||||
TRACE_MMIO_MAP,
|
||||
TRACE_BOOT,
|
||||
TRACE_FN_RET,
|
||||
|
||||
__TRACE_LAST_TYPE
|
||||
};
|
||||
|
@ -48,6 +49,15 @@ struct ftrace_entry {
|
|||
unsigned long ip;
|
||||
unsigned long parent_ip;
|
||||
};
|
||||
|
||||
/* Function return entry */
|
||||
struct ftrace_ret_entry {
|
||||
struct trace_entry ent;
|
||||
unsigned long ip;
|
||||
unsigned long parent_ip;
|
||||
unsigned long long calltime;
|
||||
unsigned long long rettime;
|
||||
};
|
||||
extern struct tracer boot_tracer;
|
||||
|
||||
/*
|
||||
|
@ -218,6 +228,7 @@ extern void __ftrace_bad_type(void);
|
|||
IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
|
||||
TRACE_MMIO_MAP); \
|
||||
IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT); \
|
||||
IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET); \
|
||||
__ftrace_bad_type(); \
|
||||
} while (0)
|
||||
|
||||
|
@ -321,6 +332,8 @@ void trace_function(struct trace_array *tr,
|
|||
unsigned long ip,
|
||||
unsigned long parent_ip,
|
||||
unsigned long flags, int pc);
|
||||
void
|
||||
trace_function_return(struct ftrace_retfunc *trace);
|
||||
|
||||
void tracing_start_cmdline_record(void);
|
||||
void tracing_stop_cmdline_record(void);
|
||||
|
@ -393,6 +406,10 @@ extern void *head_page(struct trace_array_cpu *data);
|
|||
extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
|
||||
extern void trace_seq_print_cont(struct trace_seq *s,
|
||||
struct trace_iterator *iter);
|
||||
|
||||
extern int
|
||||
seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
|
||||
unsigned long sym_flags);
|
||||
extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
|
||||
size_t cnt);
|
||||
extern long ns2usecs(cycle_t nsec);
|
||||
|
@ -400,6 +417,17 @@ extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
|
|||
|
||||
extern unsigned long trace_flags;
|
||||
|
||||
/* Standard output formatting function used for function return traces */
|
||||
#ifdef CONFIG_FUNCTION_RET_TRACER
|
||||
extern enum print_line_t print_return_function(struct trace_iterator *iter);
|
||||
#else
|
||||
static inline enum print_line_t
|
||||
print_return_function(struct trace_iterator *iter)
|
||||
{
|
||||
return TRACE_TYPE_UNHANDLED;
|
||||
}
|
||||
#endif
|
||||
|
||||
/*
|
||||
* trace_iterator_flags is an enumeration that defines bit
|
||||
* positions into trace_flags that controls the output.
|
||||
|
@ -422,6 +450,13 @@ enum trace_iterator_flags {
|
|||
TRACE_ITER_PREEMPTONLY = 0x800,
|
||||
};
|
||||
|
||||
/*
|
||||
* TRACE_ITER_SYM_MASK masks the options in trace_flags that
|
||||
* control the output of kernel symbols.
|
||||
*/
|
||||
#define TRACE_ITER_SYM_MASK \
|
||||
(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
|
||||
|
||||
extern struct tracer nop_trace;
|
||||
|
||||
/**
|
||||
|
|
|
@ -0,0 +1,82 @@
|
|||
/*
|
||||
*
|
||||
* Function return tracer.
|
||||
* Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
|
||||
* Mostly borrowed from function tracer which
|
||||
* is Copyright (c) Steven Rostedt <srostedt@redhat.com>
|
||||
*
|
||||
*/
|
||||
#include <linux/debugfs.h>
|
||||
#include <linux/uaccess.h>
|
||||
#include <linux/ftrace.h>
|
||||
#include <linux/fs.h>
|
||||
|
||||
#include "trace.h"
|
||||
|
||||
|
||||
static void start_return_trace(struct trace_array *tr)
|
||||
{
|
||||
register_ftrace_return(&trace_function_return);
|
||||
}
|
||||
|
||||
static void stop_return_trace(struct trace_array *tr)
|
||||
{
|
||||
unregister_ftrace_return();
|
||||
}
|
||||
|
||||
static void return_trace_init(struct trace_array *tr)
|
||||
{
|
||||
int cpu;
|
||||
for_each_online_cpu(cpu)
|
||||
tracing_reset(tr, cpu);
|
||||
|
||||
start_return_trace(tr);
|
||||
}
|
||||
|
||||
static void return_trace_reset(struct trace_array *tr)
|
||||
{
|
||||
stop_return_trace(tr);
|
||||
}
|
||||
|
||||
|
||||
enum print_line_t
|
||||
print_return_function(struct trace_iterator *iter)
|
||||
{
|
||||
struct trace_seq *s = &iter->seq;
|
||||
struct trace_entry *entry = iter->ent;
|
||||
struct ftrace_ret_entry *field;
|
||||
int ret;
|
||||
|
||||
if (entry->type == TRACE_FN_RET) {
|
||||
trace_assign_type(field, entry);
|
||||
ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip);
|
||||
if (!ret)
|
||||
return TRACE_TYPE_PARTIAL_LINE;
|
||||
ret = seq_print_ip_sym(s, field->ip,
|
||||
trace_flags & TRACE_ITER_SYM_MASK);
|
||||
if (!ret)
|
||||
return TRACE_TYPE_PARTIAL_LINE;
|
||||
ret = trace_seq_printf(s, " (%llu ns)\n",
|
||||
field->rettime - field->calltime);
|
||||
if (!ret)
|
||||
return TRACE_TYPE_PARTIAL_LINE;
|
||||
else
|
||||
return TRACE_TYPE_HANDLED;
|
||||
}
|
||||
return TRACE_TYPE_UNHANDLED;
|
||||
}
|
||||
|
||||
static struct tracer return_trace __read_mostly =
|
||||
{
|
||||
.name = "return",
|
||||
.init = return_trace_init,
|
||||
.reset = return_trace_reset,
|
||||
.print_line = print_return_function
|
||||
};
|
||||
|
||||
static __init int init_return_trace(void)
|
||||
{
|
||||
return register_tracer(&return_trace);
|
||||
}
|
||||
|
||||
device_initcall(init_return_trace);
|
Загрузка…
Ссылка в новой задаче