From bd95b88d9e51fcbf392a7e90338a8fcc3499cbd6 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 16 Oct 2008 09:31:27 -0400 Subject: ftrace: release functions from hash The x86 architecture uses a static recording of mcount caller locations and is not affected by this patch. For architectures still using the dynamic ftrace daemon, this patch is critical. It removes the race between the recording of a function that calls mcount, the unloading of a module, and the ftrace daemon updating the call sites. This patch adds the releasing of the hash functions that the daemon uses to update the mcount call sites. When a module is unloaded, not only are the replaced call site table update, but now so is the hash recorded functions that the ftrace daemon will use. Again, architectures that implement MCOUNT_RECORD are not affected by this (which currently only x86 has). Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4dda4f60a2a9..1f54a94189fe 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -164,10 +164,14 @@ static DEFINE_SPINLOCK(ftrace_hash_lock); #define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) #define ftrace_hash_unlock(flags) \ spin_unlock_irqrestore(&ftrace_hash_lock, flags) +static void ftrace_release_hash(unsigned long start, unsigned long end); #else /* This is protected via the ftrace_lock with MCOUNT_RECORD. */ #define ftrace_hash_lock(flags) do { (void)(flags); } while (0) #define ftrace_hash_unlock(flags) do { } while(0) +static inline void ftrace_release_hash(unsigned long start, unsigned long end) +{ +} #endif /* @@ -347,6 +351,7 @@ void ftrace_release(void *start, unsigned long size) } spin_unlock(&ftrace_lock); + ftrace_release_hash(s, e); } static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) @@ -1659,6 +1664,44 @@ void __init ftrace_init(void) ftrace_disabled = 1; } #else /* CONFIG_FTRACE_MCOUNT_RECORD */ + +static void ftrace_release_hash(unsigned long start, unsigned long end) +{ + struct dyn_ftrace *rec; + struct hlist_node *t, *n; + struct hlist_head *head, temp_list; + unsigned long flags; + int i, cpu; + + preempt_disable_notrace(); + + /* disable incase we call something that calls mcount */ + cpu = raw_smp_processor_id(); + per_cpu(ftrace_shutdown_disable_cpu, cpu)++; + + ftrace_hash_lock(flags); + + for (i = 0; i < FTRACE_HASHSIZE; i++) { + INIT_HLIST_HEAD(&temp_list); + head = &ftrace_hash[i]; + + /* all CPUS are stopped, we are safe to modify code */ + hlist_for_each_entry_safe(rec, t, n, head, node) { + if (rec->flags & FTRACE_FL_FREE) + continue; + + if ((rec->ip >= start) && (rec->ip < end)) + ftrace_free_rec(rec); + } + } + + ftrace_hash_unlock(flags); + + per_cpu(ftrace_shutdown_disable_cpu, cpu)--; + preempt_enable_notrace(); + +} + static int ftraced(void *ignore) { unsigned long usecs; -- cgit v1.2.3-59-g8ed1b From c2db8054c1eaf99983d8deee347876b01c26c2cf Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 6 Oct 2008 19:06:11 -0400 Subject: ftrace: fix depends A lot of tracers have HAVE_FTRACE as a dependent config where it really should not. The HAVE_FTRACE is a misnomer (soon to be fixed) and describes if the architecture has the function tracer (mcount) implemented. The ftrace infrastructure is implemented in all archs. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 5 ----- 1 file changed, 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 1cb3e1f616af..5866edbc2ed1 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -49,7 +49,6 @@ config IRQSOFF_TRACER default n depends on TRACE_IRQFLAGS_SUPPORT depends on GENERIC_TIME - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACE_IRQFLAGS select TRACING @@ -73,7 +72,6 @@ config PREEMPT_TRACER default n depends on GENERIC_TIME depends on PREEMPT - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACING select TRACER_MAX_TRACE @@ -101,7 +99,6 @@ config SYSPROF_TRACER config SCHED_TRACER bool "Scheduling Latency Tracer" - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACING select CONTEXT_SWITCH_TRACER @@ -112,7 +109,6 @@ config SCHED_TRACER config CONTEXT_SWITCH_TRACER bool "Trace process context switches" - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACING select MARKERS @@ -122,7 +118,6 @@ config CONTEXT_SWITCH_TRACER config BOOT_TRACER bool "Trace boot initcalls" - depends on HAVE_FTRACE depends on DEBUG_KERNEL select TRACING help -- cgit v1.2.3-59-g8ed1b From 606576ce816603d9fe1fb453a88bc6eea16ca709 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 6 Oct 2008 19:06:12 -0400 Subject: ftrace: rename FTRACE to FUNCTION_TRACER Due to confusion between the ftrace infrastructure and the gcc profiling tracer "ftrace", this patch renames the config options from FTRACE to FUNCTION_TRACER. The other two names that are offspring from FTRACE DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same. This patch was generated mostly by script, and partially by hand. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- Makefile | 2 +- arch/arm/Kconfig | 4 ++-- arch/arm/boot/compressed/Makefile | 2 +- arch/arm/include/asm/ftrace.h | 2 +- arch/arm/kernel/armksyms.c | 2 +- arch/arm/kernel/entry-common.S | 4 ++-- arch/powerpc/Kconfig | 2 +- arch/powerpc/Makefile | 2 +- arch/powerpc/include/asm/ftrace.h | 2 +- arch/powerpc/kernel/Makefile | 2 +- arch/powerpc/kernel/entry_32.S | 2 +- arch/powerpc/kernel/entry_64.S | 2 +- arch/powerpc/kernel/ppc_ksyms.c | 2 +- arch/powerpc/platforms/powermac/Makefile | 2 +- arch/sparc64/Kconfig | 2 +- arch/sparc64/Kconfig.debug | 2 +- arch/sparc64/lib/mcount.S | 4 ++-- arch/x86/Kconfig | 2 +- arch/x86/kernel/Makefile | 2 +- arch/x86/kernel/entry_32.S | 4 ++-- arch/x86/kernel/entry_64.S | 4 ++-- arch/x86/kernel/i386_ksyms_32.c | 2 +- arch/x86/kernel/x8664_ksyms_64.c | 2 +- arch/x86/xen/Makefile | 2 +- include/asm-x86/ftrace.h | 4 ++-- include/linux/ftrace.h | 12 ++++++------ kernel/Makefile | 4 ++-- kernel/sysctl.c | 2 +- kernel/trace/Kconfig | 17 +++++++++-------- kernel/trace/Makefile | 6 +++--- kernel/trace/trace.c | 2 +- kernel/trace/trace.h | 2 +- kernel/trace/trace_irqsoff.c | 4 ++-- kernel/trace/trace_sched_wakeup.c | 4 ++-- kernel/trace/trace_selftest.c | 4 ++-- lib/Makefile | 2 +- 36 files changed, 61 insertions(+), 60 deletions(-) (limited to 'kernel') diff --git a/Makefile b/Makefile index 16e3fbb968a8..b7eb70b13cad 100644 --- a/Makefile +++ b/Makefile @@ -536,7 +536,7 @@ KBUILD_CFLAGS += -g KBUILD_AFLAGS += -gdwarf-2 endif -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER KBUILD_CFLAGS += -pg endif diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4853f9df37bd..c2f18ea40500 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -16,8 +16,8 @@ config ARM select HAVE_ARCH_KGDB select HAVE_KPROBES if (!XIP_KERNEL) select HAVE_KRETPROBES if (HAVE_KPROBES) - select HAVE_FTRACE if (!XIP_KERNEL) - select HAVE_DYNAMIC_FTRACE if (HAVE_FTRACE) + select HAVE_FUNCTION_TRACER if (!XIP_KERNEL) + select HAVE_DYNAMIC_FTRACE if (HAVE_FUNCTION_TRACER) select HAVE_GENERIC_DMA_COHERENT help The ARM series is a line of low-power-consumption RISC chip designs diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index 7a03f2007882..c47f2a3f8f8f 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -70,7 +70,7 @@ SEDFLAGS = s/TEXT_START/$(ZTEXTADDR)/;s/BSS_START/$(ZBSSADDR)/ targets := vmlinux vmlinux.lds piggy.gz piggy.o font.o font.c \ head.o misc.o $(OBJS) -ifeq ($(CONFIG_FTRACE),y) +ifeq ($(CONFIG_FUNCTION_TRACER),y) ORIG_CFLAGS := $(KBUILD_CFLAGS) KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS)) endif diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h index 584ef9a8e5a5..39c8bc1a006a 100644 --- a/arch/arm/include/asm/ftrace.h +++ b/arch/arm/include/asm/ftrace.h @@ -1,7 +1,7 @@ #ifndef _ASM_ARM_FTRACE #define _ASM_ARM_FTRACE -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #define MCOUNT_ADDR ((long)(mcount)) #define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */ diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index 2357b1cf1cf9..c74f766ffc12 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -183,6 +183,6 @@ EXPORT_SYMBOL(_find_next_bit_be); EXPORT_SYMBOL(copy_page); -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER EXPORT_SYMBOL(mcount); #endif diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 3aa14dcc5bab..06269ea375c5 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -101,7 +101,7 @@ ENDPROC(ret_from_fork) #undef CALL #define CALL(x) .long x -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE ENTRY(mcount) stmdb sp!, {r0-r3, lr} @@ -149,7 +149,7 @@ trace: ftrace_stub: mov pc, lr -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ /*============================================================================= * SWI handler diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 380baa1780e9..97d86702e2d5 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -112,7 +112,7 @@ config PPC bool default y select HAVE_DYNAMIC_FTRACE - select HAVE_FTRACE + select HAVE_FUNCTION_TRACER select ARCH_WANT_OPTIONAL_GPIOLIB select HAVE_IDE select HAVE_IOREMAP_PROT diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 24dd1a37f8fb..1f0667069940 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -122,7 +122,7 @@ KBUILD_CFLAGS += -mcpu=powerpc endif # Work around a gcc code-gen bug with -fno-omit-frame-pointer. -ifeq ($(CONFIG_FTRACE),y) +ifeq ($(CONFIG_FUNCTION_TRACER),y) KBUILD_CFLAGS += -mno-sched-epilog endif diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index de921326cca8..b298f7a631e6 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -1,7 +1,7 @@ #ifndef _ASM_POWERPC_FTRACE #define _ASM_POWERPC_FTRACE -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #define MCOUNT_ADDR ((long)(_mcount)) #define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */ diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index fdb58253fa5b..92673b43858d 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -12,7 +12,7 @@ CFLAGS_prom_init.o += -fPIC CFLAGS_btext.o += -fPIC endif -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER # Do not trace early boot code CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 1cbbf7033641..7ecc0d1855c3 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -1158,7 +1158,7 @@ machine_check_in_rtas: #endif /* CONFIG_PPC_RTAS */ -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE _GLOBAL(mcount) _GLOBAL(_mcount) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index fd8b4bae9b04..e6d52845854f 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -884,7 +884,7 @@ _GLOBAL(enter_prom) mtlr r0 blr -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE _GLOBAL(mcount) _GLOBAL(_mcount) diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c index 8edc2359c419..260089dccfb0 100644 --- a/arch/powerpc/kernel/ppc_ksyms.c +++ b/arch/powerpc/kernel/ppc_ksyms.c @@ -68,7 +68,7 @@ EXPORT_SYMBOL(single_step_exception); EXPORT_SYMBOL(sys_sigreturn); #endif -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER EXPORT_SYMBOL(_mcount); #endif diff --git a/arch/powerpc/platforms/powermac/Makefile b/arch/powerpc/platforms/powermac/Makefile index be60d64be7ad..50f169392551 100644 --- a/arch/powerpc/platforms/powermac/Makefile +++ b/arch/powerpc/platforms/powermac/Makefile @@ -1,6 +1,6 @@ CFLAGS_bootx_init.o += -fPIC -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER # Do not trace early boot code CFLAGS_REMOVE_bootx_init.o = -pg -mno-sched-epilog endif diff --git a/arch/sparc64/Kconfig b/arch/sparc64/Kconfig index 5446e2a499b1..d269400d2868 100644 --- a/arch/sparc64/Kconfig +++ b/arch/sparc64/Kconfig @@ -12,7 +12,7 @@ config SPARC64 bool default y select HAVE_DYNAMIC_FTRACE - select HAVE_FTRACE + select HAVE_FUNCTION_TRACER select HAVE_IDE select HAVE_LMB select HAVE_ARCH_KGDB diff --git a/arch/sparc64/Kconfig.debug b/arch/sparc64/Kconfig.debug index d6d32d178fc8..c40515c06690 100644 --- a/arch/sparc64/Kconfig.debug +++ b/arch/sparc64/Kconfig.debug @@ -33,7 +33,7 @@ config DEBUG_PAGEALLOC config MCOUNT bool - depends on STACK_DEBUG || FTRACE + depends on STACK_DEBUG || FUNCTION_TRACER default y config FRAME_POINTER diff --git a/arch/sparc64/lib/mcount.S b/arch/sparc64/lib/mcount.S index fad90ddb3a28..7ce9c65f3592 100644 --- a/arch/sparc64/lib/mcount.S +++ b/arch/sparc64/lib/mcount.S @@ -93,7 +93,7 @@ mcount: nop 1: #endif -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE mov %o7, %o0 .globl mcount_call @@ -119,7 +119,7 @@ mcount_call: .size _mcount,.-_mcount .size mcount,.-mcount -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER .globl ftrace_stub .type ftrace_stub,#function ftrace_stub: diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 40ee80809562..290e21aa774d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -28,7 +28,7 @@ config X86 select HAVE_KRETPROBES select HAVE_FTRACE_MCOUNT_RECORD select HAVE_DYNAMIC_FTRACE - select HAVE_FTRACE + select HAVE_FUNCTION_TRACER select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64) select HAVE_ARCH_KGDB if !X86_VOYAGER select HAVE_ARCH_TRACEHOOK diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 0d41f0343dc0..ec3d30136bf0 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -6,7 +6,7 @@ extra-y := head_$(BITS).o head$(BITS).o head.o init_task.o vmlinu CPPFLAGS_vmlinux.lds += -U$(UTS_MACHINE) -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER # Do not profile debug and lowlevel utilities CFLAGS_REMOVE_tsc.o = -pg CFLAGS_REMOVE_rtc.o = -pg diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 4e4269c73bb7..9d49facc21f2 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1149,7 +1149,7 @@ ENDPROC(xen_failsafe_callback) #endif /* CONFIG_XEN */ -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE ENTRY(mcount) @@ -1204,7 +1204,7 @@ trace: jmp ftrace_stub END(mcount) #endif /* CONFIG_DYNAMIC_FTRACE */ -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ .section .rodata,"a" #include "syscall_table_32.S" diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 09e7145484c5..b86f332c96a6 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -61,7 +61,7 @@ .code64 -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE ENTRY(mcount) retq @@ -138,7 +138,7 @@ trace: jmp ftrace_stub END(mcount) #endif /* CONFIG_DYNAMIC_FTRACE */ -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ #ifndef CONFIG_PREEMPT #define retint_kernel retint_restore_args diff --git a/arch/x86/kernel/i386_ksyms_32.c b/arch/x86/kernel/i386_ksyms_32.c index dd7ebee446af..43cec6bdda63 100644 --- a/arch/x86/kernel/i386_ksyms_32.c +++ b/arch/x86/kernel/i386_ksyms_32.c @@ -5,7 +5,7 @@ #include #include -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER /* mcount is defined in assembly */ EXPORT_SYMBOL(mcount); #endif diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index b545f371b5f5..695e426aa354 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -12,7 +12,7 @@ #include #include -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER /* mcount is defined in assembly */ EXPORT_SYMBOL(mcount); #endif diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile index 313947940a1a..6dcefba7836f 100644 --- a/arch/x86/xen/Makefile +++ b/arch/x86/xen/Makefile @@ -1,4 +1,4 @@ -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER # Do not profile debug and lowlevel utilities CFLAGS_REMOVE_spinlock.o = -pg CFLAGS_REMOVE_time.o = -pg diff --git a/include/asm-x86/ftrace.h b/include/asm-x86/ftrace.h index 1bb6f9bbe1ab..233bb9b869c0 100644 --- a/include/asm-x86/ftrace.h +++ b/include/asm-x86/ftrace.h @@ -1,7 +1,7 @@ #ifndef ASM_X86__FTRACE_H #define ASM_X86__FTRACE_H -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #define MCOUNT_ADDR ((long)(mcount)) #define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */ @@ -19,6 +19,6 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr) } #endif -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ #endif /* ASM_X86__FTRACE_H */ diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index a3d46151be19..0e9529589151 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -8,7 +8,7 @@ #include #include -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER extern int ftrace_enabled; extern int @@ -36,12 +36,12 @@ void clear_ftrace_function(void); extern void ftrace_stub(unsigned long a0, unsigned long a1); -#else /* !CONFIG_FTRACE */ +#else /* !CONFIG_FUNCTION_TRACER */ # define register_ftrace_function(ops) do { } while (0) # define unregister_ftrace_function(ops) do { } while (0) # define clear_ftrace_function(ops) do { } while (0) static inline void ftrace_kill_atomic(void) { } -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ #ifdef CONFIG_DYNAMIC_FTRACE # define FTRACE_HASHBITS 10 @@ -101,7 +101,7 @@ void ftrace_kill_atomic(void); static inline void tracer_disable(void) { -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER ftrace_enabled = 0; #endif } @@ -113,7 +113,7 @@ static inline void tracer_disable(void) */ static inline int __ftrace_enabled_save(void) { -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER int saved_ftrace_enabled = ftrace_enabled; ftrace_enabled = 0; return saved_ftrace_enabled; @@ -124,7 +124,7 @@ static inline int __ftrace_enabled_save(void) static inline void __ftrace_enabled_restore(int enabled) { -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER ftrace_enabled = enabled; #endif } diff --git a/kernel/Makefile b/kernel/Makefile index 8f9ce7ec21b6..85f588a9d0b1 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -13,7 +13,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \ CFLAGS_REMOVE_sched.o = -mno-spe -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER # Do not trace debug files and internal ftrace files CFLAGS_REMOVE_lockdep.o = -pg CFLAGS_REMOVE_lockdep_proc.o = -pg @@ -86,7 +86,7 @@ obj-$(CONFIG_MARKERS) += marker.o obj-$(CONFIG_TRACEPOINTS) += tracepoint.o obj-$(CONFIG_LATENCYTOP) += latencytop.o obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o -obj-$(CONFIG_FTRACE) += trace/ +obj-$(CONFIG_FUNCTION_TRACER) += trace/ obj-$(CONFIG_TRACING) += trace/ obj-$(CONFIG_SMP) += sched_cpupri.o diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 617d41e4d6a0..619eb9f3acd8 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -464,7 +464,7 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER { .ctl_name = CTL_UNNUMBERED, .procname = "ftrace_enabled", diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 5866edbc2ed1..3533c583df47 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -1,11 +1,12 @@ # -# Architectures that offer an FTRACE implementation should select HAVE_FTRACE: +# Architectures that offer an FUNCTION_TRACER implementation should +# select HAVE_FUNCTION_TRACER: # config NOP_TRACER bool -config HAVE_FTRACE +config HAVE_FUNCTION_TRACER bool select NOP_TRACER @@ -28,9 +29,9 @@ config TRACING select STACKTRACE select TRACEPOINTS -config FTRACE +config FUNCTION_TRACER bool "Kernel Function Tracer" - depends on HAVE_FTRACE + depends on HAVE_FUNCTION_TRACER depends on DEBUG_KERNEL select FRAME_POINTER select TRACING @@ -136,9 +137,9 @@ config BOOT_TRACER config STACK_TRACER bool "Trace max stack" - depends on HAVE_FTRACE + depends on HAVE_FUNCTION_TRACER depends on DEBUG_KERNEL - select FTRACE + select FUNCTION_TRACER select STACKTRACE help This special tracer records the maximum stack footprint of the @@ -155,7 +156,7 @@ config STACK_TRACER config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" - depends on FTRACE + depends on FUNCTION_TRACER depends on HAVE_DYNAMIC_FTRACE depends on DEBUG_KERNEL default y @@ -165,7 +166,7 @@ config DYNAMIC_FTRACE with a No-Op instruction) as they are called. A table is created to dynamically enable them again. - This way a CONFIG_FTRACE kernel is slightly larger, but otherwise + This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but otherwise has native performance as long as no tracing is active. The changes to the code are done by a kernel thread that diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index a85dfba88ba0..c8228b1a49e9 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -1,7 +1,7 @@ # Do not instrument the tracer itself: -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER ORIG_CFLAGS := $(KBUILD_CFLAGS) KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS)) @@ -10,13 +10,13 @@ CFLAGS_trace_selftest_dynamic.o = -pg obj-y += trace_selftest_dynamic.o endif -obj-$(CONFIG_FTRACE) += libftrace.o +obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o obj-$(CONFIG_RING_BUFFER) += ring_buffer.o obj-$(CONFIG_TRACING) += trace.o obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o obj-$(CONFIG_SYSPROF_TRACER) += trace_sysprof.o -obj-$(CONFIG_FTRACE) += trace_functions.o +obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d345d649d073..aeb2f2505bc5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -851,7 +851,7 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) preempt_enable_notrace(); } -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER static void function_trace_call(unsigned long ip, unsigned long parent_ip) { diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f1f99572cde7..6889ca48f1f1 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -335,7 +335,7 @@ void update_max_tr_single(struct trace_array *tr, extern cycle_t ftrace_now(int cpu); -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER void tracing_start_function_trace(void); void tracing_stop_function_trace(void); #else diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index a7db7f040ae0..9c74071c10e0 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -63,7 +63,7 @@ irq_trace(void) */ static __cacheline_aligned_in_smp unsigned long max_sequence; -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER /* * irqsoff uses its own tracer function to keep the overhead down: */ @@ -104,7 +104,7 @@ static struct ftrace_ops trace_ops __read_mostly = { .func = irqsoff_tracer_call, }; -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ /* * Should this new latency be reported/recorded? diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index fe4a252c2363..3ae93f16b565 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -31,7 +31,7 @@ static raw_spinlock_t wakeup_lock = static void __wakeup_reset(struct trace_array *tr); -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER /* * irqsoff uses its own tracer function to keep the overhead down: */ @@ -96,7 +96,7 @@ static struct ftrace_ops trace_ops __read_mostly = { .func = wakeup_tracer_call, }; -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ /* * Should this new latency be reported/recorded? diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 09cf230d7eca..95815d26a041 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -70,7 +70,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) return ret; } -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE @@ -226,7 +226,7 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) return ret; } -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ #ifdef CONFIG_IRQSOFF_TRACER int diff --git a/lib/Makefile b/lib/Makefile index 16feaab057b2..7cb65d85aeb0 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -2,7 +2,7 @@ # Makefile for some libs needed in the kernel. # -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER ORIG_CFLAGS := $(KBUILD_CFLAGS) KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS)) endif -- cgit v1.2.3-59-g8ed1b From 3ce83aea86bf46fd1bff59d2e6d16f48fdce22fc Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 6 Oct 2008 19:06:13 -0400 Subject: ftrace: rename the ftrace tracer to function To avoid further confusion between the ftrace infrastructure and the function tracer. This patch renames the "ftrace" function tracer to "function". Now in available_tracers, instead of "ftrace" there will be "function". This makes more sense, since people will not know exactly what the "ftrace" tracer does. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_functions.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index e90eb0c2c56c..0f85a64003d3 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -64,7 +64,7 @@ static void function_trace_ctrl_update(struct trace_array *tr) static struct tracer function_trace __read_mostly = { - .name = "ftrace", + .name = "function", .init = function_trace_init, .reset = function_trace_reset, .ctrl_update = function_trace_ctrl_update, -- cgit v1.2.3-59-g8ed1b From 81520a1b0649d0701205b818714a8c1e1cfbbb5b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 6 Oct 2008 21:24:18 -0400 Subject: ftrace: stack tracer only record when on stack The stack trace API does not record if the stack is not on the current task's stack. That is, if the stack is the interrupt stack or NMI stack, the output does not show. Also, the size of those stacks are not consistent with the size of the thread stack, this makes the calculation of the stack size usually bogus. This all confuses the stack tracer. I unfortunately do not have time to fix all these problems, but this patch does record the worst stack when the stack pointer is on the tasks stack (instead of bogus numbers). The patch simply returns if the stack pointer is not on the task's stack. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_stack.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 74c5d9a3afae..be682b62fe58 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -44,6 +44,10 @@ static inline void check_stack(void) if (this_size <= max_stack_size) return; + /* we do not handle interrupt stacks yet */ + if (!object_is_on_stack(&this_size)) + return; + raw_local_irq_save(flags); __raw_spin_lock(&max_stack_lock); -- cgit v1.2.3-59-g8ed1b From 17d80fd07d35ae1d231b3378ee4f00ace54f9d31 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 21 Oct 2008 16:31:18 +0200 Subject: tracing: create tracers menu MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We seem to have plenty tracers, lets create a menu and not clutter the already cluttered debug menu more. Signed-off-by: Peter Zijlstra Acked-by: Frédéric Weisbecker Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 3533c583df47..bc535cb91de9 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -29,6 +29,8 @@ config TRACING select STACKTRACE select TRACEPOINTS +menu "Tracers" + config FUNCTION_TRACER bool "Kernel Function Tracer" depends on HAVE_FUNCTION_TRACER @@ -191,3 +193,5 @@ config FTRACE_STARTUP_TEST a series of tests are made to verify that the tracer is functioning properly. It will do tests on all the configured tracers of ftrace. + +endmenu -- cgit v1.2.3-59-g8ed1b From 6ae2a0765ab764da11cc305058ee5333810228f4 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 13 Oct 2008 10:22:06 -0400 Subject: ring-buffer: fix free page The pages of a buffer was originally pointing to the page struct, it now points to the page address. The freeing of the page still uses the page frame free "__free_page" instead of the correct free_page to the address. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 94af1fe56bb4..091aeefe321e 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -130,7 +130,7 @@ struct buffer_page { static inline void free_buffer_page(struct buffer_page *bpage) { if (bpage->page) - __free_page(bpage->page); + free_page((unsigned long)bpage->page); kfree(bpage); } -- cgit v1.2.3-59-g8ed1b From 593eb8a2d63e95772a5f22d746f18a997c5ee463 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:32:59 -0400 Subject: ftrace: return error on failed modified text. Have the ftrace_modify_code return error values: -EFAULT on error of reading the address -EINVAL if what is read does not match what it expected -EPERM if the write fails to update after a successful match. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 14 +++++++------- include/linux/ftrace.h | 24 ++++++++++++++++++++++-- kernel/trace/ftrace.c | 21 +++++++++++++++------ 3 files changed, 44 insertions(+), 15 deletions(-) (limited to 'kernel') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 8821ceabf51d..428291581cb2 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -62,7 +62,6 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char *new_code) { unsigned char replaced[MCOUNT_INSN_SIZE]; - int ret; /* * Note: Due to modules and __init, code can @@ -72,15 +71,16 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, * No real locking needed, this code is run through * kstop_machine, or before SMP starts. */ - if (__copy_from_user_inatomic(replaced, (char __user *)ip, MCOUNT_INSN_SIZE)) - return 1; + if (__copy_from_user_inatomic(replaced, (char __user *)ip, + MCOUNT_INSN_SIZE)) + return -EFAULT; if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0) - return 2; + return -EINVAL; - ret = __copy_to_user_inatomic((char __user *)ip, new_code, - MCOUNT_INSN_SIZE); - WARN_ON_ONCE(ret); + if (__copy_to_user_inatomic((char __user *)ip, new_code, + MCOUNT_INSN_SIZE)) + return -EPERM; sync_core(); diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 0e9529589151..79fa10cbdcfb 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -72,13 +72,33 @@ extern unsigned char *ftrace_nop_replace(void); extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr); extern int ftrace_dyn_arch_init(void *data); extern int ftrace_mcount_set(unsigned long *data); -extern int ftrace_modify_code(unsigned long ip, unsigned char *old_code, - unsigned char *new_code); extern int ftrace_update_ftrace_func(ftrace_func_t func); extern void ftrace_caller(void); extern void ftrace_call(void); extern void mcount_call(void); +/** + * ftrace_modify_code - modify code segment + * @ip: the address of the code segment + * @old_code: the contents of what is expected to be there + * @new_code: the code to patch in + * + * This is a very sensitive operation and great care needs + * to be taken by the arch. The operation should carefully + * read the location, check to see if what is read is indeed + * what we expect it to be, and then on success of the compare, + * it should write to the location. + * + * Return must be: + * 0 on success + * -EFAULT on error reading the location + * -EINVAL on a failed compare of the contents + * -EPERM on error writing to the location + * Any other value will be considered a failure. + */ +extern int ftrace_modify_code(unsigned long ip, unsigned char *old_code, + unsigned char *new_code); + extern int skip_trace(unsigned long ip); extern void ftrace_release(void *start, unsigned long size); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 1f54a94189fe..b2de8de77356 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -596,22 +596,22 @@ ftrace_code_disable(struct dyn_ftrace *rec) { unsigned long ip; unsigned char *nop, *call; - int failed; + int ret; ip = rec->ip; nop = ftrace_nop_replace(); call = ftrace_call_replace(ip, mcount_addr); - failed = ftrace_modify_code(ip, call, nop); - if (failed) { - switch (failed) { - case 1: + ret = ftrace_modify_code(ip, call, nop); + if (ret) { + switch (ret) { + case -EFAULT: WARN_ON_ONCE(1); pr_info("ftrace faulted on modifying "); print_ip_sym(ip); break; - case 2: + case -EINVAL: WARN_ON_ONCE(1); pr_info("ftrace failed to modify "); print_ip_sym(ip); @@ -620,6 +620,15 @@ ftrace_code_disable(struct dyn_ftrace *rec) print_ip_ins(" replace: ", nop); printk(KERN_CONT "\n"); break; + case -EPERM: + WARN_ON_ONCE(1); + pr_info("ftrace faulted on writing "); + print_ip_sym(ip); + break; + default: + WARN_ON_ONCE(1); + pr_info("ftrace faulted on unknown error "); + print_ip_sym(ip); } rec->flags |= FTRACE_FL_FAILED; -- cgit v1.2.3-59-g8ed1b From 81adbdc029ecc416d56563e7f159100181dd711d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:02 -0400 Subject: ftrace: only have ftrace_kill atomic When an anomaly is detected, we need a way to completely disable ftrace. Right now we have two functions: ftrace_kill and ftrace_kill_atomic. The ftrace_kill tries to do it in a "nice" way by converting everything back to a nop. The "nice" way is dangerous itself, so this patch removes it and only has the "atomic" version, which is all that is needed. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- include/linux/ftrace.h | 3 +-- kernel/trace/ftrace.c | 42 ++---------------------------------------- kernel/trace/trace.c | 2 +- 3 files changed, 4 insertions(+), 43 deletions(-) (limited to 'kernel') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 79fa10cbdcfb..ac58e94668b7 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -40,7 +40,7 @@ extern void ftrace_stub(unsigned long a0, unsigned long a1); # define register_ftrace_function(ops) do { } while (0) # define unregister_ftrace_function(ops) do { } while (0) # define clear_ftrace_function(ops) do { } while (0) -static inline void ftrace_kill_atomic(void) { } +static inline void ftrace_kill(void) { } #endif /* CONFIG_FUNCTION_TRACER */ #ifdef CONFIG_DYNAMIC_FTRACE @@ -117,7 +117,6 @@ static inline void ftrace_release(void *start, unsigned long size) { } /* totally disable ftrace - can not re-enable after this */ void ftrace_kill(void); -void ftrace_kill_atomic(void); static inline void tracer_disable(void) { diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b2de8de77356..93245ae046e1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1549,22 +1549,6 @@ int ftrace_force_update(void) return ret; } -static void ftrace_force_shutdown(void) -{ - struct task_struct *task; - int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC; - - mutex_lock(&ftraced_lock); - task = ftraced_task; - ftraced_task = NULL; - ftraced_suspend = -1; - ftrace_run_update_code(command); - mutex_unlock(&ftraced_lock); - - if (task) - kthread_stop(task); -} - static __init int ftrace_init_debugfs(void) { struct dentry *d_tracer; @@ -1795,17 +1779,16 @@ core_initcall(ftrace_dynamic_init); # define ftrace_shutdown() do { } while (0) # define ftrace_startup_sysctl() do { } while (0) # define ftrace_shutdown_sysctl() do { } while (0) -# define ftrace_force_shutdown() do { } while (0) #endif /* CONFIG_DYNAMIC_FTRACE */ /** - * ftrace_kill_atomic - kill ftrace from critical sections + * ftrace_kill - kill ftrace * * This function should be used by panic code. It stops ftrace * but in a not so nice way. If you need to simply kill ftrace * from a non-atomic section, use ftrace_kill. */ -void ftrace_kill_atomic(void) +void ftrace_kill(void) { ftrace_disabled = 1; ftrace_enabled = 0; @@ -1815,27 +1798,6 @@ void ftrace_kill_atomic(void) clear_ftrace_function(); } -/** - * ftrace_kill - totally shutdown ftrace - * - * This is a safety measure. If something was detected that seems - * wrong, calling this function will keep ftrace from doing - * any more modifications, and updates. - * used when something went wrong. - */ -void ftrace_kill(void) -{ - mutex_lock(&ftrace_sysctl_lock); - ftrace_disabled = 1; - ftrace_enabled = 0; - - clear_ftrace_function(); - mutex_unlock(&ftrace_sysctl_lock); - - /* Try to totally disable ftrace */ - ftrace_force_shutdown(); -} - /** * register_ftrace_function - register a function for profiling * @ops - ops structure that holds the function for profiling. diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index aeb2f2505bc5..333a5162149b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3097,7 +3097,7 @@ void ftrace_dump(void) dump_ran = 1; /* No turning back! */ - ftrace_kill_atomic(); + ftrace_kill(); for_each_tracing_cpu(cpu) { atomic_inc(&global_trace.data[cpu]->disabled); -- cgit v1.2.3-59-g8ed1b From 6912896e994ddaf06cc0f6d3f2098bc4b59bdd84 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:03 -0400 Subject: ftrace: add ftrace warn on to disable ftrace Add ftrace warn on to disable ftrace as well as report a warning. [ Thanks to Andrew Morton for suggesting using the WARN_ON return value ] Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 93245ae046e1..b08996ca561d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -32,6 +32,18 @@ #include "trace.h" +#define FTRACE_WARN_ON(cond) \ + do { \ + if (WARN_ON(cond)) \ + ftrace_kill(); \ + } while (0) + +#define FTRACE_WARN_ON_ONCE(cond) \ + do { \ + if (WARN_ON_ONCE(cond)) \ + ftrace_kill(); \ + } while (0) + /* ftrace_enabled is a method to turn ftrace on or off */ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; @@ -363,10 +375,8 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) rec = ftrace_free_records; if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); ftrace_free_records = NULL; - ftrace_disabled = 1; - ftrace_enabled = 0; return NULL; } @@ -415,7 +425,7 @@ ftrace_record_ip(unsigned long ip) key = hash_long(ip, FTRACE_HASHBITS); - WARN_ON_ONCE(key >= FTRACE_HASHSIZE); + FTRACE_WARN_ON_ONCE(key >= FTRACE_HASHSIZE); if (ftrace_ip_in_hash(ip, key)) goto out; @@ -607,12 +617,12 @@ ftrace_code_disable(struct dyn_ftrace *rec) if (ret) { switch (ret) { case -EFAULT: - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); pr_info("ftrace faulted on modifying "); print_ip_sym(ip); break; case -EINVAL: - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); pr_info("ftrace failed to modify "); print_ip_sym(ip); print_ip_ins(" expected: ", call); @@ -621,12 +631,12 @@ ftrace_code_disable(struct dyn_ftrace *rec) printk(KERN_CONT "\n"); break; case -EPERM: - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); pr_info("ftrace faulted on writing "); print_ip_sym(ip); break; default: - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); pr_info("ftrace faulted on unknown error "); print_ip_sym(ip); } @@ -1722,8 +1732,7 @@ static int ftraced(void *ignore) ftrace_update_cnt != 1 ? "s" : "", ftrace_update_tot_cnt, usecs, usecs != 1 ? "s" : ""); - ftrace_disabled = 1; - WARN_ON_ONCE(1); + FTRACE_WARN_ON_ONCE(1); } } mutex_unlock(&ftraced_lock); -- cgit v1.2.3-59-g8ed1b From cb7be3b2fc2cf089ee52b16f0fd9ebb29e9944e1 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:05 -0400 Subject: ftrace: remove daemon The ftrace daemon is complex and error prone. This patch strips it out of the code. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 322 ++++-------------------------------------- kernel/trace/trace_selftest.c | 14 -- 2 files changed, 28 insertions(+), 308 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b08996ca561d..e758cab0836f 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -165,25 +165,8 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) } #ifdef CONFIG_DYNAMIC_FTRACE - #ifndef CONFIG_FTRACE_MCOUNT_RECORD -/* - * The hash lock is only needed when the recording of the mcount - * callers are dynamic. That is, by the caller themselves and - * not recorded via the compilation. - */ -static DEFINE_SPINLOCK(ftrace_hash_lock); -#define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) -#define ftrace_hash_unlock(flags) \ - spin_unlock_irqrestore(&ftrace_hash_lock, flags) -static void ftrace_release_hash(unsigned long start, unsigned long end); -#else -/* This is protected via the ftrace_lock with MCOUNT_RECORD. */ -#define ftrace_hash_lock(flags) do { (void)(flags); } while (0) -#define ftrace_hash_unlock(flags) do { } while(0) -static inline void ftrace_release_hash(unsigned long start, unsigned long end) -{ -} +# error Dynamic ftrace depends on MCOUNT_RECORD #endif /* @@ -194,8 +177,6 @@ static inline void ftrace_release_hash(unsigned long start, unsigned long end) */ static unsigned long mcount_addr = MCOUNT_ADDR; -static struct task_struct *ftraced_task; - enum { FTRACE_ENABLE_CALLS = (1 << 0), FTRACE_DISABLE_CALLS = (1 << 1), @@ -212,7 +193,6 @@ static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); -static DEFINE_MUTEX(ftraced_lock); static DEFINE_MUTEX(ftrace_regex_lock); struct ftrace_page { @@ -230,10 +210,6 @@ struct ftrace_page { static struct ftrace_page *ftrace_pages_start; static struct ftrace_page *ftrace_pages; -static int ftraced_trigger; -static int ftraced_suspend; -static int ftraced_stop; - static int ftrace_record_suspend; static struct dyn_ftrace *ftrace_free_records; @@ -398,7 +374,6 @@ static void ftrace_record_ip(unsigned long ip) { struct dyn_ftrace *node; - unsigned long flags; unsigned long key; int resched; int cpu; @@ -430,24 +405,18 @@ ftrace_record_ip(unsigned long ip) if (ftrace_ip_in_hash(ip, key)) goto out; - ftrace_hash_lock(flags); - /* This ip may have hit the hash before the lock */ if (ftrace_ip_in_hash(ip, key)) - goto out_unlock; + goto out; node = ftrace_alloc_dyn_node(ip); if (!node) - goto out_unlock; + goto out; node->ip = ip; ftrace_add_hash(node, key); - ftraced_trigger = 1; - - out_unlock: - ftrace_hash_unlock(flags); out: per_cpu(ftrace_shutdown_disable_cpu, cpu)--; @@ -647,7 +616,7 @@ ftrace_code_disable(struct dyn_ftrace *rec) return 1; } -static int __ftrace_update_code(void *ignore); +static int ftrace_update_code(void *ignore); static int __ftrace_modify_code(void *data) { @@ -659,7 +628,7 @@ static int __ftrace_modify_code(void *data) * Update any recorded ips now that we have the * machine stopped */ - __ftrace_update_code(NULL); + ftrace_update_code(NULL); ftrace_replace_code(1); tracing_on = 1; } else if (*command & FTRACE_DISABLE_CALLS) { @@ -686,26 +655,9 @@ static void ftrace_run_update_code(int command) stop_machine(__ftrace_modify_code, &command, NULL); } -void ftrace_disable_daemon(void) -{ - /* Stop the daemon from calling kstop_machine */ - mutex_lock(&ftraced_lock); - ftraced_stop = 1; - mutex_unlock(&ftraced_lock); - - ftrace_force_update(); -} - -void ftrace_enable_daemon(void) -{ - mutex_lock(&ftraced_lock); - ftraced_stop = 0; - mutex_unlock(&ftraced_lock); - - ftrace_force_update(); -} - static ftrace_func_t saved_ftrace_func; +static int ftrace_start; +static DEFINE_MUTEX(ftrace_start_lock); static void ftrace_startup(void) { @@ -714,9 +666,9 @@ static void ftrace_startup(void) if (unlikely(ftrace_disabled)) return; - mutex_lock(&ftraced_lock); - ftraced_suspend++; - if (ftraced_suspend == 1) + mutex_lock(&ftrace_start_lock); + ftrace_start++; + if (ftrace_start == 1) command |= FTRACE_ENABLE_CALLS; if (saved_ftrace_func != ftrace_trace_function) { @@ -729,7 +681,7 @@ static void ftrace_startup(void) ftrace_run_update_code(command); out: - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); } static void ftrace_shutdown(void) @@ -739,9 +691,9 @@ static void ftrace_shutdown(void) if (unlikely(ftrace_disabled)) return; - mutex_lock(&ftraced_lock); - ftraced_suspend--; - if (!ftraced_suspend) + mutex_lock(&ftrace_start_lock); + ftrace_start--; + if (!ftrace_start) command |= FTRACE_DISABLE_CALLS; if (saved_ftrace_func != ftrace_trace_function) { @@ -754,7 +706,7 @@ static void ftrace_shutdown(void) ftrace_run_update_code(command); out: - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); } static void ftrace_startup_sysctl(void) @@ -764,15 +716,15 @@ static void ftrace_startup_sysctl(void) if (unlikely(ftrace_disabled)) return; - mutex_lock(&ftraced_lock); + mutex_lock(&ftrace_start_lock); /* Force update next time */ saved_ftrace_func = NULL; - /* ftraced_suspend is true if we want ftrace running */ - if (ftraced_suspend) + /* ftrace_start is true if we want ftrace running */ + if (ftrace_start) command |= FTRACE_ENABLE_CALLS; ftrace_run_update_code(command); - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); } static void ftrace_shutdown_sysctl(void) @@ -782,20 +734,20 @@ static void ftrace_shutdown_sysctl(void) if (unlikely(ftrace_disabled)) return; - mutex_lock(&ftraced_lock); - /* ftraced_suspend is true if ftrace is running */ - if (ftraced_suspend) + mutex_lock(&ftrace_start_lock); + /* ftrace_start is true if ftrace is running */ + if (ftrace_start) command |= FTRACE_DISABLE_CALLS; ftrace_run_update_code(command); - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); } static cycle_t ftrace_update_time; static unsigned long ftrace_update_cnt; unsigned long ftrace_update_tot_cnt; -static int __ftrace_update_code(void *ignore) +static int ftrace_update_code(void *ignore) { int i, save_ftrace_enabled; cycle_t start, stop; @@ -869,7 +821,6 @@ static int __ftrace_update_code(void *ignore) stop = ftrace_now(raw_smp_processor_id()); ftrace_update_time = stop - start; ftrace_update_tot_cnt += ftrace_update_cnt; - ftraced_trigger = 0; ftrace_enabled = save_ftrace_enabled; ftrace_record_suspend--; @@ -877,17 +828,6 @@ static int __ftrace_update_code(void *ignore) return 0; } -static int ftrace_update_code(void) -{ - if (unlikely(ftrace_disabled) || - !ftrace_enabled || !ftraced_trigger) - return 0; - - stop_machine(__ftrace_update_code, NULL, NULL); - - return 1; -} - static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) { struct ftrace_page *pg; @@ -1425,10 +1365,10 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable) } mutex_lock(&ftrace_sysctl_lock); - mutex_lock(&ftraced_lock); - if (iter->filtered && ftraced_suspend && ftrace_enabled) + mutex_lock(&ftrace_start_lock); + if (iter->filtered && ftrace_start && ftrace_enabled) ftrace_run_update_code(FTRACE_ENABLE_CALLS); - mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_start_lock); mutex_unlock(&ftrace_sysctl_lock); kfree(iter); @@ -1448,55 +1388,6 @@ ftrace_notrace_release(struct inode *inode, struct file *file) return ftrace_regex_release(inode, file, 0); } -static ssize_t -ftraced_read(struct file *filp, char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - /* don't worry about races */ - char *buf = ftraced_stop ? "disabled\n" : "enabled\n"; - int r = strlen(buf); - - return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); -} - -static ssize_t -ftraced_write(struct file *filp, const char __user *ubuf, - size_t cnt, loff_t *ppos) -{ - char buf[64]; - long val; - int ret; - - if (cnt >= sizeof(buf)) - return -EINVAL; - - if (copy_from_user(&buf, ubuf, cnt)) - return -EFAULT; - - if (strncmp(buf, "enable", 6) == 0) - val = 1; - else if (strncmp(buf, "disable", 7) == 0) - val = 0; - else { - buf[cnt] = 0; - - ret = strict_strtoul(buf, 10, &val); - if (ret < 0) - return ret; - - val = !!val; - } - - if (val) - ftrace_enable_daemon(); - else - ftrace_disable_daemon(); - - filp->f_pos += cnt; - - return cnt; -} - static struct file_operations ftrace_avail_fops = { .open = ftrace_avail_open, .read = seq_read, @@ -1527,38 +1418,6 @@ static struct file_operations ftrace_notrace_fops = { .release = ftrace_notrace_release, }; -static struct file_operations ftraced_fops = { - .open = tracing_open_generic, - .read = ftraced_read, - .write = ftraced_write, -}; - -/** - * ftrace_force_update - force an update to all recording ftrace functions - */ -int ftrace_force_update(void) -{ - int ret = 0; - - if (unlikely(ftrace_disabled)) - return -ENODEV; - - mutex_lock(&ftrace_sysctl_lock); - mutex_lock(&ftraced_lock); - - /* - * If ftraced_trigger is not set, then there is nothing - * to update. - */ - if (ftraced_trigger && !ftrace_update_code()) - ret = -EBUSY; - - mutex_unlock(&ftraced_lock); - mutex_unlock(&ftrace_sysctl_lock); - - return ret; -} - static __init int ftrace_init_debugfs(void) { struct dentry *d_tracer; @@ -1589,17 +1448,11 @@ static __init int ftrace_init_debugfs(void) pr_warning("Could not create debugfs " "'set_ftrace_notrace' entry\n"); - entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer, - NULL, &ftraced_fops); - if (!entry) - pr_warning("Could not create debugfs " - "'ftraced_enabled' entry\n"); return 0; } fs_initcall(ftrace_init_debugfs); -#ifdef CONFIG_FTRACE_MCOUNT_RECORD static int ftrace_convert_nops(unsigned long *start, unsigned long *end) { @@ -1619,7 +1472,7 @@ static int ftrace_convert_nops(unsigned long *start, /* p is ignored */ local_irq_save(flags); - __ftrace_update_code(p); + ftrace_update_code(p); local_irq_restore(flags); return 0; @@ -1666,122 +1519,6 @@ void __init ftrace_init(void) failed: ftrace_disabled = 1; } -#else /* CONFIG_FTRACE_MCOUNT_RECORD */ - -static void ftrace_release_hash(unsigned long start, unsigned long end) -{ - struct dyn_ftrace *rec; - struct hlist_node *t, *n; - struct hlist_head *head, temp_list; - unsigned long flags; - int i, cpu; - - preempt_disable_notrace(); - - /* disable incase we call something that calls mcount */ - cpu = raw_smp_processor_id(); - per_cpu(ftrace_shutdown_disable_cpu, cpu)++; - - ftrace_hash_lock(flags); - - for (i = 0; i < FTRACE_HASHSIZE; i++) { - INIT_HLIST_HEAD(&temp_list); - head = &ftrace_hash[i]; - - /* all CPUS are stopped, we are safe to modify code */ - hlist_for_each_entry_safe(rec, t, n, head, node) { - if (rec->flags & FTRACE_FL_FREE) - continue; - - if ((rec->ip >= start) && (rec->ip < end)) - ftrace_free_rec(rec); - } - } - - ftrace_hash_unlock(flags); - - per_cpu(ftrace_shutdown_disable_cpu, cpu)--; - preempt_enable_notrace(); - -} - -static int ftraced(void *ignore) -{ - unsigned long usecs; - - while (!kthread_should_stop()) { - - set_current_state(TASK_INTERRUPTIBLE); - - /* check once a second */ - schedule_timeout(HZ); - - if (unlikely(ftrace_disabled)) - continue; - - mutex_lock(&ftrace_sysctl_lock); - mutex_lock(&ftraced_lock); - if (!ftraced_suspend && !ftraced_stop && - ftrace_update_code()) { - usecs = nsecs_to_usecs(ftrace_update_time); - if (ftrace_update_tot_cnt > 100000) { - ftrace_update_tot_cnt = 0; - pr_info("hm, dftrace overflow: %lu change%s" - " (%lu total) in %lu usec%s\n", - ftrace_update_cnt, - ftrace_update_cnt != 1 ? "s" : "", - ftrace_update_tot_cnt, - usecs, usecs != 1 ? "s" : ""); - FTRACE_WARN_ON_ONCE(1); - } - } - mutex_unlock(&ftraced_lock); - mutex_unlock(&ftrace_sysctl_lock); - - ftrace_shutdown_replenish(); - } - __set_current_state(TASK_RUNNING); - return 0; -} - -static int __init ftrace_dynamic_init(void) -{ - struct task_struct *p; - unsigned long addr; - int ret; - - addr = (unsigned long)ftrace_record_ip; - - stop_machine(ftrace_dyn_arch_init, &addr, NULL); - - /* ftrace_dyn_arch_init places the return code in addr */ - if (addr) { - ret = (int)addr; - goto failed; - } - - ret = ftrace_dyn_table_alloc(NR_TO_INIT); - if (ret) - goto failed; - - p = kthread_run(ftraced, NULL, "ftraced"); - if (IS_ERR(p)) { - ret = -1; - goto failed; - } - - last_ftrace_enabled = ftrace_enabled = 1; - ftraced_task = p; - - return 0; - - failed: - ftrace_disabled = 1; - return ret; -} - -core_initcall(ftrace_dynamic_init); -#endif /* CONFIG_FTRACE_MCOUNT_RECORD */ #else # define ftrace_startup() do { } while (0) @@ -1801,9 +1538,6 @@ void ftrace_kill(void) { ftrace_disabled = 1; ftrace_enabled = 0; -#ifdef CONFIG_DYNAMIC_FTRACE - ftraced_suspend = -1; -#endif clear_ftrace_function(); } diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 95815d26a041..90bc752a7580 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -99,13 +99,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, /* passed in by parameter to fool gcc from optimizing */ func(); - /* update the records */ - ret = ftrace_force_update(); - if (ret) { - printk(KERN_CONT ".. ftraced failed .. "); - return ret; - } - /* * Some archs *cough*PowerPC*cough* add charachters to the * start of the function names. We simply put a '*' to @@ -183,13 +176,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) /* make sure msleep has been recorded */ msleep(1); - /* force the recorded functions to be traced */ - ret = ftrace_force_update(); - if (ret) { - printk(KERN_CONT ".. ftraced failed .. "); - return ret; - } - /* start the tracing */ ftrace_enabled = 1; tracer_enabled = 1; -- cgit v1.2.3-59-g8ed1b From 4d296c24326783bff1282ac72f310d8bac8df413 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:06 -0400 Subject: ftrace: remove mcount set The arch dependent function ftrace_mcount_set was only used by the daemon start up code. This patch removes it. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/arm/kernel/ftrace.c | 13 ------------- arch/powerpc/kernel/ftrace.c | 17 ----------------- arch/sparc64/kernel/ftrace.c | 18 ------------------ arch/x86/kernel/ftrace.c | 7 ------- include/linux/ftrace.h | 1 - kernel/trace/ftrace.c | 9 --------- 6 files changed, 65 deletions(-) (limited to 'kernel') diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index 76d50e6091bc..6c90479e8974 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -95,19 +95,6 @@ int ftrace_update_ftrace_func(ftrace_func_t func) return ret; } -int ftrace_mcount_set(unsigned long *data) -{ - unsigned long pc, old; - unsigned long *addr = data; - unsigned char *new; - - pc = (unsigned long)&mcount_call; - memcpy(&old, &mcount_call, MCOUNT_INSN_SIZE); - new = ftrace_call_replace(pc, *addr); - *addr = ftrace_modify_code(pc, (unsigned char *)&old, new); - return 0; -} - /* run from kstop_machine */ int __init ftrace_dyn_arch_init(void *data) { diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 3855ceb937b0..6b75522e8b34 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -126,23 +126,6 @@ notrace int ftrace_update_ftrace_func(ftrace_func_t func) return ret; } -notrace int ftrace_mcount_set(unsigned long *data) -{ - unsigned long ip = (long)(&mcount_call); - unsigned long *addr = data; - unsigned char old[MCOUNT_INSN_SIZE], *new; - - /* - * Replace the mcount stub with a pointer to the - * ip recorder function. - */ - memcpy(old, &mcount_call, MCOUNT_INSN_SIZE); - new = ftrace_call_replace(ip, *addr); - *addr = ftrace_modify_code(ip, old, new); - - return 0; -} - int __init ftrace_dyn_arch_init(void *data) { /* This is running in kstop_machine */ diff --git a/arch/sparc64/kernel/ftrace.c b/arch/sparc64/kernel/ftrace.c index 4298d0aee713..447942041a7c 100644 --- a/arch/sparc64/kernel/ftrace.c +++ b/arch/sparc64/kernel/ftrace.c @@ -69,24 +69,6 @@ notrace int ftrace_update_ftrace_func(ftrace_func_t func) return ftrace_modify_code(ip, old, new); } -notrace int ftrace_mcount_set(unsigned long *data) -{ - unsigned long ip = (long)(&mcount_call); - unsigned long *addr = data; - unsigned char old[MCOUNT_INSN_SIZE], *new; - - /* - * Replace the mcount stub with a pointer to the - * ip recorder function. - */ - memcpy(old, &mcount_call, MCOUNT_INSN_SIZE); - new = ftrace_call_replace(ip, *addr); - *addr = ftrace_modify_code(ip, old, new); - - return 0; -} - - int __init ftrace_dyn_arch_init(void *data) { ftrace_mcount_set(data); diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index da4fb0deecf7..b399eed23538 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -103,13 +103,6 @@ notrace int ftrace_update_ftrace_func(ftrace_func_t func) return ret; } -notrace int ftrace_mcount_set(unsigned long *data) -{ - /* mcount is initialized as a nop */ - *data = 0; - return 0; -} - int __init ftrace_dyn_arch_init(void *data) { extern const unsigned char ftrace_test_p6nop[]; diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index ac58e94668b7..1c4835f86911 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -71,7 +71,6 @@ extern int ftrace_ip_converted(unsigned long ip); extern unsigned char *ftrace_nop_replace(void); extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr); extern int ftrace_dyn_arch_init(void *data); -extern int ftrace_mcount_set(unsigned long *data); extern int ftrace_update_ftrace_func(ftrace_func_t func); extern void ftrace_caller(void); extern void ftrace_call(void); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index e758cab0836f..226fd9132d53 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -620,7 +620,6 @@ static int ftrace_update_code(void *ignore); static int __ftrace_modify_code(void *data) { - unsigned long addr; int *command = data; if (*command & FTRACE_ENABLE_CALLS) { @@ -639,14 +638,6 @@ static int __ftrace_modify_code(void *data) if (*command & FTRACE_UPDATE_TRACE_FUNC) ftrace_update_ftrace_func(ftrace_trace_function); - if (*command & FTRACE_ENABLE_MCOUNT) { - addr = (unsigned long)ftrace_record_ip; - ftrace_mcount_set(&addr); - } else if (*command & FTRACE_DISABLE_MCOUNT) { - addr = (unsigned long)ftrace_stub; - ftrace_mcount_set(&addr); - } - return 0; } -- cgit v1.2.3-59-g8ed1b From 08f5ac906d2c0faf96d608c54a0b03177376da8d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:07 -0400 Subject: ftrace: remove ftrace hash The ftrace hash was used by the ftrace_daemon code. The record ip function would place the calling address (ip) into the hash. The daemon would later read the hash and modify that code. The hash complicates the code. This patch removes it. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- include/linux/ftrace.h | 8 +- kernel/trace/ftrace.c | 243 +++++++------------------------------------------ kernel/trace/trace.c | 3 - 3 files changed, 38 insertions(+), 216 deletions(-) (limited to 'kernel') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 1c4835f86911..703eb53cfa2b 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -44,8 +44,6 @@ static inline void ftrace_kill(void) { } #endif /* CONFIG_FUNCTION_TRACER */ #ifdef CONFIG_DYNAMIC_FTRACE -# define FTRACE_HASHBITS 10 -# define FTRACE_HASHSIZE (1< #include #include -#include #include #include @@ -189,9 +188,7 @@ static int ftrace_filtered; static int tracing_on; static int frozen_record_count; -static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; - -static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); +static LIST_HEAD(ftrace_new_addrs); static DEFINE_MUTEX(ftrace_regex_lock); @@ -210,8 +207,6 @@ struct ftrace_page { static struct ftrace_page *ftrace_pages_start; static struct ftrace_page *ftrace_pages; -static int ftrace_record_suspend; - static struct dyn_ftrace *ftrace_free_records; @@ -242,72 +237,6 @@ static inline int record_frozen(struct dyn_ftrace *rec) # define record_frozen(rec) ({ 0; }) #endif /* CONFIG_KPROBES */ -int skip_trace(unsigned long ip) -{ - unsigned long fl; - struct dyn_ftrace *rec; - struct hlist_node *t; - struct hlist_head *head; - - if (frozen_record_count == 0) - return 0; - - head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)]; - hlist_for_each_entry_rcu(rec, t, head, node) { - if (rec->ip == ip) { - if (record_frozen(rec)) { - if (rec->flags & FTRACE_FL_FAILED) - return 1; - - if (!(rec->flags & FTRACE_FL_CONVERTED)) - return 1; - - if (!tracing_on || !ftrace_enabled) - return 1; - - if (ftrace_filtered) { - fl = rec->flags & (FTRACE_FL_FILTER | - FTRACE_FL_NOTRACE); - if (!fl || (fl & FTRACE_FL_NOTRACE)) - return 1; - } - } - break; - } - } - - return 0; -} - -static inline int -ftrace_ip_in_hash(unsigned long ip, unsigned long key) -{ - struct dyn_ftrace *p; - struct hlist_node *t; - int found = 0; - - hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) { - if (p->ip == ip) { - found = 1; - break; - } - } - - return found; -} - -static inline void -ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) -{ - hlist_add_head_rcu(&node->node, &ftrace_hash[key]); -} - -/* called from kstop_machine */ -static inline void ftrace_del_hash(struct dyn_ftrace *node) -{ - hlist_del(&node->node); -} - static void ftrace_free_rec(struct dyn_ftrace *rec) { rec->ip = (unsigned long)ftrace_free_records; @@ -362,69 +291,36 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) } if (ftrace_pages->index == ENTRIES_PER_PAGE) { - if (!ftrace_pages->next) - return NULL; + if (!ftrace_pages->next) { + /* allocate another page */ + ftrace_pages->next = + (void *)get_zeroed_page(GFP_KERNEL); + if (!ftrace_pages->next) + return NULL; + } ftrace_pages = ftrace_pages->next; } return &ftrace_pages->records[ftrace_pages->index++]; } -static void +static struct dyn_ftrace * ftrace_record_ip(unsigned long ip) { - struct dyn_ftrace *node; - unsigned long key; - int resched; - int cpu; + struct dyn_ftrace *rec; if (!ftrace_enabled || ftrace_disabled) - return; - - resched = need_resched(); - preempt_disable_notrace(); - - /* - * We simply need to protect against recursion. - * Use the the raw version of smp_processor_id and not - * __get_cpu_var which can call debug hooks that can - * cause a recursive crash here. - */ - cpu = raw_smp_processor_id(); - per_cpu(ftrace_shutdown_disable_cpu, cpu)++; - if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1) - goto out; - - if (unlikely(ftrace_record_suspend)) - goto out; - - key = hash_long(ip, FTRACE_HASHBITS); - - FTRACE_WARN_ON_ONCE(key >= FTRACE_HASHSIZE); - - if (ftrace_ip_in_hash(ip, key)) - goto out; - - /* This ip may have hit the hash before the lock */ - if (ftrace_ip_in_hash(ip, key)) - goto out; - - node = ftrace_alloc_dyn_node(ip); - if (!node) - goto out; + return NULL; - node->ip = ip; + rec = ftrace_alloc_dyn_node(ip); + if (!rec) + return NULL; - ftrace_add_hash(node, key); + rec->ip = ip; - out: - per_cpu(ftrace_shutdown_disable_cpu, cpu)--; + list_add(&rec->list, &ftrace_new_addrs); - /* prevent recursion with scheduler */ - if (resched) - preempt_enable_no_resched_notrace(); - else - preempt_enable_notrace(); + return rec; } #define FTRACE_ADDR ((long)(ftrace_caller)) @@ -543,7 +439,6 @@ static void ftrace_replace_code(int enable) rec->flags |= FTRACE_FL_FAILED; if ((system_state == SYSTEM_BOOTING) || !core_kernel_text(rec->ip)) { - ftrace_del_hash(rec); ftrace_free_rec(rec); } } @@ -551,15 +446,6 @@ static void ftrace_replace_code(int enable) } } -static void ftrace_shutdown_replenish(void) -{ - if (ftrace_pages->next) - return; - - /* allocate another page */ - ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); -} - static void print_ip_ins(const char *fmt, unsigned char *p) { int i; @@ -616,18 +502,11 @@ ftrace_code_disable(struct dyn_ftrace *rec) return 1; } -static int ftrace_update_code(void *ignore); - static int __ftrace_modify_code(void *data) { int *command = data; if (*command & FTRACE_ENABLE_CALLS) { - /* - * Update any recorded ips now that we have the - * machine stopped - */ - ftrace_update_code(NULL); ftrace_replace_code(1); tracing_on = 1; } else if (*command & FTRACE_DISABLE_CALLS) { @@ -738,84 +617,34 @@ static cycle_t ftrace_update_time; static unsigned long ftrace_update_cnt; unsigned long ftrace_update_tot_cnt; -static int ftrace_update_code(void *ignore) +static int ftrace_update_code(void) { - int i, save_ftrace_enabled; + struct dyn_ftrace *p, *t; cycle_t start, stop; - struct dyn_ftrace *p; - struct hlist_node *t, *n; - struct hlist_head *head, temp_list; - - /* Don't be recording funcs now */ - ftrace_record_suspend++; - save_ftrace_enabled = ftrace_enabled; - ftrace_enabled = 0; start = ftrace_now(raw_smp_processor_id()); ftrace_update_cnt = 0; - /* No locks needed, the machine is stopped! */ - for (i = 0; i < FTRACE_HASHSIZE; i++) { - INIT_HLIST_HEAD(&temp_list); - head = &ftrace_hash[i]; + list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { - /* all CPUS are stopped, we are safe to modify code */ - hlist_for_each_entry_safe(p, t, n, head, node) { - /* Skip over failed records which have not been - * freed. */ - if (p->flags & FTRACE_FL_FAILED) - continue; + /* If something went wrong, bail without enabling anything */ + if (unlikely(ftrace_disabled)) + return -1; - /* Unconverted records are always at the head of the - * hash bucket. Once we encounter a converted record, - * simply skip over to the next bucket. Saves ftraced - * some processor cycles (ftrace does its bid for - * global warming :-p ). */ - if (p->flags & (FTRACE_FL_CONVERTED)) - break; + list_del_init(&p->list); - /* Ignore updates to this record's mcount site. - * Reintroduce this record at the head of this - * bucket to attempt to "convert" it again if - * the kprobe on it is unregistered before the - * next run. */ - if (get_kprobe((void *)p->ip)) { - ftrace_del_hash(p); - INIT_HLIST_NODE(&p->node); - hlist_add_head(&p->node, &temp_list); - freeze_record(p); - continue; - } else { - unfreeze_record(p); - } - - /* convert record (i.e, patch mcount-call with NOP) */ - if (ftrace_code_disable(p)) { - p->flags |= FTRACE_FL_CONVERTED; - ftrace_update_cnt++; - } else { - if ((system_state == SYSTEM_BOOTING) || - !core_kernel_text(p->ip)) { - ftrace_del_hash(p); - ftrace_free_rec(p); - } - } - } - - hlist_for_each_entry_safe(p, t, n, &temp_list, node) { - hlist_del(&p->node); - INIT_HLIST_NODE(&p->node); - hlist_add_head(&p->node, head); - } + /* convert record (i.e, patch mcount-call with NOP) */ + if (ftrace_code_disable(p)) { + p->flags |= FTRACE_FL_CONVERTED; + ftrace_update_cnt++; + } else + ftrace_free_rec(p); } stop = ftrace_now(raw_smp_processor_id()); ftrace_update_time = stop - start; ftrace_update_tot_cnt += ftrace_update_cnt; - ftrace_enabled = save_ftrace_enabled; - ftrace_record_suspend--; - return 0; } @@ -847,7 +676,7 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) pg = ftrace_pages = ftrace_pages_start; cnt = num_to_init / ENTRIES_PER_PAGE; - pr_info("ftrace: allocating %ld hash entries in %d pages\n", + pr_info("ftrace: allocating %ld entries in %d pages\n", num_to_init, cnt); for (i = 0; i < cnt; i++) { @@ -1451,20 +1280,18 @@ static int ftrace_convert_nops(unsigned long *start, unsigned long addr; unsigned long flags; + mutex_lock(&ftrace_start_lock); p = start; while (p < end) { addr = ftrace_call_adjust(*p++); - /* should not be called from interrupt context */ - spin_lock(&ftrace_lock); ftrace_record_ip(addr); - spin_unlock(&ftrace_lock); - ftrace_shutdown_replenish(); } - /* p is ignored */ + /* disable interrupts to prevent kstop machine */ local_irq_save(flags); - ftrace_update_code(p); + ftrace_update_code(); local_irq_restore(flags); + mutex_unlock(&ftrace_start_lock); return 0; } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 333a5162149b..06951e229443 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -865,9 +865,6 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) if (unlikely(!ftrace_function_enabled)) return; - if (skip_trace(ip)) - return; - pc = preempt_count(); resched = need_resched(); preempt_disable_notrace(); -- cgit v1.2.3-59-g8ed1b From 66b0de3569b00f61978782b9f97aa4803dbec0fb Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 23 Oct 2008 16:11:03 +0200 Subject: ftrace: fix build failure fix: kernel/trace/ftrace.c: In function 'ftrace_release': kernel/trace/ftrace.c:271: error: implicit declaration of function 'ftrace_release_hash' release_hash is not needed without dftraced. Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 07762c08a944..27212321eb0d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -267,8 +267,6 @@ void ftrace_release(void *start, unsigned long size) } } spin_unlock(&ftrace_lock); - - ftrace_release_hash(s, e); } static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) -- cgit v1.2.3-59-g8ed1b From f17845e5d97ead8fbdadfd40039e058ec7cf4a42 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 24 Oct 2008 12:47:10 +0200 Subject: ftrace: warning in kernel/trace/ftrace.c MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit this warning: kernel/trace/ftrace.c:189: warning: ‘frozen_record_count’ defined but not used triggers because frozen_record_count is only used in the KCONFIG_MARKERS case. Move the variable it there. Alas, this frozen-record facility seems to have little use. The frozen_record_count variable is not used by anything, nor the flags. So this section might need a bit of dead-code-removal care as well. Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 27212321eb0d..7618c528756b 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -186,7 +186,6 @@ enum { static int ftrace_filtered; static int tracing_on; -static int frozen_record_count; static LIST_HEAD(ftrace_new_addrs); @@ -211,6 +210,9 @@ static struct dyn_ftrace *ftrace_free_records; #ifdef CONFIG_KPROBES + +static int frozen_record_count; + static inline void freeze_record(struct dyn_ftrace *rec) { if (!(rec->flags & FTRACE_FL_FROZEN)) { @@ -1443,3 +1445,4 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, mutex_unlock(&ftrace_sysctl_lock); return ret; } + -- cgit v1.2.3-59-g8ed1b From e2862c9470beb842d3f1c1965b03a2112114c160 Mon Sep 17 00:00:00 2001 From: Stephen Rothwell Date: Mon, 27 Oct 2008 17:43:28 +1100 Subject: trace: fix printk warning for u64 A powerpc ppc64_defconfig build produces these warnings: kernel/trace/ring_buffer.c: In function 'rb_add_time_stamp': kernel/trace/ring_buffer.c:969: warning: format '%llu' expects type 'long long unsigned int', but argument 2 has type 'u64' kernel/trace/ring_buffer.c:969: warning: format '%llu' expects type 'long long unsigned int', but argument 3 has type 'u64' kernel/trace/ring_buffer.c:969: warning: format '%llu' expects type 'long long unsigned int', but argument 4 has type 'u64' Just cast the u64s to unsigned long long like we do everywhere else. Signed-off-by: Stephen Rothwell Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ring_buffer.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 091aeefe321e..cedf4e268285 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -966,7 +966,9 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer, if (unlikely(*delta > (1ULL << 59) && !once++)) { printk(KERN_WARNING "Delta way too big! %llu" " ts=%llu write stamp = %llu\n", - *delta, *ts, cpu_buffer->write_stamp); + (unsigned long long)*delta, + (unsigned long long)*ts, + (unsigned long long)cpu_buffer->write_stamp); WARN_ON(1); } -- cgit v1.2.3-59-g8ed1b From f66af459a931f25807e1df7915b2b66bb5978d82 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 22 Oct 2008 19:14:55 +0200 Subject: tracepoint: check if the probe has been registered Impact: fix kernel crash that can trigger during tracing If we try to remove a probe that has not been already registered, the tracepoint_entry_remove_probe() function will dereference a NULL pointer. Check the probe before removing it to avoid crashes. Signed-off-by: Frederic Weisbecker Acked-by: Mathieu Desnoyers Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/tracepoint.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel') diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index f2b7c28a4708..af8c85664882 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -131,6 +131,9 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe) old = entry->funcs; + if (!old) + return NULL; + debug_print_probes(entry); /* (N -> M), (N > 1, M >= 0) probes */ for (nr_probes = 0; old[nr_probes]; nr_probes++) { @@ -388,6 +391,11 @@ int tracepoint_probe_unregister(const char *name, void *probe) if (entry->rcu_pending) rcu_barrier_sched(); old = tracepoint_entry_remove_probe(entry, probe); + if (!old) { + printk(KERN_WARNING "Warning: Trying to unregister a probe" + "that doesn't exist\n"); + goto end; + } mutex_unlock(&tracepoints_mutex); tracepoint_update_probes(); /* may update entry */ mutex_lock(&tracepoints_mutex); -- cgit v1.2.3-59-g8ed1b From ea31e72d753e5817a97de552f152d0cb55c7defc Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 22 Oct 2008 19:26:23 +0200 Subject: tracing/ftrace: make boot tracer select the sched_switch tracer Impact: build fix If the boot tracer is selected but not the sched_switch, there will be a build failure: kernel/built-in.o: In function `boot_trace_init': trace_boot.c:(.text+0x5ee38): undefined reference to `sched_switch_trace' kernel/built-in.o: In function `disable_boot_trace': (.text+0x5eee1): undefined reference to `tracing_stop_cmdline_record' kernel/built-in.o: In function `enable_boot_trace': (.text+0x5ef11): undefined reference to `tracing_start_cmdline_record' This patch fixes it. Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index bc535cb91de9..e0cea282e0c5 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -123,6 +123,7 @@ config BOOT_TRACER bool "Trace boot initcalls" depends on DEBUG_KERNEL select TRACING + select CONTEXT_SWITCH_TRACER help This tracer helps developers to optimize boot times: it records the timings of the initcalls and traces key events and the identity -- cgit v1.2.3-59-g8ed1b From 21798a84ab383cdac0e7ee3368e0792b718b867d Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 28 Oct 2008 09:43:26 +0100 Subject: tracing: fix a build error on alpha Impact: build fix on Alpha When tracing is enabled, some arch have included on their but others like alpha or m68k don't. Build error on alpha: kernel/trace/trace.c: In function 'tracing_cpumask_write': kernel/trace/trace.c:2145: error: implicit declaration of function 'raw_local_irq_disable' kernel/trace/trace.c:2162: error: implicit declaration of function 'raw_local_irq_enable' Tested on Alpha through a cross-compiler (should correct a similar issue on m68k). Reported-by: Alexey Dobriyan Signed-off-by: Frederic Weisbecker Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 06951e229443..bc577dcc0e47 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -34,6 +34,7 @@ #include #include +#include #include "trace.h" -- cgit v1.2.3-59-g8ed1b From 60063a66236c15f5613f91390631e06718689782 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 28 Oct 2008 10:44:24 -0400 Subject: ftrace: fix current_tracer error return The commit (in linux-tip) c2931e05ec5965597cbfb79ad332d4a29aeceb23 ( ftrace: return an error when setting a nonexistent tracer ) added useful code that would error when a bad tracer was written into the current_tracer file. But this had a bug if the amount written was more than the amount read by that code. The first iteration would set the tracer correctly, but since it did not consume the rest of what was written (usually whitespace), the userspace utility would continue to write what was not consumed. This second iteration would fail to find a tracer and return -EINVAL. Funny thing is that the tracer would have already been set. This patch just consumes all the data that is written to the file. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bc577dcc0e47..a610ca771558 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2377,9 +2377,10 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, int i; size_t ret; + ret = cnt; + if (cnt > max_tracer_type_len) cnt = max_tracer_type_len; - ret = cnt; if (copy_from_user(&buf, ubuf, cnt)) return -EFAULT; @@ -2412,8 +2413,8 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, out: mutex_unlock(&trace_types_lock); - if (ret == cnt) - filp->f_pos += cnt; + if (ret > 0) + filp->f_pos += ret; return ret; } -- cgit v1.2.3-59-g8ed1b