Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/sc…

…m/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
  tracing/urgent: warn in case of ftrace_start_up inbalance
  tracing/urgent: fix unbalanced ftrace_start_up
  function-graph: add stack frame test
  function-graph: disable when both x86_32 and optimize for size are configured
  ring-buffer: have benchmark test print to trace buffer
  ring-buffer: do not grab locks in nmi
  ring-buffer: add locks around rb_per_cpu_empty
  ring-buffer: check for less than two in size allocation
  ring-buffer: remove useless compile check for buffer_page size
  ring-buffer: remove useless warn on check
  ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index
  tracing: update sample event documentation
  tracing/filters: fix race between filter setting and module unload
  tracing/filters: free filter_string in destroy_preds()
  ring-buffer: use commit counters for commit pointer accounting
  ring-buffer: remove unused variable
  ring-buffer: have benchmark test handle discarded events
  ring-buffer: prevent adding write in discarded area
  tracing/filters: strloc should be unsigned short
  tracing/filters: operand can be negative
  ...

Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually

arch/powerpc/kernel/ftrace.c

@@ -586,7 +586,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 		return;
 	}
 
-	if (ftrace_push_return_trace(old, self_addr, &trace.depth) == -EBUSY) {
+	if (ftrace_push_return_trace(old, self_addr, &trace.depth, 0) == -EBUSY) {
 		*parent = old;
 		return;
 	}

arch/s390/kernel/ftrace.c

@@ -190,7 +190,7 @@ unsigned long prepare_ftrace_return(unsigned long ip, unsigned long parent)
 		goto out;
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		goto out;
-	if (ftrace_push_return_trace(parent, ip, &trace.depth) == -EBUSY)
+	if (ftrace_push_return_trace(parent, ip, &trace.depth, 0) == -EBUSY)
 		goto out;
 	trace.func = ftrace_mcount_call_adjust(ip) & PSW_ADDR_INSN;
 	/* Only trace if the calling function expects to. */

arch/x86/Kconfig

@@ -34,6 +34,7 @@ config X86
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
+	select HAVE_FUNCTION_GRAPH_FP_TEST
 	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
 	select HAVE_FTRACE_SYSCALLS

arch/x86/kernel/entry_32.S

@@ -1174,6 +1174,7 @@ ENTRY(ftrace_graph_caller)
 	pushl %edx
 	movl 0xc(%esp), %edx
 	lea 0x4(%ebp), %eax
+	movl (%ebp), %ecx
 	subl $MCOUNT_INSN_SIZE, %edx
 	call prepare_ftrace_return
 	popl %edx
@@ -1188,6 +1189,7 @@ return_to_handler:
 	pushl %eax
 	pushl %ecx
 	pushl %edx
+	movl %ebp, %eax
 	call ftrace_return_to_handler
 	movl %eax, 0xc(%esp)
 	popl %edx

arch/x86/kernel/entry_64.S

@@ -135,6 +135,7 @@ ENTRY(ftrace_graph_caller)
 
 	leaq 8(%rbp), %rdi
 	movq 0x38(%rsp), %rsi
+	movq (%rbp), %rdx
 	subq $MCOUNT_INSN_SIZE, %rsi
 
 	call	prepare_ftrace_return
@@ -150,6 +151,7 @@ GLOBAL(return_to_handler)
 	/* Save the return values */
 	movq %rax, (%rsp)
 	movq %rdx, 8(%rsp)
+	movq %rbp, %rdi
 
 	call ftrace_return_to_handler
 

arch/x86/kernel/ftrace.c

@@ -408,7 +408,8 @@ int ftrace_disable_ftrace_graph_caller(void)
  * Hook the return address and push it in the stack of return addrs
  * in current thread info.
  */
-void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
+void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
+			   unsigned long frame_pointer)
 {
 	unsigned long old;
 	int faulted;
@@ -453,7 +454,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 		return;
 	}
 
-	if (ftrace_push_return_trace(old, self_addr, &trace.depth) == -EBUSY) {
+	if (ftrace_push_return_trace(old, self_addr, &trace.depth,
+		    frame_pointer) == -EBUSY) {
 		*parent = old;
 		return;
 	}

include/linux/ftrace.h

@@ -362,6 +362,7 @@ struct ftrace_ret_stack {
 	unsigned long func;
 	unsigned long long calltime;
 	unsigned long long subtime;
+	unsigned long fp;
 };
 
 /*
@@ -372,7 +373,8 @@ struct ftrace_ret_stack {
 extern void return_to_handler(void);
 
 extern int
-ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth);
+ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
+			 unsigned long frame_pointer);
 
 /*
  * Sometimes we don't want to trace a function with the function

include/linux/trace_seq.h

@@ -3,6 +3,8 @@
 
 #include <linux/fs.h>
 
+#include <asm/page.h>
+
 /*
  * Trace sequences are used to allow a function to call several other functions
  * to create a string of data to use (up to a max of PAGE_SIZE.

kernel/trace/Kconfig

@@ -18,6 +18,13 @@ config HAVE_FUNCTION_TRACER
 config HAVE_FUNCTION_GRAPH_TRACER
 	bool
 
+config HAVE_FUNCTION_GRAPH_FP_TEST
+	bool
+	help
+	 An arch may pass in a unique value (frame pointer) to both the
+	 entering and exiting of a function. On exit, the value is compared
+	 and if it does not match, then it will panic the kernel.
+
 config HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	bool
 	help
@@ -121,6 +128,7 @@ config FUNCTION_GRAPH_TRACER
 	bool "Kernel Function Graph Tracer"
 	depends on HAVE_FUNCTION_GRAPH_TRACER
 	depends on FUNCTION_TRACER
+	depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
 	default y
 	help
 	  Enable the kernel to trace a function at both its return

kernel/trace/ftrace.c

@@ -1224,6 +1224,13 @@ static void ftrace_shutdown(int command)
 		return;
 
 	ftrace_start_up--;
+	/*
+	 * Just warn in case of unbalance, no need to kill ftrace, it's not
+	 * critical but the ftrace_call callers may be never nopped again after
+	 * further ftrace uses.
+	 */
+	WARN_ON_ONCE(ftrace_start_up < 0);
+
 	if (!ftrace_start_up)
 		command |= FTRACE_DISABLE_CALLS;
 

kernel/trace/kmemtrace.c

@@ -186,7 +186,7 @@ static int kmem_trace_init(struct trace_array *tr)
 	int cpu;
 	kmemtrace_array = tr;
 
-	for_each_cpu_mask(cpu, cpu_possible_map)
+	for_each_cpu(cpu, cpu_possible_mask)
 		tracing_reset(tr, cpu);
 
 	kmemtrace_start_probes();