Commit c17488d0 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing updates from Steven Rostedt:
 "Not much new with tracing for this release.  Mostly just clean ups and
  minor fixes.

  Here's what else is new:

   - A new TRACE_EVENT_FN_COND macro, combining both _FN and _COND for
     those that want both.

   - New selftest to test the instance create and delete

   - Better debug output when ftrace fails"

* tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
  ftrace: Fix the race between ftrace and insmod
  ftrace: Add infrastructure for delayed enabling of module functions
  x86: ftrace: Fix the comments for ftrace_modify_code_direct()
  tracing: Fix comment to use tracing_on over tracing_enable
  metag: ftrace: Fix the comments for ftrace_modify_code
  sh: ftrace: Fix the comments for ftrace_modify_code()
  ia64: ftrace: Fix the comments for ftrace_modify_code()
  ftrace: Clean up ftrace_module_init() code
  ftrace: Join functions ftrace_module_init() and ftrace_init_module()
  tracing: Introduce TRACE_EVENT_FN_COND macro
  tracing: Use seq_buf_used() in seq_buf_to_user() instead of len
  bpf: Constify bpf_verifier_ops structure
  ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too
  ftrace: Remove use of control list and ops
  ftrace: Fix output of enabled_functions for showing tramp
  ftrace: Fix a typo in comment
  ftrace: Show all tramps registered to a record on ftrace_bug()
  ftrace: Add variable ftrace_expected for archs to show expected code
  ftrace: Add new type to distinguish what kind of ftrace_bug()
  tracing: Update cond flag when enabling or disabling a trigger
  ...
parents 34a9304a 5156dca3

arch/ia64/kernel/ftrace.c

+5 −7
Original line number Diff line number Diff line
@@ -97,13 +97,11 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, 
	unsigned char replaced[MCOUNT_INSN_SIZE];



	/*

	 * Note: Due to modules and __init, code can

	 *  disappear and change, we need to protect against faulting

	 *  as well as code changing. We do this by using the

	 *  probe_kernel_* functions.

	 *

	 * No real locking needed, this code is run through

	 * kstop_machine, or before SMP starts.

	 * Note:

	 * We are paranoid about modifying text, as if a bug was to happen, it

	 * could cause us to read or write to someplace that could cause harm.

	 * Carefully read and modify the code with probe_kernel_*(), and make

	 * sure what we read is what we expected it to be before modifying it.

	 */



	if (!do_check)

arch/metag/kernel/ftrace.c

+5 −6
Original line number Diff line number Diff line
@@ -54,12 +54,11 @@ static int ftrace_modify_code(unsigned long pc, unsigned char *old_code, 
	unsigned char replaced[MCOUNT_INSN_SIZE];



	/*

	 * Note: Due to modules and __init, code can

	 *  disappear and change, we need to protect against faulting

	 *  as well as code changing.

	 *

	 * No real locking needed, this code is run through

	 * kstop_machine.

	 * Note:

	 * We are paranoid about modifying text, as if a bug was to happen, it

	 * could cause us to read or write to someplace that could cause harm.

	 * Carefully read and modify the code with probe_kernel_*(), and make

	 * sure what we read is what we expected it to be before modifying it.

	 */



	/* read the text we want to modify */

arch/sh/kernel/ftrace.c

+5 −7
Original line number Diff line number Diff line
@@ -212,13 +212,11 @@ static int ftrace_modify_code(unsigned long ip, unsigned char *old_code, 
	unsigned char replaced[MCOUNT_INSN_SIZE];



	/*

	 * Note: Due to modules and __init, code can

	 *  disappear and change, we need to protect against faulting

	 *  as well as code changing. We do this by using the

	 *  probe_kernel_* functions.

	 *

	 * No real locking needed, this code is run through

	 * kstop_machine, or before SMP starts.

	 * Note:

	 * We are paranoid about modifying text, as if a bug was to happen, it

	 * could cause us to read or write to someplace that could cause harm.

	 * Carefully read and modify the code with probe_kernel_*(), and make

	 * sure what we read is what we expected it to be before modifying it.

	 */



	/* read the text we want to modify */

arch/x86/kernel/ftrace.c

+14 −7
Original line number Diff line number Diff line
@@ -105,14 +105,14 @@ ftrace_modify_code_direct(unsigned long ip, unsigned const char *old_code, 
{

	unsigned char replaced[MCOUNT_INSN_SIZE];



	ftrace_expected = old_code;



	/*

	 * Note: Due to modules and __init, code can

	 *  disappear and change, we need to protect against faulting

	 *  as well as code changing. We do this by using the

	 *  probe_kernel_* functions.

	 *

	 * No real locking needed, this code is run through

	 * kstop_machine, or before SMP starts.

	 * Note:

	 * We are paranoid about modifying text, as if a bug was to happen, it

	 * could cause us to read or write to someplace that could cause harm.

	 * Carefully read and modify the code with probe_kernel_*(), and make

	 * sure what we read is what we expected it to be before modifying it.

	 */



	/* read the text we want to modify */
@@ -154,6 +154,8 @@ int ftrace_make_nop(struct module *mod, 
	if (addr == MCOUNT_ADDR)

		return ftrace_modify_code_direct(rec->ip, old, new);



	ftrace_expected = NULL;



	/* Normal cases use add_brk_on_nop */

	WARN_ONCE(1, "invalid use of ftrace_make_nop");

	return -EINVAL;
@@ -220,6 +222,7 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 
				 unsigned long addr)

{

	WARN_ON(1);

	ftrace_expected = NULL;

	return -EINVAL;

}
@@ -314,6 +317,8 @@ static int add_break(unsigned long ip, const char *old) 
	if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE))

		return -EFAULT;



	ftrace_expected = old;



	/* Make sure it is what we expect it to be */

	if (memcmp(replaced, old, MCOUNT_INSN_SIZE) != 0)

		return -EINVAL;
@@ -413,6 +418,8 @@ static int remove_breakpoint(struct dyn_ftrace *rec) 
		ftrace_addr = ftrace_get_addr_curr(rec);

		nop = ftrace_call_replace(ip, ftrace_addr);



		ftrace_expected = nop;



		if (memcmp(&ins[1], &nop[1], MCOUNT_INSN_SIZE - 1) != 0)

			return -EINVAL;

	}

include/linux/ftrace.h

+37 −19
Original line number Diff line number Diff line
@@ -76,8 +76,8 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 
 * ENABLED - set/unset when ftrace_ops is registered/unregistered

 * DYNAMIC - set when ftrace_ops is registered to denote dynamically

 *           allocated ftrace_ops which need special care

 * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops

 *           could be controled by following calls:

 * PER_CPU - set manualy by ftrace_ops user to denote the ftrace_ops

 *           could be controlled by following calls:

 *             ftrace_function_local_enable

 *             ftrace_function_local_disable

 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
@@ -121,7 +121,7 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 
enum {

	FTRACE_OPS_FL_ENABLED			= 1 << 0,

	FTRACE_OPS_FL_DYNAMIC			= 1 << 1,

	FTRACE_OPS_FL_CONTROL			= 1 << 2,

	FTRACE_OPS_FL_PER_CPU			= 1 << 2,

	FTRACE_OPS_FL_SAVE_REGS			= 1 << 3,

	FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED	= 1 << 4,

	FTRACE_OPS_FL_RECURSION_SAFE		= 1 << 5,
@@ -134,6 +134,7 @@ enum { 
	FTRACE_OPS_FL_ALLOC_TRAMP		= 1 << 12,

	FTRACE_OPS_FL_IPMODIFY			= 1 << 13,

	FTRACE_OPS_FL_PID			= 1 << 14,

	FTRACE_OPS_FL_RCU			= 1 << 15,

};



#ifdef CONFIG_DYNAMIC_FTRACE
@@ -146,11 +147,11 @@ struct ftrace_ops_hash { 
#endif



/*

 * Note, ftrace_ops can be referenced outside of RCU protection.

 * (Although, for perf, the control ops prevent that). If ftrace_ops is

 * allocated and not part of kernel core data, the unregistering of it will

 * perform a scheduling on all CPUs to make sure that there are no more users.

 * Depending on the load of the system that may take a bit of time.

 * Note, ftrace_ops can be referenced outside of RCU protection, unless

 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel

 * core data, the unregistering of it will perform a scheduling on all CPUs

 * to make sure that there are no more users. Depending on the load of the

 * system that may take a bit of time.

 *

 * Any private data added must also take care not to be freed and if private

 * data is added to a ftrace_ops that is in core code, the user of the
@@ -196,34 +197,34 @@ int unregister_ftrace_function(struct ftrace_ops *ops); 
void clear_ftrace_function(void);



/**

 * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu

 * ftrace_function_local_enable - enable ftrace_ops on current cpu

 *

 * This function enables tracing on current cpu by decreasing

 * the per cpu control variable.

 * It must be called with preemption disabled and only on ftrace_ops

 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption

 * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption

 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.

 */

static inline void ftrace_function_local_enable(struct ftrace_ops *ops)

{

	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))

	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)))

		return;



	(*this_cpu_ptr(ops->disabled))--;

}



/**

 * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu

 * ftrace_function_local_disable - disable ftrace_ops on current cpu

 *

 * This function enables tracing on current cpu by decreasing

 * This function disables tracing on current cpu by increasing

 * the per cpu control variable.

 * It must be called with preemption disabled and only on ftrace_ops

 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption

 * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption

 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.

 */

static inline void ftrace_function_local_disable(struct ftrace_ops *ops)

{

	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))

	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)))

		return;



	(*this_cpu_ptr(ops->disabled))++;
@@ -235,12 +236,12 @@ static inline void ftrace_function_local_disable(struct ftrace_ops *ops) 
 *

 * This function returns value of ftrace_ops::disabled on current cpu.

 * It must be called with preemption disabled and only on ftrace_ops

 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption

 * registered with FTRACE_OPS_FL_PER_CPU. If called without preemption

 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.

 */

static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)

{

	WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));

	WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU));

	return *this_cpu_ptr(ops->disabled);

}
@@ -296,6 +297,21 @@ int ftrace_arch_code_modify_post_process(void); 


struct dyn_ftrace;



enum ftrace_bug_type {

	FTRACE_BUG_UNKNOWN,

	FTRACE_BUG_INIT,

	FTRACE_BUG_NOP,

	FTRACE_BUG_CALL,

	FTRACE_BUG_UPDATE,

};

extern enum ftrace_bug_type ftrace_bug_type;



/*

 * Archs can set this to point to a variable that holds the value that was

 * expected at the call site before calling ftrace_bug().

 */

extern const void *ftrace_expected;



void ftrace_bug(int err, struct dyn_ftrace *rec);



struct seq_file;
@@ -341,6 +357,7 @@ bool is_ftrace_trampoline(unsigned long addr); 
 *  REGS    - the record wants the function to save regs

 *  REGS_EN - the function is set up to save regs.

 *  IPMODIFY - the record allows for the IP address to be changed.

 *  DISABLED - the record is not ready to be touched yet

 *

 * When a new ftrace_ops is registered and wants a function to save

 * pt_regs, the rec->flag REGS is set. When the function has been
@@ -355,10 +372,11 @@ enum { 
	FTRACE_FL_TRAMP		= (1UL << 28),

	FTRACE_FL_TRAMP_EN	= (1UL << 27),

	FTRACE_FL_IPMODIFY	= (1UL << 26),

	FTRACE_FL_DISABLED	= (1UL << 25),

};



#define FTRACE_REF_MAX_SHIFT	26

#define FTRACE_FL_BITS		6

#define FTRACE_REF_MAX_SHIFT	25

#define FTRACE_FL_BITS		7

#define FTRACE_FL_MASKED_BITS	((1UL << FTRACE_FL_BITS) - 1)

#define FTRACE_FL_MASK		(FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)

#define FTRACE_REF_MAX		((1UL << FTRACE_REF_MAX_SHIFT) - 1)

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