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Not much new with tracing for this release. Mostly just clean ups and

Browse Source 
minor fixes.
 
 Here's what else is new:
 
  o  A new TRACE_EVENT_FN_COND macro, combining both _FN and _COND for
     those that want both.
 
  o  New selftest to test the instance create and delete
 
  o  Better debug output when ftrace fails
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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
  ...
This commit is contained in:
Linus Torvalds 2016-01-12 20:04:15 -08:00
commit c17488d066
16 changed files with 477 additions and 277 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
arch/ia64/kernel/ftrace.c
View File

@ -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)

11
arch/metag/kernel/ftrace.c
View File

@ -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 */

12
arch/sh/kernel/ftrace.c
View File

@ -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 */

21
arch/x86/kernel/ftrace.c
View File

@ -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;
}

56
include/linux/ftrace.h
View File

@ -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)

4
include/linux/tracepoint.h
View File

@ -479,6 +479,10 @@ extern void syscall_unregfunc(void);
#define TRACE_EVENT_FN(name, proto, args, struct, \
assign, print, reg, unreg) \
DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
#define TRACE_EVENT_FN_COND(name, proto, args, cond, struct, \
assign, print, reg, unreg) \
DECLARE_TRACE_CONDITION(name, PARAMS(proto), \
PARAMS(args), PARAMS(cond))
#define TRACE_EVENT_CONDITION(name, proto, args, cond, \
struct, assign, print) \
DECLARE_TRACE_CONDITION(name, PARAMS(proto), \

6
include/trace/define_trace.h
View File

@ -40,6 +40,11 @@
assign, print, reg, unreg) \
DEFINE_TRACE_FN(name, reg, unreg)
#undef TRACE_EVENT_FN_COND
#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct, \
assign, print, reg, unreg) \
DEFINE_TRACE_FN(name, reg, unreg)
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args) \
DEFINE_TRACE(name)
@ -93,6 +98,7 @@
#undef TRACE_EVENT
#undef TRACE_EVENT_FN
#undef TRACE_EVENT_FN_COND
#undef TRACE_EVENT_CONDITION
#undef DECLARE_EVENT_CLASS
#undef DEFINE_EVENT

6
include/trace/trace_events.h
View File

@ -123,6 +123,12 @@ TRACE_MAKE_SYSTEM_STR();
TRACE_EVENT(name, PARAMS(proto), PARAMS(args), \
PARAMS(tstruct), PARAMS(assign), PARAMS(print)) \
#undef TRACE_EVENT_FN_COND
#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct, \
assign, print, reg, unreg) \
TRACE_EVENT_CONDITION(name, PARAMS(proto), PARAMS(args), PARAMS(cond), \
PARAMS(tstruct), PARAMS(assign), PARAMS(print)) \
#undef TRACE_EVENT_FLAGS
#define TRACE_EVENT_FLAGS(name, value) \
__TRACE_EVENT_FLAGS(name, value)

2
kernel/trace/bpf_trace.c
View File

@ -316,7 +316,7 @@ static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type
return true;
}
static struct bpf_verifier_ops kprobe_prog_ops = {
static const struct bpf_verifier_ops kprobe_prog_ops = {
.get_func_proto = kprobe_prog_func_proto,
.is_valid_access = kprobe_prog_is_valid_access,
};

453
kernel/trace/ftrace.c
View File

@ -62,8 +62,6 @@
#define FTRACE_HASH_DEFAULT_BITS 10
#define FTRACE_HASH_MAX_BITS 12
#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL)
#ifdef CONFIG_DYNAMIC_FTRACE
#define INIT_OPS_HASH(opsname) \
.func_hash = &opsname.local_hash, \
@ -113,14 +111,9 @@ static int ftrace_disabled __read_mostly;
static DEFINE_MUTEX(ftrace_lock);
static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
static struct ftrace_ops global_ops;
static struct ftrace_ops control_ops;
static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *regs);
#if ARCH_SUPPORTS_FTRACE_OPS
static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
@ -203,7 +196,7 @@ void clear_ftrace_function(void)
ftrace_trace_function = ftrace_stub;
}
static void control_ops_disable_all(struct ftrace_ops *ops)
static void per_cpu_ops_disable_all(struct ftrace_ops *ops)
{
int cpu;
@ -211,16 +204,19 @@ static void control_ops_disable_all(struct ftrace_ops *ops)
*per_cpu_ptr(ops->disabled, cpu) = 1;
}
static int control_ops_alloc(struct ftrace_ops *ops)
static int per_cpu_ops_alloc(struct ftrace_ops *ops)
{
int __percpu *disabled;
if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU)))
return -EINVAL;
disabled = alloc_percpu(int);
if (!disabled)
return -ENOMEM;
ops->disabled = disabled;
control_ops_disable_all(ops);
per_cpu_ops_disable_all(ops);
return 0;
}
@ -256,10 +252,11 @@ static inline void update_function_graph_func(void) { }
static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
{
/*
* If this is a dynamic ops or we force list func,
* If this is a dynamic, RCU, or per CPU ops, or we force list func,
* then it needs to call the list anyway.
*/
if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC)
if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU |
FTRACE_OPS_FL_RCU) || FTRACE_FORCE_LIST_FUNC)
return ftrace_ops_list_func;
return ftrace_ops_get_func(ops);
@ -383,26 +380,6 @@ static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
return 0;
}
static void add_ftrace_list_ops(struct ftrace_ops **list,
struct ftrace_ops *main_ops,
struct ftrace_ops *ops)
{
int first = *list == &ftrace_list_end;
add_ftrace_ops(list, ops);
if (first)
add_ftrace_ops(&ftrace_ops_list, main_ops);
}
static int remove_ftrace_list_ops(struct ftrace_ops **list,
struct ftrace_ops *main_ops,
struct ftrace_ops *ops)
{
int ret = remove_ftrace_ops(list, ops);
if (!ret && *list == &ftrace_list_end)
ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
return ret;
}
static void ftrace_update_trampoline(struct ftrace_ops *ops);
static int __register_ftrace_function(struct ftrace_ops *ops)
@ -430,14 +407,12 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
if (!core_kernel_data((unsigned long)ops))
ops->flags |= FTRACE_OPS_FL_DYNAMIC;
if (ops->flags & FTRACE_OPS_FL_CONTROL) {
if (control_ops_alloc(ops))
if (ops->flags & FTRACE_OPS_FL_PER_CPU) {
if (per_cpu_ops_alloc(ops))
return -ENOMEM;
add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
/* The control_ops needs the trampoline update */
ops = &control_ops;
} else
add_ftrace_ops(&ftrace_ops_list, ops);
}
add_ftrace_ops(&ftrace_ops_list, ops);
/* Always save the function, and reset at unregistering */
ops->saved_func = ops->func;
@ -460,11 +435,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
return -EBUSY;
if (ops->flags & FTRACE_OPS_FL_CONTROL) {
ret = remove_ftrace_list_ops(&ftrace_control_list,
&control_ops, ops);
} else
ret = remove_ftrace_ops(&ftrace_ops_list, ops);
ret = remove_ftrace_ops(&ftrace_ops_list, ops);
if (ret < 0)
return ret;
@ -1687,6 +1658,9 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
int in_hash = 0;
int match = 0;
if (rec->flags & FTRACE_FL_DISABLED)
continue;
if (all) {
/*
* Only the filter_hash affects all records.
@ -1940,7 +1914,7 @@ static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
}
static void print_ip_ins(const char *fmt, unsigned char *p)
static void print_ip_ins(const char *fmt, const unsigned char *p)
{
int i;
@ -1952,6 +1926,31 @@ static void print_ip_ins(const char *fmt, unsigned char *p)
static struct ftrace_ops *
ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
static struct ftrace_ops *
ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
enum ftrace_bug_type ftrace_bug_type;
const void *ftrace_expected;
static void print_bug_type(void)
{
switch (ftrace_bug_type) {
case FTRACE_BUG_UNKNOWN:
break;
case FTRACE_BUG_INIT:
pr_info("Initializing ftrace call sites\n");
break;
case FTRACE_BUG_NOP:
pr_info("Setting ftrace call site to NOP\n");
break;
case FTRACE_BUG_CALL:
pr_info("Setting ftrace call site to call ftrace function\n");
break;
case FTRACE_BUG_UPDATE:
pr_info("Updating ftrace call site to call a different ftrace function\n");
break;
}
}
/**
* ftrace_bug - report and shutdown function tracer
@ -1979,8 +1978,12 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec)
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace failed to modify ");
print_ip_sym(ip);
print_ip_ins(" actual: ", (unsigned char *)ip);
print_ip_ins(" actual: ", (unsigned char *)ip);
pr_cont("\n");
if (ftrace_expected) {
print_ip_ins(" expected: ", ftrace_expected);
pr_cont("\n");
}
break;
case -EPERM:
FTRACE_WARN_ON_ONCE(1);
@ -1992,6 +1995,7 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec)
pr_info("ftrace faulted on unknown error ");
print_ip_sym(ip);
}
print_bug_type();
if (rec) {
struct ftrace_ops *ops = NULL;
@ -2000,15 +2004,19 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec)
rec->flags & FTRACE_FL_REGS ? " R" : " ");
if (rec->flags & FTRACE_FL_TRAMP_EN) {
ops = ftrace_find_tramp_ops_any(rec);
if (ops)
pr_cont("\ttramp: %pS",
(void *)ops->trampoline);
else
if (ops) {
do {
pr_cont("\ttramp: %pS (%pS)",
(void *)ops->trampoline,
(void *)ops->func);
ops = ftrace_find_tramp_ops_next(rec, ops);
} while (ops);
} else
pr_cont("\ttramp: ERROR!");
}
ip = ftrace_get_addr_curr(rec);
pr_cont(" expected tramp: %lx\n", ip);
pr_cont("\n expected tramp: %lx\n", ip);
}
}
@ -2016,6 +2024,11 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
{
unsigned long flag = 0UL;
ftrace_bug_type = FTRACE_BUG_UNKNOWN;
if (rec->flags & FTRACE_FL_DISABLED)
return FTRACE_UPDATE_IGNORE;
/*
* If we are updating calls:
*
@ -2077,9 +2090,12 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
* from the save regs, to a non-save regs function or
* vice versa, or from a trampoline call.
*/
if (flag & FTRACE_FL_ENABLED)
if (flag & FTRACE_FL_ENABLED) {
ftrace_bug_type = FTRACE_BUG_CALL;
return FTRACE_UPDATE_MAKE_CALL;
}
ftrace_bug_type = FTRACE_BUG_UPDATE;
return FTRACE_UPDATE_MODIFY_CALL;
}
@ -2096,6 +2112,7 @@ static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
FTRACE_FL_REGS_EN);
}
ftrace_bug_type = FTRACE_BUG_NOP;
return FTRACE_UPDATE_MAKE_NOP;
}
@ -2144,6 +2161,24 @@ ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
return NULL;
}
static struct ftrace_ops *
ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
struct ftrace_ops *op)
{
unsigned long ip = rec->ip;
while_for_each_ftrace_op(op) {
if (!op->trampoline)
continue;
if (hash_contains_ip(ip, op->func_hash))
return op;
}
return NULL;
}
static struct ftrace_ops *
ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
{
@ -2307,17 +2342,22 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
ret = ftrace_update_record(rec, enable);
ftrace_bug_type = FTRACE_BUG_UNKNOWN;
switch (ret) {
case FTRACE_UPDATE_IGNORE:
return 0;
case FTRACE_UPDATE_MAKE_CALL:
ftrace_bug_type = FTRACE_BUG_CALL;
return ftrace_make_call(rec, ftrace_addr);
case FTRACE_UPDATE_MAKE_NOP:
ftrace_bug_type = FTRACE_BUG_NOP;
return ftrace_make_nop(NULL, rec, ftrace_old_addr);
case FTRACE_UPDATE_MODIFY_CALL:
ftrace_bug_type = FTRACE_BUG_UPDATE;
return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
}
@ -2425,6 +2465,7 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
if (ret) {
ftrace_bug_type = FTRACE_BUG_INIT;
ftrace_bug(ret, rec);
return 0;
}
@ -2566,7 +2607,7 @@ void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
{
}
static void control_ops_free(struct ftrace_ops *ops)
static void per_cpu_ops_free(struct ftrace_ops *ops)
{
free_percpu(ops->disabled);
}
@ -2667,13 +2708,13 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
if (!command || !ftrace_enabled) {
/*
* If these are control ops, they still need their
* If these are per_cpu ops, they still need their
* per_cpu field freed. Since, function tracing is
* not currently active, we can just free them
* without synchronizing all CPUs.
*/
if (ops->flags & FTRACE_OPS_FL_CONTROL)
control_ops_free(ops);
if (ops->flags & FTRACE_OPS_FL_PER_CPU)
per_cpu_ops_free(ops);
return 0;
}
@ -2714,7 +2755,7 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
/*
* Dynamic ops may be freed, we must make sure that all
* callers are done before leaving this function.
* The same goes for freeing the per_cpu data of the control
* The same goes for freeing the per_cpu data of the per_cpu
* ops.
*
* Again, normal synchronize_sched() is not good enough.
@ -2725,13 +2766,13 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
* infrastructure to do the synchronization, thus we must do it
* ourselves.
*/
if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU)) {
schedule_on_each_cpu(ftrace_sync);
arch_ftrace_trampoline_free(ops);
if (ops->flags & FTRACE_OPS_FL_CONTROL)
control_ops_free(ops);
if (ops->flags & FTRACE_OPS_FL_PER_CPU)
per_cpu_ops_free(ops);
}
return 0;
@ -2798,9 +2839,9 @@ ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
return 0;
/* If ops traces all mods, we already accounted for it */
/* If ops traces all then it includes this function */
if (ops_traces_mod(ops))
return 0;
return 1;
/* The function must be in the filter */
if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
@ -2814,64 +2855,41 @@ ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
return 1;
}
static int referenced_filters(struct dyn_ftrace *rec)
{
struct ftrace_ops *ops;
int cnt = 0;
for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
if (ops_references_rec(ops, rec))
cnt++;
}
return cnt;
}
static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
{
struct ftrace_page *pg;
struct dyn_ftrace *p;
cycle_t start, stop;
unsigned long update_cnt = 0;
unsigned long ref = 0;
bool test = false;
unsigned long rec_flags = 0;
int i;
/*
* When adding a module, we need to check if tracers are
* currently enabled and if they are set to trace all functions.
* If they are, we need to enable the module functions as well
* as update the reference counts for those function records.
*/
if (mod) {
struct ftrace_ops *ops;
for (ops = ftrace_ops_list;
ops != &ftrace_list_end; ops = ops->next) {
if (ops->flags & FTRACE_OPS_FL_ENABLED) {
if (ops_traces_mod(ops))
ref++;
else
test = true;
}
}
}
start = ftrace_now(raw_smp_processor_id());
/*
* When a module is loaded, this function is called to convert
* the calls to mcount in its text to nops, and also to create
* an entry in the ftrace data. Now, if ftrace is activated
* after this call, but before the module sets its text to
* read-only, the modification of enabling ftrace can fail if
* the read-only is done while ftrace is converting the calls.
* To prevent this, the module's records are set as disabled
* and will be enabled after the call to set the module's text
* to read-only.
*/
if (mod)
rec_flags |= FTRACE_FL_DISABLED;
for (pg = new_pgs; pg; pg = pg->next) {
for (i = 0; i < pg->index; i++) {
int cnt = ref;
/* If something went wrong, bail without enabling anything */
if (unlikely(ftrace_disabled))
return -1;
p = &pg->records[i];
if (test)
cnt += referenced_filters(p);
p->flags = cnt;
p->flags = rec_flags;
/*
* Do the initial record conversion from mcount jump
@ -2881,21 +2899,6 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
break;
update_cnt++;
/*
* If the tracing is enabled, go ahead and enable the record.
*
* The reason not to enable the record immediatelly is the
* inherent check of ftrace_make_nop/ftrace_make_call for
* correct previous instructions. Making first the NOP
* conversion puts the module to the correct state, thus
* passing the ftrace_make_call check.
*/
if (ftrace_start_up && cnt) {
int failed = __ftrace_replace_code(p, 1);
if (failed)
ftrace_bug(failed, p);
}
}
}
@ -3258,7 +3261,7 @@ static int t_show(struct seq_file *m, void *v)
seq_printf(m, "%ps", (void *)rec->ip);
if (iter->flags & FTRACE_ITER_ENABLED) {
struct ftrace_ops *ops = NULL;
struct ftrace_ops *ops;
seq_printf(m, " (%ld)%s%s",
ftrace_rec_count(rec),
@ -3266,14 +3269,19 @@ static int t_show(struct seq_file *m, void *v)
rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
if (rec->flags & FTRACE_FL_TRAMP_EN) {
ops = ftrace_find_tramp_ops_any(rec);
if (ops)
seq_printf(m, "\ttramp: %pS",
(void *)ops->trampoline);
else
if (ops) {
do {
seq_printf(m, "\ttramp: %pS (%pS)",
(void *)ops->trampoline,
(void *)ops->func);
add_trampoline_func(m, ops, rec);
ops = ftrace_find_tramp_ops_next(rec, ops);
} while (ops);
} else
seq_puts(m, "\ttramp: ERROR!");
} else {
add_trampoline_func(m, NULL, rec);
}
add_trampoline_func(m, ops, rec);
}
seq_putc(m, '\n');
@ -4898,6 +4906,19 @@ static int ftrace_process_locs(struct module *mod,
#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
static int referenced_filters(struct dyn_ftrace *rec)
{
struct ftrace_ops *ops;
int cnt = 0;
for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
if (ops_references_rec(ops, rec))
cnt++;
}
return cnt;
}
void ftrace_release_mod(struct module *mod)
{
struct dyn_ftrace *rec;
@ -4940,41 +4961,112 @@ void ftrace_release_mod(struct module *mod)
mutex_unlock(&ftrace_lock);
}
static void ftrace_init_module(struct module *mod,
unsigned long *start, unsigned long *end)
static void ftrace_module_enable(struct module *mod)
{
if (ftrace_disabled || start == end)
return;
ftrace_process_locs(mod, start, end);
struct dyn_ftrace *rec;
struct ftrace_page *pg;
mutex_lock(&ftrace_lock);
if (ftrace_disabled)
goto out_unlock;
/*
* If the tracing is enabled, go ahead and enable the record.
*
* The reason not to enable the record immediatelly is the
* inherent check of ftrace_make_nop/ftrace_make_call for
* correct previous instructions. Making first the NOP
* conversion puts the module to the correct state, thus
* passing the ftrace_make_call check.
*
* We also delay this to after the module code already set the
* text to read-only, as we now need to set it back to read-write
* so that we can modify the text.
*/
if (ftrace_start_up)
ftrace_arch_code_modify_prepare();
do_for_each_ftrace_rec(pg, rec) {
int cnt;
/*
* do_for_each_ftrace_rec() is a double loop.
* module text shares the pg. If a record is
* not part of this module, then skip this pg,
* which the "break" will do.
*/
if (!within_module_core(rec->ip, mod))
break;
cnt = 0;
/*
* When adding a module, we need to check if tracers are
* currently enabled and if they are, and can trace this record,
* we need to enable the module functions as well as update the
* reference counts for those function records.
*/
if (ftrace_start_up)
cnt += referenced_filters(rec);
/* This clears FTRACE_FL_DISABLED */
rec->flags = cnt;
if (ftrace_start_up && cnt) {
int failed = __ftrace_replace_code(rec, 1);
if (failed) {
ftrace_bug(failed, rec);
goto out_loop;
}
}
} while_for_each_ftrace_rec();
out_loop:
if (ftrace_start_up)
ftrace_arch_code_modify_post_process();
out_unlock:
mutex_unlock(&ftrace_lock);
}
void ftrace_module_init(struct module *mod)
{
ftrace_init_module(mod, mod->ftrace_callsites,
mod->ftrace_callsites +
mod->num_ftrace_callsites);
if (ftrace_disabled || !mod->num_ftrace_callsites)
return;
ftrace_process_locs(mod, mod->ftrace_callsites,
mod->ftrace_callsites + mod->num_ftrace_callsites);
}
static int ftrace_module_notify_exit(struct notifier_block *self,
unsigned long val, void *data)
static int ftrace_module_notify(struct notifier_block *self,
unsigned long val, void *data)
{
struct module *mod = data;
if (val == MODULE_STATE_GOING)
switch (val) {
case MODULE_STATE_COMING:
ftrace_module_enable(mod);
break;
case MODULE_STATE_GOING:
ftrace_release_mod(mod);
break;
default:
break;
}
return 0;
}
#else
static int ftrace_module_notify_exit(struct notifier_block *self,
unsigned long val, void *data)
static int ftrace_module_notify(struct notifier_block *self,
unsigned long val, void *data)
{
return 0;
}
#endif /* CONFIG_MODULES */
struct notifier_block ftrace_module_exit_nb = {
.notifier_call = ftrace_module_notify_exit,
struct notifier_block ftrace_module_nb = {
.notifier_call = ftrace_module_notify,
.priority = INT_MIN, /* Run after anything that can remove kprobes */
};
@ -5006,7 +5098,7 @@ void __init ftrace_init(void)
__start_mcount_loc,
__stop_mcount_loc);
ret = register_module_notifier(&ftrace_module_exit_nb);
ret = register_module_notifier(&ftrace_module_nb);
if (ret)
pr_warning("Failed to register trace ftrace module exit notifier\n");
@ -5116,44 +5208,6 @@ void ftrace_reset_array_ops(struct trace_array *tr)
tr->ops->func = ftrace_stub;
}
static void
ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *regs)
{
if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
return;
/*
* Some of the ops may be dynamically allocated,
* they must be freed after a synchronize_sched().
*/
preempt_disable_notrace();
trace_recursion_set(TRACE_CONTROL_BIT);
/*
* Control funcs (perf) uses RCU. Only trace if
* RCU is currently active.
*/
if (!rcu_is_watching())
goto out;
do_for_each_ftrace_op(op, ftrace_control_list) {
if (!(op->flags & FTRACE_OPS_FL_STUB) &&
!ftrace_function_local_disabled(op) &&
ftrace_ops_test(op, ip, regs))
op->func(ip, parent_ip, op, regs);
} while_for_each_ftrace_op(op);
out:
trace_recursion_clear(TRACE_CONTROL_BIT);
preempt_enable_notrace();
}
static struct ftrace_ops control_ops = {
.func = ftrace_ops_control_func,
.flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
INIT_OPS_HASH(control_ops)
};
static inline void
__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ignored, struct pt_regs *regs)
@ -5170,8 +5224,22 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
* they must be freed after a synchronize_sched().
*/
preempt_disable_notrace();
do_for_each_ftrace_op(op, ftrace_ops_list) {
if (ftrace_ops_test(op, ip, regs)) {
/*
* Check the following for each ops before calling their func:
* if RCU flag is set, then rcu_is_watching() must be true
* if PER_CPU is set, then ftrace_function_local_disable()
* must be false
* Otherwise test if the ip matches the ops filter
*
* If any of the above fails then the op->func() is not executed.
*/
if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
(!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
!ftrace_function_local_disabled(op)) &&
ftrace_ops_test(op, ip, regs)) {
if (FTRACE_WARN_ON(!op->func)) {
pr_warn("op=%p %pS\n", op, op);
goto out;
@ -5195,7 +5263,7 @@ out:
* being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
* Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
* An architecture can pass partial regs with ftrace_ops and still
* set the ARCH_SUPPORT_FTARCE_OPS.
* set the ARCH_SUPPORTS_FTRACE_OPS.
*/
#if ARCH_SUPPORTS_FTRACE_OPS
static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
@ -5212,20 +5280,29 @@ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
/*
* If there's only one function registered but it does not support
* recursion, this function will be called by the mcount trampoline.
* This function will handle recursion protection.
* recursion, needs RCU protection and/or requires per cpu handling, then
* this function will be called by the mcount trampoline.
*/
static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *regs)
{
int bit;
if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
return;
bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
if (bit < 0)
return;
op->func(ip, parent_ip, op, regs);
preempt_disable_notrace();
if (!(op->flags & FTRACE_OPS_FL_PER_CPU) ||
!ftrace_function_local_disabled(op)) {
op->func(ip, parent_ip, op, regs);
}
preempt_enable_notrace();
trace_clear_recursion(bit);
}
@ -5243,12 +5320,12 @@ static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
{
/*
* If the func handles its own recursion, call it directly.
* Otherwise call the recursion protected function that
* will call the ftrace ops function.
* If the function does not handle recursion, needs to be RCU safe,
* or does per cpu logic, then we need to call the assist handler.
*/
if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE))
return ftrace_ops_recurs_func;
if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
ops->flags & (FTRACE_OPS_FL_RCU | FTRACE_OPS_FL_PER_CPU))
return ftrace_ops_assist_func;
return ops->func;
}

57
kernel/trace/ring_buffer.c
View File

@ -1001,17 +1001,13 @@ static int rb_head_page_replace(struct buffer_page *old,
/*
* rb_tail_page_update - move the tail page forward
*
* Returns 1 if moved tail page, 0 if someone else did.
*/
static int rb_tail_page_update(struct ring_buffer_per_cpu *cpu_buffer,
static void rb_tail_page_update(struct ring_buffer_per_cpu *cpu_buffer,
struct buffer_page *tail_page,
struct buffer_page *next_page)
{
struct buffer_page *old_tail;
unsigned long old_entries;
unsigned long old_write;
int ret = 0;
/*
* The tail page now needs to be moved forward.
@ -1036,7 +1032,7 @@ static int rb_tail_page_update(struct ring_buffer_per_cpu *cpu_buffer,
* it is, then it is up to us to update the tail
* pointer.
*/
if (tail_page == cpu_buffer->tail_page) {
if (tail_page == READ_ONCE(cpu_buffer->tail_page)) {
/* Zero the write counter */
unsigned long val = old_write & ~RB_WRITE_MASK;
unsigned long eval = old_entries & ~RB_WRITE_MASK;
@ -1061,14 +1057,9 @@ static int rb_tail_page_update(struct ring_buffer_per_cpu *cpu_buffer,
*/
local_set(&next_page->page->commit, 0);
old_tail = cmpxchg(&cpu_buffer->tail_page,
tail_page, next_page);
if (old_tail == tail_page)
ret = 1;
/* Again, either we update tail_page or an interrupt does */
(void)cmpxchg(&cpu_buffer->tail_page, tail_page, next_page);
}
return ret;
}
static int rb_check_bpage(struct ring_buffer_per_cpu *cpu_buffer,
@ -2036,12 +2027,15 @@ rb_handle_head_page(struct ring_buffer_per_cpu *cpu_buffer,
* the tail page would have moved.
*/
if (ret == RB_PAGE_NORMAL) {
struct buffer_page *buffer_tail_page;
buffer_tail_page = READ_ONCE(cpu_buffer->tail_page);
/*
* If the tail had moved passed next, then we need
* to reset the pointer.
*/
if (cpu_buffer->tail_page != tail_page &&
cpu_buffer->tail_page != next_page)
if (buffer_tail_page != tail_page &&
buffer_tail_page != next_page)
rb_head_page_set_normal(cpu_buffer, new_head,
next_page,
RB_PAGE_HEAD);
@ -2135,6 +2129,8 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer,
local_sub(length, &tail_page->write);
}
static inline void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer);
/*
* This is the slow path, force gcc not to inline it.
*/
@ -2147,7 +2143,6 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
struct ring_buffer *buffer = cpu_buffer->buffer;
struct buffer_page *next_page;
int ret;
u64 ts;
next_page = tail_page;
@ -2221,20 +2216,17 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
}
}
ret = rb_tail_page_update(cpu_buffer, tail_page, next_page);
if (ret) {
/*
* Nested commits always have zero deltas, so
* just reread the time stamp
*/
ts = rb_time_stamp(buffer);
next_page->page->time_stamp = ts;
}
rb_tail_page_update(cpu_buffer, tail_page, next_page);
out_again:
rb_reset_tail(cpu_buffer, tail, info);
/* Commit what we have for now. */
rb_end_commit(cpu_buffer);
/* rb_end_commit() decs committing */
local_inc(&cpu_buffer->committing);
/* fail and let the caller try again */
return ERR_PTR(-EAGAIN);
@ -2362,7 +2354,7 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
addr = (unsigned long)event;
addr &= PAGE_MASK;
bpage = cpu_buffer->tail_page;
bpage = READ_ONCE(cpu_buffer->tail_page);
if (bpage->page == (void *)addr && rb_page_write(bpage) == old_index) {
unsigned long write_mask =
@ -2410,7 +2402,7 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
again:
max_count = cpu_buffer->nr_pages * 100;
while (cpu_buffer->commit_page != cpu_buffer->tail_page) {
while (cpu_buffer->commit_page != READ_ONCE(cpu_buffer->tail_page)) {
if (RB_WARN_ON(cpu_buffer, !(--max_count)))
return;
if (RB_WARN_ON(cpu_buffer,
@ -2419,8 +2411,10 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
local_set(&cpu_buffer->commit_page->page->commit,
rb_page_write(cpu_buffer->commit_page));
rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
cpu_buffer->write_stamp =
cpu_buffer->commit_page->page->time_stamp;
/* Only update the write stamp if the page has an event */
if (rb_page_write(cpu_buffer->commit_page))
cpu_buffer->write_stamp =
cpu_buffer->commit_page->page->time_stamp;
/* add barrier to keep gcc from optimizing too much */
barrier();
}
@ -2443,7 +2437,7 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
* and pushed the tail page forward, we will be left with
* a dangling commit that will never go forward.
*/
if (unlikely(cpu_buffer->commit_page != cpu_buffer->tail_page))
if (unlikely(cpu_buffer->commit_page != READ_ONCE(cpu_buffer->tail_page)))
goto again;
}
@ -2699,7 +2693,8 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
if (unlikely(info->add_timestamp))
info->length += RB_LEN_TIME_EXTEND;
tail_page = info->tail_page = cpu_buffer->tail_page;
/* Don't let the compiler play games with cpu_buffer->tail_page */
tail_page = info->tail_page = READ_ONCE(cpu_buffer->tail_page);
write = local_add_return(info->length, &tail_page->write);
/* set write to only the index of the write */

6
kernel/trace/trace.h
View File

@ -363,8 +363,8 @@ struct trace_option_dentry {
* @name: the name chosen to select it on the available_tracers file
* @init: called when one switches to this tracer (echo name > current_tracer)
* @reset: called when one switches to another tracer
* @start: called when tracing is unpaused (echo 1 > tracing_enabled)
* @stop: called when tracing is paused (echo 0 > tracing_enabled)
* @start: called when tracing is unpaused (echo 1 > tracing_on)
* @stop: called when tracing is paused (echo 0 > tracing_on)
* @update_thresh: called when tracing_thresh is updated
* @open: called when the trace file is opened
* @pipe_open: called when the trace_pipe file is opened
@ -467,8 +467,6 @@ enum {
TRACE_INTERNAL_IRQ_BIT,
TRACE_INTERNAL_SIRQ_BIT,
TRACE_CONTROL_BIT,
TRACE_BRANCH_BIT,
/*
* Abuse of the trace_recursion.

2
kernel/trace/trace_event_perf.c
View File

@ -334,7 +334,7 @@ static int perf_ftrace_function_register(struct perf_event *event)
{
struct ftrace_ops *ops = &event->ftrace_ops;
ops->flags |= FTRACE_OPS_FL_CONTROL;
ops->flags |= FTRACE_OPS_FL_PER_CPU | FTRACE_OPS_FL_RCU;
ops->func = perf_ftrace_function_call;
return register_ftrace_function(ops);
}

10
kernel/trace/trace_events_trigger.c
View File

@ -538,11 +538,12 @@ static int register_trigger(char *glob, struct event_trigger_ops *ops,
list_add_rcu(&data->list, &file->triggers);
ret++;
update_cond_flag(file);
if (trace_event_trigger_enable_disable(file, 1) < 0) {
list_del_rcu(&data->list);
update_cond_flag(file);
ret--;
}
update_cond_flag(file);
out:
return ret;
}
@ -570,8 +571,8 @@ static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
unregistered = true;
list_del_rcu(&data->list);
update_cond_flag(file);
trace_event_trigger_enable_disable(file, 0);
update_cond_flag(file);
break;
}
}
@ -1314,11 +1315,12 @@ static int event_enable_register_trigger(char *glob,
list_add_rcu(&data->list, &file->triggers);
ret++;
update_cond_flag(file);
if (trace_event_trigger_enable_disable(file, 1) < 0) {
list_del_rcu(&data->list);
update_cond_flag(file);
ret--;
}
update_cond_flag(file);
out:
return ret;
}
@ -1339,8 +1341,8 @@ static void event_enable_unregister_trigger(char *glob,
(enable_data->file == test_enable_data->file)) {
unregistered = true;
list_del_rcu(&data->list);
update_cond_flag(file);
trace_event_trigger_enable_disable(file, 0);
update_cond_flag(file);
break;
}
}

6
lib/seq_buf.c
View File

@ -306,10 +306,12 @@ int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt)
if (!cnt)
return 0;
if (s->len <= s->readpos)
len = seq_buf_used(s);
if (len <= s->readpos)
return -EBUSY;
len = seq_buf_used(s) - s->readpos;
len -= s->readpos;
if (cnt > len)
cnt = len;
ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);

90
tools/testing/selftests/ftrace/test.d/instances/instance.tc Normal file
View File

@ -0,0 +1,90 @@
#!/bin/sh
# description: Test creation and deletion of trace instances
if [ ! -d instances ] ; then
echo "no instance directory with this kernel"
exit_unsupported;
fi
fail() { # mesg
rmdir x y z 2>/dev/null
echo $1
set -e
exit $FAIL
}
cd instances
# we don't want to fail on error
set +e
mkdir x
rmdir x
result=$?
if [ $result -ne 0 ]; then
echo "instance rmdir not supported"
exit_unsupported
fi
instance_slam() {
while :; do
mkdir x
mkdir y
mkdir z
rmdir x
rmdir y
rmdir z
done 2>/dev/null
}
instance_slam &
x=`jobs -l`
p1=`echo $x | cut -d' ' -f2`
echo $p1
instance_slam &
x=`jobs -l | tail -1`
p2=`echo $x | cut -d' ' -f2`
echo $p2
instance_slam &
x=`jobs -l | tail -1`
p3=`echo $x | cut -d' ' -f2`
echo $p3
instance_slam &
x=`jobs -l | tail -1`
p4=`echo $x | cut -d' ' -f2`
echo $p4
instance_slam &
x=`jobs -l | tail -1`
p5=`echo $x | cut -d' ' -f2`
echo $p5
ls -lR >/dev/null
sleep 1
kill -1 $p1
kill -1 $p2
kill -1 $p3
kill -1 $p4
kill -1 $p5
echo "Wait for processes to finish"
wait $p1 $p2 $p3 $p4 $p5
echo "all processes finished, wait for cleanup"
mkdir x y z
ls x y z
rmdir x y z
for d in x y z; do
if [ -d $d ]; then
fail "instance $d still exists"
fi
done
set -e
exit 0