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tracing updates for v6.13:

Browse Source 
- Addition of faultable tracepoints
 
   There's a tracepoint attached to both a system call entry and exit. This
   location is known to allow page faults. The tracepoints are called under
   an rcu_read_lock() which does not allow faults that can sleep. This limits
   the ability of tracepoint handlers to page fault in user space system call
   parameters. Now these tracepoints have been made "faultable", allowing the
   callbacks to fault in user space parameters and record them.
 
   Note, only the infrastructure has been implemented. The consumers (perf,
   ftrace, BPF) now need to have their code modified to allow faults.
 
 - Fix up of BPF code for the tracepoint faultable logic
 
 - Update tracepoints to use the new static branch API
 
 - Remove trace_*_rcuidle() variants and the SRCU protection they used
 
 - Remove unused TRACE_EVENT_FL_FILTERED logic
 
 - Replace strncpy() with strscpy() and memcpy()
 
 - Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()
 
 - Fix perf events to not duplicate samples when tracing is enabled
 
 - Replace atomic64_add_return(1, counter) with atomic64_inc_return(counter)
 
 - Make stack trace buffer 4K instead of PAGE_SIZE
 
 - Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used
 
 - Get the true return address for function tracer when function graph tracer
   is also running.
 
   When function_graph trace is running along with function tracer,
   the parent function of the function tracer sometimes is
   "return_to_handler", which is the function graph trampoline to record
   the exit of the function. Use existing logic that calls into the
   fgraph infrastructure to find the real return address.
 
 - Remove (un)regfunc pointers out of tracepoint structure
 
 - Added last minute bug fix for setting pending modules in stack function
   filter.
 
   echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter
 
   Would cause a kernel NULL dereference.
 
 - Minor clean ups
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Merge tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Addition of faultable tracepoints

   There's a tracepoint attached to both a system call entry and exit.
   This location is known to allow page faults. The tracepoints are
   called under an rcu_read_lock() which does not allow faults that can
   sleep. This limits the ability of tracepoint handlers to page fault
   in user space system call parameters. Now these tracepoints have been
   made "faultable", allowing the callbacks to fault in user space
   parameters and record them.

   Note, only the infrastructure has been implemented. The consumers
   (perf, ftrace, BPF) now need to have their code modified to allow
   faults.

 - Fix up of BPF code for the tracepoint faultable logic

 - Update tracepoints to use the new static branch API

 - Remove trace_*_rcuidle() variants and the SRCU protection they used

 - Remove unused TRACE_EVENT_FL_FILTERED logic

 - Replace strncpy() with strscpy() and memcpy()

 - Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()

 - Fix perf events to not duplicate samples when tracing is enabled

 - Replace atomic64_add_return(1, counter) with
   atomic64_inc_return(counter)

 - Make stack trace buffer 4K instead of PAGE_SIZE

 - Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used

 - Get the true return address for function tracer when function graph
   tracer is also running.

   When function_graph trace is running along with function tracer, the
   parent function of the function tracer sometimes is
   "return_to_handler", which is the function graph trampoline to record
   the exit of the function. Use existing logic that calls into the
   fgraph infrastructure to find the real return address.

 - Remove (un)regfunc pointers out of tracepoint structure

 - Added last minute bug fix for setting pending modules in stack
   function filter.

     echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter

   Would cause a kernel NULL dereference.

 - Minor clean ups

* tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits)
  ftrace: Fix regression with module command in stack_trace_filter
  tracing: Fix function name for trampoline
  ftrace: Get the true parent ip for function tracer
  tracing: Remove redundant check on field->field in histograms
  bpf: ensure RCU Tasks Trace GP for sleepable raw tracepoint BPF links
  bpf: decouple BPF link/attach hook and BPF program sleepable semantics
  bpf: put bpf_link's program when link is safe to be deallocated
  tracing: Replace strncpy() with strscpy() when copying comm
  tracing: Add might_fault() check in __DECLARE_TRACE_SYSCALL
  tracing: Fix syscall tracepoint use-after-free
  tracing: Introduce tracepoint_is_faultable()
  tracing: Introduce tracepoint extended structure
  tracing: Remove TRACE_FLAG_IRQS_NOSUPPORT
  tracing: Replace multiple deprecated strncpy with memcpy
  tracing: Make percpu stack trace buffer invariant to PAGE_SIZE
  tracing: Use atomic64_inc_return() in trace_clock_counter()
  trace/trace_event_perf: remove duplicate samples on the first tracepoint event
  tracing/bpf: Add might_fault check to syscall probes
  tracing/perf: Add might_fault check to syscall probes
  tracing/ftrace: Add might_fault check to syscall probes
  ...
This commit is contained in:
Linus Torvalds 2024-11-22 13:27:01 -08:00
commit 06afb0f361
35 changed files with 452 additions and 328 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
Documentation/trace/ftrace.rst
View File

@ -1031,9 +1031,6 @@ explains which is which.
CPU#: The CPU which the process was running on.
irqs-off: 'd' interrupts are disabled. '.' otherwise.
.. caution:: If the architecture does not support a way to
read the irq flags variable, an 'X' will always
be printed here.
need-resched:
- 'N' both TIF_NEED_RESCHED and PREEMPT_NEED_RESCHED is set,

20
include/linux/bpf.h
View File

@ -1645,6 +1645,11 @@ struct bpf_link {
enum bpf_link_type type;
const struct bpf_link_ops *ops;
struct bpf_prog *prog;
/* whether BPF link itself has "sleepable" semantics, which can differ
* from underlying BPF program having a "sleepable" semantics, as BPF
* link's semantics is determined by target attach hook
*/
bool sleepable;
/* rcu is used before freeing, work can be used to schedule that
* RCU-based freeing before that, so they never overlap
*/
@ -1661,8 +1666,10 @@ struct bpf_link_ops {
*/
void (*dealloc)(struct bpf_link *link);
/* deallocate link resources callback, called after RCU grace period;
* if underlying BPF program is sleepable we go through tasks trace
* RCU GP and then "classic" RCU GP
* if either the underlying BPF program is sleepable or BPF link's
* target hook is sleepable, we'll go through tasks trace RCU GP and
* then "classic" RCU GP; this need for chaining tasks trace and
* classic RCU GPs is designated by setting bpf_link->sleepable flag
*/
void (*dealloc_deferred)(struct bpf_link *link);
int (*detach)(struct bpf_link *link);
@ -2409,6 +2416,9 @@ int bpf_prog_new_fd(struct bpf_prog *prog);
void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
const struct bpf_link_ops *ops, struct bpf_prog *prog);
void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
const struct bpf_link_ops *ops, struct bpf_prog *prog,
bool sleepable);
int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer);
int bpf_link_settle(struct bpf_link_primer *primer);
void bpf_link_cleanup(struct bpf_link_primer *primer);
@ -2764,6 +2774,12 @@ static inline void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
{
}
static inline void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
const struct bpf_link_ops *ops, struct bpf_prog *prog,
bool sleepable)
{
}
static inline int bpf_link_prime(struct bpf_link *link,
struct bpf_link_primer *primer)
{

17
include/linux/trace_events.h
View File

@ -184,7 +184,6 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status);
enum trace_flag_type {
TRACE_FLAG_IRQS_OFF = 0x01,
TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
TRACE_FLAG_NEED_RESCHED = 0x04,
TRACE_FLAG_HARDIRQ = 0x08,
TRACE_FLAG_SOFTIRQ = 0x10,
@ -193,7 +192,6 @@ enum trace_flag_type {
TRACE_FLAG_BH_OFF = 0x80,
};
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
static inline unsigned int tracing_gen_ctx_flags(unsigned long irqflags)
{
unsigned int irq_status = irqs_disabled_flags(irqflags) ?
@ -207,17 +205,6 @@ static inline unsigned int tracing_gen_ctx(void)
local_save_flags(irqflags);
return tracing_gen_ctx_flags(irqflags);
}
#else
static inline unsigned int tracing_gen_ctx_flags(unsigned long irqflags)
{
return tracing_gen_ctx_irq_test(TRACE_FLAG_IRQS_NOSUPPORT);
}
static inline unsigned int tracing_gen_ctx(void)
{
return tracing_gen_ctx_irq_test(TRACE_FLAG_IRQS_NOSUPPORT);
}
#endif
static inline unsigned int tracing_gen_ctx_dec(void)
{
@ -326,7 +313,6 @@ void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
void trace_event_buffer_commit(struct trace_event_buffer *fbuffer);
enum {
TRACE_EVENT_FL_FILTERED_BIT,
TRACE_EVENT_FL_CAP_ANY_BIT,
TRACE_EVENT_FL_NO_SET_FILTER_BIT,
TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
@ -341,7 +327,6 @@ enum {
/*
* Event flags:
* FILTERED - The event has a filter attached
* CAP_ANY - Any user can enable for perf
* NO_SET_FILTER - Set when filter has error and is to be ignored
* IGNORE_ENABLE - For trace internal events, do not enable with debugfs file
@ -356,7 +341,6 @@ enum {
* to a tracepoint yet, then it is cleared when it is.
*/
enum {
TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
TRACE_EVENT_FL_CAP_ANY = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
TRACE_EVENT_FL_NO_SET_FILTER = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
TRACE_EVENT_FL_IGNORE_ENABLE = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
@ -381,7 +365,6 @@ struct trace_event_call {
};
struct trace_event event;
char *print_fmt;
struct event_filter *filter;
/*
* Static events can disappear with modules,
* where as dynamic ones need their own ref count.

14
include/linux/tracepoint-defs.h
View File

@ -29,16 +29,22 @@ struct tracepoint_func {
int prio;
};
struct tracepoint_ext {
int (*regfunc)(void);
void (*unregfunc)(void);
/* Flags. */
unsigned int faultable:1;
};
struct tracepoint {
const char *name; /* Tracepoint name */
struct static_key key;
struct static_key_false key;
struct static_call_key *static_call_key;
void *static_call_tramp;
void *iterator;
void *probestub;
int (*regfunc)(void);
void (*unregfunc)(void);
struct tracepoint_func __rcu *funcs;
struct tracepoint_ext *ext;
};
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
@ -83,7 +89,7 @@ struct bpf_raw_event_map {
#ifdef CONFIG_TRACEPOINTS
# define tracepoint_enabled(tp) \
static_key_false(&(__tracepoint_##tp).key)
static_branch_unlikely(&(__tracepoint_##tp).key)
#else
# define tracepoint_enabled(tracepoint) false
#endif

169
include/linux/tracepoint.h
View File

@ -17,6 +17,7 @@
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/rcupdate.h>
#include <linux/rcupdate_trace.h>
#include <linux/tracepoint-defs.h>
#include <linux/static_call.h>
@ -32,8 +33,6 @@ struct trace_eval_map {
#define TRACEPOINT_DEFAULT_PRIO 10
extern struct srcu_struct tracepoint_srcu;
extern int
tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data);
extern int
@ -105,16 +104,30 @@ void for_each_tracepoint_in_module(struct module *mod,
* tracepoint_synchronize_unregister must be called between the last tracepoint
* probe unregistration and the end of module exit to make sure there is no
* caller executing a probe when it is freed.
*
* An alternative is to use the following for batch reclaim associated
* with a given tracepoint:
*
* - tracepoint_is_faultable() == false: call_rcu()
* - tracepoint_is_faultable() == true: call_rcu_tasks_trace()
*/
#ifdef CONFIG_TRACEPOINTS
static inline void tracepoint_synchronize_unregister(void)
{
synchronize_srcu(&tracepoint_srcu);
synchronize_rcu_tasks_trace();
synchronize_rcu();
}
static inline bool tracepoint_is_faultable(struct tracepoint *tp)
{
return tp->ext && tp->ext->faultable;
}
#else
static inline void tracepoint_synchronize_unregister(void)
{ }
static inline bool tracepoint_is_faultable(struct tracepoint *tp)
{
return false;
}
#endif
#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
@ -196,67 +209,36 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
#define __DO_TRACE_CALL(name, args) __traceiter_##name(NULL, args)
#endif /* CONFIG_HAVE_STATIC_CALL */
/*
* ARCH_WANTS_NO_INSTR archs are expected to have sanitized entry and idle
* code that disallow any/all tracing/instrumentation when RCU isn't watching.
*/
#ifdef CONFIG_ARCH_WANTS_NO_INSTR
#define RCUIDLE_COND(rcuidle) (rcuidle)
#else
/* srcu can't be used from NMI */
#define RCUIDLE_COND(rcuidle) (rcuidle && in_nmi())
#endif
/*
* it_func[0] is never NULL because there is at least one element in the array
* when the array itself is non NULL.
*
* With @syscall=0, the tracepoint callback array dereference is
* protected by disabling preemption.
* With @syscall=1, the tracepoint callback array dereference is
* protected by Tasks Trace RCU, which allows probes to handle page
* faults.
*/
#define __DO_TRACE(name, args, cond, rcuidle) \
#define __DO_TRACE(name, args, cond, syscall) \
do { \
int __maybe_unused __idx = 0; \
\
if (!(cond)) \
return; \
\
if (WARN_ONCE(RCUIDLE_COND(rcuidle), \
"Bad RCU usage for tracepoint")) \
return; \
\
/* keep srcu and sched-rcu usage consistent */ \
preempt_disable_notrace(); \
\
/* \
* For rcuidle callers, use srcu since sched-rcu \
* doesn't work from the idle path. \
*/ \
if (rcuidle) { \
__idx = srcu_read_lock_notrace(&tracepoint_srcu);\
ct_irq_enter_irqson(); \
} \
if (syscall) \
rcu_read_lock_trace(); \
else \
preempt_disable_notrace(); \
\
__DO_TRACE_CALL(name, TP_ARGS(args)); \
\
if (rcuidle) { \
ct_irq_exit_irqson(); \
srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\
} \
\
preempt_enable_notrace(); \
if (syscall) \
rcu_read_unlock_trace(); \
else \
preempt_enable_notrace(); \
} while (0)
#ifndef MODULE
#define __DECLARE_TRACE_RCU(name, proto, args, cond) \
static inline void trace_##name##_rcuidle(proto) \
{ \
if (static_key_false(&__tracepoint_##name.key)) \
__DO_TRACE(name, \
TP_ARGS(args), \
TP_CONDITION(cond), 1); \
}
#else
#define __DECLARE_TRACE_RCU(name, proto, args, cond)
#endif
/*
* Make sure the alignment of the structure in the __tracepoints section will
* not add unwanted padding between the beginning of the section and the
@ -268,23 +250,10 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
* site if it is not watching, as it will need to be active when the
* tracepoint is enabled.
*/
#define __DECLARE_TRACE(name, proto, args, cond, data_proto) \
#define __DECLARE_TRACE_COMMON(name, proto, args, cond, data_proto) \
extern int __traceiter_##name(data_proto); \
DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name); \
extern struct tracepoint __tracepoint_##name; \
static inline void trace_##name(proto) \
{ \
if (static_key_false(&__tracepoint_##name.key)) \
__DO_TRACE(name, \
TP_ARGS(args), \
TP_CONDITION(cond), 0); \
if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \
WARN_ONCE(!rcu_is_watching(), \
"RCU not watching for tracepoint"); \
} \
} \
__DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args), \
PARAMS(cond)) \
static inline int \
register_trace_##name(void (*probe)(data_proto), void *data) \
{ \
@ -311,7 +280,36 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
static inline bool \
trace_##name##_enabled(void) \
{ \
return static_key_false(&__tracepoint_##name.key); \
return static_branch_unlikely(&__tracepoint_##name.key);\
}
#define __DECLARE_TRACE(name, proto, args, cond, data_proto) \
__DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), cond, PARAMS(data_proto)) \
static inline void trace_##name(proto) \
{ \
if (static_branch_unlikely(&__tracepoint_##name.key)) \
__DO_TRACE(name, \
TP_ARGS(args), \
TP_CONDITION(cond), 0); \
if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \
WARN_ONCE(!rcu_is_watching(), \
"RCU not watching for tracepoint"); \
} \
}
#define __DECLARE_TRACE_SYSCALL(name, proto, args, cond, data_proto) \
__DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), cond, PARAMS(data_proto)) \
static inline void trace_##name(proto) \
{ \
might_fault(); \
if (static_branch_unlikely(&__tracepoint_##name.key)) \
__DO_TRACE(name, \
TP_ARGS(args), \
TP_CONDITION(cond), 1); \
if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \
WARN_ONCE(!rcu_is_watching(), \
"RCU not watching for tracepoint"); \
} \
}
/*
@ -319,7 +317,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
* structures, so we create an array of pointers that will be used for iteration
* on the tracepoints.
*/
#define DEFINE_TRACE_FN(_name, _reg, _unreg, proto, args) \
#define __DEFINE_TRACE_EXT(_name, _ext, proto, args) \
static const char __tpstrtab_##_name[] \
__section("__tracepoints_strings") = #_name; \
extern struct static_call_key STATIC_CALL_KEY(tp_func_##_name); \
@ -328,14 +326,14 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
struct tracepoint __tracepoint_##_name __used \
__section("__tracepoints") = { \
.name = __tpstrtab_##_name, \
.key = STATIC_KEY_INIT_FALSE, \
.key = STATIC_KEY_FALSE_INIT, \
.static_call_key = &STATIC_CALL_KEY(tp_func_##_name), \
.static_call_tramp = STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \
.iterator = &__traceiter_##_name, \
.probestub = &__probestub_##_name, \
.regfunc = _reg, \
.unregfunc = _unreg, \
.funcs = NULL }; \
.funcs = NULL, \
.ext = _ext, \
}; \
__TRACEPOINT_ENTRY(_name); \
int __traceiter_##_name(void *__data, proto) \
{ \
@ -358,8 +356,24 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
} \
DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name);
#define DEFINE_TRACE(name, proto, args) \
DEFINE_TRACE_FN(name, NULL, NULL, PARAMS(proto), PARAMS(args));
#define DEFINE_TRACE_FN(_name, _reg, _unreg, _proto, _args) \
static struct tracepoint_ext __tracepoint_ext_##_name = { \
.regfunc = _reg, \
.unregfunc = _unreg, \
.faultable = false, \
}; \
__DEFINE_TRACE_EXT(_name, &__tracepoint_ext_##_name, PARAMS(_proto), PARAMS(_args));
#define DEFINE_TRACE_SYSCALL(_name, _reg, _unreg, _proto, _args) \
static struct tracepoint_ext __tracepoint_ext_##_name = { \
.regfunc = _reg, \
.unregfunc = _unreg, \
.faultable = true, \
}; \
__DEFINE_TRACE_EXT(_name, &__tracepoint_ext_##_name, PARAMS(_proto), PARAMS(_args));
#define DEFINE_TRACE(_name, _proto, _args) \
__DEFINE_TRACE_EXT(_name, NULL, PARAMS(_proto), PARAMS(_args));
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
EXPORT_SYMBOL_GPL(__tracepoint_##name); \
@ -375,8 +389,6 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
#define __DECLARE_TRACE(name, proto, args, cond, data_proto) \
static inline void trace_##name(proto) \
{ } \
static inline void trace_##name##_rcuidle(proto) \
{ } \
static inline int \
register_trace_##name(void (*probe)(data_proto), \
void *data) \
@ -398,7 +410,10 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
return false; \
}
#define __DECLARE_TRACE_SYSCALL __DECLARE_TRACE
#define DEFINE_TRACE_FN(name, reg, unreg, proto, args)
#define DEFINE_TRACE_SYSCALL(name, reg, unreg, proto, args)
#define DEFINE_TRACE(name, proto, args)
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
#define EXPORT_TRACEPOINT_SYMBOL(name)
@ -459,6 +474,11 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
cpu_online(raw_smp_processor_id()) && (PARAMS(cond)), \
PARAMS(void *__data, proto))
#define DECLARE_TRACE_SYSCALL(name, proto, args) \
__DECLARE_TRACE_SYSCALL(name, PARAMS(proto), PARAMS(args), \
cpu_online(raw_smp_processor_id()), \
PARAMS(void *__data, proto))
#define TRACE_EVENT_FLAGS(event, flag)
#define TRACE_EVENT_PERF_PERM(event, expr...)
@ -596,6 +616,9 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
struct, assign, print) \
DECLARE_TRACE_CONDITION(name, PARAMS(proto), \
PARAMS(args), PARAMS(cond))
#define TRACE_EVENT_SYSCALL(name, proto, args, struct, assign, \
print, reg, unreg) \
DECLARE_TRACE_SYSCALL(name, PARAMS(proto), PARAMS(args))
#define TRACE_EVENT_FLAGS(event, flag)

14
include/trace/bpf_probe.h
View File

@ -53,6 +53,20 @@ __bpf_trace_##call(void *__data, proto) \
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
__BPF_DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
#define __BPF_DECLARE_TRACE_SYSCALL(call, proto, args) \
static notrace void \
__bpf_trace_##call(void *__data, proto) \
{ \
might_fault(); \
preempt_disable_notrace(); \
CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(__data, CAST_TO_U64(args)); \
preempt_enable_notrace(); \
}
#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \
__BPF_DECLARE_TRACE_SYSCALL(call, PARAMS(proto), PARAMS(args))
/*
* This part is compiled out, it is only here as a build time check
* to make sure that if the tracepoint handling changes, the

5
include/trace/define_trace.h
View File

@ -46,6 +46,10 @@
assign, print, reg, unreg) \
DEFINE_TRACE_FN(name, reg, unreg, PARAMS(proto), PARAMS(args))
#undef TRACE_EVENT_SYSCALL
#define TRACE_EVENT_SYSCALL(name, proto, args, struct, assign, print, reg, unreg) \
DEFINE_TRACE_SYSCALL(name, reg, unreg, PARAMS(proto), PARAMS(args))
#undef TRACE_EVENT_NOP
#define TRACE_EVENT_NOP(name, proto, args, struct, assign, print)
@ -107,6 +111,7 @@
#undef TRACE_EVENT
#undef TRACE_EVENT_FN
#undef TRACE_EVENT_FN_COND
#undef TRACE_EVENT_SYSCALL
#undef TRACE_EVENT_CONDITION
#undef TRACE_EVENT_NOP
#undef DEFINE_EVENT_NOP

8
include/trace/events/preemptirq.h
View File

@ -43,8 +43,6 @@ DEFINE_EVENT(preemptirq_template, irq_enable,
#else
#define trace_irq_enable(...)
#define trace_irq_disable(...)
#define trace_irq_enable_rcuidle(...)
#define trace_irq_disable_rcuidle(...)
#endif
#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
@ -58,8 +56,6 @@ DEFINE_EVENT(preemptirq_template, preempt_enable,
#else
#define trace_preempt_enable(...)
#define trace_preempt_disable(...)
#define trace_preempt_enable_rcuidle(...)
#define trace_preempt_disable_rcuidle(...)
#endif
#endif /* _TRACE_PREEMPTIRQ_H */
@ -69,10 +65,6 @@ DEFINE_EVENT(preemptirq_template, preempt_enable,
#else /* !CONFIG_PREEMPTIRQ_TRACEPOINTS */
#define trace_irq_enable(...)
#define trace_irq_disable(...)
#define trace_irq_enable_rcuidle(...)
#define trace_irq_disable_rcuidle(...)
#define trace_preempt_enable(...)
#define trace_preempt_disable(...)
#define trace_preempt_enable_rcuidle(...)
#define trace_preempt_disable_rcuidle(...)
#endif

4
include/trace/events/syscalls.h
View File

@ -15,7 +15,7 @@
#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
TRACE_EVENT_FN(sys_enter,
TRACE_EVENT_SYSCALL(sys_enter,
TP_PROTO(struct pt_regs *regs, long id),
@ -41,7 +41,7 @@ TRACE_EVENT_FN(sys_enter,
TRACE_EVENT_FLAGS(sys_enter, TRACE_EVENT_FL_CAP_ANY)
TRACE_EVENT_FN(sys_exit,
TRACE_EVENT_SYSCALL(sys_exit,
TP_PROTO(struct pt_regs *regs, long ret),

44
include/trace/perf.h
View File

@ -12,10 +12,10 @@
#undef __perf_task
#define __perf_task(t) (__task = (t))
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
#undef __DECLARE_EVENT_CLASS
#define __DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace void \
perf_trace_##call(void *__data, proto) \
do_perf_trace_##call(void *__data, proto) \
{ \
struct trace_event_call *event_call = __data; \
struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
@ -55,6 +55,41 @@ perf_trace_##call(void *__data, proto) \
head, __task); \
}
/*
* Define unused __count and __task variables to use @args to pass
* arguments to do_perf_trace_##call. This is needed because the
* macros __perf_count and __perf_task introduce the side-effect to
* store copies into those local variables.
*/
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
PARAMS(assign), PARAMS(print)) \
static notrace void \
perf_trace_##call(void *__data, proto) \
{ \
u64 __count __attribute__((unused)); \
struct task_struct *__task __attribute__((unused)); \
\
do_perf_trace_##call(__data, args); \
}
#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \
__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
PARAMS(assign), PARAMS(print)) \
static notrace void \
perf_trace_##call(void *__data, proto) \
{ \
u64 __count __attribute__((unused)); \
struct task_struct *__task __attribute__((unused)); \
\
might_fault(); \
preempt_disable_notrace(); \
do_perf_trace_##call(__data, args); \
preempt_enable_notrace(); \
}
/*
* This part is compiled out, it is only here as a build time check
* to make sure that if the tracepoint handling changes, the
@ -73,4 +108,7 @@ static inline void perf_test_probe_##call(void) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#undef __DECLARE_EVENT_CLASS
#endif /* CONFIG_PERF_EVENTS */

62
include/trace/trace_events.h
View File

@ -45,6 +45,16 @@
PARAMS(print)); \
DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
#undef TRACE_EVENT_SYSCALL
#define TRACE_EVENT_SYSCALL(name, proto, args, tstruct, assign, print, reg, unreg) \
DECLARE_EVENT_SYSCALL_CLASS(name, \
PARAMS(proto), \
PARAMS(args), \
PARAMS(tstruct), \
PARAMS(assign), \
PARAMS(print)); \
DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
#include "stages/stage1_struct_define.h"
#undef DECLARE_EVENT_CLASS
@ -57,6 +67,9 @@
\
static struct trace_event_class event_class_##name;
#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args) \
static struct trace_event_call __used \
@ -117,6 +130,9 @@
tstruct; \
};
#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args)
@ -208,6 +224,9 @@ static struct trace_event_functions trace_event_type_funcs_##call = { \
.trace = trace_raw_output_##call, \
};
#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, call, proto, args, print) \
static notrace enum print_line_t \
@ -244,6 +263,9 @@ static struct trace_event_fields trace_event_fields_##call[] = { \
tstruct \
{} };
#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print)
@ -265,6 +287,9 @@ static inline notrace int trace_event_get_offsets_##call( \
return __data_size; \
}
#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
@ -374,11 +399,11 @@ static inline notrace int trace_event_get_offsets_##call( \
#include "stages/stage6_event_callback.h"
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
\
#undef __DECLARE_EVENT_CLASS
#define __DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace void \
trace_event_raw_event_##call(void *__data, proto) \
do_trace_event_raw_event_##call(void *__data, proto) \
{ \
struct trace_event_file *trace_file = __data; \
struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
@ -403,6 +428,30 @@ trace_event_raw_event_##call(void *__data, proto) \
\
trace_event_buffer_commit(&fbuffer); \
}
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
PARAMS(assign), PARAMS(print)) \
static notrace void \
trace_event_raw_event_##call(void *__data, proto) \
{ \
do_trace_event_raw_event_##call(__data, args); \
}
#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \
__DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
PARAMS(assign), PARAMS(print)) \
static notrace void \
trace_event_raw_event_##call(void *__data, proto) \
{ \
might_fault(); \
preempt_disable_notrace(); \
do_trace_event_raw_event_##call(__data, args); \
preempt_enable_notrace(); \
}
/*
* The ftrace_test_probe is compiled out, it is only here as a build time check
* to make sure that if the tracepoint handling changes, the ftrace probe will
@ -418,6 +467,8 @@ static inline void ftrace_test_probe_##call(void) \
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#undef __DECLARE_EVENT_CLASS
#include "stages/stage7_class_define.h"
#undef DECLARE_EVENT_CLASS
@ -434,6 +485,9 @@ static struct trace_event_class __used __refdata event_class_##call = { \
_TRACE_PERF_INIT(call) \
};
#undef DECLARE_EVENT_SYSCALL_CLASS
#define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, call, proto, args) \
\

1
init/Kconfig
View File

@ -1989,6 +1989,7 @@ config BINDGEN_VERSION_TEXT
#
config TRACEPOINTS
bool
select TASKS_TRACE_RCU
source "kernel/Kconfig.kexec"

67
kernel/bpf/syscall.c
View File

@ -35,6 +35,7 @@
#include <linux/rcupdate_trace.h>
#include <linux/memcontrol.h>
#include <linux/trace_events.h>
#include <linux/tracepoint.h>
#include <net/netfilter/nf_bpf_link.h>
#include <net/netkit.h>
@ -3033,17 +3034,33 @@ static int bpf_obj_get(const union bpf_attr *attr)
attr->file_flags);
}
void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
const struct bpf_link_ops *ops, struct bpf_prog *prog)
/* bpf_link_init_sleepable() allows to specify whether BPF link itself has
* "sleepable" semantics, which normally would mean that BPF link's attach
* hook can dereference link or link's underlying program for some time after
* detachment due to RCU Tasks Trace-based lifetime protection scheme.
* BPF program itself can be non-sleepable, yet, because it's transitively
* reachable through BPF link, its freeing has to be delayed until after RCU
* Tasks Trace GP.
*/
void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
const struct bpf_link_ops *ops, struct bpf_prog *prog,
bool sleepable)
{
WARN_ON(ops->dealloc && ops->dealloc_deferred);
atomic64_set(&link->refcnt, 1);
link->type = type;
link->sleepable = sleepable;
link->id = 0;
link->ops = ops;
link->prog = prog;
}
void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
const struct bpf_link_ops *ops, struct bpf_prog *prog)
{
bpf_link_init_sleepable(link, type, ops, prog, false);
}
static void bpf_link_free_id(int id)
{
if (!id)
@ -3076,12 +3093,24 @@ void bpf_link_inc(struct bpf_link *link)
atomic64_inc(&link->refcnt);
}
static void bpf_link_dealloc(struct bpf_link *link)
{
/* now that we know that bpf_link itself can't be reached, put underlying BPF program */
if (link->prog)
bpf_prog_put(link->prog);
/* free bpf_link and its containing memory */
if (link->ops->dealloc_deferred)
link->ops->dealloc_deferred(link);
else
link->ops->dealloc(link);
}
static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
{
struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
/* free bpf_link and its containing memory */
link->ops->dealloc_deferred(link);
bpf_link_dealloc(link);
}
static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
@ -3096,26 +3125,27 @@ static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
static void bpf_link_free(struct bpf_link *link)
{
const struct bpf_link_ops *ops = link->ops;
bool sleepable = false;
bpf_link_free_id(link->id);
if (link->prog) {
sleepable = link->prog->sleepable;
/* detach BPF program, clean up used resources */
/* detach BPF program, clean up used resources */
if (link->prog)
ops->release(link);
bpf_prog_put(link->prog);
}
if (ops->dealloc_deferred) {
/* schedule BPF link deallocation; if underlying BPF program
* is sleepable, we need to first wait for RCU tasks trace
* sync, then go through "classic" RCU grace period
/* Schedule BPF link deallocation, which will only then
* trigger putting BPF program refcount.
* If underlying BPF program is sleepable or BPF link's target
* attach hookpoint is sleepable or otherwise requires RCU GPs
* to ensure link and its underlying BPF program is not
* reachable anymore, we need to first wait for RCU tasks
* trace sync, and then go through "classic" RCU grace period
*/
if (sleepable)
if (link->sleepable || (link->prog && link->prog->sleepable))
call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
else
call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
} else if (ops->dealloc)
ops->dealloc(link);
} else if (ops->dealloc) {
bpf_link_dealloc(link);
}
}
static void bpf_link_put_deferred(struct work_struct *work)
@ -3936,8 +3966,9 @@ static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
err = -ENOMEM;
goto out_put_btp;
}
bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
&bpf_raw_tp_link_lops, prog);
bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
&bpf_raw_tp_link_lops, prog,
tracepoint_is_faultable(btp->tp));
link->btp = btp;
link->cookie = cookie;

3
kernel/trace/ftrace.c
View File

@ -5093,6 +5093,9 @@ ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
char *func;
int ret;
if (!tr)
return -ENODEV;
/* match_records() modifies func, and we need the original */
func = kstrdup(func_orig, GFP_KERNEL);
if (!func)

81
kernel/trace/trace.c
View File

@ -593,19 +593,6 @@ int tracing_check_open_get_tr(struct trace_array *tr)
return 0;
}
int call_filter_check_discard(struct trace_event_call *call, void *rec,
struct trace_buffer *buffer,
struct ring_buffer_event *event)
{
if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
!filter_match_preds(call->filter, rec)) {
__trace_event_discard_commit(buffer, event);
return 1;
}
return 0;
}
/**
* trace_find_filtered_pid - check if a pid exists in a filtered_pid list
* @filtered_pids: The list of pids to check
@ -988,7 +975,8 @@ static inline void trace_access_lock_init(void)
#endif
#ifdef CONFIG_STACKTRACE
static void __ftrace_trace_stack(struct trace_buffer *buffer,
static void __ftrace_trace_stack(struct trace_array *tr,
struct trace_buffer *buffer,
unsigned int trace_ctx,
int skip, struct pt_regs *regs);
static inline void ftrace_trace_stack(struct trace_array *tr,
@ -997,7 +985,8 @@ static inline void ftrace_trace_stack(struct trace_array *tr,
int skip, struct pt_regs *regs);
#else
static inline void __ftrace_trace_stack(struct trace_buffer *buffer,
static inline void __ftrace_trace_stack(struct trace_array *tr,
struct trace_buffer *buffer,
unsigned int trace_ctx,
int skip, struct pt_regs *regs)
{
@ -1934,7 +1923,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
max_data->critical_start = data->critical_start;
max_data->critical_end = data->critical_end;
strncpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
strscpy(max_data->comm, tsk->comm);
max_data->pid = tsk->pid;
/*
* If tsk == current, then use current_uid(), as that does not use
@ -2908,7 +2897,6 @@ void
trace_function(struct trace_array *tr, unsigned long ip, unsigned long
parent_ip, unsigned int trace_ctx)
{
struct trace_event_call *call = &event_function;
struct trace_buffer *buffer = tr->array_buffer.buffer;
struct ring_buffer_event *event;
struct ftrace_entry *entry;
@ -2921,11 +2909,9 @@ trace_function(struct trace_array *tr, unsigned long ip, unsigned long
entry->ip = ip;
entry->parent_ip = parent_ip;
if (!call_filter_check_discard(call, entry, buffer, event)) {
if (static_branch_unlikely(&trace_function_exports_enabled))
ftrace_exports(event, TRACE_EXPORT_FUNCTION);
__buffer_unlock_commit(buffer, event);
}
if (static_branch_unlikely(&trace_function_exports_enabled))
ftrace_exports(event, TRACE_EXPORT_FUNCTION);
__buffer_unlock_commit(buffer, event);
}
#ifdef CONFIG_STACKTRACE
@ -2933,7 +2919,7 @@ trace_function(struct trace_array *tr, unsigned long ip, unsigned long
/* Allow 4 levels of nesting: normal, softirq, irq, NMI */
#define FTRACE_KSTACK_NESTING 4
#define FTRACE_KSTACK_ENTRIES (PAGE_SIZE / FTRACE_KSTACK_NESTING)
#define FTRACE_KSTACK_ENTRIES (SZ_4K / FTRACE_KSTACK_NESTING)
struct ftrace_stack {
unsigned long calls[FTRACE_KSTACK_ENTRIES];
@ -2947,11 +2933,11 @@ struct ftrace_stacks {
static DEFINE_PER_CPU(struct ftrace_stacks, ftrace_stacks);
static DEFINE_PER_CPU(int, ftrace_stack_reserve);
static void __ftrace_trace_stack(struct trace_buffer *buffer,
static void __ftrace_trace_stack(struct trace_array *tr,
struct trace_buffer *buffer,
unsigned int trace_ctx,
int skip, struct pt_regs *regs)
{
struct trace_event_call *call = &event_kernel_stack;
struct ring_buffer_event *event;
unsigned int size, nr_entries;
struct ftrace_stack *fstack;
@ -2994,6 +2980,20 @@ static void __ftrace_trace_stack(struct trace_buffer *buffer,
nr_entries = stack_trace_save(fstack->calls, size, skip);
}
#ifdef CONFIG_DYNAMIC_FTRACE
/* Mark entry of stack trace as trampoline code */
if (tr->ops && tr->ops->trampoline) {
unsigned long tramp_start = tr->ops->trampoline;
unsigned long tramp_end = tramp_start + tr->ops->trampoline_size;
unsigned long *calls = fstack->calls;
for (int i = 0; i < nr_entries; i++) {
if (calls[i] >= tramp_start && calls[i] < tramp_end)
calls[i] = FTRACE_TRAMPOLINE_MARKER;
}
}
#endif
event = __trace_buffer_lock_reserve(buffer, TRACE_STACK,
struct_size(entry, caller, nr_entries),
trace_ctx);
@ -3005,8 +3005,7 @@ static void __ftrace_trace_stack(struct trace_buffer *buffer,
memcpy(&entry->caller, fstack->calls,
flex_array_size(entry, caller, nr_entries));
if (!call_filter_check_discard(call, entry, buffer, event))
__buffer_unlock_commit(buffer, event);
__buffer_unlock_commit(buffer, event);
out:
/* Again, don't let gcc optimize things here */
@ -3024,7 +3023,7 @@ static inline void ftrace_trace_stack(struct trace_array *tr,
if (!(tr->trace_flags & TRACE_ITER_STACKTRACE))
return;
__ftrace_trace_stack(buffer, trace_ctx, skip, regs);
__ftrace_trace_stack(tr, buffer, trace_ctx, skip, regs);
}
void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
@ -3033,7 +3032,7 @@ void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
struct trace_buffer *buffer = tr->array_buffer.buffer;
if (rcu_is_watching()) {
__ftrace_trace_stack(buffer, trace_ctx, skip, NULL);
__ftrace_trace_stack(tr, buffer, trace_ctx, skip, NULL);
return;
}
@ -3050,7 +3049,7 @@ void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
return;
ct_irq_enter_irqson();
__ftrace_trace_stack(buffer, trace_ctx, skip, NULL);
__ftrace_trace_stack(tr, buffer, trace_ctx, skip, NULL);
ct_irq_exit_irqson();
}
@ -3067,8 +3066,8 @@ void trace_dump_stack(int skip)
/* Skip 1 to skip this function. */
skip++;
#endif
__ftrace_trace_stack(printk_trace->array_buffer.buffer,
tracing_gen_ctx(), skip, NULL);
__ftrace_trace_stack(printk_trace, printk_trace->array_buffer.buffer,
tracing_gen_ctx(), skip, NULL);
}
EXPORT_SYMBOL_GPL(trace_dump_stack);
@ -3079,7 +3078,6 @@ static void
ftrace_trace_userstack(struct trace_array *tr,
struct trace_buffer *buffer, unsigned int trace_ctx)
{
struct trace_event_call *call = &event_user_stack;
struct ring_buffer_event *event;
struct userstack_entry *entry;
@ -3113,8 +3111,7 @@ ftrace_trace_userstack(struct trace_array *tr,
memset(&entry->caller, 0, sizeof(entry->caller));
stack_trace_save_user(entry->caller, FTRACE_STACK_ENTRIES);
if (!call_filter_check_discard(call, entry, buffer, event))
__buffer_unlock_commit(buffer, event);
__buffer_unlock_commit(buffer, event);
out_drop_count:
__this_cpu_dec(user_stack_count);
@ -3283,7 +3280,6 @@ static void trace_printk_start_stop_comm(int enabled)
*/
int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
{
struct trace_event_call *call = &event_bprint;
struct ring_buffer_event *event;
struct trace_buffer *buffer;
struct trace_array *tr = READ_ONCE(printk_trace);
@ -3327,10 +3323,8 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
entry->fmt = fmt;
memcpy(entry->buf, tbuffer, sizeof(u32) * len);
if (!call_filter_check_discard(call, entry, buffer, event)) {
__buffer_unlock_commit(buffer, event);
ftrace_trace_stack(tr, buffer, trace_ctx, 6, NULL);
}
__buffer_unlock_commit(buffer, event);
ftrace_trace_stack(tr, buffer, trace_ctx, 6, NULL);
out:
ring_buffer_nest_end(buffer);
@ -3350,7 +3344,6 @@ static int
__trace_array_vprintk(struct trace_buffer *buffer,
unsigned long ip, const char *fmt, va_list args)
{
struct trace_event_call *call = &event_print;
struct ring_buffer_event *event;
int len = 0, size;
struct print_entry *entry;
@ -3385,10 +3378,8 @@ __trace_array_vprintk(struct trace_buffer *buffer,
entry->ip = ip;
memcpy(&entry->buf, tbuffer, len + 1);
if (!call_filter_check_discard(call, entry, buffer, event)) {
__buffer_unlock_commit(buffer, event);
ftrace_trace_stack(printk_trace, buffer, trace_ctx, 6, NULL);
}
__buffer_unlock_commit(buffer, event);
ftrace_trace_stack(printk_trace, buffer, trace_ctx, 6, NULL);
out:
ring_buffer_nest_end(buffer);

11
kernel/trace/trace.h
View File

@ -1440,10 +1440,6 @@ struct trace_subsystem_dir {
int nr_events;
};
extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
struct trace_buffer *buffer,
struct ring_buffer_event *event);
void trace_buffer_unlock_commit_regs(struct trace_array *tr,
struct trace_buffer *buffer,
struct ring_buffer_event *event,
@ -2187,4 +2183,11 @@ static inline int rv_init_interface(void)
}
#endif
/*
* This is used only to distinguish
* function address from trampoline code.
* So this value has no meaning.
*/
#define FTRACE_TRAMPOLINE_MARKER ((unsigned long) INT_MAX)
#endif /* _LINUX_KERNEL_TRACE_H */

10
kernel/trace/trace_branch.c
View File

@ -30,7 +30,6 @@ static struct trace_array *branch_tracer;
static void
probe_likely_condition(struct ftrace_likely_data *f, int val, int expect)
{
struct trace_event_call *call = &event_branch;
struct trace_array *tr = branch_tracer;
struct trace_buffer *buffer;
struct trace_array_cpu *data;
@ -74,16 +73,13 @@ probe_likely_condition(struct ftrace_likely_data *f, int val, int expect)
p--;
p++;
strncpy(entry->func, f->data.func, TRACE_FUNC_SIZE);
strncpy(entry->file, p, TRACE_FILE_SIZE);
entry->func[TRACE_FUNC_SIZE] = 0;
entry->file[TRACE_FILE_SIZE] = 0;
strscpy(entry->func, f->data.func);
strscpy(entry->file, p);
entry->constant = f->constant;
entry->line = f->data.line;
entry->correct = val == expect;
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit_nostack(buffer, event);
trace_buffer_unlock_commit_nostack(buffer, event);
out:
current->trace_recursion &= ~TRACE_BRANCH_BIT;

2
kernel/trace/trace_clock.c
View File

@ -154,5 +154,5 @@ static atomic64_t trace_counter;
*/
u64 notrace trace_clock_counter(void)
{
return atomic64_add_return(1, &trace_counter);
return atomic64_inc_return(&trace_counter);
}

6
kernel/trace/trace_event_perf.c
View File

@ -352,10 +352,16 @@ void perf_uprobe_destroy(struct perf_event *p_event)
int perf_trace_add(struct perf_event *p_event, int flags)
{
struct trace_event_call *tp_event = p_event->tp_event;
struct hw_perf_event *hwc = &p_event->hw;
if (!(flags & PERF_EF_START))
p_event->hw.state = PERF_HES_STOPPED;
if (is_sampling_event(p_event)) {
hwc->last_period = hwc->sample_period;
perf_swevent_set_period(p_event);
}
/*
* If TRACE_REG_PERF_ADD returns false; no custom action was performed
* and we need to take the default action of enqueueing our event on

2
kernel/trace/trace_events.c
View File

@ -3149,8 +3149,6 @@ static void __trace_remove_event_call(struct trace_event_call *call)
{
event_remove(call);
trace_destroy_fields(call);
free_event_filter(call->filter);
call->filter = NULL;
}
static int probe_remove_event_call(struct trace_event_call *call)

8
kernel/trace/trace_events_filter.c
View File

@ -1616,7 +1616,7 @@ static int parse_pred(const char *str, void *data,
goto err_free;
}
strncpy(num_buf, str + s, len);
memcpy(num_buf, str + s, len);
num_buf[len] = 0;
ret = kstrtoul(num_buf, 0, &ip);
@ -1694,7 +1694,7 @@ static int parse_pred(const char *str, void *data,
if (!pred->regex)
goto err_mem;
pred->regex->len = len;
strncpy(pred->regex->pattern, str + s, len);
memcpy(pred->regex->pattern, str + s, len);
pred->regex->pattern[len] = 0;
} else if (!strncmp(str + i, "CPUS", 4)) {
@ -1859,7 +1859,7 @@ static int parse_pred(const char *str, void *data,
if (!pred->regex)
goto err_mem;
pred->regex->len = len;
strncpy(pred->regex->pattern, str + s, len);
memcpy(pred->regex->pattern, str + s, len);
pred->regex->pattern[len] = 0;
filter_build_regex(pred);
@ -1919,7 +1919,7 @@ static int parse_pred(const char *str, void *data,
goto err_free;
}
strncpy(num_buf, str + s, len);
memcpy(num_buf, str + s, len);
num_buf[len] = 0;
/* Make sure it is a value */

11
kernel/trace/trace_events_hist.c
View File

@ -822,7 +822,7 @@ static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
{
struct tracepoint *tp = event->tp;
if (unlikely(atomic_read(&tp->key.enabled) > 0)) {
if (unlikely(static_key_enabled(&tp->key))) {
struct tracepoint_func *probe_func_ptr;
synth_probe_func_t probe_func;
void *__data;
@ -1354,10 +1354,7 @@ static const char *hist_field_name(struct hist_field *field,
} else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
field_name = "common_timestamp";
else if (field->flags & HIST_FIELD_FL_STACKTRACE) {
if (field->field)
field_name = field->field->name;
else
field_name = "common_stacktrace";
field_name = "common_stacktrace";
} else if (field->flags & HIST_FIELD_FL_HITCOUNT)
field_name = "hitcount";
@ -1599,7 +1596,7 @@ static inline void save_comm(char *comm, struct task_struct *task)
return;
}
strncpy(comm, task->comm, TASK_COMM_LEN);
strscpy(comm, task->comm, TASK_COMM_LEN);
}
static void hist_elt_data_free(struct hist_elt_data *elt_data)
@ -3405,7 +3402,7 @@ static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
elt_data = context->elt->private_data;
track_elt_data = track_data->elt.private_data;
if (elt_data->comm)
strncpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN);
strscpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN);
track_data->updated = true;

4
kernel/trace/trace_events_user.c
View File

@ -1676,7 +1676,7 @@ static void update_enable_bit_for(struct user_event *user)
struct tracepoint *tp = &user->tracepoint;
char status = 0;
if (atomic_read(&tp->key.enabled) > 0) {
if (static_key_enabled(&tp->key)) {
struct tracepoint_func *probe_func_ptr;
user_event_func_t probe_func;
@ -2280,7 +2280,7 @@ static ssize_t user_events_write_core(struct file *file, struct iov_iter *i)
* It's possible key.enabled disables after this check, however
* we don't mind if a few events are included in this condition.
*/
if (likely(atomic_read(&tp->key.enabled) > 0)) {
if (likely(static_key_enabled(&tp->key))) {
struct tracepoint_func *probe_func_ptr;
user_event_func_t probe_func;
struct iov_iter copy;

36
kernel/trace/trace_functions.c
View File

@ -176,6 +176,27 @@ static void function_trace_start(struct trace_array *tr)
tracing_reset_online_cpus(&tr->array_buffer);
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static __always_inline unsigned long
function_get_true_parent_ip(unsigned long parent_ip, struct ftrace_regs *fregs)
{
unsigned long true_parent_ip;
int idx = 0;
true_parent_ip = parent_ip;
if (unlikely(parent_ip == (unsigned long)&return_to_handler) && fregs)
true_parent_ip = ftrace_graph_ret_addr(current, &idx, parent_ip,
(unsigned long *)ftrace_regs_get_stack_pointer(fregs));
return true_parent_ip;
}
#else
static __always_inline unsigned long
function_get_true_parent_ip(unsigned long parent_ip, struct ftrace_regs *fregs)
{
return parent_ip;
}
#endif
static void
function_trace_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs)
@ -184,7 +205,6 @@ function_trace_call(unsigned long ip, unsigned long parent_ip,
struct trace_array_cpu *data;
unsigned int trace_ctx;
int bit;
int cpu;
if (unlikely(!tr->function_enabled))
return;
@ -193,10 +213,11 @@ function_trace_call(unsigned long ip, unsigned long parent_ip,
if (bit < 0)
return;
parent_ip = function_get_true_parent_ip(parent_ip, fregs);
trace_ctx = tracing_gen_ctx();
cpu = smp_processor_id();
data = per_cpu_ptr(tr->array_buffer.data, cpu);
data = this_cpu_ptr(tr->array_buffer.data);
if (!atomic_read(&data->disabled))
trace_function(tr, ip, parent_ip, trace_ctx);
@ -241,6 +262,7 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
* recursive protection is performed.
*/
local_irq_save(flags);
parent_ip = function_get_true_parent_ip(parent_ip, fregs);
cpu = raw_smp_processor_id();
data = per_cpu_ptr(tr->array_buffer.data, cpu);
disabled = atomic_inc_return(&data->disabled);
@ -300,7 +322,6 @@ function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
unsigned int trace_ctx;
unsigned long flags;
int bit;
int cpu;
if (unlikely(!tr->function_enabled))
return;
@ -309,8 +330,8 @@ function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
if (bit < 0)
return;
cpu = smp_processor_id();
data = per_cpu_ptr(tr->array_buffer.data, cpu);
parent_ip = function_get_true_parent_ip(parent_ip, fregs);
data = this_cpu_ptr(tr->array_buffer.data);
if (atomic_read(&data->disabled))
goto out;
@ -321,7 +342,7 @@ function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
* TODO: think about a solution that is better than just hoping to be
* lucky.
*/
last_info = per_cpu_ptr(tr->last_func_repeats, cpu);
last_info = this_cpu_ptr(tr->last_func_repeats);
if (is_repeat_check(tr, last_info, ip, parent_ip))
goto out;
@ -356,6 +377,7 @@ function_stack_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
* recursive protection is performed.
*/
local_irq_save(flags);
parent_ip = function_get_true_parent_ip(parent_ip, fregs);
cpu = raw_smp_processor_id();
data = per_cpu_ptr(tr->array_buffer.data, cpu);
disabled = atomic_inc_return(&data->disabled);

8
kernel/trace/trace_functions_graph.c
View File

@ -114,7 +114,6 @@ int __trace_graph_entry(struct trace_array *tr,
struct ftrace_graph_ent *trace,
unsigned int trace_ctx)
{
struct trace_event_call *call = &event_funcgraph_entry;
struct ring_buffer_event *event;
struct trace_buffer *buffer = tr->array_buffer.buffer;
struct ftrace_graph_ent_entry *entry;
@ -125,8 +124,7 @@ int __trace_graph_entry(struct trace_array *tr,
return 0;
entry = ring_buffer_event_data(event);
entry->graph_ent = *trace;
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit_nostack(buffer, event);
trace_buffer_unlock_commit_nostack(buffer, event);
return 1;
}
@ -292,7 +290,6 @@ void __trace_graph_return(struct trace_array *tr,
struct ftrace_graph_ret *trace,
unsigned int trace_ctx)
{
struct trace_event_call *call = &event_funcgraph_exit;
struct ring_buffer_event *event;
struct trace_buffer *buffer = tr->array_buffer.buffer;
struct ftrace_graph_ret_entry *entry;
@ -303,8 +300,7 @@ void __trace_graph_return(struct trace_array *tr,
return;
entry = ring_buffer_event_data(event);
entry->ret = *trace;
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit_nostack(buffer, event);
trace_buffer_unlock_commit_nostack(buffer, event);
}
static void handle_nosleeptime(struct ftrace_graph_ret *trace,

4
kernel/trace/trace_hwlat.c
View File

@ -130,7 +130,6 @@ static bool hwlat_busy;
static void trace_hwlat_sample(struct hwlat_sample *sample)
{
struct trace_array *tr = hwlat_trace;
struct trace_event_call *call = &event_hwlat;
struct trace_buffer *buffer = tr->array_buffer.buffer;
struct ring_buffer_event *event;
struct hwlat_entry *entry;
@ -148,8 +147,7 @@ static void trace_hwlat_sample(struct hwlat_sample *sample)
entry->nmi_count = sample->nmi_count;
entry->count = sample->count;
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit_nostack(buffer, event);
trace_buffer_unlock_commit_nostack(buffer, event);
}
/* Macros to encapsulate the time capturing infrastructure */

8
kernel/trace/trace_mmiotrace.c
View File

@ -294,7 +294,6 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
struct trace_array_cpu *data,
struct mmiotrace_rw *rw)
{
struct trace_event_call *call = &event_mmiotrace_rw;
struct trace_buffer *buffer = tr->array_buffer.buffer;
struct ring_buffer_event *event;
struct trace_mmiotrace_rw *entry;
@ -310,8 +309,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
entry = ring_buffer_event_data(event);
entry->rw = *rw;
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
}
void mmio_trace_rw(struct mmiotrace_rw *rw)
@ -325,7 +323,6 @@ static void __trace_mmiotrace_map(struct trace_array *tr,
struct trace_array_cpu *data,
struct mmiotrace_map *map)
{
struct trace_event_call *call = &event_mmiotrace_map;
struct trace_buffer *buffer = tr->array_buffer.buffer;
struct ring_buffer_event *event;
struct trace_mmiotrace_map *entry;
@ -341,8 +338,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr,
entry = ring_buffer_event_data(event);
entry->map = *map;
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
}
void mmio_trace_mapping(struct mmiotrace_map *map)

12
kernel/trace/trace_osnoise.c
View File

@ -499,7 +499,6 @@ static void print_osnoise_headers(struct seq_file *s)
static void
__trace_osnoise_sample(struct osnoise_sample *sample, struct trace_buffer *buffer)
{
struct trace_event_call *call = &event_osnoise;
struct ring_buffer_event *event;
struct osnoise_entry *entry;
@ -517,8 +516,7 @@ __trace_osnoise_sample(struct osnoise_sample *sample, struct trace_buffer *buffe
entry->softirq_count = sample->softirq_count;
entry->thread_count = sample->thread_count;
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit_nostack(buffer, event);
trace_buffer_unlock_commit_nostack(buffer, event);
}
/*
@ -578,7 +576,6 @@ static void print_timerlat_headers(struct seq_file *s)
static void
__trace_timerlat_sample(struct timerlat_sample *sample, struct trace_buffer *buffer)
{
struct trace_event_call *call = &event_osnoise;
struct ring_buffer_event *event;
struct timerlat_entry *entry;
@ -591,8 +588,7 @@ __trace_timerlat_sample(struct timerlat_sample *sample, struct trace_buffer *buf
entry->context = sample->context;
entry->timer_latency = sample->timer_latency;
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit_nostack(buffer, event);
trace_buffer_unlock_commit_nostack(buffer, event);
}
/*
@ -654,7 +650,6 @@ static void timerlat_save_stack(int skip)
static void
__timerlat_dump_stack(struct trace_buffer *buffer, struct trace_stack *fstack, unsigned int size)
{
struct trace_event_call *call = &event_osnoise;
struct ring_buffer_event *event;
struct stack_entry *entry;
@ -668,8 +663,7 @@ __timerlat_dump_stack(struct trace_buffer *buffer, struct trace_stack *fstack, u
memcpy(&entry->caller, fstack->calls, size);
entry->size = fstack->nr_entries;
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit_nostack(buffer, event);
trace_buffer_unlock_commit_nostack(buffer, event);
}
/*

5
kernel/trace/trace_output.c
View File

@ -460,7 +460,6 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
(entry->flags & TRACE_FLAG_IRQS_OFF && bh_off) ? 'D' :
(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
bh_off ? 'b' :
(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
'.';
switch (entry->flags & (TRACE_FLAG_NEED_RESCHED |
@ -1246,6 +1245,10 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
break;
trace_seq_puts(s, " => ");
if ((*p) == FTRACE_TRAMPOLINE_MARKER) {
trace_seq_puts(s, "[FTRACE TRAMPOLINE]\n");
continue;
}
seq_print_ip_sym(s, (*p) + delta, flags);
trace_seq_putc(s, '\n');
}

26
kernel/trace/trace_preemptirq.c
View File

@ -15,20 +15,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/preemptirq.h>
/*
* Use regular trace points on architectures that implement noinstr
* tooling: these calls will only happen with RCU enabled, which can
* use a regular tracepoint.
*
* On older architectures, use the rcuidle tracing methods (which
* aren't NMI-safe - so exclude NMI contexts):
*/
#ifdef CONFIG_ARCH_WANTS_NO_INSTR
#define trace(point) trace_##point
#else
#define trace(point) if (!in_nmi()) trace_##point##_rcuidle
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
/* Per-cpu variable to prevent redundant calls when IRQs already off */
static DEFINE_PER_CPU(int, tracing_irq_cpu);
@ -42,7 +28,7 @@ static DEFINE_PER_CPU(int, tracing_irq_cpu);
void trace_hardirqs_on_prepare(void)
{
if (this_cpu_read(tracing_irq_cpu)) {
trace(irq_enable)(CALLER_ADDR0, CALLER_ADDR1);
trace_irq_enable(CALLER_ADDR0, CALLER_ADDR1);
tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
this_cpu_write(tracing_irq_cpu, 0);
}
@ -53,7 +39,7 @@ NOKPROBE_SYMBOL(trace_hardirqs_on_prepare);
void trace_hardirqs_on(void)
{
if (this_cpu_read(tracing_irq_cpu)) {
trace(irq_enable)(CALLER_ADDR0, CALLER_ADDR1);
trace_irq_enable(CALLER_ADDR0, CALLER_ADDR1);
tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);
this_cpu_write(tracing_irq_cpu, 0);
}
@ -75,7 +61,7 @@ void trace_hardirqs_off_finish(void)
if (!this_cpu_read(tracing_irq_cpu)) {
this_cpu_write(tracing_irq_cpu, 1);
tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
trace(irq_disable)(CALLER_ADDR0, CALLER_ADDR1);
trace_irq_disable(CALLER_ADDR0, CALLER_ADDR1);
}
}
@ -89,7 +75,7 @@ void trace_hardirqs_off(void)
if (!this_cpu_read(tracing_irq_cpu)) {
this_cpu_write(tracing_irq_cpu, 1);
tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
trace(irq_disable)(CALLER_ADDR0, CALLER_ADDR1);
trace_irq_disable(CALLER_ADDR0, CALLER_ADDR1);
}
}
EXPORT_SYMBOL(trace_hardirqs_off);
@ -100,13 +86,13 @@ NOKPROBE_SYMBOL(trace_hardirqs_off);
void trace_preempt_on(unsigned long a0, unsigned long a1)
{
trace(preempt_enable)(a0, a1);
trace_preempt_enable(a0, a1);
tracer_preempt_on(a0, a1);
}
void trace_preempt_off(unsigned long a0, unsigned long a1)
{
trace(preempt_disable)(a0, a1);
trace_preempt_disable(a0, a1);
tracer_preempt_off(a0, a1);
}
#endif

2
kernel/trace/trace_sched_switch.c
View File

@ -187,7 +187,7 @@ static inline char *get_saved_cmdlines(int idx)
static inline void set_cmdline(int idx, const char *cmdline)
{
strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
strscpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
}
static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)

8
kernel/trace/trace_sched_wakeup.c
View File

@ -378,7 +378,6 @@ tracing_sched_switch_trace(struct trace_array *tr,
struct task_struct *next,
unsigned int trace_ctx)
{
struct trace_event_call *call = &event_context_switch;
struct trace_buffer *buffer = tr->array_buffer.buffer;
struct ring_buffer_event *event;
struct ctx_switch_entry *entry;
@ -396,8 +395,7 @@ tracing_sched_switch_trace(struct trace_array *tr,
entry->next_state = task_state_index(next);
entry->next_cpu = task_cpu(next);
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
}
static void
@ -406,7 +404,6 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
struct task_struct *curr,
unsigned int trace_ctx)
{
struct trace_event_call *call = &event_wakeup;
struct ring_buffer_event *event;
struct ctx_switch_entry *entry;
struct trace_buffer *buffer = tr->array_buffer.buffer;
@ -424,8 +421,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
entry->next_state = task_state_index(wakee);
entry->next_cpu = task_cpu(wakee);
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
}
static void notrace

28
kernel/trace/trace_syscalls.c
View File

@ -299,6 +299,13 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
int syscall_nr;
int size;
/*
* Syscall probe called with preemption enabled, but the ring
* buffer and per-cpu data require preemption to be disabled.
*/
might_fault();
guard(preempt_notrace)();
syscall_nr = trace_get_syscall_nr(current, regs);
if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
@ -338,6 +345,13 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
struct trace_event_buffer fbuffer;
int syscall_nr;
/*
* Syscall probe called with preemption enabled, but the ring
* buffer and per-cpu data require preemption to be disabled.
*/
might_fault();
guard(preempt_notrace)();
syscall_nr = trace_get_syscall_nr(current, regs);
if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
@ -584,6 +598,13 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
int rctx;
int size;
/*
* Syscall probe called with preemption enabled, but the ring
* buffer and per-cpu data require preemption to be disabled.
*/
might_fault();
guard(preempt_notrace)();
syscall_nr = trace_get_syscall_nr(current, regs);
if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
@ -686,6 +707,13 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
int rctx;
int size;
/*
* Syscall probe called with preemption enabled, but the ring
* buffer and per-cpu data require preemption to be disabled.
*/
might_fault();
guard(preempt_notrace)();
syscall_nr = trace_get_syscall_nr(current, regs);
if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;

75
kernel/tracepoint.c
View File

@ -25,9 +25,6 @@ enum tp_func_state {
extern tracepoint_ptr_t __start___tracepoints_ptrs[];
extern tracepoint_ptr_t __stop___tracepoints_ptrs[];
DEFINE_SRCU(tracepoint_srcu);
EXPORT_SYMBOL_GPL(tracepoint_srcu);
enum tp_transition_sync {
TP_TRANSITION_SYNC_1_0_1,
TP_TRANSITION_SYNC_N_2_1,
@ -37,7 +34,6 @@ enum tp_transition_sync {
struct tp_transition_snapshot {
unsigned long rcu;
unsigned long srcu;
bool ongoing;
};
@ -50,7 +46,6 @@ static void tp_rcu_get_state(enum tp_transition_sync sync)
/* Keep the latest get_state snapshot. */
snapshot->rcu = get_state_synchronize_rcu();
snapshot->srcu = start_poll_synchronize_srcu(&tracepoint_srcu);
snapshot->ongoing = true;
}
@ -61,8 +56,6 @@ static void tp_rcu_cond_sync(enum tp_transition_sync sync)
if (!snapshot->ongoing)
return;
cond_synchronize_rcu(snapshot->rcu);
if (!poll_state_synchronize_srcu(&tracepoint_srcu, snapshot->srcu))
synchronize_srcu(&tracepoint_srcu);
snapshot->ongoing = false;
}
@ -85,9 +78,6 @@ static LIST_HEAD(tracepoint_module_list);
*/
static DEFINE_MUTEX(tracepoints_mutex);
static struct rcu_head *early_probes;
static bool ok_to_free_tracepoints;
/*
* Note about RCU :
* It is used to delay the free of multiple probes array until a quiescent
@ -111,57 +101,21 @@ static inline void *allocate_probes(int count)
return p == NULL ? NULL : p->probes;
}
static void srcu_free_old_probes(struct rcu_head *head)
static void rcu_free_old_probes(struct rcu_head *head)
{
kfree(container_of(head, struct tp_probes, rcu));
}
static void rcu_free_old_probes(struct rcu_head *head)
{
call_srcu(&tracepoint_srcu, head, srcu_free_old_probes);
}
static __init int release_early_probes(void)
{
struct rcu_head *tmp;
ok_to_free_tracepoints = true;
while (early_probes) {
tmp = early_probes;
early_probes = tmp->next;
call_rcu(tmp, rcu_free_old_probes);
}
return 0;
}
/* SRCU is initialized at core_initcall */
postcore_initcall(release_early_probes);
static inline void release_probes(struct tracepoint_func *old)
static inline void release_probes(struct tracepoint *tp, struct tracepoint_func *old)
{
if (old) {
struct tp_probes *tp_probes = container_of(old,
struct tp_probes, probes[0]);
/*
* We can't free probes if SRCU is not initialized yet.
* Postpone the freeing till after SRCU is initialized.
*/
if (unlikely(!ok_to_free_tracepoints)) {
tp_probes->rcu.next = early_probes;
early_probes = &tp_probes->rcu;
return;
}
/*
* Tracepoint probes are protected by both sched RCU and SRCU,
* by calling the SRCU callback in the sched RCU callback we
* cover both cases. So let us chain the SRCU and sched RCU
* callbacks to wait for both grace periods.
*/
call_rcu(&tp_probes->rcu, rcu_free_old_probes);
if (tracepoint_is_faultable(tp))
call_rcu_tasks_trace(&tp_probes->rcu, rcu_free_old_probes);
else
call_rcu(&tp_probes->rcu, rcu_free_old_probes);
}
}
@ -327,8 +281,8 @@ static int tracepoint_add_func(struct tracepoint *tp,
struct tracepoint_func *old, *tp_funcs;
int ret;
if (tp->regfunc && !static_key_enabled(&tp->key)) {
ret = tp->regfunc();
if (tp->ext && tp->ext->regfunc && !static_key_enabled(&tp->key)) {
ret = tp->ext->regfunc();
if (ret < 0)
return ret;
}
@ -358,7 +312,7 @@ static int tracepoint_add_func(struct tracepoint *tp,
tracepoint_update_call(tp, tp_funcs);
/* Both iterator and static call handle NULL tp->funcs */
rcu_assign_pointer(tp->funcs, tp_funcs);
static_key_enable(&tp->key);
static_branch_enable(&tp->key);
break;
case TP_FUNC_2: /* 1->2 */
/* Set iterator static call */
@ -383,7 +337,7 @@ static int tracepoint_add_func(struct tracepoint *tp,
break;
}
release_probes(old);
release_probes(tp, old);
return 0;
}
@ -411,10 +365,9 @@ static int tracepoint_remove_func(struct tracepoint *tp,
switch (nr_func_state(tp_funcs)) {
case TP_FUNC_0: /* 1->0 */
/* Removed last function */
if (tp->unregfunc && static_key_enabled(&tp->key))
tp->unregfunc();
static_key_disable(&tp->key);
if (tp->ext && tp->ext->unregfunc && static_key_enabled(&tp->key))
tp->ext->unregfunc();
static_branch_disable(&tp->key);
/* Set iterator static call */
tracepoint_update_call(tp, tp_funcs);
/* Both iterator and static call handle NULL tp->funcs */
@ -455,7 +408,7 @@ static int tracepoint_remove_func(struct tracepoint *tp,
WARN_ON_ONCE(1);
break;
}
release_probes(old);
release_probes(tp, old);
return 0;
}

2
scripts/tags.sh
View File

@ -152,9 +152,7 @@ regex_c=(
'/^BPF_CALL_[0-9]([[:space:]]*\([[:alnum:]_]*\).*/\1/'
'/^COMPAT_SYSCALL_DEFINE[0-9]([[:space:]]*\([[:alnum:]_]*\).*/compat_sys_\1/'
'/^TRACE_EVENT([[:space:]]*\([[:alnum:]_]*\).*/trace_\1/'
'/^TRACE_EVENT([[:space:]]*\([[:alnum:]_]*\).*/trace_\1_rcuidle/'
'/^DEFINE_EVENT([^,)]*,[[:space:]]*\([[:alnum:]_]*\).*/trace_\1/'
'/^DEFINE_EVENT([^,)]*,[[:space:]]*\([[:alnum:]_]*\).*/trace_\1_rcuidle/'
'/^DEFINE_INSN_CACHE_OPS([[:space:]]*\([[:alnum:]_]*\).*/get_\1_slot/'
'/^DEFINE_INSN_CACHE_OPS([[:space:]]*\([[:alnum:]_]*\).*/free_\1_slot/'
'/^PAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/Page\1/'