diff --git a/Documentation/admin-guide/bootconfig.rst b/Documentation/admin-guide/bootconfig.rst
index d6b3b77a412966c441997ee9efdb54a7360ef983..a22024f9175e70f64898ff3ff4a5d123b3188752 100644
--- a/Documentation/admin-guide/bootconfig.rst
+++ b/Documentation/admin-guide/bootconfig.rst
@@ -71,6 +71,16 @@ For example,::
foo = bar, baz
foo = qux # !ERROR! we can not re-define same key
+If you want to update the value, you must use the override operator
+``:=`` explicitly. For example::
+
+ foo = bar, baz
+ foo := qux
+
+then, the ``qux`` is assigned to ``foo`` key. This is useful for
+overriding the default value by adding (partial) custom bootconfigs
+without parsing the default bootconfig.
+
If you want to append the value to existing key as an array member,
you can use ``+=`` operator. For example::
@@ -84,6 +94,7 @@ For example, following config is NOT allowed.::
foo = value1
foo.bar = value2 # !ERROR! subkey "bar" and value "value1" can NOT co-exist
+ foo.bar := value2 # !ERROR! even with the override operator, this is NOT allowed.
Comments
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 51504566b3a6cd697f4be770ec81fe1df579fc4d..7edbd5ee5ed435ae01a26731f9681504d707b4e7 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -286,6 +286,7 @@ extern void ftrace_regs_caller_ret(void);
extern void ftrace_caller_end(void);
extern void ftrace_caller_op_ptr(void);
extern void ftrace_regs_caller_op_ptr(void);
+extern void ftrace_regs_caller_jmp(void);
/* movq function_trace_op(%rip), %rdx */
/* 0x48 0x8b 0x15 <offset-to-ftrace_trace_op (4 bytes)> */
@@ -316,6 +317,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
unsigned long end_offset;
unsigned long op_offset;
unsigned long call_offset;
+ unsigned long jmp_offset;
unsigned long offset;
unsigned long npages;
unsigned long size;
@@ -333,11 +335,13 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
end_offset = (unsigned long)ftrace_regs_caller_end;
op_offset = (unsigned long)ftrace_regs_caller_op_ptr;
call_offset = (unsigned long)ftrace_regs_call;
+ jmp_offset = (unsigned long)ftrace_regs_caller_jmp;
} else {
start_offset = (unsigned long)ftrace_caller;
end_offset = (unsigned long)ftrace_caller_end;
op_offset = (unsigned long)ftrace_caller_op_ptr;
call_offset = (unsigned long)ftrace_call;
+ jmp_offset = 0;
}
size = end_offset - start_offset;
@@ -367,10 +371,14 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
if (WARN_ON(ret < 0))
goto fail;
+ /* No need to test direct calls on created trampolines */
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
- ip = trampoline + (ftrace_regs_caller_ret - ftrace_regs_caller);
- ret = copy_from_kernel_nofault(ip, (void *)retq, RET_SIZE);
- if (WARN_ON(ret < 0))
+ /* NOP the jnz 1f; but make sure it's a 2 byte jnz */
+ ip = trampoline + (jmp_offset - start_offset);
+ if (WARN_ON(*(char *)ip != 0x75))
+ goto fail;
+ ret = copy_from_kernel_nofault(ip, ideal_nops[2], 2);
+ if (ret < 0)
goto fail;
}
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 083a3da7bb738a048829ce5f1aeed4ae766f3aba..ac3d5f22fe64b9900dbe00117173bd5276b6fd76 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -241,22 +241,10 @@ SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL)
*/
movq ORIG_RAX(%rsp), %rax
testq %rax, %rax
- jz 1f
+SYM_INNER_LABEL(ftrace_regs_caller_jmp, SYM_L_GLOBAL)
+ jnz 1f
- /* Swap the flags with orig_rax */
- movq MCOUNT_REG_SIZE(%rsp), %rdi
- movq %rdi, MCOUNT_REG_SIZE-8(%rsp)
- movq %rax, MCOUNT_REG_SIZE(%rsp)
-
- restore_mcount_regs 8
- /* Restore flags */
- popfq
-
-SYM_INNER_LABEL(ftrace_regs_caller_ret, SYM_L_GLOBAL);
- UNWIND_HINT_RET_OFFSET
- jmp ftrace_epilogue
-
-1: restore_mcount_regs
+ restore_mcount_regs
/* Restore flags */
popfq
@@ -269,6 +257,17 @@ SYM_INNER_LABEL(ftrace_regs_caller_ret, SYM_L_GLOBAL);
SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL)
jmp ftrace_epilogue
+ /* Swap the flags with orig_rax */
+1: movq MCOUNT_REG_SIZE(%rsp), %rdi
+ movq %rdi, MCOUNT_REG_SIZE-8(%rsp)
+ movq %rax, MCOUNT_REG_SIZE(%rsp)
+
+ restore_mcount_regs 8
+ /* Restore flags */
+ popfq
+ UNWIND_HINT_RET_OFFSET
+ jmp ftrace_epilogue
+
SYM_FUNC_END(ftrace_regs_caller)
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 45b8cdc9fad76ceafa1aa512b792d82ae503d9b4..9be1bff4f586a61573ecc8b806b2137e3b187613 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -227,7 +227,6 @@ extern int arch_prepare_kprobe(struct kprobe *p);
extern void arch_arm_kprobe(struct kprobe *p);
extern void arch_disarm_kprobe(struct kprobe *p);
extern int arch_init_kprobes(void);
-extern void show_registers(struct pt_regs *regs);
extern void kprobes_inc_nmissed_count(struct kprobe *p);
extern bool arch_within_kprobe_blacklist(unsigned long addr);
extern int arch_populate_kprobe_blacklist(void);
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index c76b2f3b3ac4011ca35fda3f9981b96cc70e54ff..136ea0997e6df6c6d7e7910d02d2c54799ca85d8 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -143,6 +143,7 @@ bool ring_buffer_iter_dropped(struct ring_buffer_iter *iter);
unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu);
void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu);
+void ring_buffer_reset_online_cpus(struct trace_buffer *buffer);
void ring_buffer_reset(struct trace_buffer *buffer);
#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
diff --git a/include/linux/trace.h b/include/linux/trace.h
index 7fd86d3c691f55a19087f6eb675cae37788b02a5..36d255d66f88f97f8c848f4ba2b9c8d4e0a9679c 100644
--- a/include/linux/trace.h
+++ b/include/linux/trace.h
@@ -29,6 +29,7 @@ struct trace_array;
void trace_printk_init_buffers(void);
int trace_array_printk(struct trace_array *tr, unsigned long ip,
const char *fmt, ...);
+int trace_array_init_printk(struct trace_array *tr);
void trace_array_put(struct trace_array *tr);
struct trace_array *trace_array_get_by_name(const char *name);
int trace_array_destroy(struct trace_array *tr);
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index a1fecf31162174036352198afee3260cdbab3670..598fec9f9dbf8712db870a24c2c0c6e92884aac5 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -116,8 +116,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
#define __TRACEPOINT_ENTRY(name) \
static tracepoint_ptr_t __tracepoint_ptr_##name __used \
- __attribute__((section("__tracepoints_ptrs"))) = \
- &__tracepoint_##name
+ __section(__tracepoints_ptrs) = &__tracepoint_##name
#endif
#endif /* _LINUX_TRACEPOINT_H */
@@ -280,9 +279,9 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
*/
#define DEFINE_TRACE_FN(name, reg, unreg) \
static const char __tpstrtab_##name[] \
- __attribute__((section("__tracepoints_strings"))) = #name; \
- struct tracepoint __tracepoint_##name \
- __attribute__((section("__tracepoints"), used)) = \
+ __section(__tracepoints_strings) = #name; \
+ struct tracepoint __tracepoint_##name __used \
+ __section(__tracepoints) = \
{ __tpstrtab_##name, STATIC_KEY_INIT_FALSE, reg, unreg, NULL };\
__TRACEPOINT_ENTRY(name);
@@ -361,7 +360,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
static const char *___tp_str __tracepoint_string = str; \
___tp_str; \
})
-#define __tracepoint_string __attribute__((section("__tracepoint_str")))
+#define __tracepoint_string __used __section(__tracepoint_str)
#else
/*
* tracepoint_string() is used to save the string address for userspace
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 502c7be50b8d95234b781059d810fec86d62165c..1bc3e7bba9a44ba9bfba02e634ce7320d96bbcda 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -210,8 +210,7 @@ TRACE_MAKE_SYSTEM_STR();
#define DEFINE_EVENT(template, name, proto, args)
#undef DEFINE_EVENT_PRINT
-#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
- DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)
#undef TRACE_EVENT_FLAGS
#define TRACE_EVENT_FLAGS(event, flag)
@@ -443,12 +442,8 @@ static struct trace_event_fields trace_event_fields_##call[] = { \
tstruct \
{} };
-#undef DEFINE_EVENT
-#define DEFINE_EVENT(template, name, proto, args)
-
#undef DEFINE_EVENT_PRINT
-#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
- DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
@@ -523,13 +518,6 @@ static inline notrace int trace_event_get_offsets_##call( \
return __data_size; \
}
-#undef DEFINE_EVENT
-#define DEFINE_EVENT(template, name, proto, args)
-
-#undef DEFINE_EVENT_PRINT
-#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
- DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
-
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/*
@@ -721,9 +709,6 @@ static inline void ftrace_test_probe_##call(void) \
check_trace_callback_type_##call(trace_event_raw_event_##template); \
}
-#undef DEFINE_EVENT_PRINT
-#define DEFINE_EVENT_PRINT(template, name, proto, args, print)
-
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
#undef __entry
diff --git a/init/main.c b/init/main.c
index de2f9fa6bb4a8b021753b6edcf878949ad1819ed..ae78fb68d2310543b8d5435ba1bb31d9e4c3c6d2 100644
--- a/init/main.c
+++ b/init/main.c
@@ -388,8 +388,6 @@ static int __init bootconfig_params(char *param, char *val,
{
if (strcmp(param, "bootconfig") == 0) {
bootconfig_found = true;
- } else if (strcmp(param, "--") == 0) {
- initargs_found = true;
}
return 0;
}
@@ -400,19 +398,23 @@ static void __init setup_boot_config(const char *cmdline)
const char *msg;
int pos;
u32 size, csum;
- char *data, *copy;
+ char *data, *copy, *err;
int ret;
/* Cut out the bootconfig data even if we have no bootconfig option */
data = get_boot_config_from_initrd(&size, &csum);
strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
- parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
- bootconfig_params);
+ err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
+ bootconfig_params);
- if (!bootconfig_found)
+ if (IS_ERR(err) || !bootconfig_found)
return;
+ /* parse_args() stops at '--' and returns an address */
+ if (err)
+ initargs_found = true;
+
if (!data) {
pr_err("'bootconfig' found on command line, but no bootconfig found\n");
return;
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index e87679a48ba2fd30d37f447d6d895c9398f5489e..287b263c9cb95781148bb16d7dbc61e417347709 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1111,9 +1111,20 @@ static int disarm_kprobe_ftrace(struct kprobe *p)
ipmodify ? &kprobe_ipmodify_enabled : &kprobe_ftrace_enabled);
}
#else /* !CONFIG_KPROBES_ON_FTRACE */
-#define prepare_kprobe(p) arch_prepare_kprobe(p)
-#define arm_kprobe_ftrace(p) (-ENODEV)
-#define disarm_kprobe_ftrace(p) (-ENODEV)
+static inline int prepare_kprobe(struct kprobe *p)
+{
+ return arch_prepare_kprobe(p);
+}
+
+static inline int arm_kprobe_ftrace(struct kprobe *p)
+{
+ return -ENODEV;
+}
+
+static inline int disarm_kprobe_ftrace(struct kprobe *p)
+{
+ return -ENODEV;
+}
#endif
/* Arm a kprobe with text_mutex */
@@ -2145,6 +2156,13 @@ static void kill_kprobe(struct kprobe *p)
* the original probed function (which will be freed soon) any more.
*/
arch_remove_kprobe(p);
+
+ /*
+ * The module is going away. We should disarm the kprobe which
+ * is using ftrace.
+ */
+ if (kprobe_ftrace(p))
+ disarm_kprobe_ftrace(p);
}
/* Disable one kprobe */
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 72064541bef277862bf46684492bfb07a42cbdc1..275441254bb57b69591b6407067aeea6491e2a06 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -139,9 +139,6 @@ static inline void ftrace_ops_init(struct ftrace_ops *ops)
#endif
}
-#define FTRACE_PID_IGNORE -1
-#define FTRACE_PID_TRACE -2
-
static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *regs)
{
@@ -2388,6 +2385,14 @@ struct ftrace_ops direct_ops = {
.flags = FTRACE_OPS_FL_IPMODIFY | FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS
| FTRACE_OPS_FL_PERMANENT,
+ /*
+ * By declaring the main trampoline as this trampoline
+ * it will never have one allocated for it. Allocated
+ * trampolines should not call direct functions.
+ * The direct_ops should only be called by the builtin
+ * ftrace_regs_caller trampoline.
+ */
+ .trampoline = FTRACE_REGS_ADDR,
};
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
@@ -6255,8 +6260,19 @@ static int referenced_filters(struct dyn_ftrace *rec)
int cnt = 0;
for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
- if (ops_references_rec(ops, rec))
- cnt++;
+ if (ops_references_rec(ops, rec)) {
+ if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT))
+ continue;
+ if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY))
+ continue;
+ cnt++;
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
+ rec->flags |= FTRACE_FL_REGS;
+ if (cnt == 1 && ops->trampoline)
+ rec->flags |= FTRACE_FL_TRAMP;
+ else
+ rec->flags &= ~FTRACE_FL_TRAMP;
+ }
}
return cnt;
@@ -6435,8 +6451,8 @@ void ftrace_module_enable(struct module *mod)
if (ftrace_start_up)
cnt += referenced_filters(rec);
- /* This clears FTRACE_FL_DISABLED */
- rec->flags = cnt;
+ rec->flags &= ~FTRACE_FL_DISABLED;
+ rec->flags += cnt;
if (ftrace_start_up && cnt) {
int failed = __ftrace_replace_code(rec, 1);
@@ -7066,12 +7082,12 @@ void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
if (enable) {
register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
tr);
- register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
+ register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit,
tr);
} else {
unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
tr);
- unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
+ unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit,
tr);
}
}
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f15471ce969e84ae682f79cc321db79ef67ade9d..93ef0ab6ea20154b7498e891f8f8af5afcc15732 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -270,6 +270,9 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data);
#define for_each_buffer_cpu(buffer, cpu) \
for_each_cpu(cpu, buffer->cpumask)
+#define for_each_online_buffer_cpu(buffer, cpu) \
+ for_each_cpu_and(cpu, buffer->cpumask, cpu_online_mask)
+
#define TS_SHIFT 27
#define TS_MASK ((1ULL << TS_SHIFT) - 1)
#define TS_DELTA_TEST (~TS_MASK)
@@ -413,11 +416,26 @@ struct rb_irq_work {
struct rb_event_info {
u64 ts;
u64 delta;
+ u64 before;
+ u64 after;
unsigned long length;
struct buffer_page *tail_page;
int add_timestamp;
};
+/*
+ * Used for the add_timestamp
+ * NONE
+ * EXTEND - wants a time extend
+ * ABSOLUTE - the buffer requests all events to have absolute time stamps
+ * FORCE - force a full time stamp.
+ */
+enum {
+ RB_ADD_STAMP_NONE = 0,
+ RB_ADD_STAMP_EXTEND = BIT(1),
+ RB_ADD_STAMP_ABSOLUTE = BIT(2),
+ RB_ADD_STAMP_FORCE = BIT(3)
+};
/*
* Used for which event context the event is in.
* NMI = 0
@@ -435,6 +453,28 @@ enum {
RB_CTX_MAX
};
+#if BITS_PER_LONG == 32
+#define RB_TIME_32
+#endif
+
+/* To test on 64 bit machines */
+//#define RB_TIME_32
+
+#ifdef RB_TIME_32
+
+struct rb_time_struct {
+ local_t cnt;
+ local_t top;
+ local_t bottom;
+};
+#else
+#include <asm/local64.h>
+struct rb_time_struct {
+ local64_t time;
+};
+#endif
+typedef struct rb_time_struct rb_time_t;
+
/*
* head_page == tail_page && head == tail then buffer is empty.
*/
@@ -470,7 +510,8 @@ struct ring_buffer_per_cpu {
size_t shortest_full;
unsigned long read;
unsigned long read_bytes;
- u64 write_stamp;
+ rb_time_t write_stamp;
+ rb_time_t before_stamp;
u64 read_stamp;
/* ring buffer pages to update, > 0 to add, < 0 to remove */
long nr_pages_to_update;
@@ -513,6 +554,189 @@ struct ring_buffer_iter {
int missed_events;
};
+#ifdef RB_TIME_32
+
+/*
+ * On 32 bit machines, local64_t is very expensive. As the ring
+ * buffer doesn't need all the features of a true 64 bit atomic,
+ * on 32 bit, it uses these functions (64 still uses local64_t).
+ *
+ * For the ring buffer, 64 bit required operations for the time is
+ * the following:
+ *
+ * - Only need 59 bits (uses 60 to make it even).
+ * - Reads may fail if it interrupted a modification of the time stamp.
+ * It will succeed if it did not interrupt another write even if
+ * the read itself is interrupted by a write.
+ * It returns whether it was successful or not.
+ *
+ * - Writes always succeed and will overwrite other writes and writes
+ * that were done by events interrupting the current write.
+ *
+ * - A write followed by a read of the same time stamp will always succeed,
+ * but may not contain the same value.
+ *
+ * - A cmpxchg will fail if it interrupted another write or cmpxchg.
+ * Other than that, it acts like a normal cmpxchg.
+ *
+ * The 60 bit time stamp is broken up by 30 bits in a top and bottom half
+ * (bottom being the least significant 30 bits of the 60 bit time stamp).
+ *
+ * The two most significant bits of each half holds a 2 bit counter (0-3).
+ * Each update will increment this counter by one.
+ * When reading the top and bottom, if the two counter bits match then the
+ * top and bottom together make a valid 60 bit number.
+ */
+#define RB_TIME_SHIFT 30
+#define RB_TIME_VAL_MASK ((1 << RB_TIME_SHIFT) - 1)
+
+static inline int rb_time_cnt(unsigned long val)
+{
+ return (val >> RB_TIME_SHIFT) & 3;
+}
+
+static inline u64 rb_time_val(unsigned long top, unsigned long bottom)
+{
+ u64 val;
+
+ val = top & RB_TIME_VAL_MASK;
+ val <<= RB_TIME_SHIFT;
+ val |= bottom & RB_TIME_VAL_MASK;
+
+ return val;
+}
+
+static inline bool __rb_time_read(rb_time_t *t, u64 *ret, unsigned long *cnt)
+{
+ unsigned long top, bottom;
+ unsigned long c;
+
+ /*
+ * If the read is interrupted by a write, then the cnt will
+ * be different. Loop until both top and bottom have been read
+ * without interruption.
+ */
+ do {
+ c = local_read(&t->cnt);
+ top = local_read(&t->top);
+ bottom = local_read(&t->bottom);
+ } while (c != local_read(&t->cnt));
+
+ *cnt = rb_time_cnt(top);
+
+ /* If top and bottom counts don't match, this interrupted a write */
+ if (*cnt != rb_time_cnt(bottom))
+ return false;
+
+ *ret = rb_time_val(top, bottom);
+ return true;
+}
+
+static bool rb_time_read(rb_time_t *t, u64 *ret)
+{
+ unsigned long cnt;
+
+ return __rb_time_read(t, ret, &cnt);
+}
+
+static inline unsigned long rb_time_val_cnt(unsigned long val, unsigned long cnt)
+{
+ return (val & RB_TIME_VAL_MASK) | ((cnt & 3) << RB_TIME_SHIFT);
+}
+
+static inline void rb_time_split(u64 val, unsigned long *top, unsigned long *bottom)
+{
+ *top = (unsigned long)((val >> RB_TIME_SHIFT) & RB_TIME_VAL_MASK);
+ *bottom = (unsigned long)(val & RB_TIME_VAL_MASK);
+}
+
+static inline void rb_time_val_set(local_t *t, unsigned long val, unsigned long cnt)
+{
+ val = rb_time_val_cnt(val, cnt);
+ local_set(t, val);
+}
+
+static void rb_time_set(rb_time_t *t, u64 val)
+{
+ unsigned long cnt, top, bottom;
+
+ rb_time_split(val, &top, &bottom);
+
+ /* Writes always succeed with a valid number even if it gets interrupted. */
+ do {
+ cnt = local_inc_return(&t->cnt);
+ rb_time_val_set(&t->top, top, cnt);
+ rb_time_val_set(&t->bottom, bottom, cnt);
+ } while (cnt != local_read(&t->cnt));
+}
+
+static inline bool
+rb_time_read_cmpxchg(local_t *l, unsigned long expect, unsigned long set)
+{
+ unsigned long ret;
+
+ ret = local_cmpxchg(l, expect, set);
+ return ret == expect;
+}
+
+static int rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
+{
+ unsigned long cnt, top, bottom;
+ unsigned long cnt2, top2, bottom2;
+ u64 val;
+
+ /* The cmpxchg always fails if it interrupted an update */
+ if (!__rb_time_read(t, &val, &cnt2))
+ return false;
+
+ if (val != expect)
+ return false;
+
+ cnt = local_read(&t->cnt);
+ if ((cnt & 3) != cnt2)
+ return false;
+
+ cnt2 = cnt + 1;
+
+ rb_time_split(val, &top, &bottom);
+ top = rb_time_val_cnt(top, cnt);
+ bottom = rb_time_val_cnt(bottom, cnt);
+
+ rb_time_split(set, &top2, &bottom2);
+ top2 = rb_time_val_cnt(top2, cnt2);
+ bottom2 = rb_time_val_cnt(bottom2, cnt2);
+
+ if (!rb_time_read_cmpxchg(&t->cnt, cnt, cnt2))
+ return false;
+ if (!rb_time_read_cmpxchg(&t->top, top, top2))
+ return false;
+ if (!rb_time_read_cmpxchg(&t->bottom, bottom, bottom2))
+ return false;
+ return true;
+}
+
+#else /* 64 bits */
+
+/* local64_t always succeeds */
+
+static inline bool rb_time_read(rb_time_t *t, u64 *ret)
+{
+ *ret = local64_read(&t->time);
+ return true;
+}
+static void rb_time_set(rb_time_t *t, u64 val)
+{
+ local64_set(&t->time, val);
+}
+
+static bool rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
+{
+ u64 val;
+ val = local64_cmpxchg(&t->time, expect, set);
+ return val == expect;
+}
+#endif
+
/**
* ring_buffer_nr_pages - get the number of buffer pages in the ring buffer
* @buffer: The ring_buffer to get the number of pages from
@@ -746,8 +970,16 @@ __poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
static inline u64 rb_time_stamp(struct trace_buffer *buffer)
{
+ u64 ts;
+
+ /* Skip retpolines :-( */
+ if (IS_ENABLED(CONFIG_RETPOLINE) && likely(buffer->clock == trace_clock_local))
+ ts = trace_clock_local();
+ else
+ ts = buffer->clock();
+
/* shift to debug/test normalization and TIME_EXTENTS */
- return buffer->clock() << DEBUG_SHIFT;
+ return ts << DEBUG_SHIFT;
}
u64 ring_buffer_time_stamp(struct trace_buffer *buffer, int cpu)
@@ -2372,8 +2604,8 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
return NULL;
}
-/* Slow path, do not inline */
-static noinline struct ring_buffer_event *
+/* Slow path */
+static struct ring_buffer_event *
rb_add_time_stamp(struct ring_buffer_event *event, u64 delta, bool abs)
{
if (abs)
@@ -2397,6 +2629,66 @@ rb_add_time_stamp(struct ring_buffer_event *event, u64 delta, bool abs)
static inline bool rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
struct ring_buffer_event *event);
+#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
+static inline bool sched_clock_stable(void)
+{
+ return true;
+}
+#endif
+
+static void
+rb_check_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
+ struct rb_event_info *info)
+{
+ u64 write_stamp;
+
+ WARN_ONCE(1, "Delta way too big! %llu ts=%llu before=%llu after=%llu write stamp=%llu\n%s",
+ (unsigned long long)info->delta,
+ (unsigned long long)info->ts,
+ (unsigned long long)info->before,
+ (unsigned long long)info->after,
+ (unsigned long long)(rb_time_read(&cpu_buffer->write_stamp, &write_stamp) ? write_stamp : 0),
+ sched_clock_stable() ? "" :
+ "If you just came from a suspend/resume,\n"
+ "please switch to the trace global clock:\n"
+ " echo global > /sys/kernel/debug/tracing/trace_clock\n"
+ "or add trace_clock=global to the kernel command line\n");
+}
+
+static void rb_add_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event **event,
+ struct rb_event_info *info,
+ u64 *delta,
+ unsigned int *length)
+{
+ bool abs = info->add_timestamp &
+ (RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE);
+
+ if (unlikely(info->delta > (1ULL << 59))) {
+ /* did the clock go backwards */
+ if (info->before == info->after && info->before > info->ts) {
+ /* not interrupted */
+ static int once;
+
+ /*
+ * This is possible with a recalibrating of the TSC.
+ * Do not produce a call stack, but just report it.
+ */
+ if (!once) {
+ once++;
+ pr_warn("Ring buffer clock went backwards: %llu -> %llu\n",
+ info->before, info->ts);
+ }
+ } else
+ rb_check_timestamp(cpu_buffer, info);
+ if (!abs)
+ info->delta = 0;
+ }
+ *event = rb_add_time_stamp(*event, info->delta, abs);
+ *length -= RB_LEN_TIME_EXTEND;
+ *delta = 0;
+}
+
/**
* rb_update_event - update event type and data
* @cpu_buffer: The per cpu buffer of the @event
@@ -2416,21 +2708,12 @@ rb_update_event(struct ring_buffer_per_cpu *cpu_buffer,
unsigned length = info->length;
u64 delta = info->delta;
- /* Only a commit updates the timestamp */
- if (unlikely(!rb_event_is_commit(cpu_buffer, event)))
- delta = 0;
-
/*
* If we need to add a timestamp, then we
* add it to the start of the reserved space.
*/
- if (unlikely(info->add_timestamp)) {
- bool abs = ring_buffer_time_stamp_abs(cpu_buffer->buffer);
-
- event = rb_add_time_stamp(event, abs ? info->delta : delta, abs);
- length -= RB_LEN_TIME_EXTEND;
- delta = 0;
- }
+ if (unlikely(info->add_timestamp))
+ rb_add_timestamp(cpu_buffer, &event, info, &delta, &length);
event->time_delta = delta;
length -= RB_EVNT_HDR_SIZE;
@@ -2473,12 +2756,38 @@ static unsigned rb_calculate_event_length(unsigned length)
return length;
}
-#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
-static inline bool sched_clock_stable(void)
+static __always_inline bool
+rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event)
{
- return true;
+ unsigned long addr = (unsigned long)event;
+ unsigned long index;
+
+ index = rb_event_index(event);
+ addr &= PAGE_MASK;
+
+ return cpu_buffer->commit_page->page == (void *)addr &&
+ rb_commit_index(cpu_buffer) == index;
+}
+
+static u64 rb_time_delta(struct ring_buffer_event *event)
+{
+ switch (event->type_len) {
+ case RINGBUF_TYPE_PADDING:
+ return 0;
+
+ case RINGBUF_TYPE_TIME_EXTEND:
+ return ring_buffer_event_time_stamp(event);
+
+ case RINGBUF_TYPE_TIME_STAMP:
+ return 0;
+
+ case RINGBUF_TYPE_DATA:
+ return event->time_delta;
+ default:
+ return 0;
+ }
}
-#endif
static inline int
rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
@@ -2488,6 +2797,8 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
struct buffer_page *bpage;
unsigned long index;
unsigned long addr;
+ u64 write_stamp;
+ u64 delta;
new_index = rb_event_index(event);
old_index = new_index + rb_event_ts_length(event);
@@ -2496,10 +2807,32 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
bpage = READ_ONCE(cpu_buffer->tail_page);
+ delta = rb_time_delta(event);
+
+ if (!rb_time_read(&cpu_buffer->write_stamp, &write_stamp))
+ return 0;
+
+ /* Make sure the write stamp is read before testing the location */
+ barrier();
+
if (bpage->page == (void *)addr && rb_page_write(bpage) == old_index) {
unsigned long write_mask =
local_read(&bpage->write) & ~RB_WRITE_MASK;
unsigned long event_length = rb_event_length(event);
+
+ /* Something came in, can't discard */
+ if (!rb_time_cmpxchg(&cpu_buffer->write_stamp,
+ write_stamp, write_stamp - delta))
+ return 0;
+
+ /*
+ * If an event were to come in now, it would see that the
+ * write_stamp and the before_stamp are different, and assume
+ * that this event just added itself before updating
+ * the write stamp. The interrupting event will fix the
+ * write stamp for us, and use the before stamp as its delta.
+ */
+
/*
* This is on the tail page. It is possible that
* a write could come in and move the tail page
@@ -2551,10 +2884,6 @@ 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);
- /* 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();
}
@@ -2626,54 +2955,10 @@ static inline void rb_event_discard(struct ring_buffer_event *event)
event->time_delta = 1;
}
-static __always_inline bool
-rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
- struct ring_buffer_event *event)
-{
- unsigned long addr = (unsigned long)event;
- unsigned long index;
-
- index = rb_event_index(event);
- addr &= PAGE_MASK;
-
- return cpu_buffer->commit_page->page == (void *)addr &&
- rb_commit_index(cpu_buffer) == index;
-}
-
-static __always_inline void
-rb_update_write_stamp(struct ring_buffer_per_cpu *cpu_buffer,
- struct ring_buffer_event *event)
-{
- u64 delta;
-
- /*
- * The event first in the commit queue updates the
- * time stamp.
- */
- if (rb_event_is_commit(cpu_buffer, event)) {
- /*
- * A commit event that is first on a page
- * updates the write timestamp with the page stamp
- */
- if (!rb_event_index(event))
- cpu_buffer->write_stamp =
- cpu_buffer->commit_page->page->time_stamp;
- else if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) {
- delta = ring_buffer_event_time_stamp(event);
- cpu_buffer->write_stamp += delta;
- } else if (event->type_len == RINGBUF_TYPE_TIME_STAMP) {
- delta = ring_buffer_event_time_stamp(event);
- cpu_buffer->write_stamp = delta;
- } else
- cpu_buffer->write_stamp += event->time_delta;
- }
-}
-
static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
struct ring_buffer_event *event)
{
local_inc(&cpu_buffer->entries);
- rb_update_write_stamp(cpu_buffer, event);
rb_end_commit(cpu_buffer);
}
@@ -2864,58 +3149,138 @@ int ring_buffer_unlock_commit(struct trace_buffer *buffer,
}
EXPORT_SYMBOL_GPL(ring_buffer_unlock_commit);
-static noinline void
-rb_handle_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
- struct rb_event_info *info)
-{
- WARN_ONCE(info->delta > (1ULL << 59),
- KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n%s",
- (unsigned long long)info->delta,
- (unsigned long long)info->ts,
- (unsigned long long)cpu_buffer->write_stamp,
- sched_clock_stable() ? "" :
- "If you just came from a suspend/resume,\n"
- "please switch to the trace global clock:\n"
- " echo global > /sys/kernel/debug/tracing/trace_clock\n"
- "or add trace_clock=global to the kernel command line\n");
- info->add_timestamp = 1;
-}
-
static struct ring_buffer_event *
__rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
struct rb_event_info *info)
{
struct ring_buffer_event *event;
struct buffer_page *tail_page;
- unsigned long tail, write;
-
- /*
- * If the time delta since the last event is too big to
- * hold in the time field of the event, then we append a
- * TIME EXTEND event ahead of the data event.
- */
- if (unlikely(info->add_timestamp))
- info->length += RB_LEN_TIME_EXTEND;
+ unsigned long tail, write, w;
+ bool a_ok;
+ bool b_ok;
/* 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);
+
+ /*A*/ w = local_read(&tail_page->write) & RB_WRITE_MASK;
+ barrier();
+ b_ok = rb_time_read(&cpu_buffer->before_stamp, &info->before);
+ a_ok = rb_time_read(&cpu_buffer->write_stamp, &info->after);
+ barrier();
+ info->ts = rb_time_stamp(cpu_buffer->buffer);
+
+ if ((info->add_timestamp & RB_ADD_STAMP_ABSOLUTE)) {
+ info->delta = info->ts;
+ } else {
+ /*
+ * If interrupting an event time update, we may need an
+ * absolute timestamp.
+ * Don't bother if this is the start of a new page (w == 0).
+ */
+ if (unlikely(!a_ok || !b_ok || (info->before != info->after && w))) {
+ info->add_timestamp |= RB_ADD_STAMP_FORCE | RB_ADD_STAMP_EXTEND;
+ info->length += RB_LEN_TIME_EXTEND;
+ } else {
+ info->delta = info->ts - info->after;
+ if (unlikely(test_time_stamp(info->delta))) {
+ info->add_timestamp |= RB_ADD_STAMP_EXTEND;
+ info->length += RB_LEN_TIME_EXTEND;
+ }
+ }
+ }
+
+ /*B*/ rb_time_set(&cpu_buffer->before_stamp, info->ts);
+
+ /*C*/ write = local_add_return(info->length, &tail_page->write);
/* set write to only the index of the write */
write &= RB_WRITE_MASK;
+
tail = write - info->length;
+ /* See if we shot pass the end of this buffer page */
+ if (unlikely(write > BUF_PAGE_SIZE)) {
+ if (tail != w) {
+ /* before and after may now different, fix it up*/
+ b_ok = rb_time_read(&cpu_buffer->before_stamp, &info->before);
+ a_ok = rb_time_read(&cpu_buffer->write_stamp, &info->after);
+ if (a_ok && b_ok && info->before != info->after)
+ (void)rb_time_cmpxchg(&cpu_buffer->before_stamp,
+ info->before, info->after);
+ }
+ return rb_move_tail(cpu_buffer, tail, info);
+ }
+
+ if (likely(tail == w)) {
+ u64 save_before;
+ bool s_ok;
+
+ /* Nothing interrupted us between A and C */
+ /*D*/ rb_time_set(&cpu_buffer->write_stamp, info->ts);
+ barrier();
+ /*E*/ s_ok = rb_time_read(&cpu_buffer->before_stamp, &save_before);
+ RB_WARN_ON(cpu_buffer, !s_ok);
+ if (likely(!(info->add_timestamp &
+ (RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE))))
+ /* This did not interrupt any time update */
+ info->delta = info->ts - info->after;
+ else
+ /* Just use full timestamp for inerrupting event */
+ info->delta = info->ts;
+ barrier();
+ if (unlikely(info->ts != save_before)) {
+ /* SLOW PATH - Interrupted between C and E */
+
+ a_ok = rb_time_read(&cpu_buffer->write_stamp, &info->after);
+ RB_WARN_ON(cpu_buffer, !a_ok);
+
+ /* Write stamp must only go forward */
+ if (save_before > info->after) {
+ /*
+ * We do not care about the result, only that
+ * it gets updated atomically.
+ */
+ (void)rb_time_cmpxchg(&cpu_buffer->write_stamp,
+ info->after, save_before);
+ }
+ }
+ } else {
+ u64 ts;
+ /* SLOW PATH - Interrupted between A and C */
+ a_ok = rb_time_read(&cpu_buffer->write_stamp, &info->after);
+ /* Was interrupted before here, write_stamp must be valid */
+ RB_WARN_ON(cpu_buffer, !a_ok);
+ ts = rb_time_stamp(cpu_buffer->buffer);
+ barrier();
+ /*E*/ if (write == (local_read(&tail_page->write) & RB_WRITE_MASK) &&
+ info->after < ts) {
+ /* Nothing came after this event between C and E */
+ info->delta = ts - info->after;
+ (void)rb_time_cmpxchg(&cpu_buffer->write_stamp,
+ info->after, info->ts);
+ info->ts = ts;
+ } else {
+ /*
+ * Interrupted beween C and E:
+ * Lost the previous events time stamp. Just set the
+ * delta to zero, and this will be the same time as
+ * the event this event interrupted. And the events that
+ * came after this will still be correct (as they would
+ * have built their delta on the previous event.
+ */
+ info->delta = 0;
+ }
+ info->add_timestamp &= ~RB_ADD_STAMP_FORCE;
+ }
+
/*
* If this is the first commit on the page, then it has the same
* timestamp as the page itself.
*/
- if (!tail && !ring_buffer_time_stamp_abs(cpu_buffer->buffer))
+ if (unlikely(!tail && !(info->add_timestamp &
+ (RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE))))
info->delta = 0;
- /* See if we shot pass the end of this buffer page */
- if (unlikely(write > BUF_PAGE_SIZE))
- return rb_move_tail(cpu_buffer, tail, info);
-
/* We reserved something on the buffer */
event = __rb_page_index(tail_page, tail);
@@ -2927,7 +3292,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
* If this is the first commit on the page, then update
* its timestamp.
*/
- if (!tail)
+ if (unlikely(!tail))
tail_page->page->time_stamp = info->ts;
/* account for these added bytes */
@@ -2944,9 +3309,10 @@ rb_reserve_next_event(struct trace_buffer *buffer,
struct ring_buffer_event *event;
struct rb_event_info info;
int nr_loops = 0;
- u64 diff;
+ int add_ts_default;
rb_start_commit(cpu_buffer);
+ /* The commit page can not change after this */
#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
/*
@@ -2964,8 +3330,16 @@ rb_reserve_next_event(struct trace_buffer *buffer,
#endif
info.length = rb_calculate_event_length(length);
+
+ if (ring_buffer_time_stamp_abs(cpu_buffer->buffer)) {
+ add_ts_default = RB_ADD_STAMP_ABSOLUTE;
+ info.length += RB_LEN_TIME_EXTEND;
+ } else {
+ add_ts_default = RB_ADD_STAMP_NONE;
+ }
+
again:
- info.add_timestamp = 0;
+ info.add_timestamp = add_ts_default;
info.delta = 0;
/*
@@ -2980,35 +3354,16 @@ rb_reserve_next_event(struct trace_buffer *buffer,
if (RB_WARN_ON(cpu_buffer, ++nr_loops > 1000))
goto out_fail;
- info.ts = rb_time_stamp(cpu_buffer->buffer);
- diff = info.ts - cpu_buffer->write_stamp;
-
- /* make sure this diff is calculated here */
- barrier();
-
- if (ring_buffer_time_stamp_abs(buffer)) {
- info.delta = info.ts;
- rb_handle_timestamp(cpu_buffer, &info);
- } else /* Did the write stamp get updated already? */
- if (likely(info.ts >= cpu_buffer->write_stamp)) {
- info.delta = diff;
- if (unlikely(test_time_stamp(info.delta)))
- rb_handle_timestamp(cpu_buffer, &info);
- }
-
event = __rb_reserve_next(cpu_buffer, &info);
if (unlikely(PTR_ERR(event) == -EAGAIN)) {
- if (info.add_timestamp)
+ if (info.add_timestamp & (RB_ADD_STAMP_FORCE | RB_ADD_STAMP_EXTEND))
info.length -= RB_LEN_TIME_EXTEND;
goto again;
}
- if (!event)
- goto out_fail;
-
- return event;
-
+ if (likely(event))
+ return event;
out_fail:
rb_end_commit(cpu_buffer);
return NULL;
@@ -3154,11 +3509,6 @@ void ring_buffer_discard_commit(struct trace_buffer *buffer,
if (rb_try_to_discard(cpu_buffer, event))
goto out;
- /*
- * The commit is still visible by the reader, so we
- * must still update the timestamp.
- */
- rb_update_write_stamp(cpu_buffer, event);
out:
rb_end_commit(cpu_buffer);
@@ -4475,8 +4825,8 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
cpu_buffer->read = 0;
cpu_buffer->read_bytes = 0;
- cpu_buffer->write_stamp = 0;
- cpu_buffer->read_stamp = 0;
+ rb_time_set(&cpu_buffer->write_stamp, 0);
+ rb_time_set(&cpu_buffer->before_stamp, 0);
cpu_buffer->lost_events = 0;
cpu_buffer->last_overrun = 0;
@@ -4484,6 +4834,26 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
rb_head_page_activate(cpu_buffer);
}
+/* Must have disabled the cpu buffer then done a synchronize_rcu */
+static void reset_disabled_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+
+ if (RB_WARN_ON(cpu_buffer, local_read(&cpu_buffer->committing)))
+ goto out;
+
+ arch_spin_lock(&cpu_buffer->lock);
+
+ rb_reset_cpu(cpu_buffer);
+
+ arch_spin_unlock(&cpu_buffer->lock);
+
+ out:
+ raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+}
+
/**
* ring_buffer_reset_cpu - reset a ring buffer per CPU buffer
* @buffer: The ring buffer to reset a per cpu buffer of
@@ -4492,7 +4862,6 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu)
{
struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
- unsigned long flags;
if (!cpumask_test_cpu(cpu, buffer->cpumask))
return;
@@ -4503,24 +4872,42 @@ void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu)
/* Make sure all commits have finished */
synchronize_rcu();
- raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+ reset_disabled_cpu_buffer(cpu_buffer);
- if (RB_WARN_ON(cpu_buffer, local_read(&cpu_buffer->committing)))
- goto out;
+ atomic_dec(&cpu_buffer->record_disabled);
+ atomic_dec(&cpu_buffer->resize_disabled);
+}
+EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);
- arch_spin_lock(&cpu_buffer->lock);
+/**
+ * ring_buffer_reset_cpu - reset a ring buffer per CPU buffer
+ * @buffer: The ring buffer to reset a per cpu buffer of
+ * @cpu: The CPU buffer to be reset
+ */
+void ring_buffer_reset_online_cpus(struct trace_buffer *buffer)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ int cpu;
- rb_reset_cpu(cpu_buffer);
+ for_each_online_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
- arch_spin_unlock(&cpu_buffer->lock);
+ atomic_inc(&cpu_buffer->resize_disabled);
+ atomic_inc(&cpu_buffer->record_disabled);
+ }
- out:
- raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+ /* Make sure all commits have finished */
+ synchronize_rcu();
- atomic_dec(&cpu_buffer->record_disabled);
- atomic_dec(&cpu_buffer->resize_disabled);
+ for_each_online_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+
+ reset_disabled_cpu_buffer(cpu_buffer);
+
+ atomic_dec(&cpu_buffer->record_disabled);
+ atomic_dec(&cpu_buffer->resize_disabled);
+ }
}
-EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);
/**
* ring_buffer_reset - reset a ring buffer
@@ -4528,10 +4915,27 @@ EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);
*/
void ring_buffer_reset(struct trace_buffer *buffer)
{
+ struct ring_buffer_per_cpu *cpu_buffer;
int cpu;
- for_each_buffer_cpu(buffer, cpu)
- ring_buffer_reset_cpu(buffer, cpu);
+ for_each_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+
+ atomic_inc(&cpu_buffer->resize_disabled);
+ atomic_inc(&cpu_buffer->record_disabled);
+ }
+
+ /* Make sure all commits have finished */
+ synchronize_rcu();
+
+ for_each_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+
+ reset_disabled_cpu_buffer(cpu_buffer);
+
+ atomic_dec(&cpu_buffer->record_disabled);
+ atomic_dec(&cpu_buffer->resize_disabled);
+ }
}
EXPORT_SYMBOL_GPL(ring_buffer_reset);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b0c338ecc3180b4979c05c6fc4c48c9abc78da92..f40d850ebabcc7bb60c47c57898d176fec09dd1e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2002,7 +2002,6 @@ static void tracing_reset_cpu(struct array_buffer *buf, int cpu)
void tracing_reset_online_cpus(struct array_buffer *buf)
{
struct trace_buffer *buffer = buf->buffer;
- int cpu;
if (!buffer)
return;
@@ -2014,8 +2013,7 @@ void tracing_reset_online_cpus(struct array_buffer *buf)
buf->time_start = buffer_ftrace_now(buf, buf->cpu);
- for_each_online_cpu(cpu)
- ring_buffer_reset_cpu(buffer, cpu);
+ ring_buffer_reset_online_cpus(buffer);
ring_buffer_record_enable(buffer);
}
@@ -2931,12 +2929,6 @@ static void __ftrace_trace_stack(struct trace_buffer *buffer,
skip++;
#endif
- /*
- * Since events can happen in NMIs there's no safe way to
- * use the per cpu ftrace_stacks. We reserve it and if an interrupt
- * or NMI comes in, it will just have to use the default
- * FTRACE_STACK_SIZE.
- */
preempt_disable_notrace();
stackidx = __this_cpu_inc_return(ftrace_stack_reserve) - 1;
@@ -3136,6 +3128,9 @@ static int alloc_percpu_trace_buffer(void)
{
struct trace_buffer_struct *buffers;
+ if (trace_percpu_buffer)
+ return 0;
+
buffers = alloc_percpu(struct trace_buffer_struct);
if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer"))
return -ENOMEM;
@@ -3338,6 +3333,26 @@ int trace_array_vprintk(struct trace_array *tr,
return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args);
}
+/**
+ * trace_array_printk - Print a message to a specific instance
+ * @tr: The instance trace_array descriptor
+ * @ip: The instruction pointer that this is called from.
+ * @fmt: The format to print (printf format)
+ *
+ * If a subsystem sets up its own instance, they have the right to
+ * printk strings into their tracing instance buffer using this
+ * function. Note, this function will not write into the top level
+ * buffer (use trace_printk() for that), as writing into the top level
+ * buffer should only have events that can be individually disabled.
+ * trace_printk() is only used for debugging a kernel, and should not
+ * be ever encorporated in normal use.
+ *
+ * trace_array_printk() can be used, as it will not add noise to the
+ * top level tracing buffer.
+ *
+ * Note, trace_array_init_printk() must be called on @tr before this
+ * can be used.
+ */
__printf(3, 0)
int trace_array_printk(struct trace_array *tr,
unsigned long ip, const char *fmt, ...)
@@ -3345,12 +3360,16 @@ int trace_array_printk(struct trace_array *tr,
int ret;
va_list ap;
- if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
- return 0;
-
if (!tr)
return -ENOENT;
+ /* This is only allowed for created instances */
+ if (tr == &global_trace)
+ return 0;
+
+ if (!(tr->trace_flags & TRACE_ITER_PRINTK))
+ return 0;
+
va_start(ap, fmt);
ret = trace_array_vprintk(tr, ip, fmt, ap);
va_end(ap);
@@ -3358,6 +3377,27 @@ int trace_array_printk(struct trace_array *tr,
}
EXPORT_SYMBOL_GPL(trace_array_printk);
+/**
+ * trace_array_init_printk - Initialize buffers for trace_array_printk()
+ * @tr: The trace array to initialize the buffers for
+ *
+ * As trace_array_printk() only writes into instances, they are OK to
+ * have in the kernel (unlike trace_printk()). This needs to be called
+ * before trace_array_printk() can be used on a trace_array.
+ */
+int trace_array_init_printk(struct trace_array *tr)
+{
+ if (!tr)
+ return -ENOENT;
+
+ /* This is only allowed for created instances */
+ if (tr == &global_trace)
+ return -EINVAL;
+
+ return alloc_percpu_trace_buffer();
+}
+EXPORT_SYMBOL_GPL(trace_array_init_printk);
+
__printf(3, 4)
int trace_array_printk_buf(struct trace_buffer *buffer,
unsigned long ip, const char *fmt, ...)
@@ -5886,7 +5926,7 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
}
/* If trace pipe files are being read, we can't change the tracer */
- if (tr->current_trace->ref) {
+ if (tr->trace_ref) {
ret = -EBUSY;
goto out;
}
@@ -6102,7 +6142,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
nonseekable_open(inode, filp);
- tr->current_trace->ref++;
+ tr->trace_ref++;
out:
mutex_unlock(&trace_types_lock);
return ret;
@@ -6121,7 +6161,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
mutex_lock(&trace_types_lock);
- tr->current_trace->ref--;
+ tr->trace_ref--;
if (iter->trace->pipe_close)
iter->trace->pipe_close(iter);
@@ -7405,7 +7445,7 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp)
if (ret)
return ret;
- info = kzalloc(sizeof(*info), GFP_KERNEL);
+ info = kvzalloc(sizeof(*info), GFP_KERNEL);
if (!info) {
trace_array_put(tr);
return -ENOMEM;
@@ -7423,7 +7463,7 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp)
filp->private_data = info;
- tr->current_trace->ref++;
+ tr->trace_ref++;
mutex_unlock(&trace_types_lock);
@@ -7524,14 +7564,14 @@ static int tracing_buffers_release(struct inode *inode, struct file *file)
mutex_lock(&trace_types_lock);
- iter->tr->current_trace->ref--;
+ iter->tr->trace_ref--;
__trace_array_put(iter->tr);
if (info->spare)
ring_buffer_free_read_page(iter->array_buffer->buffer,
info->spare_cpu, info->spare);
- kfree(info);
+ kvfree(info);
mutex_unlock(&trace_types_lock);
@@ -8732,7 +8772,7 @@ static int __remove_instance(struct trace_array *tr)
int i;
/* Reference counter for a newly created trace array = 1. */
- if (tr->ref > 1 || (tr->current_trace && tr->current_trace->ref))
+ if (tr->ref > 1 || (tr->current_trace && tr->trace_ref))
return -EBUSY;
list_del(&tr->list);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 13db4000af3fe20906737364a8be78d71e797bbd..610d21355526d45fb5366fea60c1c2ac3182cf43 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -356,6 +356,7 @@ struct trace_array {
struct trace_event_file *trace_marker_file;
cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
int ref;
+ int trace_ref;
#ifdef CONFIG_FUNCTION_TRACER
struct ftrace_ops *ops;
struct trace_pid_list __rcu *function_pids;
@@ -547,7 +548,6 @@ struct tracer {
struct tracer *next;
struct tracer_flags *flags;
int enabled;
- int ref;
bool print_max;
bool allow_instances;
#ifdef CONFIG_TRACER_MAX_TRACE
@@ -1103,6 +1103,10 @@ print_graph_function_flags(struct trace_iterator *iter, u32 flags)
extern struct list_head ftrace_pids;
#ifdef CONFIG_FUNCTION_TRACER
+
+#define FTRACE_PID_IGNORE -1
+#define FTRACE_PID_TRACE -2
+
struct ftrace_func_command {
struct list_head list;
char *name;
@@ -1114,7 +1118,8 @@ struct ftrace_func_command {
extern bool ftrace_filter_param __initdata;
static inline int ftrace_trace_task(struct trace_array *tr)
{
- return !this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
+ return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
+ FTRACE_PID_IGNORE;
}
extern int ftrace_is_dead(void);
int ftrace_create_function_files(struct trace_array *tr,
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f6f55682d3e2d027b9e8127a01efbf2cb2317eb1..a85effb2373bf0eb56fcf65df288a620481cbe6c 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -538,12 +538,12 @@ void trace_event_follow_fork(struct trace_array *tr, bool enable)
if (enable) {
register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
tr, INT_MIN);
- register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit,
+ register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
tr, INT_MAX);
} else {
unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
tr);
- unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit,
+ unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
tr);
}
}
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index e2be7bb7ef7e29cfe355e16dad1c8e916d708567..17873e5d03531f6e10c4f449bde946b6bf02a6b2 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -283,6 +283,7 @@ static bool disable_migrate;
static void move_to_next_cpu(void)
{
struct cpumask *current_mask = &save_cpumask;
+ struct trace_array *tr = hwlat_trace;
int next_cpu;
if (disable_migrate)
@@ -296,7 +297,7 @@ static void move_to_next_cpu(void)
goto disable;
get_online_cpus();
- cpumask_and(current_mask, cpu_online_mask, tracing_buffer_mask);
+ cpumask_and(current_mask, cpu_online_mask, tr->tracing_cpumask);
next_cpu = cpumask_next(smp_processor_id(), current_mask);
put_online_cpus();
@@ -371,9 +372,8 @@ static int start_kthread(struct trace_array *tr)
return 0;
/* Just pick the first CPU on first iteration */
- current_mask = &save_cpumask;
get_online_cpus();
- cpumask_and(current_mask, cpu_online_mask, tracing_buffer_mask);
+ cpumask_and(current_mask, cpu_online_mask, tr->tracing_cpumask);
put_online_cpus();
next_cpu = cpumask_first(current_mask);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 73976de7f8cc814e5f5f2b5155a127750ca8cfcf..4d1893564912da00d3ec3814820d5cf807349a57 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -20,7 +20,7 @@ DECLARE_RWSEM(trace_event_sem);
static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
-static int next_event_type = __TRACE_LAST_TYPE + 1;
+static int next_event_type = __TRACE_LAST_TYPE;
enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
{
@@ -675,11 +675,11 @@ static LIST_HEAD(ftrace_event_list);
static int trace_search_list(struct list_head **list)
{
struct trace_event *e;
- int last = __TRACE_LAST_TYPE;
+ int next = __TRACE_LAST_TYPE;
if (list_empty(&ftrace_event_list)) {
*list = &ftrace_event_list;
- return last + 1;
+ return next;
}
/*
@@ -687,17 +687,17 @@ static int trace_search_list(struct list_head **list)
* lets see if somebody freed one.
*/
list_for_each_entry(e, &ftrace_event_list, list) {
- if (e->type != last + 1)
+ if (e->type != next)
break;
- last++;
+ next++;
}
/* Did we used up all 65 thousand events??? */
- if ((last + 1) > TRACE_EVENT_TYPE_MAX)
+ if (next > TRACE_EVENT_TYPE_MAX)
return 0;
*list = &e->list;
- return last + 1;
+ return next;
}
void trace_event_read_lock(void)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index fdd47f99b18fdb640346dcdaf0a76f1e1d15d116..f4286c9bdeb490909f09508f133c4f1f0904743b 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1456,7 +1456,6 @@ trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
default:
return 0;
}
- return 0;
}
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 912ef4921398687d8c4483004a38b48319d08758..a5f701161f6bd13ce285729256bbbafa2882cb47 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -329,22 +329,30 @@ const char * __init xbc_node_find_next_key_value(struct xbc_node *root,
/* XBC parse and tree build */
+static int __init xbc_init_node(struct xbc_node *node, char *data, u32 flag)
+{
+ unsigned long offset = data - xbc_data;
+
+ if (WARN_ON(offset >= XBC_DATA_MAX))
+ return -EINVAL;
+
+ node->data = (u16)offset | flag;
+ node->child = 0;
+ node->next = 0;
+
+ return 0;
+}
+
static struct xbc_node * __init xbc_add_node(char *data, u32 flag)
{
struct xbc_node *node;
- unsigned long offset;
if (xbc_node_num == XBC_NODE_MAX)
return NULL;
node = &xbc_nodes[xbc_node_num++];
- offset = data - xbc_data;
- node->data = (u16)offset;
- if (WARN_ON(offset >= XBC_DATA_MAX))
+ if (xbc_init_node(node, data, flag) < 0)
return NULL;
- node->data |= flag;
- node->child = 0;
- node->next = 0;
return node;
}
@@ -603,7 +611,9 @@ static int __init xbc_parse_kv(char **k, char *v, int op)
if (c < 0)
return c;
- if (!xbc_add_sibling(v, XBC_VALUE))
+ if (op == ':' && child) {
+ xbc_init_node(child, v, XBC_VALUE);
+ } else if (!xbc_add_sibling(v, XBC_VALUE))
return -ENOMEM;
if (c == ',') { /* Array */
@@ -787,7 +797,7 @@ int __init xbc_init(char *buf, const char **emsg, int *epos)
p = buf;
do {
- q = strpbrk(p, "{}=+;\n#");
+ q = strpbrk(p, "{}=+;:\n#");
if (!q) {
p = skip_spaces(p);
if (*p != '\0')
@@ -798,9 +808,12 @@ int __init xbc_init(char *buf, const char **emsg, int *epos)
c = *q;
*q++ = '\0';
switch (c) {
+ case ':':
case '+':
if (*q++ != '=') {
- ret = xbc_parse_error("Wrong '+' operator",
+ ret = xbc_parse_error(c == '+' ?
+ "Wrong '+' operator" :
+ "Wrong ':' operator",
q - 2);
break;
}
diff --git a/tools/bootconfig/samples/bad-override.bconf b/tools/bootconfig/samples/bad-override.bconf
new file mode 100644
index 0000000000000000000000000000000000000000..fde6c561512e16fcde7cfbeaa48692d23d4b6d4c
--- /dev/null
+++ b/tools/bootconfig/samples/bad-override.bconf
@@ -0,0 +1,3 @@
+key.subkey = value
+# We can not override pre-defined subkeys with value
+key := value
diff --git a/tools/bootconfig/samples/bad-override2.bconf b/tools/bootconfig/samples/bad-override2.bconf
new file mode 100644
index 0000000000000000000000000000000000000000..688587cb023c3792bc757895cae1efc036470eb2
--- /dev/null
+++ b/tools/bootconfig/samples/bad-override2.bconf
@@ -0,0 +1,3 @@
+key = value
+# We can not override pre-defined value with subkey
+key.subkey := value
diff --git a/tools/bootconfig/samples/good-override.bconf b/tools/bootconfig/samples/good-override.bconf
new file mode 100644
index 0000000000000000000000000000000000000000..7d31d5f8fbd8c01df44c38983363ed2cea2a7f07
--- /dev/null
+++ b/tools/bootconfig/samples/good-override.bconf
@@ -0,0 +1,6 @@
+# Override the value
+key.word = 1,2,4
+key.word := 2,3
+
+# No pre-defined key
+key.new.word := "new"
diff --git a/tools/bootconfig/test-bootconfig.sh b/tools/bootconfig/test-bootconfig.sh
index 3c2ab9e757303d4480bbed8fa4c91e1cf16e0dfe..56284b98d8f0bc263515543820fb07eafd537b77 100755
--- a/tools/bootconfig/test-bootconfig.sh
+++ b/tools/bootconfig/test-bootconfig.sh
@@ -117,6 +117,19 @@ xpass grep -q "bar" $OUTFILE
xpass grep -q "baz" $OUTFILE
xpass grep -q "qux" $OUTFILE
+echo "Override same-key values"
+cat > $TEMPCONF << EOF
+key = bar, baz
+key := qux
+EOF
+echo > $INITRD
+
+xpass $BOOTCONF -a $TEMPCONF $INITRD
+$BOOTCONF $INITRD > $OUTFILE
+xfail grep -q "bar" $OUTFILE
+xfail grep -q "baz" $OUTFILE
+xpass grep -q "qux" $OUTFILE
+
echo "Double/single quotes test"
echo "key = '\"string\"';" > $TEMPCONF
$BOOTCONF -a $TEMPCONF $INITRD