From: pengdonglin <[email protected]>
Currently, funcgraph-args and funcgraph-retaddr cannot be used together. This
patch
resolves the conflict by having funcgraph-retaddr reuse the implementation of
funcgraph-args -- specifically, storing the return address in the last entry of
the
args array.
As a result, both features now coexist seamlessly and function as intended.
To verify the change, use perf to trace vfs_write with both options enabled:
# perf_6_17 ftrace -G vfs_write --graph-opts args,retaddr
......
0) | down_read(sem=0xffff8880100bea78) { /*
<-n_tty_write+0xa3/0x540 */
0) 0.075 us | __cond_resched(); /* <-down_read+0x12/0x160 */
0) 0.079 us | preempt_count_add(val=1); /* <-down_read+0x3b/0x160 */
0) 0.077 us | preempt_count_sub(val=1); /* <-down_read+0x8b/0x160 */
0) 0.754 us | }
Cc: Steven Rostedt (Google) <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Signed-off-by: pengdonglin <[email protected]>
Signed-off-by: pengdonglin <[email protected]>
---
include/linux/ftrace.h | 11 --
kernel/trace/trace.h | 7 --
kernel/trace/trace_entries.h | 29 +-----
kernel/trace/trace_functions_graph.c | 148 +++++++++++----------------
kernel/trace/trace_selftest.c | 1 -
5 files changed, 58 insertions(+), 138 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 7ded7df6e9b5..88cb54d73bdb 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -1129,17 +1129,6 @@ struct ftrace_graph_ent {
int depth;
} __packed;
-/*
- * Structure that defines an entry function trace with retaddr.
- * It's already packed but the attribute "packed" is needed
- * to remove extra padding at the end.
- */
-struct fgraph_retaddr_ent {
- unsigned long func; /* Current function */
- int depth;
- unsigned long retaddr; /* Return address */
-} __packed;
-
/*
* Structure that defines a return function trace.
* It's already packed but the attribute "packed" is needed
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 85eabb454bee..956cdbe36995 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -47,7 +47,6 @@ enum trace_type {
TRACE_BRANCH,
TRACE_GRAPH_RET,
TRACE_GRAPH_ENT,
- TRACE_GRAPH_RETADDR_ENT,
TRACE_USER_STACK,
TRACE_BLK,
TRACE_BPUTS,
@@ -540,8 +539,6 @@ extern void __ftrace_bad_type(void);
IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \
TRACE_GRAPH_ENT); \
- IF_ASSIGN(var, ent, struct fgraph_retaddr_ent_entry,\
- TRACE_GRAPH_RETADDR_ENT); \
IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \
TRACE_GRAPH_RET); \
IF_ASSIGN(var, ent, struct func_repeats_entry, \
@@ -955,10 +952,6 @@ extern void graph_trace_close(struct trace_iterator *iter);
extern int __trace_graph_entry(struct trace_array *tr,
struct ftrace_graph_ent *trace,
unsigned int trace_ctx);
-extern int __trace_graph_retaddr_entry(struct trace_array *tr,
- struct ftrace_graph_ent *trace,
- unsigned int trace_ctx,
- unsigned long retaddr);
extern void __trace_graph_return(struct trace_array *tr,
struct ftrace_graph_ret *trace,
unsigned int trace_ctx,
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index de294ae2c5c5..4e9d6779ccba 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -87,35 +87,9 @@ FTRACE_ENTRY(funcgraph_entry, ftrace_graph_ent_entry,
F_printk("--> %ps (%u)", (void *)__entry->func, __entry->depth)
);
-#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
-
-/* Function call entry with a return address */
-FTRACE_ENTRY_PACKED(fgraph_retaddr_entry, fgraph_retaddr_ent_entry,
-
- TRACE_GRAPH_RETADDR_ENT,
-
- F_STRUCT(
- __field_struct( struct fgraph_retaddr_ent, graph_ent
)
- __field_packed( unsigned long, graph_ent, func
)
- __field_packed( unsigned int, graph_ent, depth
)
- __field_packed( unsigned long, graph_ent, retaddr
)
- ),
-
- F_printk("--> %ps (%u) <- %ps", (void *)__entry->func, __entry->depth,
- (void *)__entry->retaddr)
-);
-
-#else
-
-#ifndef fgraph_retaddr_ent_entry
-#define fgraph_retaddr_ent_entry ftrace_graph_ent_entry
-#endif
-
-#endif
-
+/* Function return entry */
#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
-/* Function return entry */
FTRACE_ENTRY_PACKED(funcgraph_exit, ftrace_graph_ret_entry,
TRACE_GRAPH_RET,
@@ -138,7 +112,6 @@ FTRACE_ENTRY_PACKED(funcgraph_exit, ftrace_graph_ret_entry,
#else
-/* Function return entry */
FTRACE_ENTRY_PACKED(funcgraph_exit, ftrace_graph_ret_entry,
TRACE_GRAPH_RET,
diff --git a/kernel/trace/trace_functions_graph.c
b/kernel/trace/trace_functions_graph.c
index a7f4b9a47a71..b618b6a673b7 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -16,6 +16,12 @@
#include "trace.h"
#include "trace_output.h"
+#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
+#define STORE_RETADDR 1
+#else
+#define STORE_RETADDR 0
+#endif
+
/* When set, irq functions will be ignored */
static int ftrace_graph_skip_irqs;
@@ -29,19 +35,17 @@ struct fgraph_cpu_data {
struct fgraph_ent_args {
struct ftrace_graph_ent_entry ent;
- /* Force the sizeof of args[] to have FTRACE_REGS_MAX_ARGS entries */
- unsigned long args[FTRACE_REGS_MAX_ARGS];
+ /* Force the sizeof of args[] to have
(FTRACE_REGS_MAX_ARGS+STORE_RETADDR) entries,
+ * and the last entry is used to store the retaddr
+ */
+ unsigned long args[FTRACE_REGS_MAX_ARGS +
STORE_RETADDR];
};
struct fgraph_data {
struct fgraph_cpu_data __percpu *cpu_data;
/* Place to preserve last processed entry. */
- union {
- struct fgraph_ent_args ent;
- /* TODO allow retaddr to have args */
- struct fgraph_retaddr_ent_entry rent;
- };
+ struct fgraph_ent_args ent;
struct ftrace_graph_ret_entry ret;
int failed;
int cpu;
@@ -127,11 +131,19 @@ static int __graph_entry(struct trace_array *tr, struct
ftrace_graph_ent *trace,
struct ring_buffer_event *event;
struct trace_buffer *buffer = tr->array_buffer.buffer;
struct ftrace_graph_ent_entry *entry;
+ unsigned long retaddr = 0;
int size;
+ int i = 0;
/* If fregs is defined, add FTRACE_REGS_MAX_ARGS long size words */
size = sizeof(*entry) + (FTRACE_REGS_MAX_ARGS * !!fregs * sizeof(long));
+ if (IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) &&
+ tracer_flags_is_set(TRACE_GRAPH_PRINT_RETADDR)) {
+ retaddr = ftrace_graph_top_ret_addr(current);
+ size += sizeof(long);
+ }
+
event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT, size,
trace_ctx);
if (!event)
return 0;
@@ -141,11 +153,17 @@ static int __graph_entry(struct trace_array *tr, struct
ftrace_graph_ent *trace,
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
if (fregs) {
- for (int i = 0; i < FTRACE_REGS_MAX_ARGS; i++)
+ for (; i < FTRACE_REGS_MAX_ARGS; i++)
entry->args[i] = ftrace_regs_get_argument(fregs, i);
}
#endif
+ /*
+ * Store retaddr to [0] if fregs is NULL, else to [FTRACE_REGS_MAX_ARGS]
+ */
+ if (retaddr)
+ entry->args[i] = retaddr;
+
trace_buffer_unlock_commit_nostack(buffer, event);
return 1;
@@ -158,38 +176,6 @@ int __trace_graph_entry(struct trace_array *tr,
return __graph_entry(tr, trace, trace_ctx, NULL);
}
-#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
-int __trace_graph_retaddr_entry(struct trace_array *tr,
- struct ftrace_graph_ent *trace,
- unsigned int trace_ctx,
- unsigned long retaddr)
-{
- struct ring_buffer_event *event;
- struct trace_buffer *buffer = tr->array_buffer.buffer;
- struct fgraph_retaddr_ent_entry *entry;
-
- event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RETADDR_ENT,
- sizeof(*entry), trace_ctx);
- if (!event)
- return 0;
- entry = ring_buffer_event_data(event);
- entry->graph_ent.func = trace->func;
- entry->graph_ent.depth = trace->depth;
- entry->graph_ent.retaddr = retaddr;
- trace_buffer_unlock_commit_nostack(buffer, event);
-
- return 1;
-}
-#else
-int __trace_graph_retaddr_entry(struct trace_array *tr,
- struct ftrace_graph_ent *trace,
- unsigned int trace_ctx,
- unsigned long retaddr)
-{
- return 1;
-}
-#endif
-
static inline int ftrace_graph_ignore_irqs(void)
{
if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
@@ -262,13 +248,7 @@ static int graph_entry(struct ftrace_graph_ent *trace,
return 1;
trace_ctx = tracing_gen_ctx();
- if (IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) &&
- tracer_flags_is_set(TRACE_GRAPH_PRINT_RETADDR)) {
- unsigned long retaddr = ftrace_graph_top_ret_addr(current);
- ret = __trace_graph_retaddr_entry(tr, trace, trace_ctx,
retaddr);
- } else {
- ret = __graph_entry(tr, trace, trace_ctx, fregs);
- }
+ ret = __graph_entry(tr, trace, trace_ctx, fregs);
return ret;
}
@@ -634,13 +614,9 @@ get_return_for_leaf(struct trace_iterator *iter,
* Save current and next entries for later reference
* if the output fails.
*/
- if (unlikely(curr->ent.type ==
TRACE_GRAPH_RETADDR_ENT)) {
- data->rent = *(struct fgraph_retaddr_ent_entry
*)curr;
- } else {
- int size = min((int)sizeof(data->ent),
(int)iter->ent_size);
+ int size = min((int)sizeof(data->ent),
(int)iter->ent_size);
- memcpy(&data->ent, curr, size);
- }
+ memcpy(&data->ent, curr, size);
/*
* If the next event is not a return type, then
* we only care about what type it is. Otherwise we can
@@ -811,21 +787,21 @@ print_graph_duration(struct trace_array *tr, unsigned
long long duration,
#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
#define __TRACE_GRAPH_PRINT_RETADDR TRACE_GRAPH_PRINT_RETADDR
-static void print_graph_retaddr(struct trace_seq *s, struct
fgraph_retaddr_ent_entry *entry,
- u32 trace_flags, bool comment)
+static void print_graph_retaddr(struct trace_seq *s, unsigned long retaddr,
u32 trace_flags,
+ bool comment)
{
if (comment)
trace_seq_puts(s, " /*");
trace_seq_puts(s, " <-");
- seq_print_ip_sym(s, entry->graph_ent.retaddr, trace_flags |
TRACE_ITER_SYM_OFFSET);
+ seq_print_ip_sym(s, retaddr, trace_flags | TRACE_ITER_SYM_OFFSET);
if (comment)
trace_seq_puts(s, " */");
}
#else
#define __TRACE_GRAPH_PRINT_RETADDR 0
-#define print_graph_retaddr(_seq, _entry, _tflags, _comment) do { }
while (0)
+#define print_graph_retaddr(_seq, _retaddr, _tflags, _comment) do { }
while (0)
#endif
#if defined(CONFIG_FUNCTION_GRAPH_RETVAL) ||
defined(CONFIG_FUNCTION_GRAPH_RETADDR)
@@ -836,6 +812,7 @@ static void print_graph_retval(struct trace_seq *s, struct
ftrace_graph_ent_entr
{
unsigned long err_code = 0;
unsigned long retval = 0;
+ unsigned long retaddr = 0;
bool print_retaddr = false;
bool print_retval = false;
bool hex_format = !!(opt_flags & TRACE_GRAPH_PRINT_RETVAL_HEX);
@@ -863,9 +840,6 @@ static void print_graph_retval(struct trace_seq *s, struct
ftrace_graph_ent_entr
}
if (entry) {
- if (entry->ent.type != TRACE_GRAPH_RETADDR_ENT)
- print_retaddr = false;
-
trace_seq_printf(s, "%ps", func);
if (args_size >= FTRACE_REGS_MAX_ARGS * sizeof(long)) {
@@ -874,6 +848,16 @@ static void print_graph_retval(struct trace_seq *s, struct
ftrace_graph_ent_entr
} else
trace_seq_puts(s, "();");
+ if (print_retaddr) {
+ if (args_size > FTRACE_REGS_MAX_ARGS * sizeof(long))
+ retaddr = entry->args[FTRACE_REGS_MAX_ARGS];
+ else if (args_size == sizeof(long))
+ retaddr = entry->args[0];
+
+ if (!retaddr)
+ print_retaddr = false;
+ }
+
if (print_retval || print_retaddr)
trace_seq_puts(s, " /*");
} else {
@@ -882,8 +866,7 @@ static void print_graph_retval(struct trace_seq *s, struct
ftrace_graph_ent_entr
}
if (print_retaddr)
- print_graph_retaddr(s, (struct fgraph_retaddr_ent_entry *)entry,
- trace_flags, false);
+ print_graph_retaddr(s, retaddr, trace_flags, false);
if (print_retval) {
if (hex_format || (err_code == 0))
@@ -1022,10 +1005,17 @@ print_graph_entry_nested(struct trace_iterator *iter,
trace_seq_puts(s, " {");
- if (flags & __TRACE_GRAPH_PRINT_RETADDR &&
- entry->ent.type == TRACE_GRAPH_RETADDR_ENT)
- print_graph_retaddr(s, (struct fgraph_retaddr_ent_entry *)entry,
- tr->trace_flags, true);
+ if (flags & __TRACE_GRAPH_PRINT_RETADDR) {
+ unsigned long retaddr = 0;
+
+ if (args_size > FTRACE_REGS_MAX_ARGS * sizeof(long))
+ retaddr = entry->args[FTRACE_REGS_MAX_ARGS];
+ else if (args_size == sizeof(long))
+ retaddr = entry->args[0];
+
+ if (retaddr)
+ print_graph_retaddr(s, retaddr, tr->trace_flags, true);
+ }
trace_seq_putc(s, '\n');
if (trace_seq_has_overflowed(s))
@@ -1202,7 +1192,7 @@ print_graph_entry(struct ftrace_graph_ent_entry *field,
struct trace_seq *s,
* it can be safely saved at the stack.
*/
struct ftrace_graph_ent_entry *entry;
- u8 save_buf[sizeof(*entry) + FTRACE_REGS_MAX_ARGS * sizeof(long)];
+ u8 save_buf[sizeof(*entry) + (FTRACE_REGS_MAX_ARGS + STORE_RETADDR) *
sizeof(long)];
/* The ent_size is expected to be as big as the entry */
if (iter->ent_size > sizeof(save_buf))
@@ -1429,16 +1419,6 @@ print_graph_function_flags(struct trace_iterator *iter,
u32 flags)
trace_assign_type(field, entry);
return print_graph_entry(field, s, iter, flags);
}
-#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
- case TRACE_GRAPH_RETADDR_ENT: {
- struct fgraph_retaddr_ent_entry saved;
- struct fgraph_retaddr_ent_entry *rfield;
-
- trace_assign_type(rfield, entry);
- saved = *rfield;
- return print_graph_entry((struct ftrace_graph_ent_entry
*)&saved, s, iter, flags);
- }
-#endif
case TRACE_GRAPH_RET: {
struct ftrace_graph_ret_entry *field;
trace_assign_type(field, entry);
@@ -1637,13 +1617,6 @@ static struct trace_event graph_trace_entry_event = {
.funcs = &graph_functions,
};
-#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
-static struct trace_event graph_trace_retaddr_entry_event = {
- .type = TRACE_GRAPH_RETADDR_ENT,
- .funcs = &graph_functions,
-};
-#endif
-
static struct trace_event graph_trace_ret_event = {
.type = TRACE_GRAPH_RET,
.funcs = &graph_functions
@@ -1730,13 +1703,6 @@ static __init int init_graph_trace(void)
return 1;
}
-#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
- if (!register_trace_event(&graph_trace_retaddr_entry_event)) {
- pr_warn("Warning: could not register graph trace retaddr
events\n");
- return 1;
- }
-#endif
-
if (!register_trace_event(&graph_trace_ret_event)) {
pr_warn("Warning: could not register graph trace events\n");
return 1;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index d88c44f1dfa5..c56f6f1bbac3 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -17,7 +17,6 @@ static inline int trace_valid_entry(struct trace_entry *entry)
case TRACE_PRINT:
case TRACE_BRANCH:
case TRACE_GRAPH_ENT:
- case TRACE_GRAPH_RETADDR_ENT:
case TRACE_GRAPH_RET:
return 1;
}
--
2.34.1
