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function_graph: Move set_graph_function tests to shadow stack global var

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The use of the task->trace_recursion for the logic used for the
set_graph_function was a bit of an abuse of that variable. Now that there
exists global vars that are per stack for registered graph traces, use that
instead.

Link: https://lore.kernel.org/linux-trace-kernel/171509105520.162236.10339831553995971290.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.472955399@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (VMware) 2024-06-03 15:07:20 -04:00 committed by Steven Rostedt (Google)
parent 4497412a1f
commit 12117f3307
5 changed files with 29 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
include/linux/trace_recursion.h
View File

@ -44,9 +44,6 @@ enum {
*/
TRACE_IRQ_BIT,
/* Set if the function is in the set_graph_function file */
TRACE_GRAPH_BIT,
/*
* In the very unlikely case that an interrupt came in
* at a start of graph tracing, and we want to trace
@ -60,7 +57,7 @@ enum {
* that preempted a softirq start of a function that
* preempted normal context!!!! Luckily, it can't be
* greater than 3, so the next two bits are a mask
* of what the depth is when we set TRACE_GRAPH_BIT
* of what the depth is when we set TRACE_GRAPH_FL
*/
TRACE_GRAPH_DEPTH_START_BIT,

32
kernel/trace/trace.h
View File

@ -898,11 +898,16 @@ extern void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops
extern int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops);
extern void free_fgraph_ops(struct trace_array *tr);
enum {
TRACE_GRAPH_FL = 1,
};
#ifdef CONFIG_DYNAMIC_FTRACE
extern struct ftrace_hash __rcu *ftrace_graph_hash;
extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
static inline int
ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
{
unsigned long addr = trace->func;
int ret = 0;
@ -924,12 +929,11 @@ static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
}
if (ftrace_lookup_ip(hash, addr)) {
/*
* This needs to be cleared on the return functions
* when the depth is zero.
*/
trace_recursion_set(TRACE_GRAPH_BIT);
*task_var |= TRACE_GRAPH_FL;
trace_recursion_set_depth(trace->depth);
/*
@ -949,11 +953,14 @@ out:
return ret;
}
static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
static inline void
ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
{
if (trace_recursion_test(TRACE_GRAPH_BIT) &&
unsigned long *task_var = fgraph_get_task_var(gops);
if ((*task_var & TRACE_GRAPH_FL) &&
trace->depth == trace_recursion_depth())
trace_recursion_clear(TRACE_GRAPH_BIT);
*task_var &= ~TRACE_GRAPH_FL;
}
static inline int ftrace_graph_notrace_addr(unsigned long addr)
@ -979,7 +986,7 @@ static inline int ftrace_graph_notrace_addr(unsigned long addr)
return ret;
}
#else
static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
static inline int ftrace_graph_addr(unsigned long *task_var, struct ftrace_graph_ent *trace)
{
return 1;
}
@ -988,17 +995,20 @@ static inline int ftrace_graph_notrace_addr(unsigned long addr)
{
return 0;
}
static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
static inline void ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftrace_graph_ret *trace)
{ }
#endif /* CONFIG_DYNAMIC_FTRACE */
extern unsigned int fgraph_max_depth;
static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
static inline bool
ftrace_graph_ignore_func(struct fgraph_ops *gops, struct ftrace_graph_ent *trace)
{
unsigned long *task_var = fgraph_get_task_var(gops);
/* trace it when it is-nested-in or is a function enabled. */
return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
ftrace_graph_addr(trace)) ||
return !((*task_var & TRACE_GRAPH_FL) ||
ftrace_graph_addr(task_var, trace)) ||
(trace->depth < 0) ||
(fgraph_max_depth && trace->depth >= fgraph_max_depth);
}

6
kernel/trace/trace_functions_graph.c
View File

@ -160,7 +160,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace,
if (!ftrace_trace_task(tr))
return 0;
if (ftrace_graph_ignore_func(trace))
if (ftrace_graph_ignore_func(gops, trace))
return 0;
if (ftrace_graph_ignore_irqs())
@ -247,7 +247,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace,
long disabled;
int cpu;
ftrace_graph_addr_finish(trace);
ftrace_graph_addr_finish(gops, trace);
if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
@ -269,7 +269,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace,
static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
struct fgraph_ops *gops)
{
ftrace_graph_addr_finish(trace);
ftrace_graph_addr_finish(gops, trace);
if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);

4
kernel/trace/trace_irqsoff.c
View File

@ -184,7 +184,7 @@ static int irqsoff_graph_entry(struct ftrace_graph_ent *trace,
unsigned int trace_ctx;
int ret;
if (ftrace_graph_ignore_func(trace))
if (ftrace_graph_ignore_func(gops, trace))
return 0;
/*
* Do not trace a function if it's filtered by set_graph_notrace.
@ -214,7 +214,7 @@ static void irqsoff_graph_return(struct ftrace_graph_ret *trace,
unsigned long flags;
unsigned int trace_ctx;
ftrace_graph_addr_finish(trace);
ftrace_graph_addr_finish(gops, trace);
if (!func_prolog_dec(tr, &data, &flags))
return;

4
kernel/trace/trace_sched_wakeup.c
View File

@ -120,7 +120,7 @@ static int wakeup_graph_entry(struct ftrace_graph_ent *trace,
unsigned int trace_ctx;
int ret = 0;
if (ftrace_graph_ignore_func(trace))
if (ftrace_graph_ignore_func(gops, trace))
return 0;
/*
* Do not trace a function if it's filtered by set_graph_notrace.
@ -149,7 +149,7 @@ static void wakeup_graph_return(struct ftrace_graph_ret *trace,
struct trace_array_cpu *data;
unsigned int trace_ctx;
ftrace_graph_addr_finish(trace);
ftrace_graph_addr_finish(gops, trace);
if (!func_prolog_preempt_disable(tr, &data, &trace_ctx))
return;