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function_graph: Move graph notrace bit to shadow stack global var

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The use of the task->trace_recursion for the logic used for the function
graph no-trace 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/171509107907.162236.6564679266777519065.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.796709456@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 15:07:22 -04:00 committed by Steven Rostedt (Google)
parent 068da098eb
commit b84214890a
3 changed files with 15 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
include/linux/trace_recursion.h
View File

@ -44,13 +44,6 @@ enum {
*/
TRACE_IRQ_BIT,
/*
* To implement set_graph_notrace, if this bit is set, we ignore
* function graph tracing of called functions, until the return
* function is called to clear it.
*/
TRACE_GRAPH_NOTRACE_BIT,
/* Used to prevent recursion recording from recursing. */
TRACE_RECORD_RECURSION_BIT,
};

9
kernel/trace/trace.h
View File

@ -919,8 +919,17 @@ enum {
TRACE_GRAPH_DEPTH_START_BIT,
TRACE_GRAPH_DEPTH_END_BIT,
/*
* To implement set_graph_notrace, if this bit is set, we ignore
* function graph tracing of called functions, until the return
* function is called to clear it.
*/
TRACE_GRAPH_NOTRACE_BIT,
};
#define TRACE_GRAPH_NOTRACE (1 << TRACE_GRAPH_NOTRACE_BIT)
static inline unsigned long ftrace_graph_depth(unsigned long *task_var)
{
return (*task_var >> TRACE_GRAPH_DEPTH_START_BIT) & 3;

10
kernel/trace/trace_functions_graph.c
View File

@ -130,6 +130,7 @@ static inline int ftrace_graph_ignore_irqs(void)
int trace_graph_entry(struct ftrace_graph_ent *trace,
struct fgraph_ops *gops)
{
unsigned long *task_var = fgraph_get_task_var(gops);
struct trace_array *tr = gops->private;
struct trace_array_cpu *data;
unsigned long flags;
@ -138,7 +139,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace,
int ret;
int cpu;
if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT))
if (*task_var & TRACE_GRAPH_NOTRACE)
return 0;
/*
@ -149,7 +150,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace,
* returning from the function.
*/
if (ftrace_graph_notrace_addr(trace->func)) {
trace_recursion_set(TRACE_GRAPH_NOTRACE_BIT);
*task_var |= TRACE_GRAPH_NOTRACE_BIT;
/*
* Need to return 1 to have the return called
* that will clear the NOTRACE bit.
@ -240,6 +241,7 @@ void __trace_graph_return(struct trace_array *tr,
void trace_graph_return(struct ftrace_graph_ret *trace,
struct fgraph_ops *gops)
{
unsigned long *task_var = fgraph_get_task_var(gops);
struct trace_array *tr = gops->private;
struct trace_array_cpu *data;
unsigned long flags;
@ -249,8 +251,8 @@ void trace_graph_return(struct ftrace_graph_ret *trace,
ftrace_graph_addr_finish(gops, trace);
if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
if (*task_var & TRACE_GRAPH_NOTRACE) {
*task_var &= ~TRACE_GRAPH_NOTRACE;
return;
}