[PATCH 19/20] function_graph: Use for_each_set_bit() in __ftrace_return_to_handler()

Steven Rostedt
2024-05-25T02:36:56Z

From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

Instead of iterating through the entire fgraph_array[] and seeing if one
of the bitmap bits are set to know to call the array's retfunc() function,
use for_each_set_bit() on the bitmap itself. This will only iterate for
the number of set bits.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/fgraph.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 4d503b3e45ad..5e8e13ffcfb6 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -827,11 +827,10 @@ static unsigned long __ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs
#endif

bitmap = get_bitmap_bits(current, offset);
- for (i = 0; i < FGRAPH_ARRAY_SIZE; i++) {
+
+ for_each_set_bit(i, &bitmap, sizeof(bitmap) * BITS_PER_BYTE) {
struct fgraph_ops *gops = fgraph_array[i];

- if (!(bitmap & BIT(i)))
- continue;
if (gops == &fgraph_stub)
continue;

--
2.43.0