riscv: Fix ftrace_graph_ret_addr() to use the correct task pointer

The walk_stackframe() function is used to unwind the stack of a given
task. When function graph tracing is enabled, ftrace_graph_ret_addr()
is called to resolve the original return address if it was modified by
the tracer.

The current code incorrectly passes 'current' instead of 'task' to
ftrace_graph_ret_addr(). This causes incorrect return address resolution
when unwinding a stack of a different task (e.g., when the task is
blocked in __switch_to).

Fix this by passing 'task' instead of 'current' to match the behavior
of other architectures (arm64, loongarch, powerpc, s390, x86).

Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Link: https://patch.msgid.link/20260408092915.46408-1-qirui.001@bytedance.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
This commit is contained in:
Rui Qi 2026-06-06 20:17:53 -06:00 committed by Paul Walmsley
parent 84894ceb3c
commit ecbf894165

View File

@ -87,7 +87,7 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
} else {
fp = READ_ONCE_TASK_STACK(task, frame->fp);
pc = READ_ONCE_TASK_STACK(task, frame->ra);
pc = ftrace_graph_ret_addr(current, &graph_idx, pc,
pc = ftrace_graph_ret_addr(task, &graph_idx, pc,
&frame->ra);
if (pc >= (unsigned long)handle_exception &&
pc < (unsigned long)&ret_from_exception_end) {