[PATCH v2 01/33] ftrace: Unpoison ftrace_regs in ftrace_ops_list_func()

From: Ilya Leoshkevich
Date: Tue Nov 21 2023 - 17:02:58 EST


Architectures use assembly code to initialize ftrace_regs and call
ftrace_ops_list_func(). Therefore, from the KMSAN's point of view,
ftrace_regs is poisoned on ftrace_ops_list_func entry(). This causes
KMSAN warnings when running the ftrace testsuite.

Fix by trusting the architecture-specific assembly code and always
unpoisoning ftrace_regs in ftrace_ops_list_func.

Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
---
kernel/trace/ftrace.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8de8bec5f366..dfb8b26966aa 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -7399,6 +7399,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs)
{
+ kmsan_unpoison_memory(fregs, sizeof(*fregs));
__ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
}
#else
--
2.41.0