s390 uses assembly code to initialize ftrace_regs and call kprobe_ftrace_handler(). Therefore, from the KMSAN's point of view, ftrace_regs is poisoned on kprobe_ftrace_handler() entry. This causes KMSAN warnings when running the ftrace testsuite. Fix by trusting the assembly code and always unpoisoning ftrace_regs in kprobe_ftrace_handler(). Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx> Acked-by: Heiko Carstens <hca@xxxxxxxxxxxxx> Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx> --- arch/s390/kernel/ftrace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index ddf2ee47cb87..0bd6adc40a34 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -12,6 +12,7 @@ #include <linux/ftrace.h> #include <linux/kernel.h> #include <linux/types.h> +#include <linux/kmsan-checks.h> #include <linux/kprobes.h> #include <linux/execmem.h> #include <trace/syscall.h> @@ -303,6 +304,7 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, if (bit < 0) return; + kmsan_unpoison_memory(fregs, sizeof(*fregs)); regs = ftrace_get_regs(fregs); p = get_kprobe((kprobe_opcode_t *)ip); if (!regs || unlikely(!p) || kprobe_disabled(p)) -- 2.45.1
