diff mbox series

[v4,27/35] s390/ftrace: Unpoison ftrace_regs in kprobe_ftrace_handler()

Message ID 20240613153924.961511-28-iii@linux.ibm.com (mailing list archive)
State New
Headers show
Series kmsan: Enable on s390 | expand

Commit Message

Ilya Leoshkevich June 13, 2024, 3:34 p.m. UTC
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

Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
 arch/s390/kernel/ftrace.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series


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)
+	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))