From 2c5df0dfeaf878f0f09485b7a80c79aea36d194e Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Fri, 10 Oct 2025 19:41:53 -0400
Subject: kern: systm: Add copyoutstr()

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 src/sys/include/os/systm.h | 12 ++++++++++++
 src/sys/os/os_systm.c      | 10 ++++++++++
 2 files changed, 22 insertions(+)

(limited to 'src')

diff --git a/src/sys/include/os/systm.h b/src/sys/include/os/systm.h
index 24f21db..4cb526e 100644
--- a/src/sys/include/os/systm.h
+++ b/src/sys/include/os/systm.h
@@ -68,4 +68,16 @@ int copyin(const void *uaddr, void *kaddr, size_t len);
  */
 int copyout(const void *kaddr, void *uaddr, size_t len);
 
+/*
+ * Copy kernel string to userland safely
+ *
+ * @kaddr: Kernel space address to copy from
+ * @uaddr: User space address to copy to
+ * @len: Length of bytes to copy
+ *
+ * Returns zero on success, otherwise a less than
+ * zero value.
+ */
+int copyoutstr(const void *kaddr, void *addr, size_t len);
+
 #endif  /* !_OS_SYSTM_H_ */
diff --git a/src/sys/os/os_systm.c b/src/sys/os/os_systm.c
index 69fab30..0e28372 100644
--- a/src/sys/os/os_systm.c
+++ b/src/sys/os/os_systm.c
@@ -117,3 +117,13 @@ copyinstr(const void *uaddr, char *kaddr, size_t len)
 
     return 0;
 }
+
+int
+copyoutstr(const void *kaddr, void *addr, size_t len)
+{
+    size_t slen;
+
+    slen = strlen(kaddr);
+    len = MIN(slen, len);
+    return copyout(kaddr, addr, len);
+}
-- 
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