diff --git a/sys/amd64/linux/linux.h b/sys/amd64/linux/linux.h
--- a/sys/amd64/linux/linux.h
+++ b/sys/amd64/linux/linux.h
@@ -459,7 +459,7 @@
 
 struct reg;
 
-void	bsd_to_linux_regset(struct reg *b_reg,
+void	bsd_to_linux_regset(const struct reg *b_reg,
 	    struct linux_pt_regset *l_regset);
 
 #endif /* !_AMD64_LINUX_H_ */
diff --git a/sys/amd64/linux/linux_machdep.c b/sys/amd64/linux/linux_machdep.c
--- a/sys/amd64/linux/linux_machdep.c
+++ b/sys/amd64/linux/linux_machdep.c
@@ -299,7 +299,7 @@
 }
 
 void
-bsd_to_linux_regset(struct reg *b_reg, struct linux_pt_regset *l_regset)
+bsd_to_linux_regset(const struct reg *b_reg, struct linux_pt_regset *l_regset)
 {
 
 	l_regset->r15 = b_reg->r_r15;
diff --git a/sys/amd64/linux32/linux.h b/sys/amd64/linux32/linux.h
--- a/sys/amd64/linux32/linux.h
+++ b/sys/amd64/linux32/linux.h
@@ -634,7 +634,7 @@
 
 struct reg32;
 
-void	bsd_to_linux_regset32(struct reg32 *b_reg,
+void	bsd_to_linux_regset32(const struct reg32 *b_reg,
 	    struct linux_pt_regset32 *l_regset);
 
 #endif /* !_AMD64_LINUX_H_ */
diff --git a/sys/amd64/linux32/linux32_machdep.c b/sys/amd64/linux32/linux32_machdep.c
--- a/sys/amd64/linux32/linux32_machdep.c
+++ b/sys/amd64/linux32/linux32_machdep.c
@@ -678,7 +678,8 @@
 }
 
 void
-bsd_to_linux_regset32(struct reg32 *b_reg, struct linux_pt_regset32 *l_regset)
+bsd_to_linux_regset32(const struct reg32 *b_reg,
+    struct linux_pt_regset32 *l_regset)
 {
 
 	l_regset->ebx = b_reg->r_ebx;
diff --git a/sys/arm64/linux/linux.h b/sys/arm64/linux/linux.h
--- a/sys/arm64/linux/linux.h
+++ b/sys/arm64/linux/linux.h
@@ -322,7 +322,7 @@
 
 struct reg;
 
-void	bsd_to_linux_regset(struct reg *b_reg,
+void	bsd_to_linux_regset(const struct reg *b_reg,
 	    struct linux_pt_regset *l_regset);
 
 #endif /* _ARM64_LINUX_H_ */
diff --git a/sys/arm64/linux/linux_machdep.c b/sys/arm64/linux/linux_machdep.c
--- a/sys/arm64/linux/linux_machdep.c
+++ b/sys/arm64/linux/linux_machdep.c
@@ -133,7 +133,7 @@
 }
 
 void
-bsd_to_linux_regset(struct reg *b_reg, struct linux_pt_regset *l_regset)
+bsd_to_linux_regset(const struct reg *b_reg, struct linux_pt_regset *l_regset)
 {
 
 	KASSERT(sizeof(l_regset->x) == sizeof(b_reg->x) + sizeof(l_ulong),