Index: sys/amd64/linux/linux_machdep.c
===================================================================
--- sys/amd64/linux/linux_machdep.c
+++ sys/amd64/linux/linux_machdep.c
@@ -141,6 +141,13 @@
 }
 
 int
+linux_madvise(struct thread *td, struct linux_madvise_args *uap)
+{
+
+	return (linux_madvise_common(td, PTROUT(uap->addr), uap->len, uap->behav));
+}
+
+int
 linux_iopl(struct thread *td, struct linux_iopl_args *args)
 {
 	int error;
Index: sys/amd64/linux/syscalls.master
===================================================================
--- sys/amd64/linux/syscalls.master
+++ sys/amd64/linux/syscalls.master
@@ -94,7 +94,7 @@
 				    l_size_t len, l_int fl); }
 27	AUE_MINCORE	STD	{ int linux_mincore(l_ulong start, \
 				    l_size_t len, u_char *vec); }
-28	AUE_MADVISE	NOPROTO	{ int madvise(void *addr, size_t len, \
+28	AUE_MADVISE	STD	{ int linux_madvise(void *addr, size_t len, \
 				    int behav); }
 29	AUE_NULL	STD	{ int linux_shmget(l_key_t key, l_size_t size, \
 				    l_int shmflg); }
Index: sys/amd64/linux32/linux32_machdep.c
===================================================================
--- sys/amd64/linux32/linux32_machdep.c
+++ sys/amd64/linux32/linux32_machdep.c
@@ -469,6 +469,13 @@
 }
 
 int
+linux_madvise(struct thread *td, struct linux_madvise_args *uap)
+{
+
+	return (linux_madvise_common(td, PTROUT(uap->addr), uap->len, uap->behav));
+}
+
+int
 linux_iopl(struct thread *td, struct linux_iopl_args *args)
 {
 	int error;
Index: sys/amd64/linux32/syscalls.master
===================================================================
--- sys/amd64/linux32/syscalls.master
+++ sys/amd64/linux32/syscalls.master
@@ -390,7 +390,7 @@
 				    char *put_old); }
 218	AUE_MINCORE	STD	{ int linux_mincore(l_ulong start, \
 				    l_size_t len, u_char *vec); }
-219	AUE_MADVISE	NOPROTO	{ int madvise(void *addr, size_t len, \
+219	AUE_MADVISE	STD	{ int linux_madvise(void *addr, size_t len, \
 				    int behav); }
 220	AUE_GETDIRENTRIES	STD { int linux_getdents64(l_uint fd, \
 				    void *dirent, l_uint count); }
Index: sys/arm64/linux/linux_machdep.c
===================================================================
--- sys/arm64/linux/linux_machdep.c
+++ sys/arm64/linux/linux_machdep.c
@@ -104,6 +104,13 @@
 	    uap->prot));
 }
 
+int
+linux_madvise(struct thread *td, struct linux_madvise_args *uap)
+{
+
+	return (linux_madvise_common(td, PTROUT(uap->addr), uap->len, uap->behav));
+}
+
 /* LINUXTODO: implement arm64 linux_rt_sigsuspend */
 int
 linux_rt_sigsuspend(struct thread *td, struct linux_rt_sigsuspend_args *uap)
Index: sys/arm64/linux/syscalls.master
===================================================================
--- sys/arm64/linux/syscalls.master
+++ sys/arm64/linux/syscalls.master
@@ -1310,8 +1310,9 @@
 		    u_char *vec
 		);
 	}
-233	AUE_MADVISE	NOPROTO	{
-		int madvise(void *addr,
+233	AUE_MADVISE	STD	{
+		int linux_madvise(
+		    void *addr,
 		    size_t len,
 		    int behav
 		);
Index: sys/compat/linux/linux_mmap.h
===================================================================
--- sys/compat/linux/linux_mmap.h
+++ sys/compat/linux/linux_mmap.h
@@ -45,8 +45,29 @@
 #define	LINUX_PROT_GROWSDOWN	0x01000000
 #define	LINUX_PROT_GROWSUP	0x02000000
 
+#define	LINUX_MADV_NORMAL	0
+#define	LINUX_MADV_RANDOM	1
+#define	LINUX_MADV_SEQUENTIAL	2
+#define	LINUX_MADV_WILLNEED	3
+#define	LINUX_MADV_DONTNEED	4
+#define	LINUX_MADV_FREE		8
+#define	LINUX_MADV_REMOVE	9
+#define	LINUX_MADV_DONTFORK	10
+#define	LINUX_MADV_DOFORK	11
+#define	LINUX_MADV_MERGEABLE	12
+#define	LINUX_MADV_UNMERGEABLE	13
+#define	LINUX_MADV_HUGEPAGE	14
+#define	LINUX_MADV_NOHUGEPAGE	15
+#define	LINUX_MADV_DONTDUMP	16
+#define	LINUX_MADV_DODUMP	17
+#define	LINUX_MADV_WIPEONFORK	18
+#define	LINUX_MADV_KEEPONFORK	19
+#define	LINUX_MADV_HWPOISON	100
+#define	LINUX_MADV_SOFT_OFFLINE	101
+
 int linux_mmap_common(struct thread *, uintptr_t, size_t, int, int,
 			int, off_t);
 int linux_mprotect_common(struct thread *, uintptr_t, size_t, int);
+int linux_madvise_common(struct thread *, uintptr_t, size_t, int);
 
 #endif	/* _LINUX_MMAP_H_ */
Index: sys/compat/linux/linux_mmap.c
===================================================================
--- sys/compat/linux/linux_mmap.c
+++ sys/compat/linux/linux_mmap.c
@@ -242,6 +242,62 @@
 	return (kern_mprotect(td, addr, len, prot));
 }
 
+int
+linux_madvise_common(struct thread *td, uintptr_t addr, size_t len, int behav)
+{
+
+	switch (behav) {
+	case LINUX_MADV_NORMAL:
+		return (kern_madvise(td, addr, len, MADV_NORMAL));
+	case LINUX_MADV_RANDOM:
+		return (kern_madvise(td, addr, len, MADV_RANDOM));
+	case LINUX_MADV_SEQUENTIAL:
+		return (kern_madvise(td, addr, len, MADV_SEQUENTIAL));
+	case LINUX_MADV_WILLNEED:
+		return (kern_madvise(td, addr, len, MADV_WILLNEED));
+	case LINUX_MADV_DONTNEED:
+		return (kern_madvise(td, addr, len, MADV_DONTNEED));
+	case LINUX_MADV_FREE:
+		return (kern_madvise(td, addr, len, MADV_FREE));
+	case LINUX_MADV_REMOVE:
+		linux_msg(curthread, "unsupported madvise MADV_REMOVE");
+		return (EINVAL);
+	case LINUX_MADV_DONTFORK:
+		return (kern_minherit(td, addr, len, INHERIT_NONE));
+	case LINUX_MADV_DOFORK:
+		return (kern_minherit(td, addr, len, INHERIT_COPY));
+	case LINUX_MADV_MERGEABLE:
+		linux_msg(curthread, "unsupported madvise MADV_MERGEABLE");
+		return (EINVAL);
+	case LINUX_MADV_UNMERGEABLE:
+		/* We don't merge anyway. */
+		return (0);
+	case LINUX_MADV_HUGEPAGE:
+		/* Ignored; on FreeBSD huge pages are always on. */
+		return (0);
+	case LINUX_MADV_NOHUGEPAGE:
+		linux_msg(curthread, "unsupported madvise MADV_NOHUGEPAGE");
+		return (EINVAL);
+	case LINUX_MADV_DONTDUMP:
+		return (kern_madvise(td, addr, len, MADV_NOCORE));
+	case LINUX_MADV_DODUMP:
+		return (kern_madvise(td, addr, len, MADV_CORE));
+	case LINUX_MADV_WIPEONFORK:
+		return (kern_minherit(td, addr, len, INHERIT_ZERO));
+	case LINUX_MADV_KEEPONFORK:
+		return (kern_minherit(td, addr, len, INHERIT_COPY));
+	case LINUX_MADV_HWPOISON:
+		linux_msg(curthread, "unsupported madvise MADV_HWPOISON");
+		return (EINVAL);
+	case LINUX_MADV_SOFT_OFFLINE:
+		linux_msg(curthread, "unsupported madvise MADV_SOFT_OFFLINE");
+		return (EINVAL);
+	default:
+		linux_msg(curthread, "unsupported madvise behav %d", behav);
+		return (EINVAL);
+	}
+}
+
 #if defined(__amd64__)
 static void
 linux_fixup_prot(struct thread *td, int *prot)
Index: sys/i386/linux/linux_machdep.c
===================================================================
--- sys/i386/linux/linux_machdep.c
+++ sys/i386/linux/linux_machdep.c
@@ -354,6 +354,13 @@
 }
 
 int
+linux_madvise(struct thread *td, struct linux_madvise_args *uap)
+{
+
+	return (linux_madvise_common(td, PTROUT(uap->addr), uap->len, uap->behav));
+}
+
+int
 linux_ioperm(struct thread *td, struct linux_ioperm_args *args)
 {
 	int error;
Index: sys/i386/linux/syscalls.master
===================================================================
--- sys/i386/linux/syscalls.master
+++ sys/i386/linux/syscalls.master
@@ -393,7 +393,7 @@
 				    char *put_old); }
 218	AUE_MINCORE	STD	{ int linux_mincore(l_ulong start, \
 				    l_size_t len, u_char *vec); }
-219	AUE_MADVISE	NOPROTO	{ int madvise(void *addr, size_t len, \
+219	AUE_MADVISE	STD	{ int linux_madvise(void *addr, size_t len, \
 				    int behav); }
 220	AUE_GETDIRENTRIES	STD { int linux_getdents64(l_uint fd, \
 				    void *dirent, l_uint count); }
Index: sys/sys/syscallsubr.h
===================================================================
--- sys/sys/syscallsubr.h
+++ sys/sys/syscallsubr.h
@@ -185,6 +185,8 @@
 	    struct timeval *tptr, enum uio_seg tptrseg);
 int	kern_madvise(struct thread *td, uintptr_t addr, size_t len, int behav);
 int	kern_mincore(struct thread *td, uintptr_t addr, size_t len, char *vec);
+int	kern_minherit(struct thread *td, uintptr_t addr, size_t len,
+	    int inherit);
 int	kern_mkdirat(struct thread *td, int fd, const char *path,
 	    enum uio_seg segflg, int mode);
 int	kern_mkfifoat(struct thread *td, int fd, const char *path,
Index: sys/vm/vm_mmap.c
===================================================================
--- sys/vm/vm_mmap.c
+++ sys/vm/vm_mmap.c
@@ -709,13 +709,21 @@
 int
 sys_minherit(struct thread *td, struct minherit_args *uap)
 {
+
+	return (kern_minherit(td, (uintptr_t)uap->addr, uap->len,
+	    uap->inherit));
+}
+
+int
+kern_minherit(struct thread *td, uintptr_t addr0, size_t len, int inherit0)
+{
 	vm_offset_t addr;
 	vm_size_t size, pageoff;
 	vm_inherit_t inherit;
 
-	addr = (vm_offset_t)uap->addr;
-	size = uap->len;
-	inherit = uap->inherit;
+	addr = (vm_offset_t)addr0;
+	size = len;
+	inherit = inherit0;
 
 	pageoff = (addr & PAGE_MASK);
 	addr -= pageoff;