6 files changed, 76 insertions, 5 deletions
diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c
index 3a6bc2af0961..014eb35fd13b 100644
--- a/arch/um/os-Linux/aio.c
+++ b/arch/um/os-Linux/aio.c
@@ -104,8 +104,7 @@ static int aio_thread(void *arg)
 	struct io_event event;
 	int err, n, reply_fd;
 
-	signal(SIGWINCH, SIG_IGN);
-
+	os_fix_helper_signals();
 	while (1) {
 		n = io_getevents(ctx, 1, 1, &event, NULL);
 		if (n < 0) {
@@ -173,7 +172,7 @@ static int not_aio_thread(void *arg)
 	struct aio_thread_reply reply;
 	int err;
 
-	signal(SIGWINCH, SIG_IGN);
+	os_fix_helper_signals();
 	while (1) {
 		err = read(aio_req_fd_r, &req, sizeof(req));
 		if (err != sizeof(req)) {
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index c17bd6f7d674..07a750197bb0 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -266,6 +266,15 @@ int os_write_file(int fd, const void *buf, int len)
 	return n;
 }
 
+int os_sync_file(int fd)
+{
+	int n = fsync(fd);
+
+	if (n < 0)
+		return -errno;
+	return n;
+}
+
 int os_file_size(const char *file, unsigned long long *size_out)
 {
 	struct uml_stat buf;
diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
index 749c96da7b99..e1704ff600ff 100644
--- a/arch/um/os-Linux/main.c
+++ b/arch/um/os-Linux/main.c
@@ -123,6 +123,8 @@ int __init main(int argc, char **argv, char **envp)
 
 	setup_env_path();
 
+	setsid();
+
 	new_argv = malloc((argc + 1) * sizeof(char *));
 	if (new_argv == NULL) {
 		perror("Mallocing argv");
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index b8f34c9e53ae..33496fe2bb52 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -4,6 +4,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>
 #include <signal.h>
@@ -232,6 +233,57 @@ out:
 	return ok;
 }
 
+static int os_page_mincore(void *addr)
+{
+	char vec[2];
+	int ret;
+
+	ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
+	if (ret < 0) {
+		if (errno == ENOMEM || errno == EINVAL)
+			return 0;
+		else
+			return -errno;
+	}
+
+	return vec[0] & 1;
+}
+
+int os_mincore(void *addr, unsigned long len)
+{
+	char *vec;
+	int ret, i;
+
+	if (len <= UM_KERN_PAGE_SIZE)
+		return os_page_mincore(addr);
+
+	vec = calloc(1, (len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE);
+	if (!vec)
+		return -ENOMEM;
+
+	ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
+	if (ret < 0) {
+		if (errno == ENOMEM || errno == EINVAL)
+			ret = 0;
+		else
+			ret = -errno;
+
+		goto out;
+	}
+
+	for (i = 0; i < ((len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); i++) {
+		if (!(vec[i] & 1)) {
+			ret = 0;
+			goto out;
+		}
+	}
+
+	ret = 1;
+out:
+	free(vec);
+	return ret;
+}
+
 void init_new_thread_signals(void)
 {
 	set_handler(SIGSEGV);
@@ -242,5 +294,4 @@ void init_new_thread_signals(void)
 	signal(SIGHUP, SIG_IGN);
 	set_handler(SIGIO);
 	signal(SIGWINCH, SIG_IGN);
-	signal(SIGTERM, SIG_DFL);
 }
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 8b61cc0e82c8..46e762f926eb 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -55,7 +55,7 @@ static int write_sigio_thread(void *unused)
 	int i, n, respond_fd;
 	char c;
 
-	signal(SIGWINCH, SIG_IGN);
+	os_fix_helper_signals();
 	fds = &current_poll;
 	while (1) {
 		n = poll(fds->poll, fds->used, -1);
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index 492ef5e6e166..faee55ef6d2f 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -94,6 +94,16 @@ static inline void __attribute__ ((noreturn)) uml_abort(void)
 			exit(127);
 }
 
+/*
+ * UML helper threads must not handle SIGWINCH/INT/TERM
+ */
+void os_fix_helper_signals(void)
+{
+	signal(SIGWINCH, SIG_IGN);
+	signal(SIGINT, SIG_DFL);
+	signal(SIGTERM, SIG_DFL);
+}
+
 void os_dump_core(void)
 {
 	int pid;