From 770d8abae736535c9bff17ee82bd48aea0e5fea4 Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@bsdimp.com>
Date: Mon, 31 Jan 2022 16:34:03 -0700
Subject: [PATCH] bsd-user/bsd-file.h: Meat of the write system calls

Implement write, writev, pwrite and pwritev and connect them to the
system call dispatch routine.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 bsd-user/bsd-file.h           | 84 +++++++++++++++++++++++++++++++++++
 bsd-user/freebsd/os-syscall.c | 22 +++++++++
 2 files changed, 106 insertions(+)

diff --git a/bsd-user/bsd-file.h b/bsd-user/bsd-file.h
index 839f8c5c55..e9e2c85eb6 100644
--- a/bsd-user/bsd-file.h
+++ b/bsd-user/bsd-file.h
@@ -32,6 +32,11 @@ ssize_t safe_pread(int fd, void *buf, size_t nbytes, off_t offset);
 ssize_t safe_readv(int fd, const struct iovec *iov, int iovcnt);
 ssize_t safe_preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset);
 
+ssize_t safe_write(int fd, void *buf, size_t nbytes);
+ssize_t safe_pwrite(int fd, void *buf, size_t nbytes, off_t offset);
+ssize_t safe_writev(int fd, const struct iovec *iov, int iovcnt);
+ssize_t safe_pwritev(int fd, const struct iovec *iov, int iovcnt, off_t offset);
+
 /* read(2) */
 static abi_long do_bsd_read(abi_long arg1, abi_long arg2, abi_long arg3)
 {
@@ -106,4 +111,83 @@ static abi_long do_bsd_preadv(void *cpu_env, abi_long arg1,
     return ret;
 }
 
+/* write(2) */
+static abi_long do_bsd_write(abi_long arg1, abi_long arg2, abi_long arg3)
+{
+    abi_long nbytes, ret;
+    void *p;
+
+    /* nbytes < 0 implies that it was larger than SIZE_MAX. */
+    nbytes = arg3;
+    if (nbytes < 0) {
+        return -TARGET_EINVAL;
+    }
+    p = lock_user(VERIFY_READ, arg2, nbytes, 1);
+    if (p == NULL) {
+        return -TARGET_EFAULT;
+    }
+    ret = get_errno(safe_write(arg1, p, arg3));
+    unlock_user(p, arg2, 0);
+
+    return ret;
+}
+
+/* pwrite(2) */
+static abi_long do_bsd_pwrite(void *cpu_env, abi_long arg1,
+    abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
+{
+    abi_long ret;
+    void *p;
+
+    p = lock_user(VERIFY_READ, arg2, arg3, 1);
+    if (p == NULL) {
+        return -TARGET_EFAULT;
+    }
+    if (regpairs_aligned(cpu_env) != 0) {
+        arg4 = arg5;
+        arg5 = arg6;
+    }
+    ret = get_errno(safe_pwrite(arg1, p, arg3, target_arg64(arg4, arg5)));
+    unlock_user(p, arg2, 0);
+
+    return ret;
+}
+
+/* writev(2) */
+static abi_long do_bsd_writev(abi_long arg1, abi_long arg2, abi_long arg3)
+{
+    abi_long ret;
+    struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);
+
+    if (vec != NULL) {
+        ret = get_errno(safe_writev(arg1, vec, arg3));
+        unlock_iovec(vec, arg2, arg3, 0);
+    } else {
+        ret = -host_to_target_errno(errno);
+    }
+
+    return ret;
+}
+
+/* pwritev(2) */
+static abi_long do_bsd_pwritev(void *cpu_env, abi_long arg1,
+    abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
+{
+    abi_long ret;
+    struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);
+
+    if (vec != NULL) {
+        if (regpairs_aligned(cpu_env) != 0) {
+            arg4 = arg5;
+            arg5 = arg6;
+        }
+        ret = get_errno(safe_pwritev(arg1, vec, arg3, target_arg64(arg4, arg5)));
+        unlock_iovec(vec, arg2, arg3, 0);
+    } else {
+        ret = -host_to_target_errno(errno);
+    }
+
+    return ret;
+}
+
 #endif /* BSD_FILE_H */
diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c
index 8ca92f2985..3a33d54fa4 100644
--- a/bsd-user/freebsd/os-syscall.c
+++ b/bsd-user/freebsd/os-syscall.c
@@ -50,6 +50,13 @@ safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt);
 safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt,
     off_t, offset);
 
+safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes);
+safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t,
+    offset);
+safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt);
+safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt,
+    off_t, offset);
+
 void target_set_brk(abi_ulong new_brk)
 {
 }
@@ -226,6 +233,21 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
 
     case TARGET_FREEBSD_NR_preadv: /* preadv(2) */
         ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
+
+    case TARGET_FREEBSD_NR_write: /* write(2) */
+        ret = do_bsd_write(arg1, arg2, arg3);
+        break;
+
+    case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */
+        ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
+        break;
+
+    case TARGET_FREEBSD_NR_writev: /* writev(2) */
+        ret = do_bsd_writev(arg1, arg2, arg3);
+        break;
+
+    case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */
+        ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
         break;
 
     default: