[PATCH v2 4/6] bsd-user/bsd-file.h: Add implementations for read, pread, readv and preadv

[Warner Losh]

Implement do_bsd_{read,pread,readv,preadv}. Connect them to the system
call table.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
---
 bsd-user/bsd-file.h           | 79 +++++++++++++++++++++++++++++++++++
 bsd-user/freebsd/os-syscall.c | 28 +++++++++++++
 2 files changed, 107 insertions(+)

diff --git a/bsd-user/bsd-file.h b/bsd-user/bsd-file.h
index a6bff3b8c26..839f8c5c55a 100644
--- a/bsd-user/bsd-file.h
+++ b/bsd-user/bsd-file.h
@@ -27,4 +27,83 @@ extern struct iovec *lock_iovec(int type, abi_ulong 
target_addr, int count,
 extern void unlock_iovec(struct iovec *vec, abi_ulong target_addr, int count,
         int copy);
 
+ssize_t safe_read(int fd, void *buf, size_t nbytes);
+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);
+
+/* read(2) */
+static abi_long do_bsd_read(abi_long arg1, abi_long arg2, abi_long arg3)
+{
+    abi_long ret;
+    void *p;
+
+    p = lock_user(VERIFY_WRITE, arg2, arg3, 0);
+    if (p == NULL) {
+        return -TARGET_EFAULT;
+    }
+    ret = get_errno(safe_read(arg1, p, arg3));
+    unlock_user(p, arg2, ret);
+
+    return ret;
+}
+
+/* pread(2) */
+static abi_long do_bsd_pread(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_WRITE, arg2, arg3, 0);
+    if (p == NULL) {
+        return -TARGET_EFAULT;
+    }
+    if (regpairs_aligned(cpu_env) != 0) {
+        arg4 = arg5;
+        arg5 = arg6;
+    }
+    ret = get_errno(safe_pread(arg1, p, arg3, target_arg64(arg4, arg5)));
+    unlock_user(p, arg2, ret);
+
+    return ret;
+}
+
+/* readv(2) */
+static abi_long do_bsd_readv(abi_long arg1, abi_long arg2, abi_long arg3)
+{
+    abi_long ret;
+    struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 0);
+
+    if (vec != NULL) {
+        ret = get_errno(safe_readv(arg1, vec, arg3));
+        unlock_iovec(vec, arg2, arg3, 1);
+    } else {
+        ret = -host_to_target_errno(errno);
+    }
+
+    return ret;
+}
+
+/* preadv(2) */
+static abi_long do_bsd_preadv(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_WRITE, arg2, arg3, 1);
+
+    if (vec != NULL) {
+        if (regpairs_aligned(cpu_env) != 0) {
+            arg4 = arg5;
+            arg5 = arg6;
+        }
+        ret = get_errno(safe_preadv(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 1c4c9983f1a..8ca92f29857 100644
--- a/bsd-user/freebsd/os-syscall.c
+++ b/bsd-user/freebsd/os-syscall.c
@@ -42,6 +42,14 @@
 
 #include "bsd-file.h"
 
+/* I/O */
+safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes);
+safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t,
+    offset);
+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);
+
 void target_set_brk(abi_ulong new_brk)
 {
 }
@@ -200,6 +208,26 @@ static abi_long freebsd_syscall(void *cpu_env, int num, 
abi_long arg1,
     abi_long ret;
 
     switch (num) {
+
+        /*
+         * File system calls.
+         */
+    case TARGET_FREEBSD_NR_read: /* read(2) */
+        ret = do_bsd_read(arg1, arg2, arg3);
+        break;
+
+    case TARGET_FREEBSD_NR_pread: /* pread(2) */
+        ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
+        break;
+
+    case TARGET_FREEBSD_NR_readv: /* readv(2) */
+        ret = do_bsd_readv(arg1, arg2, arg3);
+        break;
+
+    case TARGET_FREEBSD_NR_preadv: /* preadv(2) */
+        ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
+        break;
+
     default:
         qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
         ret = -TARGET_ENOSYS;
-- 
2.33.1