[UNIKRAFT PATCH 3/8] lib/vfscore: Register `open` to syscall_shim

[Constantin Raducanu <raducanu.costi@xxxxxxxxx>]

Registers `open` system call to syscall_shim library.
The signature of the `open` library call is different from signature
of the `open` syscall, forcing us to use the macro UK_LLSYSCALL_R_DEFINE.

Signed-off-by: Constantin Raducanu <raducanu.costi@xxxxxxxxx>
---
 lib/vfscore/Makefile.uk   |  3 ++-
 lib/vfscore/exportsyms.uk |  2 ++
 lib/vfscore/main.c        | 42 ++++++++++++++++++++++-----------------
 3 files changed, 28 insertions(+), 19 deletions(-)

diff --git a/lib/vfscore/Makefile.uk b/lib/vfscore/Makefile.uk
index c8451e7..1fe5eb6 100644
--- a/lib/vfscore/Makefile.uk
+++ b/lib/vfscore/Makefile.uk
@@ -56,4 +56,5 @@ UK_PROVIDED_SYSCALLS-$(CONFIG_LIBVFSCORE) += umask-1
 UK_PROVIDED_SYSCALLS-$(CONFIG_LIBVFSCORE) += lstat-2
 UK_PROVIDED_SYSCALLS-$(CONFIG_LIBVFSCORE) += flock-2
 UK_PROVIDED_SYSCALLS-$(CONFIG_LIBVFSCORE) += unlink-1
-UK_PROVIDED_SYSCALLS-$(CONFIG_LIBVFSCORE) += stat-2
\ No newline at end of file
+UK_PROVIDED_SYSCALLS-$(CONFIG_LIBVFSCORE) += stat-2
+UK_PROVIDED_SYSCALLS-$(CONFIG_LIBVFSCORE) += open-3
\ No newline at end of file
diff --git a/lib/vfscore/exportsyms.uk b/lib/vfscore/exportsyms.uk
index 3e9642b..7e2f7ea 100644
--- a/lib/vfscore/exportsyms.uk
+++ b/lib/vfscore/exportsyms.uk
@@ -13,6 +13,8 @@ vfscore_vop_einval
 vfscore_vop_eperm
 vfscore_vop_erofs
 open
+uk_syscall_e_open
+uk_syscall_r_open
 creat
 write
 uk_syscall_e_write
diff --git a/lib/vfscore/main.c b/lib/vfscore/main.c
index db190b9..1bbbbd4 100644
--- a/lib/vfscore/main.c
+++ b/lib/vfscore/main.c
@@ -84,16 +84,8 @@ UK_TRACEPOINT(trace_vfs_open_err, "%d", int);
 
 struct task *main_task;        /* we only have a single process */
 
-int open(const char *pathname, int flags, ...)
+UK_LLSYSCALL_R_DEFINE(int, open, const char*, pathname, int, flags, mode_t, 
mode)
 {
-       mode_t mode = 0;
-       if (flags & O_CREAT) {
-               va_list ap;
-               va_start(ap, flags);
-               mode = apply_umask(va_arg(ap, mode_t));
-               va_end(ap);
-       }
-
        trace_vfs_open(pathname, flags, mode);
 
        struct task *t = main_task;
@@ -117,11 +109,11 @@ int open(const char *pathname, int flags, ...)
 
        error = task_conv(t, pathname, acc, path);
        if (error)
-               goto out_errno;
+               goto out_error;
 
        error = sys_open(path, flags, mode, &fp);
        if (error)
-               goto out_errno;
+               goto out_error;
 
        error = fdalloc(fp, &fd);
        if (error)
@@ -132,10 +124,22 @@ int open(const char *pathname, int flags, ...)
 
        out_fput:
        fdrop(fp);
-       out_errno:
-       errno = error;
+       out_error:
        trace_vfs_open_err(error);
-       return -1;
+       return -error;
+}
+
+int open(const char *pathname, int flags, ...)
+{
+       mode_t mode = 0;
+       if (flags & O_CREAT) {
+               va_list ap;
+               va_start(ap, flags);
+               mode = apply_umask(va_arg(ap, mode_t));
+               va_end(ap);
+       }
+
+       return uk_syscall_e_open((long int)pathname, flags, mode);
 }
 
 LFS64(open);
@@ -151,7 +155,7 @@ int openat(int dirfd, const char *pathname, int flags, ...)
        }
 
        if (pathname[0] == '/' || dirfd == AT_FDCWD) {
-               return open(pathname, flags, mode);
+               return uk_syscall_e_open((long int)pathname, flags, mode);
        }
 
        struct vfscore_file *fp;
@@ -172,7 +176,7 @@ int openat(int dirfd, const char *pathname, int flags, ...)
        strlcat(p, "/", PATH_MAX);
        strlcat(p, pathname, PATH_MAX);
 
-       error = open(p, flags, mode);
+       error = uk_syscall_e_open((long int)p, flags, mode);
 
        vn_unlock(vp);
        fdrop(fp);
@@ -183,7 +187,8 @@ LFS64(openat);
 
 int creat(const char *pathname, mode_t mode)
 {
-       return open(pathname, O_CREAT|O_WRONLY|O_TRUNC, mode);
+       return uk_syscall_e_open((long int) pathname,
+               O_CREAT|O_WRONLY|O_TRUNC, mode);
 }
 LFS64(creat);
 
@@ -646,6 +651,7 @@ DIR *opendir(const char *path)
 {
        DIR *dir;
        struct stat st;
+       mode_t mode = 0;
 
        dir = malloc(sizeof(*dir));
        if (!dir) {
@@ -653,7 +659,7 @@ DIR *opendir(const char *path)
                goto out_err;
        }
 
-       dir->fd = open(path, O_RDONLY);
+       dir->fd = uk_syscall_e_open((long int)path, O_RDONLY, mode);
        if (dir->fd < 0)
                goto out_free_dir;
 
-- 
2.17.1