feat(vfs): 新增creat系统调用支持 (#1482)

* feat(vfs): 新增creat系统调用支持

- 实现creat系统调用处理器，遵循Linux语义：创建新文件或截断现有文件并打开为只写模式
- 在x86_64架构下注册creat系统调用到系统调用表
- 在gvisor测试白名单中添加creat测试项

Signed-off-by: longjin <longjin@DragonOS.org>

* feat(rust-jhash): Update Cargo.toml to specify Rust edition 2021

---------

Signed-off-by: longjin <longjin@DragonOS.org>

Author: fslongjin

kernel/crates/rust-jhash/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "jhash"
 version = "0.1.1"
+edition = "2021"
 authors = ["Keunhong Lee <dlrmsghd@gmail.com>"]
 
 homepage = "https://github.com/ANLAB-KAIST/rust-jhash"

kernel/src/filesystem/vfs/syscall/mod.rs

@@ -80,6 +80,8 @@ mod sys_epoll_create;
 #[cfg(target_arch = "x86_64")]
 mod sys_epoll_wait;
 
+#[cfg(target_arch = "x86_64")]
+mod sys_creat;
 #[cfg(target_arch = "x86_64")]
 mod sys_futimesat;
 #[cfg(target_arch = "x86_64")]

kernel/src/filesystem/vfs/syscall/sys_creat.rs

@@ -0,0 +1,72 @@
+//! System call handler for creating files (creat).
+//!
+//! The `creat` system call is a legacy interface that is equivalent to:
+//! `open(path, O_WRONLY | O_CREAT | O_TRUNC, mode)`
+//!
+//! This implementation follows Linux semantics:
+//! - Creates a new file if it doesn't exist
+//! - Truncates an existing file to zero length
+//! - Opens the file in write-only mode
+//! - Returns ENAMETOOLONG if the filename is too long
+
+use system_error::SystemError;
+
+use crate::arch::interrupt::TrapFrame;
+use crate::arch::syscall::nr::SYS_CREAT;
+use crate::filesystem::vfs::file::FileFlags;
+use crate::syscall::table::FormattedSyscallParam;
+use crate::syscall::table::Syscall;
+
+use alloc::string::ToString;
+use alloc::vec::Vec;
+
+/// Handler for the `creat` system call.
+pub struct SysCreatHandle;
+
+impl Syscall for SysCreatHandle {
+    /// Returns the number of arguments this syscall takes (2).
+    fn num_args(&self) -> usize {
+        2
+    }
+
+    /// Handles the creat syscall by extracting arguments and calling `do_open`
+    /// with O_WRONLY | O_CREAT | O_TRUNC flags.
+    ///
+    /// # Arguments
+    /// * `args[0]` - Path to the file (pointer to C string)
+    /// * `args[1]` - File mode/permissions
+    ///
+    /// # Returns
+    /// File descriptor on success, or error code on failure.
+    fn handle(&self, args: &[usize], _frame: &mut TrapFrame) -> Result<usize, SystemError> {
+        let path = Self::path(args);
+        let mode = Self::mode(args);
+
+        // creat(path, mode) is equivalent to open(path, O_WRONLY | O_CREAT | O_TRUNC, mode)
+        let flags = (FileFlags::O_WRONLY | FileFlags::O_CREAT | FileFlags::O_TRUNC).bits();
+
+        super::open_utils::do_open(path, flags, mode)
+    }
+
+    /// Formats the syscall arguments for display/debugging purposes.
+    fn entry_format(&self, args: &[usize]) -> Vec<FormattedSyscallParam> {
+        vec![
+            FormattedSyscallParam::new("path", format!("{:#x}", Self::path(args) as usize)),
+            FormattedSyscallParam::new("mode", Self::mode(args).to_string()),
+        ]
+    }
+}
+
+impl SysCreatHandle {
+    /// Extracts the path argument from syscall parameters.
+    fn path(args: &[usize]) -> *const u8 {
+        args[0] as *const u8
+    }
+
+    /// Extracts the mode argument from syscall parameters.
+    fn mode(args: &[usize]) -> u32 {
+        args[1] as u32
+    }
+}
+
+syscall_table_macros::declare_syscall!(SYS_CREAT, SysCreatHandle);

user/apps/tests/syscall/gvisor/whitelist.txt

@@ -13,6 +13,7 @@ getcpu_host_test
 
 # 文件系统相关测试
 chroot_test
+creat_test
 dup_test
 write_test
 mkdir_test
@@ -80,4 +81,4 @@ pipe_test
 fifo_test
 unshare_test
 pty_root_test
-time_test
+time_test