Get arm64 up to speed in os2 linux

Readded open flags for arm64 to sys/linux/bits.odin. Make process_start
name based instead of descriptor based to allow running of scripts. Fix
bug in heap_linux. Fix and simplify os2.remove.

core/os/os2/file_linux.odin

@@ -272,28 +272,12 @@ _truncate :: proc(f: ^File, size: i64) -> Error {
 }
 
 _remove :: proc(name: string) -> Error {
-	is_dir_fd :: proc(fd: linux.Fd) -> bool {
-		s: linux.Stat
-		if linux.fstat(fd, &s) != .NONE {
-			return false
-		}
-		return linux.S_ISDIR(s.mode)
-	}
-
 	TEMP_ALLOCATOR_GUARD()
 	name_cstr := temp_cstring(name) or_return
 
-	fd, errno := linux.open(name_cstr, {.NOFOLLOW})
-	#partial switch (errno) {
-	case .ELOOP:
-		/* symlink */
-	case .NONE:
-		defer linux.close(fd)
-		if is_dir_fd(fd) {
-			return _get_platform_error(linux.rmdir(name_cstr))
-		}
-	case:
-		return _get_platform_error(errno)
+	if fd, errno := linux.open(name_cstr, _OPENDIR_FLAGS); errno == .NONE {
+		linux.close(fd)
+		return _get_platform_error(linux.rmdir(name_cstr))
 	}
 
 	return _get_platform_error(linux.unlink(name_cstr))

core/os/os2/heap_linux.odin

@@ -415,7 +415,7 @@ _region_resize :: proc(alloc: ^Allocation_Header, new_size: int, alloc_is_free_l
 	back_idx := -1
 	idx: u16
 	infinite: for {
-		for i := 0; i < len(region_iter.hdr.free_list); i += 1 {
+		for i := 0; i < int(region_iter.hdr.free_list_len); i += 1 {
 			idx = region_iter.hdr.free_list[i]
 			if _get_block_count(region_iter.memory[idx]) >= new_block_count {
 				break infinite

core/os/os2/process_linux.odin

@@ -384,14 +384,6 @@ _Sys_Process_Attributes :: struct {}
 
 @(private="package")
 _process_start :: proc(desc: Process_Desc) -> (process: Process, err: Error) {
-	has_executable_permissions :: proc(fd: linux.Fd) -> bool {
-		backing: [48]u8
-		b := strings.builder_from_bytes(backing[:])
-		strings.write_string(&b, "/proc/self/fd/")
-		strings.write_int(&b, int(fd))
-		return linux.access(strings.to_cstring(&b), linux.X_OK) == .NONE
-	}
-
 	TEMP_ALLOCATOR_GUARD()
 
 	if len(desc.command) == 0 {
@@ -411,7 +403,7 @@ _process_start :: proc(desc: Process_Desc) -> (process: Process, err: Error) {
 	}
 
 	// search PATH if just a plain name is provided
-	exe_fd: linux.Fd
+	exe_path: cstring
 	executable_name := desc.command[0]
 	if strings.index_byte(executable_name, '/') < 0 {
 		path_env := get_env("PATH", temp_allocator())
@@ -426,16 +418,11 @@ _process_start :: proc(desc: Process_Desc) -> (process: Process, err: Error) {
 			strings.write_byte(&exe_builder, '/')
 			strings.write_string(&exe_builder, executable_name)
 
-			exe_path := strings.to_cstring(&exe_builder)
-			if exe_fd, errno = linux.openat(dir_fd, exe_path, {.PATH, .CLOEXEC}); errno != .NONE {
-				continue
-			}
-			if !has_executable_permissions(exe_fd) {
-				linux.close(exe_fd)
-				continue
+			exe_path = strings.to_cstring(&exe_builder)
+			if linux.access(exe_path, linux.X_OK) == .NONE {
+				found = true
+				break
 			}
-			found = true
-			break
 		}
 		if !found {
 			// check in cwd to match windows behavior
@@ -443,29 +430,18 @@ _process_start :: proc(desc: Process_Desc) -> (process: Process, err: Error) {
 			strings.write_string(&exe_builder, "./")
 			strings.write_string(&exe_builder, executable_name)
 
-			exe_path := strings.to_cstring(&exe_builder)
-			if exe_fd, errno = linux.openat(dir_fd, exe_path, {.PATH, .CLOEXEC}); errno != .NONE {
+			exe_path = strings.to_cstring(&exe_builder)
+			if linux.access(exe_path, linux.X_OK) != .NONE {
 				return process, .Not_Exist
 			}
-			if !has_executable_permissions(exe_fd) {
-				linux.close(exe_fd)
-				return process, .Permission_Denied
-			}
 		}
 	} else {
-		exe_path := temp_cstring(executable_name) or_return
-		if exe_fd, errno = linux.openat(dir_fd, exe_path, {.PATH, .CLOEXEC}); errno != .NONE {
-			return process, _get_platform_error(errno)
-		}
-		if !has_executable_permissions(exe_fd) {
-			linux.close(exe_fd)
-			return process, .Permission_Denied
+		exe_path = temp_cstring(executable_name) or_return
+		if linux.access(exe_path, linux.X_OK) != .NONE {
+			return process, .Not_Exist
 		}
 	}
 
-	// At this point, we have an executable.
-	defer linux.close(exe_fd)
-
 	// args and environment need to be a list of cstrings
 	// that are terminated by a nil pointer.
 	cargs := make([]cstring, len(desc.command) + 1, temp_allocator()) or_return
@@ -492,7 +468,6 @@ _process_start :: proc(desc: Process_Desc) -> (process: Process, err: Error) {
 	}
 	defer linux.close(child_pipe_fds[READ])
 
-
 	// TODO: This is the traditional textbook implementation with fork.
 	//       A more efficient implementation with vfork:
 	//
@@ -573,7 +548,7 @@ _process_start :: proc(desc: Process_Desc) -> (process: Process, err: Error) {
 			write_errno_to_parent_and_abort(child_pipe_fds[WRITE], errno)
 		}
 
-		errno = linux.execveat(exe_fd, "", &cargs[0], env, {.AT_EMPTY_PATH})
+		errno = linux.execveat(dir_fd, exe_path, &cargs[0], env)
 		assert(errno != nil)
 		write_errno_to_parent_and_abort(child_pipe_fds[WRITE], errno)
 	}

core/sys/linux/bits.odin

@@ -152,43 +152,65 @@ Errno :: enum i32 {
 	RDONLY flag is not present, because it has the value of 0, i.e. it is the
 	default, unless WRONLY or RDWR is specified.
 */
-Open_Flags_Bits :: enum {
-	WRONLY    = 0,
-	RDWR      = 1,
-	CREAT     = 6,
-	EXCL      = 7,
-	NOCTTY    = 8,
-	TRUNC     = 9,
-	APPEND    = 10,
-	NONBLOCK  = 11,
-	DSYNC     = 12,
-	ASYNC     = 13,
-	DIRECT    = 14,
-	LARGEFILE = 15,
-	DIRECTORY = 16,
-	NOFOLLOW  = 17,
-	NOATIME   = 18,
-	CLOEXEC   = 19,
-	PATH      = 21,
-}
-// https://github.com/torvalds/linux/blob/7367539ad4b0f8f9b396baf02110962333719a48/include/uapi/asm-generic/fcntl.h#L19
-#assert(1 << uint(Open_Flags_Bits.WRONLY)    == 0o0000000_1)
-#assert(1 << uint(Open_Flags_Bits.RDWR)      == 0o0000000_2)
-#assert(1 << uint(Open_Flags_Bits.CREAT)     == 0o00000_100)
-#assert(1 << uint(Open_Flags_Bits.EXCL)      == 0o00000_200)
-#assert(1 << uint(Open_Flags_Bits.NOCTTY)    == 0o00000_400)
-#assert(1 << uint(Open_Flags_Bits.TRUNC)     == 0o0000_1000)
-#assert(1 << uint(Open_Flags_Bits.APPEND)    == 0o0000_2000)
-#assert(1 << uint(Open_Flags_Bits.NONBLOCK)  == 0o0000_4000)
-#assert(1 << uint(Open_Flags_Bits.DSYNC)     == 0o000_10000)
-#assert(1 << uint(Open_Flags_Bits.ASYNC)     == 0o000_20000)
-#assert(1 << uint(Open_Flags_Bits.DIRECT)    == 0o000_40000)
-#assert(1 << uint(Open_Flags_Bits.LARGEFILE) == 0o00_100000)
-#assert(1 << uint(Open_Flags_Bits.DIRECTORY) == 0o00_200000)
-#assert(1 << uint(Open_Flags_Bits.NOFOLLOW)  == 0o00_400000)
-#assert(1 << uint(Open_Flags_Bits.NOATIME)   == 0o0_1000000)
-#assert(1 << uint(Open_Flags_Bits.CLOEXEC)   == 0o0_2000000)
-#assert(1 << uint(Open_Flags_Bits.PATH)      == 0o_10000000)
+when ODIN_ARCH != .arm64 && ODIN_ARCH != .arm32 {
+	Open_Flags_Bits :: enum {
+		WRONLY    = 0,
+		RDWR      = 1,
+		CREAT     = 6,
+		EXCL      = 7,
+		NOCTTY    = 8,
+		TRUNC     = 9,
+		APPEND    = 10,
+		NONBLOCK  = 11,
+		DSYNC     = 12,
+		ASYNC     = 13,
+		DIRECT    = 14,
+		LARGEFILE = 15,
+		DIRECTORY = 16,
+		NOFOLLOW  = 17,
+		NOATIME   = 18,
+		CLOEXEC   = 19,
+		PATH      = 21,
+	}
+	// https://github.com/torvalds/linux/blob/7367539ad4b0f8f9b396baf02110962333719a48/include/uapi/asm-generic/fcntl.h#L19
+	#assert(1 << uint(Open_Flags_Bits.WRONLY)    == 0o0000000_1)
+	#assert(1 << uint(Open_Flags_Bits.RDWR)      == 0o0000000_2)
+	#assert(1 << uint(Open_Flags_Bits.CREAT)     == 0o00000_100)
+	#assert(1 << uint(Open_Flags_Bits.EXCL)      == 0o00000_200)
+	#assert(1 << uint(Open_Flags_Bits.NOCTTY)    == 0o00000_400)
+	#assert(1 << uint(Open_Flags_Bits.TRUNC)     == 0o0000_1000)
+	#assert(1 << uint(Open_Flags_Bits.APPEND)    == 0o0000_2000)
+	#assert(1 << uint(Open_Flags_Bits.NONBLOCK)  == 0o0000_4000)
+	#assert(1 << uint(Open_Flags_Bits.DSYNC)     == 0o000_10000)
+	#assert(1 << uint(Open_Flags_Bits.ASYNC)     == 0o000_20000)
+	#assert(1 << uint(Open_Flags_Bits.DIRECT)    == 0o000_40000)
+	#assert(1 << uint(Open_Flags_Bits.LARGEFILE) == 0o00_100000)
+	#assert(1 << uint(Open_Flags_Bits.DIRECTORY) == 0o00_200000)
+	#assert(1 << uint(Open_Flags_Bits.NOFOLLOW)  == 0o00_400000)
+	#assert(1 << uint(Open_Flags_Bits.NOATIME)   == 0o0_1000000)
+	#assert(1 << uint(Open_Flags_Bits.CLOEXEC)   == 0o0_2000000)
+	#assert(1 << uint(Open_Flags_Bits.PATH)      == 0o_10000000)
+} else {
+	Open_Flags_Bits :: enum {
+		WRONLY    = 0,
+		RDWR      = 1,
+		CREAT     = 6,
+		EXCL      = 7,
+		NOCTTY    = 8,
+		TRUNC     = 9,
+		APPEND    = 10,
+		NONBLOCK  = 11,
+		DSYNC     = 12,
+		ASYNC     = 13,
+		DIRECTORY = 14,
+		NOFOLLOW  = 15,
+		DIRECT    = 16,
+		LARGEFILE = 17,
+		NOATIME   = 18,
+		CLOEXEC   = 19,
+		PATH      = 21,
+	}
+}
 
 /*
 	Bits for FD_Flags bitset