// Copyright 2022, The Android Open Source Project // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. //! Low-level compatibility layer between baremetal Rust and Bionic C functions. use core::ffi::c_char; use core::ffi::c_int; use core::ffi::c_void; use core::ffi::CStr; use core::slice; use core::str; use crate::console; use crate::eprintln; use crate::linker; const EOF: c_int = -1; /// Reference to __stack_chk_guard. pub static STACK_CHK_GUARD: &u64 = unsafe { &linker::__stack_chk_guard }; #[no_mangle] extern "C" fn __stack_chk_fail() -> ! { panic!("stack guard check failed"); } /// Called from C to cause abnormal program termination. #[no_mangle] extern "C" fn abort() -> ! { panic!("C code called abort()") } /// Error number set and read by C functions. pub static mut ERRNO: c_int = 0; #[no_mangle] unsafe extern "C" fn __errno() -> *mut c_int { &mut ERRNO as *mut _ } fn set_errno(value: c_int) { // SAFETY - vmbase is currently single-threaded. unsafe { ERRNO = value }; } /// Reports a fatal error detected by Bionic. /// /// # Safety /// /// Input strings `prefix` and `format` must be properly NULL-terminated. /// /// # Note /// /// This Rust functions is missing the last argument of its C/C++ counterpart, a va_list. #[no_mangle] unsafe extern "C" fn async_safe_fatal_va_list(prefix: *const c_char, format: *const c_char) { let prefix = CStr::from_ptr(prefix); let format = CStr::from_ptr(format); if let (Ok(prefix), Ok(format)) = (prefix.to_str(), format.to_str()) { // We don't bother with printf formatting. eprintln!("FATAL BIONIC ERROR: {prefix}: \"{format}\" (unformatted)"); } } #[repr(usize)] /// Arbitrary token FILE pseudo-pointers used by C to refer to the default streams. enum File { Stdout = 0x7670cf00, Stderr = 0x9d118200, } impl TryFrom for File { type Error = &'static str; fn try_from(value: usize) -> Result { match value { x if x == File::Stdout as _ => Ok(File::Stdout), x if x == File::Stderr as _ => Ok(File::Stderr), _ => Err("Received Invalid FILE* from C"), } } } #[no_mangle] static stdout: File = File::Stdout; #[no_mangle] static stderr: File = File::Stderr; #[no_mangle] extern "C" fn fputs(c_str: *const c_char, stream: usize) -> c_int { // SAFETY - Just like libc, we need to assume that `s` is a valid NULL-terminated string. let c_str = unsafe { CStr::from_ptr(c_str) }; if let (Ok(s), Ok(_)) = (c_str.to_str(), File::try_from(stream)) { console::write_str(s); 0 } else { set_errno(EOF); EOF } } #[no_mangle] extern "C" fn fwrite(ptr: *const c_void, size: usize, nmemb: usize, stream: usize) -> usize { let length = size.saturating_mul(nmemb); // SAFETY - Just like libc, we need to assume that `ptr` is valid. let bytes = unsafe { slice::from_raw_parts(ptr as *const u8, length) }; if let (Ok(s), Ok(_)) = (str::from_utf8(bytes), File::try_from(stream)) { console::write_str(s); length } else { 0 } } #[no_mangle] extern "C" fn strerror(n: c_int) -> *mut c_char { // Messages taken from errno(1). let s = match n { 0 => "Success", 1 => "Operation not permitted", 2 => "No such file or directory", 3 => "No such process", 4 => "Interrupted system call", 5 => "Input/output error", 6 => "No such device or address", 7 => "Argument list too long", 8 => "Exec format error", 9 => "Bad file descriptor", 10 => "No child processes", 11 => "Resource temporarily unavailable", 12 => "Cannot allocate memory", 13 => "Permission denied", 14 => "Bad address", 15 => "Block device required", 16 => "Device or resource busy", 17 => "File exists", 18 => "Invalid cross-device link", 19 => "No such device", 20 => "Not a directory", 21 => "Is a directory", 22 => "Invalid argument", 23 => "Too many open files in system", 24 => "Too many open files", 25 => "Inappropriate ioctl for device", 26 => "Text file busy", 27 => "File too large", 28 => "No space left on device", 29 => "Illegal seek", 30 => "Read-only file system", 31 => "Too many links", 32 => "Broken pipe", 33 => "Numerical argument out of domain", 34 => "Numerical result out of range", 35 => "Resource deadlock avoided", 36 => "File name too long", 37 => "No locks available", 38 => "Function not implemented", 39 => "Directory not empty", 40 => "Too many levels of symbolic links", 42 => "No message of desired type", 43 => "Identifier removed", 44 => "Channel number out of range", 45 => "Level 2 not synchronized", 46 => "Level 3 halted", 47 => "Level 3 reset", 48 => "Link number out of range", 49 => "Protocol driver not attached", 50 => "No CSI structure available", 51 => "Level 2 halted", 52 => "Invalid exchange", 53 => "Invalid request descriptor", 54 => "Exchange full", 55 => "No anode", 56 => "Invalid request code", 57 => "Invalid slot", 59 => "Bad font file format", 60 => "Device not a stream", 61 => "No data available", 62 => "Timer expired", 63 => "Out of streams resources", 64 => "Machine is not on the network", 65 => "Package not installed", 66 => "Object is remote", 67 => "Link has been severed", 68 => "Advertise error", 69 => "Srmount error", 70 => "Communication error on send", 71 => "Protocol error", 72 => "Multihop attempted", 73 => "RFS specific error", 74 => "Bad message", 75 => "Value too large for defined data type", 76 => "Name not unique on network", 77 => "File descriptor in bad state", 78 => "Remote address changed", 79 => "Can not access a needed shared library", 80 => "Accessing a corrupted shared library", 81 => ".lib section in a.out corrupted", 82 => "Attempting to link in too many shared libraries", 83 => "Cannot exec a shared library directly", 84 => "Invalid or incomplete multibyte or wide character", 85 => "Interrupted system call should be restarted", 86 => "Streams pipe error", 87 => "Too many users", 88 => "Socket operation on non-socket", 89 => "Destination address required", 90 => "Message too long", 91 => "Protocol wrong type for socket", 92 => "Protocol not available", 93 => "Protocol not supported", 94 => "Socket type not supported", 95 => "Operation not supported", 96 => "Protocol family not supported", 97 => "Address family not supported by protocol", 98 => "Address already in use", 99 => "Cannot assign requested address", 100 => "Network is down", 101 => "Network is unreachable", 102 => "Network dropped connection on reset", 103 => "Software caused connection abort", 104 => "Connection reset by peer", 105 => "No buffer space available", 106 => "Transport endpoint is already connected", 107 => "Transport endpoint is not connected", 108 => "Cannot send after transport endpoint shutdown", 109 => "Too many references: cannot splice", 110 => "Connection timed out", 111 => "Connection refused", 112 => "Host is down", 113 => "No route to host", 114 => "Operation already in progress", 115 => "Operation now in progress", 116 => "Stale file handle", 117 => "Structure needs cleaning", 118 => "Not a XENIX named type file", 119 => "No XENIX semaphores available", 120 => "Is a named type file", 121 => "Remote I/O error", 122 => "Disk quota exceeded", 123 => "No medium found", 124 => "Wrong medium type", 125 => "Operation canceled", 126 => "Required key not available", 127 => "Key has expired", 128 => "Key has been revoked", 129 => "Key was rejected by service", 130 => "Owner died", 131 => "State not recoverable", 132 => "Operation not possible due to RF-kill", 133 => "Memory page has hardware error", _ => "Unknown errno value", }; s.as_ptr().cast_mut().cast() }