[libc-commits] [libc] [libc][uefi] Encode the error bit in EFI_STATUS error codes (PR #235071)

[Prabhu Rajasekaran via libc-commits]

================
@@ -1,104 +1,87 @@
-//===----------------------------------------------------------------------===//
+//===-- Definition of UEFI error utilities --------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-///
-/// \file
-/// UEFI implementation of error utils.
-///
-//===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_UEFI_ERROR_H
 #define LLVM_LIBC_SRC___SUPPORT_OSUTIL_UEFI_ERROR_H
 
 #include "hdr/errno_macros.h"
 #include "include/llvm-libc-types/EFI_STATUS.h"
 #include "src/__support/CPP/array.h"
-#include "src/__support/CPP/limits.h"
 #include "src/__support/macros/attributes.h"
 #include "src/__support/macros/config.h"
 
 namespace LIBC_NAMESPACE_DECL {
 
-static constexpr int EFI_ERROR_MAX_BIT = cpp::numeric_limits<EFI_STATUS>::max();
-
-static constexpr int EFI_ENCODE_ERROR(int value) {
-  return EFI_ERROR_MAX_BIT | (EFI_ERROR_MAX_BIT >> 2) | (value);
-}
-
-static constexpr int EFI_ENCODE_WARNING(int value) {
-  return (EFI_ERROR_MAX_BIT >> 2) | (value);
-}
-
 struct UefiStatusErrnoEntry {
   EFI_STATUS status;
   int errno_value;
 };
 
-static constexpr cpp::array<UefiStatusErrnoEntry, 43> UEFI_STATUS_ERRNO_MAP = {{
+// The EFI_* macros already carry the error bit as defined by the UEFI
+// specification; warnings are plain values.
+static constexpr cpp::array<UefiStatusErrnoEntry, 42> UEFI_STATUS_ERRNO_MAP = {{
     {EFI_SUCCESS, 0},
-    {EFI_ENCODE_ERROR(EFI_LOAD_ERROR), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_INVALID_PARAMETER), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_BAD_BUFFER_SIZE), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_NOT_READY), EBUSY},
-    {EFI_ENCODE_ERROR(EFI_DEVICE_ERROR), EIO},
-    {EFI_ENCODE_ERROR(EFI_WRITE_PROTECTED), EPERM},
-    {EFI_ENCODE_ERROR(EFI_OUT_OF_RESOURCES), ENOMEM},
-    {EFI_ENCODE_ERROR(EFI_VOLUME_CORRUPTED), EROFS},
-    {EFI_ENCODE_ERROR(EFI_VOLUME_FULL), ENOSPC},
-    {EFI_ENCODE_ERROR(EFI_NO_MEDIA), ENODEV},
-    {EFI_ENCODE_ERROR(EFI_MEDIA_CHANGED), ENXIO},
-    {EFI_ENCODE_ERROR(EFI_NOT_FOUND), ENOENT},
-    {EFI_ENCODE_ERROR(EFI_ACCESS_DENIED), EACCES},
-    {EFI_ENCODE_ERROR(EFI_NO_RESPONSE), EBUSY},
-    {EFI_ENCODE_ERROR(EFI_NO_MAPPING), ENODEV},
-    {EFI_ENCODE_ERROR(EFI_TIMEOUT), EBUSY},
-    {EFI_ENCODE_ERROR(EFI_NOT_STARTED), EAGAIN},
-    {EFI_ENCODE_ERROR(EFI_ALREADY_STARTED), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_ABORTED), EFAULT},
-    {EFI_ENCODE_ERROR(EFI_ICMP_ERROR), EIO},
-    {EFI_ENCODE_ERROR(EFI_TFTP_ERROR), EIO},
-    {EFI_ENCODE_ERROR(EFI_PROTOCOL_ERROR), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_INCOMPATIBLE_VERSION), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_SECURITY_VIOLATION), EPERM},
-    {EFI_ENCODE_ERROR(EFI_CRC_ERROR), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_END_OF_MEDIA), EPIPE},
-    {EFI_ENCODE_ERROR(EFI_END_OF_FILE), EPIPE},
-    {EFI_ENCODE_ERROR(EFI_INVALID_LANGUAGE), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_COMPROMISED_DATA), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_IP_ADDRESS_CONFLICT), EINVAL},
-    {EFI_ENCODE_ERROR(EFI_HTTP_ERROR), EIO},
-    {EFI_ENCODE_WARNING(EFI_WARN_UNKNOWN_GLYPH), EINVAL},
-    {EFI_ENCODE_WARNING(EFI_WARN_DELETE_FAILURE), EROFS},
-    {EFI_ENCODE_WARNING(EFI_WARN_WRITE_FAILURE), EROFS},
-    {EFI_ENCODE_WARNING(EFI_WARN_BUFFER_TOO_SMALL), E2BIG},
-    {EFI_ENCODE_WARNING(EFI_WARN_STALE_DATA), EINVAL},
-    {EFI_ENCODE_WARNING(EFI_WARN_FILE_SYSTEM), EROFS},
-    {EFI_ENCODE_WARNING(EFI_WARN_RESET_REQUIRED), EINTR},
+    {EFI_LOAD_ERROR, EINVAL},
+    {EFI_INVALID_PARAMETER, EINVAL},
+    {EFI_UNSUPPORTED, EINVAL},
+    {EFI_BAD_BUFFER_SIZE, EINVAL},
+    {EFI_BUFFER_TOO_SMALL, ERANGE},
+    {EFI_NOT_READY, EBUSY},
+    {EFI_DEVICE_ERROR, EIO},
+    {EFI_WRITE_PROTECTED, EPERM},
+    {EFI_OUT_OF_RESOURCES, ENOMEM},
+    {EFI_VOLUME_CORRUPTED, EROFS},
+    {EFI_VOLUME_FULL, ENOSPC},
+    {EFI_NO_MEDIA, ENODEV},
+    {EFI_MEDIA_CHANGED, ENXIO},
+    {EFI_NOT_FOUND, ENOENT},
+    {EFI_ACCESS_DENIED, EACCES},
+    {EFI_NO_RESPONSE, EBUSY},
+    {EFI_NO_MAPPING, ENODEV},
+    {EFI_TIMEOUT, EBUSY},
+    {EFI_NOT_STARTED, EAGAIN},
+    {EFI_ALREADY_STARTED, EINVAL},
+    {EFI_ABORTED, EFAULT},
+    {EFI_ICMP_ERROR, EIO},
+    {EFI_TFTP_ERROR, EIO},
+    {EFI_PROTOCOL_ERROR, EINVAL},
+    {EFI_INCOMPATIBLE_VERSION, EINVAL},
+    {EFI_SECURITY_VIOLATION, EPERM},
+    {EFI_CRC_ERROR, EINVAL},
+    {EFI_END_OF_MEDIA, EPIPE},
+    {EFI_END_OF_FILE, EPIPE},
+    {EFI_INVALID_LANGUAGE, EINVAL},
+    {EFI_COMPROMISED_DATA, EINVAL},
+    {EFI_IP_ADDRESS_CONFLICT, EINVAL},
+    {EFI_HTTP_ERROR, EIO},
+    {EFI_WARN_UNKNOWN_GLYPH, EINVAL},
+    {EFI_WARN_DELETE_FAILURE, EROFS},
+    {EFI_WARN_WRITE_FAILURE, EROFS},
+    {EFI_WARN_BUFFER_TOO_SMALL, E2BIG},
+    {EFI_WARN_STALE_DATA, EINVAL},
+    {EFI_WARN_FILE_SYSTEM, EROFS},
+    {EFI_WARN_RESET_REQUIRED, EINTR},
 }};
 
 LIBC_INLINE int uefi_status_to_errno(EFI_STATUS status) {
-  for (auto it = UEFI_STATUS_ERRNO_MAP.begin();
-       it != UEFI_STATUS_ERRNO_MAP.end(); it++) {
-    const struct UefiStatusErrnoEntry entry = *it;
+  for (const UefiStatusErrnoEntry &entry : UEFI_STATUS_ERRNO_MAP)
     if (entry.status == status)
       return entry.errno_value;
-  }
 
-  // Unknown type
-  return EINVAL;
+  // Unknown status; report it as an I/O error if it is an error code and as
+  // success otherwise, since warnings do not fail the operation.
+  return EFI_ERROR(status) ? EIO : 0;
 }
 
 LIBC_INLINE EFI_STATUS errno_to_uefi_status(int errno_value) {
-  for (auto it = UEFI_STATUS_ERRNO_MAP.begin();
-       it != UEFI_STATUS_ERRNO_MAP.end(); it++) {
-    const struct UefiStatusErrnoEntry entry = *it;
+  for (const UefiStatusErrnoEntry &entry : UEFI_STATUS_ERRNO_MAP)
     if (entry.errno_value == errno_value)
       return entry.status;
-  }
 
   // Unknown type
----------------
Prabhuk wrote:

Done.

https://github.com/llvm/llvm-project/pull/235071