[lib][uefi] Add error checking for certain block reads

Author: zhangxp1998

lib/uefi/pe.h

@@ -63,6 +63,7 @@ struct IMAGE_DOS_HEADER { // DOS .EXE header
   u16 e_res2[10];         // Reserved words
   u32 e_lfanew;           // File address of new exe header
 
+  // ASCII "PE\x0\x0"
   constexpr bool CheckMagic() const { return LE32(e_magic) == 0x5A4D; }
   IMAGE_NT_HEADERS64 *GetPEHeader() {
     auto address = reinterpret_cast<char *>(this);

lib/uefi/uefi.cpp

@@ -51,8 +51,6 @@ namespace {
 constexpr auto EFI_SYSTEM_TABLE_SIGNATURE =
     static_cast<u64>(0x5453595320494249ULL);
 
-// ASCII "PE\x0\x0"
-
 using EfiEntry = int (*)(void *, struct EfiSystemTable *);
 
 template <typename T>
@@ -103,12 +101,22 @@ int load_sections_and_execute(bdev_t *dev,
   }
   memset(image_base, 0, virtual_size);
   DEFER { free_pages(image_base, virtual_size / PAGE_SIZE); };
-  bio_read(dev, image_base, 0, section_header[0].PointerToRawData);
+  ssize_t bytes_reads =
+      bio_read(dev, image_base, 0, section_header[0].PointerToRawData);
+  if (bytes_reads != section_header[0].SizeOfRawData) {
+    printf("Failed to read section %s\n", section_header[0].Name);
+    return ERR_IO;
+  }
 
   for (size_t i = 0; i < sections; i++) {
     const auto &section = section_header[i];
-    bio_read(dev, image_base + section.VirtualAddress, section.PointerToRawData,
-             section.SizeOfRawData);
+    ssize_t bytes_read =
+        bio_read(dev, image_base + section.VirtualAddress,
+                 section.PointerToRawData, section.SizeOfRawData);
+    if (bytes_read != section.SizeOfRawData) {
+      printf("Failed to read section %s %zu\n", section.Name, bytes_read);
+      return ERR_IO;
+    }
   }
   printf("Relocating image from 0x%llx to %p\n", optional_header->ImageBase,
          image_base);