From 98f57101ba066e247c87b7b39b53df2e597805ee Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Thu, 9 Jun 2016 12:22:29 -0400
Subject: [PATCH 160/192] Re-work some intricacies of PE loading.
The PE spec is not a well written document, and awesomely every place
where there's an ambiguous way to read something, Windows' bootmgfw.efi
takes a different read than either of them.
---
grub-core/loader/efi/chainloader.c | 156 +++++++++++++++++++++++++++++--------
include/grub/efi/pe32.h | 32 +++++++-
2 files changed, 152 insertions(+), 36 deletions(-)
diff --git a/grub-core/loader/efi/chainloader.c b/grub-core/loader/efi/chainloader.c
index aee8e6bec..4b77a7d5a 100644
--- a/grub-core/loader/efi/chainloader.c
+++ b/grub-core/loader/efi/chainloader.c
@@ -301,7 +301,7 @@ image_is_64_bit (grub_pe_header_t *pe_hdr)
return 0;
}
-static const grub_uint16_t machine_type =
+static const grub_uint16_t machine_type __attribute__((__unused__)) =
#if defined(__x86_64__)
GRUB_PE32_MACHINE_X86_64;
#elif defined(__aarch64__)
@@ -367,10 +367,10 @@ relocate_coff (pe_coff_loader_image_context_t *context,
reloc_base = image_address (orig, size, section->raw_data_offset);
reloc_base_end = image_address (orig, size, section->raw_data_offset
- + section->virtual_size - 1);
+ + section->virtual_size);
- grub_dprintf ("chain", "reloc_base %p reloc_base_end %p\n", reloc_base,
- reloc_base_end);
+ grub_dprintf ("chain", "relocate_coff(): reloc_base %p reloc_base_end %p\n",
+ reloc_base, reloc_base_end);
if (!reloc_base && !reloc_base_end)
return GRUB_EFI_SUCCESS;
@@ -507,12 +507,13 @@ handle_image (void *data, grub_efi_uint32_t datasize)
grub_efi_status_t efi_status;
char *buffer = NULL;
char *buffer_aligned = NULL;
- grub_efi_uint32_t i, size;
+ grub_efi_uint32_t i;
struct grub_pe32_section_table *section;
char *base, *end;
pe_coff_loader_image_context_t context;
grub_uint32_t section_alignment;
grub_uint32_t buffer_size;
+ int found_entry_point = 0;
b = grub_efi_system_table->boot_services;
@@ -526,8 +527,28 @@ handle_image (void *data, grub_efi_uint32_t datasize)
goto error_exit;
}
+ /*
+ * The spec says, uselessly, of SectionAlignment:
+ * =====
+ * The alignment (in bytes) of sections when they are loaded into
+ * memory. It must be greater than or equal to FileAlignment. The
+ * default is the page size for the architecture.
+ * =====
+ * Which doesn't tell you whose responsibility it is to enforce the
+ * "default", or when. It implies that the value in the field must
+ * be > FileAlignment (also poorly defined), but it appears visual
+ * studio will happily write 512 for FileAlignment (its default) and
+ * 0 for SectionAlignment, intending to imply PAGE_SIZE.
+ *
+ * We only support one page size, so if it's zero, nerf it to 4096.
+ */
section_alignment = context.section_alignment;
+ if (section_alignment == 0)
+ section_alignment = 4096;
+
buffer_size = context.image_size + section_alignment;
+ grub_dprintf ("chain", "image size is %08lx, datasize is %08x\n",
+ context.image_size, datasize);
efi_status = efi_call_3 (b->allocate_pool, GRUB_EFI_LOADER_DATA,
buffer_size, &buffer);
@@ -539,7 +560,6 @@ handle_image (void *data, grub_efi_uint32_t datasize)
}
buffer_aligned = (char *)ALIGN_UP ((grub_addr_t)buffer, section_alignment);
-
if (!buffer_aligned)
{
grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
@@ -548,27 +568,62 @@ handle_image (void *data, grub_efi_uint32_t datasize)
grub_memcpy (buffer_aligned, data, context.size_of_headers);
+ entry_point = image_address (buffer_aligned, context.image_size,
+ context.entry_point);
+
+ grub_dprintf ("chain", "entry_point: %p\n", entry_point);
+ if (!entry_point)
+ {
+ grub_error (GRUB_ERR_BAD_ARGUMENT, "invalid entry point");
+ goto error_exit;
+ }
+
char *reloc_base, *reloc_base_end;
- reloc_base = image_address (buffer_aligned, datasize,
+ grub_dprintf ("chain", "reloc_dir: %p reloc_size: 0x%08x\n",
+ (void *)(unsigned long long)context.reloc_dir->rva,
+ context.reloc_dir->size);
+ reloc_base = image_address (buffer_aligned, context.image_size,
context.reloc_dir->rva);
/* RelocBaseEnd here is the address of the last byte of the table */
- reloc_base_end = image_address (buffer_aligned, datasize,
+ reloc_base_end = image_address (buffer_aligned, context.image_size,
context.reloc_dir->rva
+ context.reloc_dir->size - 1);
+ grub_dprintf ("chain", "reloc_base: %p reloc_base_end: %p\n",
+ reloc_base, reloc_base_end);
+
struct grub_pe32_section_table *reloc_section = NULL;
section = context.first_section;
for (i = 0; i < context.number_of_sections; i++, section++)
{
- size = section->virtual_size;
- if (size > section->raw_data_size)
- size = section->raw_data_size;
+ char name[9];
base = image_address (buffer_aligned, context.image_size,
section->virtual_address);
end = image_address (buffer_aligned, context.image_size,
- section->virtual_address + size - 1);
+ section->virtual_address + section->virtual_size -1);
+ grub_strncpy(name, section->name, 9);
+ name[8] = '\0';
+ grub_dprintf ("chain", "Section %d \"%s\" at %p..%p\n", i,
+ name, base, end);
+
+ if (end < base)
+ {
+ grub_dprintf ("chain", " base is %p but end is %p... bad.\n",
+ base, end);
+ grub_error (GRUB_ERR_BAD_ARGUMENT,
+ "Image has invalid negative size");
+ goto error_exit;
+ }
+
+ if (section->virtual_address <= context.entry_point &&
+ (section->virtual_address + section->raw_data_size - 1)
+ > context.entry_point)
+ {
+ found_entry_point++;
+ grub_dprintf ("chain", " section contains entry point\n");
+ }
/* We do want to process .reloc, but it's often marked
* discardable, so we don't want to memcpy it. */
@@ -587,21 +642,46 @@ handle_image (void *data, grub_efi_uint32_t datasize)
if (section->raw_data_size && section->virtual_size &&
base && end && reloc_base == base && reloc_base_end == end)
{
+ grub_dprintf ("chain", " section is relocation section\n");
reloc_section = section;
}
+ else
+ {
+ grub_dprintf ("chain", " section is not reloc section?\n");
+ grub_dprintf ("chain", " rds: 0x%08x, vs: %08x\n",
+ section->raw_data_size, section->virtual_size);
+ grub_dprintf ("chain", " base: %p end: %p\n", base, end);
+ grub_dprintf ("chain", " reloc_base: %p reloc_base_end: %p\n",
+ reloc_base, reloc_base_end);
+ }
}
- if (section->characteristics && GRUB_PE32_SCN_MEM_DISCARDABLE)
- continue;
+ grub_dprintf ("chain", " Section characteristics are %08x\n",
+ section->characteristics);
+ grub_dprintf ("chain", " Section virtual size: %08x\n",
+ section->virtual_size);
+ grub_dprintf ("chain", " Section raw_data size: %08x\n",
+ section->raw_data_size);
+ if (section->characteristics & GRUB_PE32_SCN_MEM_DISCARDABLE)
+ {
+ grub_dprintf ("chain", " Discarding section\n");
+ continue;
+ }
if (!base || !end)
{
+ grub_dprintf ("chain", " section is invalid\n");
grub_error (GRUB_ERR_BAD_ARGUMENT, "Invalid section size");
goto error_exit;
}
- if (section->virtual_address < context.size_of_headers ||
- section->raw_data_offset < context.size_of_headers)
+ if (section->characteristics & GRUB_PE32_SCN_CNT_UNINITIALIZED_DATA)
+ {
+ if (section->raw_data_size != 0)
+ grub_dprintf ("chain", " UNINITIALIZED_DATA section has data?\n");
+ }
+ else if (section->virtual_address < context.size_of_headers ||
+ section->raw_data_offset < context.size_of_headers)
{
grub_error (GRUB_ERR_BAD_ARGUMENT,
"Section %d is inside image headers", i);
@@ -609,13 +689,24 @@ handle_image (void *data, grub_efi_uint32_t datasize)
}
if (section->raw_data_size > 0)
- grub_memcpy (base, (grub_efi_uint8_t*)data + section->raw_data_offset,
- size);
+ {
+ grub_dprintf ("chain", " copying 0x%08x bytes to %p\n",
+ section->raw_data_size, base);
+ grub_memcpy (base,
+ (grub_efi_uint8_t*)data + section->raw_data_offset,
+ section->raw_data_size);
+ }
- if (size < section->virtual_size)
- grub_memset (base + size, 0, section->virtual_size - size);
+ if (section->raw_data_size < section->virtual_size)
+ {
+ grub_dprintf ("chain", " padding with 0x%08x bytes at %p\n",
+ section->virtual_size - section->raw_data_size,
+ base + section->raw_data_size);
+ grub_memset (base + section->raw_data_size, 0,
+ section->virtual_size - section->raw_data_size);
+ }
- grub_dprintf ("chain", "copied section %s\n", section->name);
+ grub_dprintf ("chain", " finished section %s\n", name);
}
/* 5 == EFI_IMAGE_DIRECTORY_ENTRY_BASERELOC */
@@ -638,12 +729,15 @@ handle_image (void *data, grub_efi_uint32_t datasize)
}
}
- entry_point = image_address (buffer_aligned, context.image_size,
- context.entry_point);
-
- if (!entry_point)
+ if (!found_entry_point)
{
- grub_error (GRUB_ERR_BAD_ARGUMENT, "invalid entry point");
+ grub_error (GRUB_ERR_BAD_ARGUMENT, "entry point is not within sections");
+ goto error_exit;
+ }
+ if (found_entry_point > 1)
+ {
+ grub_error (GRUB_ERR_BAD_ARGUMENT, "%d sections contain entry point",
+ found_entry_point);
goto error_exit;
}
@@ -661,26 +755,24 @@ handle_image (void *data, grub_efi_uint32_t datasize)
li->load_options_size = cmdline_len;
li->file_path = grub_efi_get_media_file_path (file_path);
li->device_handle = dev_handle;
- if (li->file_path)
- {
- grub_printf ("file path: ");
- grub_efi_print_device_path (li->file_path);
- }
- else
+ if (!li->file_path)
{
grub_error (GRUB_ERR_UNKNOWN_DEVICE, "no matching file path found");
goto error_exit;
}
+ grub_dprintf ("chain", "booting via entry point\n");
efi_status = efi_call_2 (entry_point, grub_efi_image_handle,
grub_efi_system_table);
+ grub_dprintf ("chain", "entry_point returned %ld\n", efi_status);
grub_memcpy (li, &li_bak, sizeof (grub_efi_loaded_image_t));
efi_status = efi_call_1 (b->free_pool, buffer);
return 1;
error_exit:
+ grub_dprintf ("chain", "error_exit: grub_errno: %d\n", grub_errno);
if (buffer)
efi_call_1 (b->free_pool, buffer);
diff --git a/include/grub/efi/pe32.h b/include/grub/efi/pe32.h
index 6e24dae2c..c03cc599f 100644
--- a/include/grub/efi/pe32.h
+++ b/include/grub/efi/pe32.h
@@ -229,12 +229,18 @@ struct grub_pe32_section_table
grub_uint32_t characteristics;
};
+#define GRUB_PE32_SCN_TYPE_NO_PAD 0x00000008
#define GRUB_PE32_SCN_CNT_CODE 0x00000020
#define GRUB_PE32_SCN_CNT_INITIALIZED_DATA 0x00000040
-#define GRUB_PE32_SCN_MEM_DISCARDABLE 0x02000000
-#define GRUB_PE32_SCN_MEM_EXECUTE 0x20000000
-#define GRUB_PE32_SCN_MEM_READ 0x40000000
-#define GRUB_PE32_SCN_MEM_WRITE 0x80000000
+#define GRUB_PE32_SCN_CNT_UNINITIALIZED_DATA 0x00000080
+#define GRUB_PE32_SCN_LNK_OTHER 0x00000100
+#define GRUB_PE32_SCN_LNK_INFO 0x00000200
+#define GRUB_PE32_SCN_LNK_REMOVE 0x00000800
+#define GRUB_PE32_SCN_LNK_COMDAT 0x00001000
+#define GRUB_PE32_SCN_GPREL 0x00008000
+#define GRUB_PE32_SCN_MEM_16BIT 0x00020000
+#define GRUB_PE32_SCN_MEM_LOCKED 0x00040000
+#define GRUB_PE32_SCN_MEM_PRELOAD 0x00080000
#define GRUB_PE32_SCN_ALIGN_1BYTES 0x00100000
#define GRUB_PE32_SCN_ALIGN_2BYTES 0x00200000
@@ -243,10 +249,28 @@ struct grub_pe32_section_table
#define GRUB_PE32_SCN_ALIGN_16BYTES 0x00500000
#define GRUB_PE32_SCN_ALIGN_32BYTES 0x00600000
#define GRUB_PE32_SCN_ALIGN_64BYTES 0x00700000
+#define GRUB_PE32_SCN_ALIGN_128BYTES 0x00800000
+#define GRUB_PE32_SCN_ALIGN_256BYTES 0x00900000
+#define GRUB_PE32_SCN_ALIGN_512BYTES 0x00A00000
+#define GRUB_PE32_SCN_ALIGN_1024BYTES 0x00B00000
+#define GRUB_PE32_SCN_ALIGN_2048BYTES 0x00C00000
+#define GRUB_PE32_SCN_ALIGN_4096BYTES 0x00D00000
+#define GRUB_PE32_SCN_ALIGN_8192BYTES 0x00E00000
#define GRUB_PE32_SCN_ALIGN_SHIFT 20
#define GRUB_PE32_SCN_ALIGN_MASK 7
+#define GRUB_PE32_SCN_LNK_NRELOC_OVFL 0x01000000
+#define GRUB_PE32_SCN_MEM_DISCARDABLE 0x02000000
+#define GRUB_PE32_SCN_MEM_NOT_CACHED 0x04000000
+#define GRUB_PE32_SCN_MEM_NOT_PAGED 0x08000000
+#define GRUB_PE32_SCN_MEM_SHARED 0x10000000
+#define GRUB_PE32_SCN_MEM_EXECUTE 0x20000000
+#define GRUB_PE32_SCN_MEM_READ 0x40000000
+#define GRUB_PE32_SCN_MEM_WRITE 0x80000000
+
+
+
#define GRUB_PE32_SIGNATURE_SIZE 4
struct grub_pe32_header
--
2.13.4