* [PATCH v8 1/5] efi/boot.c: add file.need_to_free
2020-09-30 12:00 [PATCH v8 0/5] efi: Unified Xen hypervisor/kernel/initrd images Trammell Hudson
@ 2020-09-30 12:00 ` Trammell Hudson
2020-10-02 8:15 ` Jan Beulich
2020-09-30 12:00 ` [PATCH v8 2/5] efi/boot.c: add handle_file_info() Trammell Hudson
` (3 subsequent siblings)
4 siblings, 1 reply; 11+ messages in thread
From: Trammell Hudson @ 2020-09-30 12:00 UTC (permalink / raw)
To: xen-devel; +Cc: roger.pau, jbeulich, andrew.cooper3, wl
The config file, kernel, initrd, etc should only be freed if they
are allocated with the UEFI allocator. On x86 the ucode, and on
ARM the dtb, are also marked as need_to_free when allocated or
expanded.
This also fixes a memory leak in ARM fdt_increase_size() if there
is an error in building the new device tree.
Signed-off-by: Trammell Hudson <hudson@trmm.net>
---
xen/arch/arm/efi/efi-boot.h | 11 +++++++++--
xen/arch/x86/efi/efi-boot.h | 2 +-
xen/common/efi/boot.c | 10 ++++++----
3 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/xen/arch/arm/efi/efi-boot.h b/xen/arch/arm/efi/efi-boot.h
index 27dd0b1a94..c6200fda0e 100644
--- a/xen/arch/arm/efi/efi-boot.h
+++ b/xen/arch/arm/efi/efi-boot.h
@@ -314,7 +314,10 @@ static void __init *fdt_increase_size(struct file *fdtfile, int add_size)
if ( fdt_size )
{
if ( fdt_open_into(dtbfile.ptr, new_fdt, pages * EFI_PAGE_SIZE) )
+ {
+ efi_bs->FreePages(fdt_addr, pages);
return NULL;
+ }
}
else
{
@@ -326,7 +329,10 @@ static void __init *fdt_increase_size(struct file *fdtfile, int add_size)
* system table that is passed in the FDT.
*/
if ( fdt_create_empty_tree(new_fdt, pages * EFI_PAGE_SIZE) )
+ {
+ efi_bs->FreePages(fdt_addr, pages);
return NULL;
+ }
}
/*
@@ -335,12 +341,13 @@ static void __init *fdt_increase_size(struct file *fdtfile, int add_size)
* code will free it. If the original FDT came from a configuration
* table, we don't own that memory and can't free it.
*/
- if ( dtbfile.size )
+ if ( dtbfile.need_to_free )
efi_bs->FreePages(dtbfile.addr, PFN_UP(dtbfile.size));
/* Update 'file' info for new memory so we clean it up on error exits */
dtbfile.addr = fdt_addr;
dtbfile.size = pages * EFI_PAGE_SIZE;
+ dtbfile.need_to_free = true;
return new_fdt;
}
@@ -546,7 +553,7 @@ static void __init efi_arch_cpu(void)
static void __init efi_arch_blexit(void)
{
- if ( dtbfile.addr && dtbfile.size )
+ if ( dtbfile.need_to_free )
efi_bs->FreePages(dtbfile.addr, PFN_UP(dtbfile.size));
if ( memmap )
efi_bs->FreePool(memmap);
diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
index eef3f52789..1025000afd 100644
--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -689,7 +689,7 @@ static void __init efi_arch_cpu(void)
static void __init efi_arch_blexit(void)
{
- if ( ucode.addr )
+ if ( ucode.need_to_free )
efi_bs->FreePages(ucode.addr, PFN_UP(ucode.size));
}
diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index 157fe0e8c5..c2ce0c7294 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -102,6 +102,7 @@ union string {
struct file {
UINTN size;
+ bool need_to_free;
union {
EFI_PHYSICAL_ADDRESS addr;
char *str;
@@ -280,13 +281,13 @@ void __init noreturn blexit(const CHAR16 *str)
if ( !efi_bs )
efi_arch_halt();
- if ( cfg.addr )
+ if ( cfg.need_to_free )
efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
- if ( kernel.addr )
+ if ( kernel.need_to_free )
efi_bs->FreePages(kernel.addr, PFN_UP(kernel.size));
- if ( ramdisk.addr )
+ if ( ramdisk.need_to_free )
efi_bs->FreePages(ramdisk.addr, PFN_UP(ramdisk.size));
- if ( xsm.addr )
+ if ( xsm.need_to_free )
efi_bs->FreePages(xsm.addr, PFN_UP(xsm.size));
efi_arch_blexit();
@@ -581,6 +582,7 @@ static bool __init read_file(EFI_FILE_HANDLE dir_handle, CHAR16 *name,
}
else
{
+ file->need_to_free = true;
file->size = size;
if ( file != &cfg )
{
--
2.25.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v8 4/5] efi: Enable booting unified hypervisor/kernel/initrd images
2020-09-30 12:00 [PATCH v8 0/5] efi: Unified Xen hypervisor/kernel/initrd images Trammell Hudson
` (2 preceding siblings ...)
2020-09-30 12:00 ` [PATCH v8 3/5] efi/boot.c: wrap PrintStr/PrintErr to allow const CHAR16* arguments Trammell Hudson
@ 2020-09-30 12:00 ` Trammell Hudson
2020-10-02 8:27 ` Jan Beulich
2020-09-30 12:00 ` [PATCH v8 5/5] efi: Do not use command line if unified config is included Trammell Hudson
4 siblings, 1 reply; 11+ messages in thread
From: Trammell Hudson @ 2020-09-30 12:00 UTC (permalink / raw)
To: xen-devel; +Cc: roger.pau, jbeulich, andrew.cooper3, wl
This patch adds support for bundling the xen.efi hypervisor, the xen.cfg
configuration file, the Linux kernel and initrd, as well as the XSM,
and architectural specific files into a single "unified" EFI executable.
This allows an administrator to update the components independently
without requiring rebuilding xen, as well as to replace the components
in an existing image.
The resulting EFI executable can be invoked directly from the UEFI Boot
Manager, removing the need to use a separate loader like grub as well
as removing dependencies on local filesystem access. And since it is
a single file, it can be signed and validated by UEFI Secure Boot without
requring the shim protocol.
It is inspired by systemd-boot's unified kernel technique and borrows the
function to locate PE sections from systemd's LGPL'ed code. During EFI
boot, Xen looks at its own loaded image to locate the PE sections for
the Xen configuration (`.config`), dom0 kernel (`.kernel`), dom0 initrd
(`.ramdisk`), and XSM config (`.xsm`), which are included after building
xen.efi using objcopy to add named sections for each input file.
For x86, the CPU ucode can be included in a section named `.ucode`,
which is loaded in the efi_arch_cfg_file_late() stage of the boot process.
On ARM systems the Device Tree can be included in a section named
`.dtb`, which is loaded during the efi_arch_cfg_file_early() stage of
the boot process.
Note that the system will fall back to loading files from disk if
the named sections do not exist. This allows distributions to continue
with the status quo if they want a signed kernel + config, while still
allowing a user provided initrd (which is how the shim protocol currently
works as well).
This patch also adds constness to the section parameter of
efi_arch_cfg_file_early() and efi_arch_cfg_file_late(),
changes pe_find_section() to use a const CHAR16 section name,
and adds pe_name_compare() to match section names.
Signed-off-by: Trammell Hudson <hudson@trmm.net>
---
.gitignore | 1 +
docs/misc/efi.pandoc | 49 ++++++++++++
xen/arch/arm/efi/efi-boot.h | 25 ++++--
xen/arch/x86/efi/Makefile | 2 +-
xen/arch/x86/efi/efi-boot.h | 11 ++-
xen/common/efi/boot.c | 64 ++++++++++-----
xen/common/efi/efi.h | 3 +
xen/common/efi/pe.c | 153 ++++++++++++++++++++++++++++++++++++
8 files changed, 279 insertions(+), 29 deletions(-)
create mode 100644 xen/common/efi/pe.c
diff --git a/.gitignore b/.gitignore
index 5e8c47e2db..2857fd76eb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -317,6 +317,7 @@ xen/arch/*/efi/boot.c
xen/arch/*/efi/compat.c
xen/arch/*/efi/ebmalloc.c
xen/arch/*/efi/efi.h
+xen/arch/*/efi/pe.c
xen/arch/*/efi/runtime.c
xen/common/config_data.S
xen/common/config.gz
diff --git a/docs/misc/efi.pandoc b/docs/misc/efi.pandoc
index 23c1a2732d..ac3cd58cae 100644
--- a/docs/misc/efi.pandoc
+++ b/docs/misc/efi.pandoc
@@ -116,3 +116,52 @@ Filenames must be specified relative to the location of the EFI binary.
Extra options to be passed to Xen can also be specified on the command line,
following a `--` separator option.
+
+## Unified Xen kernel image
+
+The "Unified" kernel image can be generated by adding additional
+sections to the Xen EFI executable with objcopy, similar to how
+[systemd-boot uses the stub to add them to the Linux kernel](https://wiki.archlinux.org/index.php/systemd-boot#Preparing_a_unified_kernel_image)
+
+The sections for the xen configuration file, the dom0 kernel, dom0 initrd,
+XSM and CPU microcode should be added after the Xen `.pad` section, the
+ending address of which can be located with:
+
+```
+objdump -h xen.efi \
+ | perl -ane '/\.pad/ && printf "0x%016x\n", hex($F[2]) + hex($F[3])'
+```
+
+For all the examples the `.pad` section ended at 0xffff82d041000000.
+All the sections are optional (`.config`, `.kernel`, `.ramdisk`, `.xsm`,
+`.ucode` (x86) and `.dtb` (ARM)) and the order does not matter.
+The virtual addresses do not need to be contiguous, although they should not
+be overlapping and should all be greater than the last virtual address of the
+hypervisor components.
+
+```
+objcopy \
+ --add-section .config=xen.cfg \
+ --change-section-vma .config=0xffff82d041000000
+ --add-section .ucode=ucode.bin \
+ --change-section-vma .ucode=0xffff82d041010000 \
+ --add-section .xsm=xsm.cfg \
+ --change-section-vma .xsm=0xffff82d041080000 \
+ --add-section .kernel=vmlinux \
+ --change-section-vma .kernel=0xffff82d041100000 \
+ --add-section .ramdisk=initrd.img \
+ --change-section-vma .ramdisk=0xffff82d042000000 \
+ xen.efi \
+ xen.unified.efi
+```
+
+The unified executable can be signed with sbsigntool to make
+it usable with UEFI secure boot:
+
+```
+sbsign \
+ --key signing.key \
+ --cert cert.pem \
+ --output xen.signed.efi \
+ xen.unified.efi
+```
diff --git a/xen/arch/arm/efi/efi-boot.h b/xen/arch/arm/efi/efi-boot.h
index c6200fda0e..f64a6604af 100644
--- a/xen/arch/arm/efi/efi-boot.h
+++ b/xen/arch/arm/efi/efi-boot.h
@@ -382,27 +382,36 @@ static void __init noreturn efi_arch_post_exit_boot(void)
efi_xen_start(fdt, fdt_totalsize(fdt));
}
-static void __init efi_arch_cfg_file_early(EFI_FILE_HANDLE dir_handle, char *section)
+static void __init efi_arch_cfg_file_early(const EFI_LOADED_IMAGE *image,
+ EFI_FILE_HANDLE dir_handle,
+ const char *section)
{
union string name;
/*
* The DTB must be processed before any other entries in the configuration
- * file, as the DTB is updated as modules are loaded.
+ * file, as the DTB is updated as modules are loaded. Prefer the one
+ * stored as a PE section in a unified image, and fall back to a file
+ * on disk if the section is not present.
*/
- name.s = get_value(&cfg, section, "dtb");
- if ( name.s )
+ if ( !read_section(image, L"dtb", &dtbfile, NULL) )
{
- split_string(name.s);
- read_file(dir_handle, s2w(&name), &dtbfile, NULL);
- efi_bs->FreePool(name.w);
+ name.s = get_value(&cfg, section, "dtb");
+ if ( name.s )
+ {
+ split_string(name.s);
+ read_file(dir_handle, s2w(&name), &dtbfile, NULL);
+ efi_bs->FreePool(name.w);
+ }
}
fdt = fdt_increase_size(&dtbfile, cfg.size + EFI_PAGE_SIZE);
if ( !fdt )
blexit(L"Unable to create new FDT");
}
-static void __init efi_arch_cfg_file_late(EFI_FILE_HANDLE dir_handle, char *section)
+static void __init efi_arch_cfg_file_late(const EFI_LOADED_IMAGE *image,
+ EFI_FILE_HANDLE dir_handle,
+ const char *section)
{
}
diff --git a/xen/arch/x86/efi/Makefile b/xen/arch/x86/efi/Makefile
index 770438a029..e857c0f2cc 100644
--- a/xen/arch/x86/efi/Makefile
+++ b/xen/arch/x86/efi/Makefile
@@ -8,7 +8,7 @@ cmd_objcopy_o_ihex = $(OBJCOPY) -I ihex -O binary $< $@
boot.init.o: buildid.o
-EFIOBJ := boot.init.o ebmalloc.o compat.o runtime.o
+EFIOBJ := boot.init.o pe.init.o ebmalloc.o compat.o runtime.o
$(call cc-option-add,cflags-stack-boundary,CC,-mpreferred-stack-boundary=4)
$(EFIOBJ): CFLAGS-stack-boundary := $(cflags-stack-boundary)
diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
index 1025000afd..2541ba1f32 100644
--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -272,14 +272,21 @@ static void __init noreturn efi_arch_post_exit_boot(void)
unreachable();
}
-static void __init efi_arch_cfg_file_early(EFI_FILE_HANDLE dir_handle, char *section)
+static void __init efi_arch_cfg_file_early(const EFI_LOADED_IMAGE *image,
+ EFI_FILE_HANDLE dir_handle,
+ const char *section)
{
}
-static void __init efi_arch_cfg_file_late(EFI_FILE_HANDLE dir_handle, char *section)
+static void __init efi_arch_cfg_file_late(const EFI_LOADED_IMAGE *image,
+ EFI_FILE_HANDLE dir_handle,
+ const char *section)
{
union string name;
+ if ( read_section(image, L"ucode", &ucode, NULL) )
+ return;
+
name.s = get_value(&cfg, section, "ucode");
if ( !name.s )
name.s = get_value(&cfg, "global", "ucode");
diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index bd629eb658..072b1cecd1 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -122,6 +122,8 @@ static CHAR16 *s2w(union string *str);
static char *w2s(const union string *str);
static bool read_file(EFI_FILE_HANDLE dir_handle, CHAR16 *name,
struct file *file, const char *options);
+static bool read_section(const EFI_LOADED_IMAGE *image, const CHAR16 *name,
+ struct file *file, const char *options);
static size_t wstrlen(const CHAR16 * s);
static int set_color(u32 mask, int bpp, u8 *pos, u8 *sz);
static bool match_guid(const EFI_GUID *guid1, const EFI_GUID *guid2);
@@ -631,6 +633,20 @@ static bool __init read_file(EFI_FILE_HANDLE dir_handle, CHAR16 *name,
return true;
}
+static bool __init read_section(const EFI_LOADED_IMAGE *image,
+ const CHAR16 *name, struct file *file,
+ const char *options)
+{
+ file->ptr = pe_find_section(image->ImageBase, image->ImageSize,
+ name, &file->size);
+ if ( !file->ptr )
+ return false;
+
+ handle_file_info(name, file, options);
+
+ return true;
+}
+
static void __init pre_parse(const struct file *cfg)
{
char *ptr = cfg->str, *end = ptr + cfg->size;
@@ -1215,9 +1231,11 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
/* Get the file system interface. */
dir_handle = get_parent_handle(loaded_image, &file_name);
- /* Read and parse the config file. */
- if ( !cfg_file_name )
+ if ( read_section(loaded_image, L"config", &cfg, NULL) )
+ PrintStr(L"Using builtin config file\r\n");
+ else if ( !cfg_file_name )
{
+ /* Read and parse the config file. */
CHAR16 *tail;
while ( (tail = point_tail(file_name)) != NULL )
@@ -1266,29 +1284,39 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
if ( !name.s )
blexit(L"No Dom0 kernel image specified.");
- efi_arch_cfg_file_early(dir_handle, section.s);
+ efi_arch_cfg_file_early(loaded_image, dir_handle, section.s);
option_str = split_string(name.s);
- read_file(dir_handle, s2w(&name), &kernel, option_str);
- efi_bs->FreePool(name.w);
-
- if ( !EFI_ERROR(efi_bs->LocateProtocol(&shim_lock_guid, NULL,
- (void **)&shim_lock)) &&
- (status = shim_lock->Verify(kernel.ptr, kernel.size)) != EFI_SUCCESS )
- PrintErrMesg(L"Dom0 kernel image could not be verified", status);
- name.s = get_value(&cfg, section.s, "ramdisk");
- if ( name.s )
+ if ( !read_section(loaded_image, L"kernel", &kernel, option_str) )
{
- read_file(dir_handle, s2w(&name), &ramdisk, NULL);
+ read_file(dir_handle, s2w(&name), &kernel, option_str);
efi_bs->FreePool(name.w);
+
+ if ( !EFI_ERROR(efi_bs->LocateProtocol(&shim_lock_guid, NULL,
+ (void **)&shim_lock)) &&
+ (status = shim_lock->Verify(kernel.ptr, kernel.size)) != EFI_SUCCESS )
+ PrintErrMesg(L"Dom0 kernel image could not be verified", status);
}
- name.s = get_value(&cfg, section.s, "xsm");
- if ( name.s )
+ if ( !read_section(loaded_image, L"ramdisk", &ramdisk, NULL) )
{
- read_file(dir_handle, s2w(&name), &xsm, NULL);
- efi_bs->FreePool(name.w);
+ name.s = get_value(&cfg, section.s, "ramdisk");
+ if ( name.s )
+ {
+ read_file(dir_handle, s2w(&name), &ramdisk, NULL);
+ efi_bs->FreePool(name.w);
+ }
+ }
+
+ if ( !read_section(loaded_image, L"xsm", &xsm, NULL) )
+ {
+ name.s = get_value(&cfg, section.s, "xsm");
+ if ( name.s )
+ {
+ read_file(dir_handle, s2w(&name), &xsm, NULL);
+ efi_bs->FreePool(name.w);
+ }
}
/*
@@ -1324,7 +1352,7 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
}
}
- efi_arch_cfg_file_late(dir_handle, section.s);
+ efi_arch_cfg_file_late(loaded_image, dir_handle, section.s);
efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
cfg.addr = 0;
diff --git a/xen/common/efi/efi.h b/xen/common/efi/efi.h
index 4845d84913..663a8b5000 100644
--- a/xen/common/efi/efi.h
+++ b/xen/common/efi/efi.h
@@ -47,3 +47,6 @@ const CHAR16 *wmemchr(const CHAR16 *s, CHAR16 c, UINTN n);
/* EFI boot allocator. */
void *ebmalloc(size_t size);
void free_ebmalloc_unused_mem(void);
+
+const void *pe_find_section(const void *image_base, const size_t image_size,
+ const CHAR16 *section_name, UINTN *size_out);
diff --git a/xen/common/efi/pe.c b/xen/common/efi/pe.c
new file mode 100644
index 0000000000..5c1700be03
--- /dev/null
+++ b/xen/common/efi/pe.c
@@ -0,0 +1,153 @@
+/*
+ * xen/common/efi/pe.c
+ *
+ * PE executable header parser.
+ *
+ * Derived from https://github.com/systemd/systemd/blob/master/src/boot/efi/pe.c
+ * commit 07d5ed536ec0a76b08229c7a80b910cb9acaf6b1
+ *
+ * Copyright (C) 2015 Kay Sievers <kay@vrfy.org>
+ * Copyright (C) 2020 Trammell Hudson <hudson@trmm.net>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ */
+
+
+#include "efi.h"
+
+struct DosFileHeader {
+ UINT8 Magic[2];
+ UINT16 LastSize;
+ UINT16 nBlocks;
+ UINT16 nReloc;
+ UINT16 HdrSize;
+ UINT16 MinAlloc;
+ UINT16 MaxAlloc;
+ UINT16 ss;
+ UINT16 sp;
+ UINT16 Checksum;
+ UINT16 ip;
+ UINT16 cs;
+ UINT16 RelocPos;
+ UINT16 nOverlay;
+ UINT16 reserved[4];
+ UINT16 OEMId;
+ UINT16 OEMInfo;
+ UINT16 reserved2[10];
+ UINT32 ExeHeader;
+};
+
+#if defined(__arm__) || defined (__aarch64__)
+#define PE_HEADER_MACHINE 0xaa64
+#elif defined(__x86_64__)
+#define PE_HEADER_MACHINE 0x8664
+#else
+#error "Unknown architecture"
+#endif
+
+struct PeFileHeader {
+ UINT16 Machine;
+ UINT16 NumberOfSections;
+ UINT32 TimeDateStamp;
+ UINT32 PointerToSymbolTable;
+ UINT32 NumberOfSymbols;
+ UINT16 SizeOfOptionalHeader;
+ UINT16 Characteristics;
+};
+
+struct PeHeader {
+ UINT8 Magic[4];
+ struct PeFileHeader FileHeader;
+};
+
+struct PeSectionHeader {
+ CHAR8 Name[8];
+ UINT32 VirtualSize;
+ UINT32 VirtualAddress;
+ UINT32 SizeOfRawData;
+ UINT32 PointerToRawData;
+ UINT32 PointerToRelocations;
+ UINT32 PointerToLinenumbers;
+ UINT16 NumberOfRelocations;
+ UINT16 NumberOfLinenumbers;
+ UINT32 Characteristics;
+};
+
+static bool __init pe_name_compare(const struct PeSectionHeader *sect,
+ const CHAR16 *name)
+{
+ size_t i;
+
+ if ( sect->Name[0] != '.' )
+ return -1;
+
+ for ( i = 1; i < sizeof(sect->Name); i++ )
+ {
+ const char c = sect->Name[i];
+ const CHAR16 cw = name[i - 1];
+
+ if ( cw == L'\0' && c == '\0' )
+ return true;
+ if ( cw != c )
+ return false;
+ }
+
+ return name[i - 1] == L'\0';
+}
+
+const void *__init pe_find_section(const void *image, const UINTN image_size,
+ const CHAR16 *section_name, UINTN *size_out)
+{
+ const struct DosFileHeader *dos = image;
+ const struct PeHeader *pe;
+ const struct PeSectionHeader *sect;
+ UINTN offset, i;
+
+ if ( image_size < sizeof(*dos) ||
+ memcmp(dos->Magic, "MZ", 2) != 0 )
+ return NULL;
+
+ offset = dos->ExeHeader;
+ pe = image + offset;
+
+ offset += sizeof(*pe);
+ if ( image_size < offset ||
+ memcmp(pe->Magic, "PE\0\0", 4) != 0 )
+ return NULL;
+
+ if ( pe->FileHeader.Machine != PE_HEADER_MACHINE )
+ return NULL;
+
+ offset += pe->FileHeader.SizeOfOptionalHeader;
+
+ for ( i = 0; i < pe->FileHeader.NumberOfSections; i++ )
+ {
+ sect = image + offset;
+ if ( image_size < offset + sizeof(*sect) )
+ return NULL;
+
+ if ( !pe_name_compare(sect, section_name) )
+ {
+ offset += sizeof(*sect);
+ continue;
+ }
+
+ if ( image_size < sect->VirtualSize + sect->VirtualAddress )
+ blexit(L"PE invalid section size + address");
+
+ if ( size_out )
+ *size_out = sect->VirtualSize;
+
+ return image + sect->VirtualAddress;
+ }
+
+ return NULL;
+}
--
2.25.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v8 5/5] efi: Do not use command line if unified config is included
2020-09-30 12:00 [PATCH v8 0/5] efi: Unified Xen hypervisor/kernel/initrd images Trammell Hudson
` (3 preceding siblings ...)
2020-09-30 12:00 ` [PATCH v8 4/5] efi: Enable booting unified hypervisor/kernel/initrd images Trammell Hudson
@ 2020-09-30 12:00 ` Trammell Hudson
4 siblings, 0 replies; 11+ messages in thread
From: Trammell Hudson @ 2020-09-30 12:00 UTC (permalink / raw)
To: xen-devel; +Cc: roger.pau, jbeulich, andrew.cooper3, wl
If a unified Xen image is used, then the bundled configuration,
Xen command line, dom0 kernel, and ramdisk are prefered over
any files listed in the config file or provided on the command line.
Unlike the shim based verification, the PE signature on a unified image
covers all of the Xen+config+kernel+initrd modules linked into the
unified image. This also ensures that, on properly configured UEFI Secure Boot
platforms, the entire runtime will be measured into the TPM for unsealing
secrets or remote attestation.
Signed-off-by: Trammell Hudson <hudson@trmm.net>
---
xen/common/efi/boot.c | 43 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 38 insertions(+), 5 deletions(-)
diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index 072b1cecd1..07ea5b3512 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -950,6 +950,35 @@ static void __init setup_efi_pci(void)
efi_bs->FreePool(handles);
}
+/*
+ * Logic should remain sync'ed with linux/arch/x86/xen/efi.c
+ * Secure Boot is enabled iff 'SecureBoot' is set and the system is
+ * not in Setup Mode.
+ */
+static bool __init efi_secure_boot(void)
+{
+ static __initdata EFI_GUID global_guid = EFI_GLOBAL_VARIABLE;
+ uint8_t secboot, setupmode;
+ UINTN secboot_size = sizeof(secboot);
+ UINTN setupmode_size = sizeof(setupmode);
+ EFI_STATUS rc;
+
+ rc = efi_rs->GetVariable(L"SecureBoot", &global_guid,
+ NULL, &secboot_size, &secboot);
+ if ( rc != EFI_SUCCESS )
+ return false;
+
+ rc = efi_rs->GetVariable(L"SetupMode", &global_guid,
+ NULL, &setupmode_size, &setupmode);
+ if ( rc != EFI_SUCCESS )
+ return false;
+
+ if ( secboot > 1 || setupmode > 1 )
+ blexit(L"Invalid SecureBoot/SetupMode variables");
+
+ return secboot == 1 && setupmode == 0;
+}
+
static void __init efi_variables(void)
{
EFI_STATUS status;
@@ -1126,15 +1155,15 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
static EFI_GUID __initdata shim_lock_guid = SHIM_LOCK_PROTOCOL_GUID;
EFI_LOADED_IMAGE *loaded_image;
EFI_STATUS status;
- unsigned int i, argc;
- CHAR16 **argv, *file_name, *cfg_file_name = NULL, *options = NULL;
+ unsigned int i, argc = 0;
+ CHAR16 **argv = NULL, *file_name, *cfg_file_name = NULL, *options = NULL;
UINTN gop_mode = ~0;
EFI_SHIM_LOCK_PROTOCOL *shim_lock;
EFI_GRAPHICS_OUTPUT_PROTOCOL *gop = NULL;
union string section = { NULL }, name;
bool base_video = false;
const char *option_str;
- bool use_cfg_file;
+ bool use_cfg_file, secure;
__set_bit(EFI_BOOT, &efi_flags);
__set_bit(EFI_LOADER, &efi_flags);
@@ -1153,8 +1182,10 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
PrintErrMesg(L"No Loaded Image Protocol", status);
efi_arch_load_addr_check(loaded_image);
+ secure = efi_secure_boot();
- if ( use_cfg_file )
+ if ( use_cfg_file &&
+ !read_section(loaded_image, L"config", &cfg, NULL) )
{
UINTN offset = 0;
@@ -1212,6 +1243,8 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
PrintStr(L"Xen " __stringify(XEN_VERSION) "." __stringify(XEN_SUBVERSION)
XEN_EXTRAVERSION " (c/s " XEN_CHANGESET ") EFI loader\r\n");
+ if ( secure )
+ PrintStr(L"UEFI Secure Boot enabled\r\n");
efi_arch_relocate_image(0);
@@ -1231,7 +1264,7 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
/* Get the file system interface. */
dir_handle = get_parent_handle(loaded_image, &file_name);
- if ( read_section(loaded_image, L"config", &cfg, NULL) )
+ if ( cfg.ptr )
PrintStr(L"Using builtin config file\r\n");
else if ( !cfg_file_name )
{
--
2.25.1
^ permalink raw reply related [flat|nested] 11+ messages in thread