Adding upstream version 252.22.upstream/252.22

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 155 insertions, 0 deletions

diff --git a/src/boot/efi/linux.c b/src/boot/efi/linux.c
new file mode 100644
index 0000000..48801f9
--- /dev/null
+++ b/src/boot/efi/linux.c
@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+/*
+ * Generic Linux boot protocol using the EFI/PE entry point of the kernel. Passes
+ * initrd with the LINUX_INITRD_MEDIA_GUID DevicePath and cmdline with
+ * EFI LoadedImageProtocol.
+ *
+ * This method works for Linux 5.8 and newer on ARM/Aarch64, x86/x68_64 and RISC-V.
+ */
+
+#include <efi.h>
+#include <efilib.h>
+
+#include "initrd.h"
+#include "linux.h"
+#include "pe.h"
+#include "secure-boot.h"
+#include "util.h"
+
+#define STUB_PAYLOAD_GUID \
+        { 0x55c5d1f8, 0x04cd, 0x46b5, { 0x8a, 0x20, 0xe5, 0x6c, 0xbb, 0x30, 0x52, 0xd0 } }
+
+typedef struct {
+        const void *addr;
+        size_t len;
+        const EFI_DEVICE_PATH *device_path;
+} ValidationContext;
+
+static bool validate_payload(
+                const void *ctx, const EFI_DEVICE_PATH *device_path, const void *file_buffer, size_t file_size) {
+
+        const ValidationContext *payload = ASSERT_PTR(ctx);
+
+        if (device_path != payload->device_path)
+                return false;
+
+        /* Security arch (1) protocol does not provide a file buffer. Instead we are supposed to fetch the payload
+         * ourselves, which is not needed as we already have everything in memory and the device paths match. */
+        if (file_buffer && (file_buffer != payload->addr || file_size != payload->len))
+                return false;
+
+        return true;
+}
+
+static EFI_STATUS load_image(EFI_HANDLE parent, const void *source, size_t len, EFI_HANDLE *ret_image) {
+        assert(parent);
+        assert(source);
+        assert(ret_image);
+
+        /* We could pass a NULL device path, but it's nicer to provide something and it allows us to identify
+         * the loaded image from within the security hooks. */
+        struct {
+                VENDOR_DEVICE_PATH payload;
+                EFI_DEVICE_PATH end;
+        } _packed_ payload_device_path = {
+                .payload = {
+                        .Header = {
+                                .Type = MEDIA_DEVICE_PATH,
+                                .SubType = MEDIA_VENDOR_DP,
+                                .Length = { sizeof(payload_device_path.payload), 0 },
+                        },
+                        .Guid = STUB_PAYLOAD_GUID,
+                },
+                .end = {
+                        .Type = END_DEVICE_PATH_TYPE,
+                        .SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE,
+                        .Length = { sizeof(payload_device_path.end), 0 },
+                },
+        };
+
+        /* We want to support unsigned kernel images as payload, which is safe to do under secure boot
+         * because it is embedded in this stub loader (and since it is already running it must be trusted). */
+        install_security_override(
+                        validate_payload,
+                        &(ValidationContext) {
+                                .addr = source,
+                                .len = len,
+                                .device_path = &payload_device_path.payload.Header,
+                        });
+
+        EFI_STATUS ret = BS->LoadImage(
+                        /*BootPolicy=*/false,
+                        parent,
+                        &payload_device_path.payload.Header,
+                        (void *) source,
+                        len,
+                        ret_image);
+
+        uninstall_security_override();
+
+        return ret;
+}
+
+EFI_STATUS linux_exec(
+                EFI_HANDLE parent,
+                const char16_t *cmdline,
+                const void *linux_buffer,
+                size_t linux_length,
+                const void *initrd_buffer,
+                size_t initrd_length) {
+
+        uint32_t compat_address;
+        EFI_STATUS err;
+
+        assert(parent);
+        assert(linux_buffer && linux_length > 0);
+        assert(initrd_buffer || initrd_length == 0);
+
+        err = pe_kernel_info(linux_buffer, &compat_address);
+#if defined(__i386__) || defined(__x86_64__)
+        if (err == EFI_UNSUPPORTED)
+                /* Kernel is too old to support LINUX_INITRD_MEDIA_GUID, try the deprecated EFI handover
+                 * protocol. */
+                return linux_exec_efi_handover(
+                                parent,
+                                cmdline,
+                                linux_buffer,
+                                linux_length,
+                                initrd_buffer,
+                                initrd_length);
+#endif
+        if (err != EFI_SUCCESS)
+                return log_error_status_stall(err, u"Bad kernel image: %r", err);
+
+        _cleanup_(unload_imagep) EFI_HANDLE kernel_image = NULL;
+        err = load_image(parent, linux_buffer, linux_length, &kernel_image);
+        if (err != EFI_SUCCESS)
+                return log_error_status_stall(err, u"Error loading kernel image: %r", err);
+
+        EFI_LOADED_IMAGE_PROTOCOL *loaded_image;
+        err = BS->HandleProtocol(kernel_image, &LoadedImageProtocol, (void **) &loaded_image);
+        if (err != EFI_SUCCESS)
+                return log_error_status_stall(err, u"Error getting kernel loaded image protocol: %r", err);
+
+        if (cmdline) {
+                loaded_image->LoadOptions = (void *) cmdline;
+                loaded_image->LoadOptionsSize = strsize16(loaded_image->LoadOptions);
+        }
+
+        _cleanup_(cleanup_initrd) EFI_HANDLE initrd_handle = NULL;
+        err = initrd_register(initrd_buffer, initrd_length, &initrd_handle);
+        if (err != EFI_SUCCESS)
+                return log_error_status_stall(err, u"Error registering initrd: %r", err);
+
+        err = BS->StartImage(kernel_image, NULL, NULL);
+
+        /* Try calling the kernel compat entry point if one exists. */
+        if (err == EFI_UNSUPPORTED && compat_address > 0) {
+                EFI_IMAGE_ENTRY_POINT compat_entry =
+                                (EFI_IMAGE_ENTRY_POINT) ((uint8_t *) loaded_image->ImageBase + compat_address);
+                err = compat_entry(kernel_image, ST);
+        }
+
+        return log_error_status_stall(err, u"Error starting kernel image: %r", err);
+}