| Message ID | 20201023120825.30466-4-ard.biesheuvel@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | linux: implement LoadFile2 initrd loading | expand |
initrd typo in subject minor style comments below On Fri, Oct 23, 2020 at 14:08:24 +0200, Ard Biesheuvel wrote: > Recent Linux kernels will invoke the LoadFile2 protocol installed on > a well-known vendor media path to load the initrd if it is exposed by > the firmware. Using this method is preferred for two reasons: > - the Linux kernel is in charge of allocating the memory, and so it can > implement any placement policy it wants (given that these tend to > change between kernel versions), > - it is no longer necessary to modify the device tree provided by the > firmware. > > So let's install this protocol when handling the 'initrd' command if > such a recent kernel was detected (based on the PE/COFF image version), > and defer loading the initrd contents until the point where the kernel > invokes the LoadFile2 protocol. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com> > --- > grub-core/loader/arm64/linux.c | 117 +++++++++++++++++++- > 1 file changed, 116 insertions(+), 1 deletion(-) > > diff --git a/grub-core/loader/arm64/linux.c b/grub-core/loader/arm64/linux.c > index ef3e9f9444ca..285422c7bd43 100644 > --- a/grub-core/loader/arm64/linux.c > +++ b/grub-core/loader/arm64/linux.c > @@ -48,9 +48,16 @@ static grub_uint32_t cmdline_size; > static grub_addr_t initrd_start; > static grub_addr_t initrd_end; > > +static struct grub_linux_initrd_context initrd_ctx = { 0, 0, 0 }; > +static grub_efi_handle_t initrd_lf2_handle; > +static int initrd_use_loadfile2; > + > grub_err_t > grub_arch_efi_linux_check_image (struct linux_arch_kernel_header * lh) > { > + struct grub_pe32_coff_header *coff_header; > + struct grub_pe32_optional_header *optional_header; > + > if (lh->magic != GRUB_LINUX_ARMXX_MAGIC_SIGNATURE) > return grub_error(GRUB_ERR_BAD_OS, "invalid magic number"); > > @@ -61,6 +68,21 @@ grub_arch_efi_linux_check_image (struct linux_arch_kernel_header * lh) > grub_dprintf ("linux", "UEFI stub kernel:\n"); > grub_dprintf ("linux", "PE/COFF header @ %08x\n", lh->hdr_offset); > > + coff_header = (struct grub_pe32_coff_header *)((unsigned long)lh + lh->hdr_offset); > + optional_header = (struct grub_pe32_optional_header *)(coff_header + 1); > + > + /* > + * Linux kernels built for any architecture are guaranteed to support the > + * LoadFile2 based initrd loading protocol if the image version is >= 1. > + */ > + if (optional_header->major_image_version >= 1) > + initrd_use_loadfile2 = 1; > + else funky indentation > + initrd_use_loadfile2 = 0; > + > + grub_dprintf ("linux", "LoadFile2 initrd loading %sabled\n", > + initrd_use_loadfile2 ? "en" : "dis"); > + > return GRUB_ERR_NONE; > } > > @@ -230,13 +252,88 @@ allocate_initrd_mem (int initrd_pages) > GRUB_EFI_LOADER_DATA); > } > > +struct initrd_media_device_path { > + grub_efi_vendor_media_device_path_t vendor; > + grub_efi_device_path_t end; > +} GRUB_PACKED; > + > +#define LINUX_EFI_INITRD_MEDIA_GUID \ > + { 0x5568e427, 0x68fc, 0x4f3d, \ > + { 0xac, 0x74, 0xca, 0x55, 0x52, 0x31, 0xcc, 0x68 } \ > + } > + > +static struct initrd_media_device_path initrd_lf2_device_path = { > + { > + { > + GRUB_EFI_MEDIA_DEVICE_PATH_TYPE, > + GRUB_EFI_VENDOR_MEDIA_DEVICE_PATH_SUBTYPE, > + sizeof(grub_efi_vendor_media_device_path_t), > + }, > + LINUX_EFI_INITRD_MEDIA_GUID > + }, { > + GRUB_EFI_END_DEVICE_PATH_TYPE, > + GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE, > + sizeof(grub_efi_device_path_t) > + } > +}; > + > +static grub_efi_status_t > +grub_efi_initrd_load_file2(grub_efi_load_file2_t *this, Static functions don't need global prefixes (i.e., initrd_load_file2 would be sufficient). > + grub_efi_device_path_t *device_path, > + grub_efi_boolean_t boot_policy, > + grub_efi_uintn_t *buffer_size, > + void *buffer); > + > +static grub_efi_load_file2_t initrd_lf2 = { > + grub_efi_initrd_load_file2 > +}; > + > +static grub_efi_status_t > +grub_efi_initrd_load_file2(grub_efi_load_file2_t *this, > + grub_efi_device_path_t *device_path, > + grub_efi_boolean_t boot_policy, > + grub_efi_uintn_t *buffer_size, > + void *buffer) > +{ > + grub_efi_status_t status = GRUB_EFI_SUCCESS; > + grub_efi_uintn_t initrd_size; > + > + if (!this || this != &initrd_lf2 || !buffer_size) > + return GRUB_EFI_INVALID_PARAMETER; > + > + if (device_path->type != GRUB_EFI_END_DEVICE_PATH_TYPE || > + device_path->subtype != GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE) > + return GRUB_EFI_NOT_FOUND; > + > + if (boot_policy) > + return GRUB_EFI_UNSUPPORTED; > + > + initrd_size = grub_get_initrd_size (&initrd_ctx); > + if (!buffer || *buffer_size < initrd_size) > + { > + *buffer_size = initrd_size; > + return GRUB_EFI_BUFFER_TOO_SMALL; > + } > + > + grub_dprintf ("linux", "Loading initrd via LOAD_FILE2_PROTOCOL\n"); > + > + if (grub_initrd_load (&initrd_ctx, NULL, buffer)) > + status = GRUB_EFI_LOAD_ERROR; > + > + grub_initrd_close (&initrd_ctx); > + return status; > +} > + > static grub_err_t > grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), > int argc, char *argv[]) > { > - struct grub_linux_initrd_context initrd_ctx = { 0, 0, 0 }; > int initrd_size, initrd_pages; > void *initrd_mem = NULL; > + grub_efi_guid_t load_file2_guid = GRUB_EFI_LOAD_FILE2_PROTOCOL_GUID; > + grub_efi_guid_t device_path_guid = GRUB_EFI_DEVICE_PATH_GUID; > + grub_efi_boot_services_t *b; > + grub_efi_status_t status; > > if (argc == 0) > { > @@ -254,6 +351,24 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), > if (grub_initrd_init (argc, argv, &initrd_ctx)) > goto fail; > > + if (initrd_use_loadfile2 && !initrd_lf2_handle) > + { > + b = grub_efi_system_table->boot_services; > + status = b->install_multiple_protocol_interfaces (&initrd_lf2_handle, > + &load_file2_guid, > + &initrd_lf2, > + &device_path_guid, > + &initrd_lf2_device_path, > + NULL); > + if (status == GRUB_EFI_OUT_OF_RESOURCES) > + { indented by spaces > + grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); > + return grub_errno; > + } indented with tab / Leif > + grub_dprintf ("linux", "LoadFile2 initrd loading protocol installed\n"); > + return GRUB_ERR_NONE; > + } > + > initrd_size = grub_get_initrd_size (&initrd_ctx); > grub_dprintf ("linux", "Loading initrd\n"); > > -- > 2.17.1 >
diff --git a/grub-core/loader/arm64/linux.c b/grub-core/loader/arm64/linux.c index ef3e9f9444ca..285422c7bd43 100644 --- a/grub-core/loader/arm64/linux.c +++ b/grub-core/loader/arm64/linux.c @@ -48,9 +48,16 @@ static grub_uint32_t cmdline_size; static grub_addr_t initrd_start; static grub_addr_t initrd_end; +static struct grub_linux_initrd_context initrd_ctx = { 0, 0, 0 }; +static grub_efi_handle_t initrd_lf2_handle; +static int initrd_use_loadfile2; + grub_err_t grub_arch_efi_linux_check_image (struct linux_arch_kernel_header * lh) { + struct grub_pe32_coff_header *coff_header; + struct grub_pe32_optional_header *optional_header; + if (lh->magic != GRUB_LINUX_ARMXX_MAGIC_SIGNATURE) return grub_error(GRUB_ERR_BAD_OS, "invalid magic number"); @@ -61,6 +68,21 @@ grub_arch_efi_linux_check_image (struct linux_arch_kernel_header * lh) grub_dprintf ("linux", "UEFI stub kernel:\n"); grub_dprintf ("linux", "PE/COFF header @ %08x\n", lh->hdr_offset); + coff_header = (struct grub_pe32_coff_header *)((unsigned long)lh + lh->hdr_offset); + optional_header = (struct grub_pe32_optional_header *)(coff_header + 1); + + /* + * Linux kernels built for any architecture are guaranteed to support the + * LoadFile2 based initrd loading protocol if the image version is >= 1. + */ + if (optional_header->major_image_version >= 1) + initrd_use_loadfile2 = 1; + else + initrd_use_loadfile2 = 0; + + grub_dprintf ("linux", "LoadFile2 initrd loading %sabled\n", + initrd_use_loadfile2 ? "en" : "dis"); + return GRUB_ERR_NONE; } @@ -230,13 +252,88 @@ allocate_initrd_mem (int initrd_pages) GRUB_EFI_LOADER_DATA); } +struct initrd_media_device_path { + grub_efi_vendor_media_device_path_t vendor; + grub_efi_device_path_t end; +} GRUB_PACKED; + +#define LINUX_EFI_INITRD_MEDIA_GUID \ + { 0x5568e427, 0x68fc, 0x4f3d, \ + { 0xac, 0x74, 0xca, 0x55, 0x52, 0x31, 0xcc, 0x68 } \ + } + +static struct initrd_media_device_path initrd_lf2_device_path = { + { + { + GRUB_EFI_MEDIA_DEVICE_PATH_TYPE, + GRUB_EFI_VENDOR_MEDIA_DEVICE_PATH_SUBTYPE, + sizeof(grub_efi_vendor_media_device_path_t), + }, + LINUX_EFI_INITRD_MEDIA_GUID + }, { + GRUB_EFI_END_DEVICE_PATH_TYPE, + GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE, + sizeof(grub_efi_device_path_t) + } +}; + +static grub_efi_status_t +grub_efi_initrd_load_file2(grub_efi_load_file2_t *this, + grub_efi_device_path_t *device_path, + grub_efi_boolean_t boot_policy, + grub_efi_uintn_t *buffer_size, + void *buffer); + +static grub_efi_load_file2_t initrd_lf2 = { + grub_efi_initrd_load_file2 +}; + +static grub_efi_status_t +grub_efi_initrd_load_file2(grub_efi_load_file2_t *this, + grub_efi_device_path_t *device_path, + grub_efi_boolean_t boot_policy, + grub_efi_uintn_t *buffer_size, + void *buffer) +{ + grub_efi_status_t status = GRUB_EFI_SUCCESS; + grub_efi_uintn_t initrd_size; + + if (!this || this != &initrd_lf2 || !buffer_size) + return GRUB_EFI_INVALID_PARAMETER; + + if (device_path->type != GRUB_EFI_END_DEVICE_PATH_TYPE || + device_path->subtype != GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE) + return GRUB_EFI_NOT_FOUND; + + if (boot_policy) + return GRUB_EFI_UNSUPPORTED; + + initrd_size = grub_get_initrd_size (&initrd_ctx); + if (!buffer || *buffer_size < initrd_size) + { + *buffer_size = initrd_size; + return GRUB_EFI_BUFFER_TOO_SMALL; + } + + grub_dprintf ("linux", "Loading initrd via LOAD_FILE2_PROTOCOL\n"); + + if (grub_initrd_load (&initrd_ctx, NULL, buffer)) + status = GRUB_EFI_LOAD_ERROR; + + grub_initrd_close (&initrd_ctx); + return status; +} + static grub_err_t grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), int argc, char *argv[]) { - struct grub_linux_initrd_context initrd_ctx = { 0, 0, 0 }; int initrd_size, initrd_pages; void *initrd_mem = NULL; + grub_efi_guid_t load_file2_guid = GRUB_EFI_LOAD_FILE2_PROTOCOL_GUID; + grub_efi_guid_t device_path_guid = GRUB_EFI_DEVICE_PATH_GUID; + grub_efi_boot_services_t *b; + grub_efi_status_t status; if (argc == 0) { @@ -254,6 +351,24 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), if (grub_initrd_init (argc, argv, &initrd_ctx)) goto fail; + if (initrd_use_loadfile2 && !initrd_lf2_handle) + { + b = grub_efi_system_table->boot_services; + status = b->install_multiple_protocol_interfaces (&initrd_lf2_handle, + &load_file2_guid, + &initrd_lf2, + &device_path_guid, + &initrd_lf2_device_path, + NULL); + if (status == GRUB_EFI_OUT_OF_RESOURCES) + { + grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); + return grub_errno; + } + grub_dprintf ("linux", "LoadFile2 initrd loading protocol installed\n"); + return GRUB_ERR_NONE; + } + initrd_size = grub_get_initrd_size (&initrd_ctx); grub_dprintf ("linux", "Loading initrd\n");
Recent Linux kernels will invoke the LoadFile2 protocol installed on a well-known vendor media path to load the initrd if it is exposed by the firmware. Using this method is preferred for two reasons: - the Linux kernel is in charge of allocating the memory, and so it can implement any placement policy it wants (given that these tend to change between kernel versions), - it is no longer necessary to modify the device tree provided by the firmware. So let's install this protocol when handling the 'initrd' command if such a recent kernel was detected (based on the PE/COFF image version), and defer loading the initrd contents until the point where the kernel invokes the LoadFile2 protocol. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com> --- grub-core/loader/arm64/linux.c | 117 +++++++++++++++++++- 1 file changed, 116 insertions(+), 1 deletion(-)