From 25069a23257ba9c6db644bbe6114dafb879063e5 Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Mon, 8 Jul 2019 12:32:37 +0200 Subject: [PATCH 03/11] Handle multi-arch (64-on-32) boot in linuxefi loader. Allow booting 64-bit kernels on 32-bit EFI on x86. Signed-off-by: Peter Jones --- grub-core/loader/efi/linux.c | 11 ++- grub-core/loader/i386/efi/linux.c | 127 +++++++++++++++++++----------- include/grub/i386/linux.h | 7 +- 3 files changed, 97 insertions(+), 48 deletions(-) --- a/grub-core/loader/i386/efi/linux.c +++ b/grub-core/loader/i386/efi/linux.c @@ -44,14 +44,10 @@ static grub_err_t grub_linuxefi_boot (void) { - int offset = 0; - -#ifdef __x86_64__ - offset = 512; -#endif asm volatile ("cli"); - return grub_efi_linux_boot ((char *)kernel_mem, handover_offset + offset, + return grub_efi_linux_boot ((char *)kernel_mem, + handover_offset, params); } @@ -147,14 +143,20 @@ return grub_errno; } +#define MIN(a, b) \ + ({ typeof (a) _a = (a); \ + typeof (b) _b = (b); \ + _a < _b ? _a : _b; }) + static grub_err_t grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), int argc, char *argv[]) { grub_file_t file = 0; - struct linux_i386_kernel_header lh; - grub_ssize_t len, start, filelen; + struct linux_i386_kernel_header *lh = NULL; + grub_ssize_t start, filelen; void *kernel = NULL; + int setup_header_end_offset; grub_err_t err; grub_dl_ref (my_mod); @@ -185,45 +187,79 @@ goto fail; } - params = grub_efi_allocate_pages_max (0x3fffffff, BYTES_TO_PAGES(16384)); - + params = grub_efi_allocate_pages_max (0x3fffffff, + BYTES_TO_PAGES(sizeof(*params))); if (! params) { grub_error (GRUB_ERR_OUT_OF_MEMORY, "cannot allocate kernel parameters"); goto fail; } - grub_memset (params, 0, 16384); + grub_dprintf ("linux", "params = %p\n", params); - grub_memcpy (&lh, kernel, sizeof (lh)); + grub_memset (params, 0, sizeof(*params)); - if (lh.boot_flag != grub_cpu_to_le16 (0xaa55)) + setup_header_end_offset = *((grub_uint8_t *)kernel + 0x201); + grub_dprintf ("linux", "copying %lu bytes from %p to %p\n", + MIN((grub_size_t)0x202+setup_header_end_offset, + sizeof (*params)) - 0x1f1, + (grub_uint8_t *)kernel + 0x1f1, + (grub_uint8_t *)params + 0x1f1); + grub_memcpy ((grub_uint8_t *)params + 0x1f1, + (grub_uint8_t *)kernel + 0x1f1, + MIN((grub_size_t)0x202+setup_header_end_offset,sizeof (*params)) - 0x1f1); + lh = (struct linux_i386_kernel_header *)params; + grub_dprintf ("linux", "lh is at %p\n", lh); + grub_dprintf ("linux", "checking lh->boot_flag\n"); + if (lh->boot_flag != grub_cpu_to_le16 (0xaa55)) { grub_error (GRUB_ERR_BAD_OS, N_("invalid magic number")); goto fail; } - if (lh.setup_sects > GRUB_LINUX_MAX_SETUP_SECTS) + grub_dprintf ("linux", "checking lh->setup_sects\n"); + if (lh->setup_sects > GRUB_LINUX_MAX_SETUP_SECTS) { grub_error (GRUB_ERR_BAD_OS, N_("too many setup sectors")); goto fail; } - if (lh.version < grub_cpu_to_le16 (0x020b)) + grub_dprintf ("linux", "checking lh->version\n"); + if (lh->version < grub_cpu_to_le16 (0x020b)) { grub_error (GRUB_ERR_BAD_OS, N_("kernel too old")); goto fail; } - if (!lh.handover_offset) + grub_dprintf ("linux", "checking lh->handover_offset\n"); + if (!lh->handover_offset) { grub_error (GRUB_ERR_BAD_OS, N_("kernel doesn't support EFI handover")); goto fail; } - linux_cmdline = grub_efi_allocate_pages_max(0x3fffffff, - BYTES_TO_PAGES(lh.cmdline_size + 1)); +#if defined(__x86_64__) || defined(__aarch64__) + grub_dprintf ("linux", "checking lh->xloadflags\n"); + if (!(lh->xloadflags & LINUX_XLF_KERNEL_64)) + { + grub_error (GRUB_ERR_BAD_OS, N_("kernel doesn't support 64-bit CPUs")); + goto fail; + } +#endif +#if defined(__i386__) + if ((lh->xloadflags & LINUX_XLF_KERNEL_64) && + !(lh->xloadflags & LINUX_XLF_EFI_HANDOVER_32)) + { + grub_error (GRUB_ERR_BAD_OS, + N_("kernel doesn't support 32-bit handover")); + goto fail; + } +#endif + + grub_dprintf ("linux", "setting up cmdline\n"); + linux_cmdline = grub_efi_allocate_pages_max(0x3fffffff, + BYTES_TO_PAGES(lh->cmdline_size + 1)); if (!linux_cmdline) { grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("can't allocate cmdline")); @@ -233,27 +269,26 @@ grub_memcpy (linux_cmdline, LINUX_IMAGE, sizeof (LINUX_IMAGE)); err = grub_create_loader_cmdline (argc, argv, linux_cmdline + sizeof (LINUX_IMAGE) - 1, - lh.cmdline_size - (sizeof (LINUX_IMAGE) - 1), + lh->cmdline_size - (sizeof (LINUX_IMAGE) - 1), GRUB_VERIFY_KERNEL_CMDLINE); if (err) goto fail; - lh.cmd_line_ptr = (grub_uint32_t)(grub_addr_t)linux_cmdline; + grub_dprintf ("linux", "cmdline:%s\n", linux_cmdline); + grub_dprintf ("linux", "setting lh->cmd_line_ptr\n"); + lh->cmd_line_ptr = (grub_uint32_t)(grub_addr_t)linux_cmdline; - handover_offset = lh.handover_offset; + grub_dprintf ("linux", "computing handover offset\n"); + handover_offset = lh->handover_offset; - start = (lh.setup_sects + 1) * 512; - len = grub_file_size(file) - start; + start = (lh->setup_sects + 1) * 512; - kernel_mem = grub_efi_allocate_fixed (lh.pref_address, - BYTES_TO_PAGES(lh.init_size)); + kernel_mem = grub_efi_allocate_pages_max(lh->pref_address, + BYTES_TO_PAGES(lh->init_size)); if (!kernel_mem) - { - grub_errno = GRUB_ERR_NONE; - kernel_mem = grub_efi_allocate_pages_max(0x3fffffff, - BYTES_TO_PAGES(lh.init_size)); - } + kernel_mem = grub_efi_allocate_pages_max(0x3fffffff, + BYTES_TO_PAGES(lh->init_size)); if (!kernel_mem) { @@ -261,21 +296,23 @@ goto fail; } - grub_memcpy (kernel_mem, (char *)kernel + start, len); + grub_dprintf ("linux", "kernel_mem = %lx\n", (unsigned long) kernel_mem); + grub_loader_set (grub_linuxefi_boot, grub_linuxefi_unload, 0); loaded=1; + grub_dprintf ("linux", "setting lh->code32_start to %p\n", kernel_mem); + lh->code32_start = (grub_uint32_t)(grub_addr_t) kernel_mem; - lh.code32_start = (grub_uint32_t)(grub_uint64_t) kernel_mem; - /* Grub linuxefi erroneously initialize linux's boot_params with non-zero values. (bsc#1025563) + grub_memcpy (kernel_mem, (char *)kernel + start, filelen - start); - From https://www.kernel.org/doc/Documentation/x86/boot.txt: - The memory for struct boot_params could be allocated anywhere (even above 4G) - and initialized to all zero. - Then, the setup header at offset 0x01f1 of kernel image on should be - loaded into struct boot_params and examined. */ - grub_memcpy (¶ms->setup_sects, &lh.setup_sects, sizeof (lh) - 0x01f1); + grub_dprintf ("linux", "setting lh->type_of_loader\n"); + lh->type_of_loader = 0x6; - params->type_of_loader = 0x21; + grub_dprintf ("linux", "setting lh->ext_loader_{type,ver}\n"); + params->ext_loader_type = 0; + params->ext_loader_ver = 2; + grub_dprintf("linux", "kernel_mem: %p handover_offset: %08x\n", + kernel_mem, handover_offset); fail: @@ -291,8 +328,10 @@ loaded = 0; } - if (linux_cmdline && !loaded) - grub_efi_free_pages((grub_efi_physical_address_t)(grub_addr_t)linux_cmdline, BYTES_TO_PAGES(lh.cmdline_size + 1)); + if (linux_cmdline && lh && !loaded) + grub_efi_free_pages ((grub_efi_physical_address_t)(grub_addr_t) + linux_cmdline, + BYTES_TO_PAGES(lh->cmdline_size + 1)); if (kernel_mem && !loaded) grub_efi_free_pages((grub_efi_physical_address_t)(grub_addr_t)kernel_mem, BYTES_TO_PAGES(kernel_size)); --- a/include/grub/i386/linux.h +++ b/include/grub/i386/linux.h @@ -148,6 +148,11 @@ grub_uint32_t kernel_alignment; grub_uint8_t relocatable; grub_uint8_t min_alignment; +#define LINUX_XLF_KERNEL_64 (1<<0) +#define LINUX_XLF_CAN_BE_LOADED_ABOVE_4G (1<<1) +#define LINUX_XLF_EFI_HANDOVER_32 (1<<2) +#define LINUX_XLF_EFI_HANDOVER_64 (1<<3) +#define LINUX_XLF_EFI_KEXEC (1<<4) grub_uint16_t xloadflags; grub_uint32_t cmdline_size; grub_uint32_t hardware_subarch; --- a/grub-core/loader/efi/linux_boot.c +++ b/grub-core/loader/efi/linux_boot.c @@ -30,11 +30,16 @@ typedef void (*handover_func) (void *, grub_efi_system_table_t *, void *); grub_err_t -grub_efi_linux_boot (void *kernel_addr, grub_off_t offset, +grub_efi_linux_boot (void *kernel_addr, grub_off_t handover_offset, void *kernel_params) { grub_efi_loaded_image_t *loaded_image = NULL; handover_func hf; + int offset = 0; + +#ifdef __x86_64__ + offset = 512; +#endif /* * Since the EFI loader is not calling the LoadImage() and StartImage() @@ -48,8 +53,8 @@ grub_dprintf ("linux", "Loaded Image base address could not be set\n"); grub_dprintf ("linux", "kernel_addr: %p handover_offset: %p params: %p\n", - kernel_addr, (void *)(grub_efi_uintn_t)offset, kernel_params); - hf = (handover_func)((char *)kernel_addr + offset); + kernel_addr, (void *)(grub_efi_uintn_t)handover_offset, kernel_params); + hf = (handover_func)((char *)kernel_addr + handover_offset + offset); hf (grub_efi_image_handle, grub_efi_system_table, kernel_params); return GRUB_ERR_BUG;