From 271f2a4a9576b87ed1f8584909d6d270039e52ea Mon Sep 17 00:00:00 2001 From: Wang Yao Date: Wed, 6 Dec 2023 08:24:27 +0800 Subject: efi/loongarch: Use load address to calculate kernel entry address The efi_relocate_kernel() may load the PIE kernel to anywhere, the loaded address may not be equal to link address or EFI_KIMG_PREFERRED_ADDRESS. Acked-by: Huacai Chen Signed-off-by: Wang Yao Signed-off-by: Ard Biesheuvel --- arch/loongarch/include/asm/efi.h | 2 +- drivers/firmware/efi/libstub/loongarch-stub.c | 4 ++-- drivers/firmware/efi/libstub/loongarch.c | 6 +++--- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/loongarch/include/asm/efi.h b/arch/loongarch/include/asm/efi.h index 091897d40b03..91d81f9730ab 100644 --- a/arch/loongarch/include/asm/efi.h +++ b/arch/loongarch/include/asm/efi.h @@ -32,6 +32,6 @@ static inline unsigned long efi_get_kimg_min_align(void) #define EFI_KIMG_PREFERRED_ADDRESS PHYSADDR(VMLINUX_LOAD_ADDRESS) -unsigned long kernel_entry_address(void); +unsigned long kernel_entry_address(unsigned long kernel_addr); #endif /* _ASM_LOONGARCH_EFI_H */ diff --git a/drivers/firmware/efi/libstub/loongarch-stub.c b/drivers/firmware/efi/libstub/loongarch-stub.c index 72c71ae201f0..d6ec5d4b8dbe 100644 --- a/drivers/firmware/efi/libstub/loongarch-stub.c +++ b/drivers/firmware/efi/libstub/loongarch-stub.c @@ -35,9 +35,9 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, return status; } -unsigned long kernel_entry_address(void) +unsigned long kernel_entry_address(unsigned long kernel_addr) { unsigned long base = (unsigned long)&kernel_offset - kernel_offset; - return (unsigned long)&kernel_entry - base + VMLINUX_LOAD_ADDRESS; + return (unsigned long)&kernel_entry - base + kernel_addr; } diff --git a/drivers/firmware/efi/libstub/loongarch.c b/drivers/firmware/efi/libstub/loongarch.c index 807cba2693fc..0e0aa6cda73f 100644 --- a/drivers/firmware/efi/libstub/loongarch.c +++ b/drivers/firmware/efi/libstub/loongarch.c @@ -37,9 +37,9 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv) return EFI_SUCCESS; } -unsigned long __weak kernel_entry_address(void) +unsigned long __weak kernel_entry_address(unsigned long kernel_addr) { - return *(unsigned long *)(PHYSADDR(VMLINUX_LOAD_ADDRESS) + 8); + return *(unsigned long *)(kernel_addr + 8) - VMLINUX_LOAD_ADDRESS + kernel_addr; } efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image, @@ -73,7 +73,7 @@ efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image, csr_write64(CSR_DMW0_INIT, LOONGARCH_CSR_DMWIN0); csr_write64(CSR_DMW1_INIT, LOONGARCH_CSR_DMWIN1); - real_kernel_entry = (void *)kernel_entry_address(); + real_kernel_entry = (void *)kernel_entry_address(kernel_addr); real_kernel_entry(true, (unsigned long)cmdline_ptr, (unsigned long)efi_system_table); -- cgit v1.2.3 From 50d7cdf7a9b1ab6f4f74a69c84e974d5dc0c1bf1 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 11 Dec 2023 10:00:57 +0100 Subject: efi/x86: Avoid physical KASLR on older Dell systems River reports boot hangs with v6.6 and v6.7, and the bisect points to commit a1b87d54f4e4 ("x86/efistub: Avoid legacy decompressor when doing EFI boot") which moves the memory allocation and kernel decompression from the legacy decompressor (which executes *after* ExitBootServices()) to the EFI stub, using boot services for allocating the memory. The memory allocation succeeds but the subsequent call to decompress_kernel() never returns, resulting in a failed boot and a hanging system. As it turns out, this issue only occurs when physical address randomization (KASLR) is enabled, and given that this is a feature we can live without (virtual KASLR is much more important), let's disable the physical part of KASLR when booting on AMI UEFI firmware claiming to implement revision v2.0 of the specification (which was released in 2006), as this is the version these systems advertise. Fixes: a1b87d54f4e4 ("x86/efistub: Avoid legacy decompressor when doing EFI boot") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218173 Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/libstub/x86-stub.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index 1bfdae34df39..da9b7b8d0716 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -307,17 +307,20 @@ static void setup_unaccepted_memory(void) efi_err("Memory acceptance protocol failed\n"); } +static efi_char16_t *efistub_fw_vendor(void) +{ + unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor); + + return (efi_char16_t *)vendor; +} + static const efi_char16_t apple[] = L"Apple"; static void setup_quirks(struct boot_params *boot_params) { - efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long) - efi_table_attr(efi_system_table, fw_vendor); - - if (!memcmp(fw_vendor, apple, sizeof(apple))) { - if (IS_ENABLED(CONFIG_APPLE_PROPERTIES)) - retrieve_apple_device_properties(boot_params); - } + if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) && + !memcmp(efistub_fw_vendor(), apple, sizeof(apple))) + retrieve_apple_device_properties(boot_params); } /* @@ -765,11 +768,25 @@ static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry) if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) { u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size; + static const efi_char16_t ami[] = L"American Megatrends"; efi_get_seed(seed, sizeof(seed)); virt_addr += (range * seed[1]) >> 32; virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1); + + /* + * Older Dell systems with AMI UEFI firmware v2.0 may hang + * while decompressing the kernel if physical address + * randomization is enabled. + * + * https://bugzilla.kernel.org/show_bug.cgi?id=218173 + */ + if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION && + !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) { + efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n"); + seed[0] = 0; + } } status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr, -- cgit v1.2.3