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authorLinus Torvalds <torvalds@linux-foundation.org>2022-10-09 18:56:54 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-10-09 18:56:54 +0300
commit0e470763d84dcad27284067647dfb4b1a94dfce0 (patch)
tree34b7ab8b490ce5bb74255c5810357fc6fc819eba /arch/arm
parenta6afa4199d3d038fbfdff5511f7523b0e30cb774 (diff)
parentd3549a938b73f203ef522562ae9f2d38aa43d234 (diff)
downloadlinux-0e470763d84dcad27284067647dfb4b1a94dfce0.tar.xz
Merge tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI updates from Ard Biesheuvel: "A bit more going on than usual in the EFI subsystem. The main driver for this has been the introduction of the LoonArch architecture last cycle, which inspired some cleanup and refactoring of the EFI code. Another driver for EFI changes this cycle and in the future is confidential compute. The LoongArch architecture does not use either struct bootparams or DT natively [yet], and so passing information between the EFI stub and the core kernel using either of those is undesirable. And in general, overloading DT has been a source of issues on arm64, so using DT for this on new architectures is a to avoid for the time being (even if we might converge on something DT based for non-x86 architectures in the future). For this reason, in addition to the patch that enables EFI boot for LoongArch, there are a number of refactoring patches applied on top of which separate the DT bits from the generic EFI stub bits. These changes are on a separate topich branch that has been shared with the LoongArch maintainers, who will include it in their pull request as well. This is not ideal, but the best way to manage the conflicts without stalling LoongArch for another cycle. Another development inspired by LoongArch is the newly added support for EFI based decompressors. Instead of adding yet another arch-specific incarnation of this pattern for LoongArch, we are introducing an EFI app based on the existing EFI libstub infrastructure that encapulates the decompression code we use on other architectures, but in a way that is fully generic. This has been developed and tested in collaboration with distro and systemd folks, who are eager to start using this for systemd-boot and also for arm64 secure boot on Fedora. Note that the EFI zimage files this introduces can also be decompressed by non-EFI bootloaders if needed, as the image header describes the location of the payload inside the image, and the type of compression that was used. (Note that Fedora's arm64 GRUB is buggy [0] so you'll need a recent version or switch to systemd-boot in order to use this.) Finally, we are adding TPM measurement of the kernel command line provided by EFI. There is an oversight in the TCG spec which results in a blind spot for command line arguments passed to loaded images, which means that either the loader or the stub needs to take the measurement. Given the combinatorial explosion I am anticipating when it comes to firmware/bootloader stacks and firmware based attestation protocols (SEV-SNP, TDX, DICE, DRTM), it is good to set a baseline now when it comes to EFI measured boot, which is that the kernel measures the initrd and command line. Intermediate loaders can measure additional assets if needed, but with the baseline in place, we can deploy measured boot in a meaningful way even if you boot into Linux straight from the EFI firmware. Summary: - implement EFI boot support for LoongArch - implement generic EFI compressed boot support for arm64, RISC-V and LoongArch, none of which implement a decompressor today - measure the kernel command line into the TPM if measured boot is in effect - refactor the EFI stub code in order to isolate DT dependencies for architectures other than x86 - avoid calling SetVirtualAddressMap() on arm64 if the configured size of the VA space guarantees that doing so is unnecessary - move some ARM specific code out of the generic EFI source files - unmap kernel code from the x86 mixed mode 1:1 page tables" * tag 'efi-next-for-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits) efi/arm64: libstub: avoid SetVirtualAddressMap() when possible efi: zboot: create MemoryMapped() device path for the parent if needed efi: libstub: fix up the last remaining open coded boot service call efi/arm: libstub: move ARM specific code out of generic routines efi/libstub: measure EFI LoadOptions efi/libstub: refactor the initrd measuring functions efi/loongarch: libstub: remove dependency on flattened DT efi: libstub: install boot-time memory map as config table efi: libstub: remove DT dependency from generic stub efi: libstub: unify initrd loading between architectures efi: libstub: remove pointless goto kludge efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmap efi: libstub: avoid efi_get_memory_map() for allocating the virt map efi: libstub: drop pointless get_memory_map() call efi: libstub: fix type confusion for load_options_size arm64: efi: enable generic EFI compressed boot loongarch: efi: enable generic EFI compressed boot riscv: efi: enable generic EFI compressed boot efi/libstub: implement generic EFI zboot efi/libstub: move efi_system_table global var into separate object ...
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/efi.h3
-rw-r--r--arch/arm/kernel/efi.c79
-rw-r--r--arch/arm/kernel/setup.c2
3 files changed, 82 insertions, 2 deletions
diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h
index 3088ef72704e..4bdd930167c0 100644
--- a/arch/arm/include/asm/efi.h
+++ b/arch/arm/include/asm/efi.h
@@ -17,6 +17,7 @@
#ifdef CONFIG_EFI
void efi_init(void);
+void arm_efi_init(void);
int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
@@ -37,7 +38,7 @@ void efi_virtmap_load(void);
void efi_virtmap_unload(void);
#else
-#define efi_init()
+#define arm_efi_init()
#endif /* CONFIG_EFI */
/* arch specific definitions used by the stub code */
diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c
index e57dbcc89123..e50ad7eefc02 100644
--- a/arch/arm/kernel/efi.c
+++ b/arch/arm/kernel/efi.c
@@ -4,6 +4,7 @@
*/
#include <linux/efi.h>
+#include <linux/memblock.h>
#include <asm/efi.h>
#include <asm/mach/map.h>
#include <asm/mmu_context.h>
@@ -73,3 +74,81 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
return efi_set_mapping_permissions(mm, md);
return 0;
}
+
+static unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR;
+static unsigned long __initdata cpu_state_table = EFI_INVALID_TABLE_ADDR;
+
+const efi_config_table_type_t efi_arch_tables[] __initconst = {
+ {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, &screen_info_table},
+ {LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table},
+ {}
+};
+
+static void __init load_screen_info_table(void)
+{
+ struct screen_info *si;
+
+ if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
+ si = early_memremap_ro(screen_info_table, sizeof(*si));
+ if (!si) {
+ pr_err("Could not map screen_info config table\n");
+ return;
+ }
+ screen_info = *si;
+ early_memunmap(si, sizeof(*si));
+
+ /* dummycon on ARM needs non-zero values for columns/lines */
+ screen_info.orig_video_cols = 80;
+ screen_info.orig_video_lines = 25;
+
+ if (memblock_is_map_memory(screen_info.lfb_base))
+ memblock_mark_nomap(screen_info.lfb_base,
+ screen_info.lfb_size);
+ }
+}
+
+static void __init load_cpu_state_table(void)
+{
+ if (cpu_state_table != EFI_INVALID_TABLE_ADDR) {
+ struct efi_arm_entry_state *state;
+ bool dump_state = true;
+
+ state = early_memremap_ro(cpu_state_table,
+ sizeof(struct efi_arm_entry_state));
+ if (state == NULL) {
+ pr_warn("Unable to map CPU entry state table.\n");
+ return;
+ }
+
+ if ((state->sctlr_before_ebs & 1) == 0)
+ pr_warn(FW_BUG "EFI stub was entered with MMU and Dcache disabled, please fix your firmware!\n");
+ else if ((state->sctlr_after_ebs & 1) == 0)
+ pr_warn(FW_BUG "ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware!\n");
+ else
+ dump_state = false;
+
+ if (dump_state || efi_enabled(EFI_DBG)) {
+ pr_info("CPSR at EFI stub entry : 0x%08x\n",
+ state->cpsr_before_ebs);
+ pr_info("SCTLR at EFI stub entry : 0x%08x\n",
+ state->sctlr_before_ebs);
+ pr_info("CPSR after ExitBootServices() : 0x%08x\n",
+ state->cpsr_after_ebs);
+ pr_info("SCTLR after ExitBootServices(): 0x%08x\n",
+ state->sctlr_after_ebs);
+ }
+ early_memunmap(state, sizeof(struct efi_arm_entry_state));
+ }
+}
+
+void __init arm_efi_init(void)
+{
+ efi_init();
+
+ load_screen_info_table();
+
+ /* ARM does not permit early mappings to persist across paging_init() */
+ efi_memmap_unmap();
+
+ load_cpu_state_table();
+}
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 1e8a50a97edf..cb88c6e69377 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1141,7 +1141,7 @@ void __init setup_arch(char **cmdline_p)
#endif
setup_dma_zone(mdesc);
xen_early_init();
- efi_init();
+ arm_efi_init();
/*
* Make sure the calculation for lowmem/highmem is set appropriately
* before reserving/allocating any memory