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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/kernel/tboot.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/kernel/tboot.c')
-rw-r--r-- | arch/x86/kernel/tboot.c | 517 |
1 files changed, 517 insertions, 0 deletions
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c new file mode 100644 index 000000000..4c1bcb605 --- /dev/null +++ b/arch/x86/kernel/tboot.c @@ -0,0 +1,517 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * tboot.c: main implementation of helper functions used by kernel for + * runtime support of Intel(R) Trusted Execution Technology + * + * Copyright (c) 2006-2009, Intel Corporation + */ + +#include <linux/init_task.h> +#include <linux/spinlock.h> +#include <linux/export.h> +#include <linux/delay.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/dmar.h> +#include <linux/cpu.h> +#include <linux/pfn.h> +#include <linux/mm.h> +#include <linux/tboot.h> +#include <linux/debugfs.h> + +#include <asm/realmode.h> +#include <asm/processor.h> +#include <asm/bootparam.h> +#include <asm/pgalloc.h> +#include <asm/fixmap.h> +#include <asm/proto.h> +#include <asm/setup.h> +#include <asm/e820/api.h> +#include <asm/io.h> + +#include "../realmode/rm/wakeup.h" + +/* Global pointer to shared data; NULL means no measured launch. */ +static struct tboot *tboot __read_mostly; + +/* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ +#define AP_WAIT_TIMEOUT 1 + +#undef pr_fmt +#define pr_fmt(fmt) "tboot: " fmt + +static u8 tboot_uuid[16] __initdata = TBOOT_UUID; + +bool tboot_enabled(void) +{ + return tboot != NULL; +} + +/* noinline to prevent gcc from warning about dereferencing constant fixaddr */ +static noinline __init bool check_tboot_version(void) +{ + if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) { + pr_warn("tboot at 0x%llx is invalid\n", boot_params.tboot_addr); + return false; + } + + if (tboot->version < 5) { + pr_warn("tboot version is invalid: %u\n", tboot->version); + return false; + } + + pr_info("found shared page at phys addr 0x%llx:\n", + boot_params.tboot_addr); + pr_debug("version: %d\n", tboot->version); + pr_debug("log_addr: 0x%08x\n", tboot->log_addr); + pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry); + pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base); + pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); + + return true; +} + +void __init tboot_probe(void) +{ + /* Look for valid page-aligned address for shared page. */ + if (!boot_params.tboot_addr) + return; + /* + * also verify that it is mapped as we expect it before calling + * set_fixmap(), to reduce chance of garbage value causing crash + */ + if (!e820__mapped_any(boot_params.tboot_addr, + boot_params.tboot_addr, E820_TYPE_RESERVED)) { + pr_warn("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n"); + return; + } + + /* Map and check for tboot UUID. */ + set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); + tboot = (void *)fix_to_virt(FIX_TBOOT_BASE); + if (!check_tboot_version()) + tboot = NULL; +} + +static pgd_t *tboot_pg_dir; +static struct mm_struct tboot_mm = { + .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, tboot_mm.mmap_lock), + .pgd = swapper_pg_dir, + .mm_users = ATOMIC_INIT(2), + .mm_count = ATOMIC_INIT(1), + .write_protect_seq = SEQCNT_ZERO(tboot_mm.write_protect_seq), + MMAP_LOCK_INITIALIZER(init_mm) + .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), + .mmlist = LIST_HEAD_INIT(init_mm.mmlist), +}; + +static inline void switch_to_tboot_pt(void) +{ + write_cr3(virt_to_phys(tboot_pg_dir)); +} + +static int map_tboot_page(unsigned long vaddr, unsigned long pfn, + pgprot_t prot) +{ + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + pgd = pgd_offset(&tboot_mm, vaddr); + p4d = p4d_alloc(&tboot_mm, pgd, vaddr); + if (!p4d) + return -1; + pud = pud_alloc(&tboot_mm, p4d, vaddr); + if (!pud) + return -1; + pmd = pmd_alloc(&tboot_mm, pud, vaddr); + if (!pmd) + return -1; + pte = pte_alloc_map(&tboot_mm, pmd, vaddr); + if (!pte) + return -1; + set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); + pte_unmap(pte); + + /* + * PTI poisons low addresses in the kernel page tables in the + * name of making them unusable for userspace. To execute + * code at such a low address, the poison must be cleared. + * + * Note: 'pgd' actually gets set in p4d_alloc() _or_ + * pud_alloc() depending on 4/5-level paging. + */ + pgd->pgd &= ~_PAGE_NX; + + return 0; +} + +static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, + unsigned long nr) +{ + /* Reuse the original kernel mapping */ + tboot_pg_dir = pgd_alloc(&tboot_mm); + if (!tboot_pg_dir) + return -1; + + for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { + if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) + return -1; + } + + return 0; +} + +static void tboot_create_trampoline(void) +{ + u32 map_base, map_size; + + /* Create identity map for tboot shutdown code. */ + map_base = PFN_DOWN(tboot->tboot_base); + map_size = PFN_UP(tboot->tboot_size); + if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) + panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", + map_base, map_size); +} + +#ifdef CONFIG_ACPI_SLEEP + +static void add_mac_region(phys_addr_t start, unsigned long size) +{ + struct tboot_mac_region *mr; + phys_addr_t end = start + size; + + if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) + panic("tboot: Too many MAC regions\n"); + + if (start && size) { + mr = &tboot->mac_regions[tboot->num_mac_regions++]; + mr->start = round_down(start, PAGE_SIZE); + mr->size = round_up(end, PAGE_SIZE) - mr->start; + } +} + +static int tboot_setup_sleep(void) +{ + int i; + + tboot->num_mac_regions = 0; + + for (i = 0; i < e820_table->nr_entries; i++) { + if ((e820_table->entries[i].type != E820_TYPE_RAM) + && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN)) + continue; + + add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size); + } + + tboot->acpi_sinfo.kernel_s3_resume_vector = + real_mode_header->wakeup_start; + + return 0; +} + +#else /* no CONFIG_ACPI_SLEEP */ + +static int tboot_setup_sleep(void) +{ + /* S3 shutdown requested, but S3 not supported by the kernel... */ + BUG(); + return -1; +} + +#endif + +void tboot_shutdown(u32 shutdown_type) +{ + void (*shutdown)(void); + + if (!tboot_enabled()) + return; + + /* + * if we're being called before the 1:1 mapping is set up then just + * return and let the normal shutdown happen; this should only be + * due to very early panic() + */ + if (!tboot_pg_dir) + return; + + /* if this is S3 then set regions to MAC */ + if (shutdown_type == TB_SHUTDOWN_S3) + if (tboot_setup_sleep()) + return; + + tboot->shutdown_type = shutdown_type; + + switch_to_tboot_pt(); + + shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; + shutdown(); + + /* should not reach here */ + while (1) + halt(); +} + +static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) +{ +#define TB_COPY_GAS(tbg, g) \ + tbg.space_id = g.space_id; \ + tbg.bit_width = g.bit_width; \ + tbg.bit_offset = g.bit_offset; \ + tbg.access_width = g.access_width; \ + tbg.address = g.address; + + TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); + TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); + TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); + TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); + + /* + * We need phys addr of waking vector, but can't use virt_to_phys() on + * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys + * addr. + */ + tboot->acpi_sinfo.wakeup_vector = fadt->facs + + offsetof(struct acpi_table_facs, firmware_waking_vector); +} + +static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) +{ + static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { + /* S0,1,2: */ -1, -1, -1, + /* S3: */ TB_SHUTDOWN_S3, + /* S4: */ TB_SHUTDOWN_S4, + /* S5: */ TB_SHUTDOWN_S5 }; + + if (!tboot_enabled()) + return 0; + + tboot_copy_fadt(&acpi_gbl_FADT); + tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; + tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; + /* we always use the 32b wakeup vector */ + tboot->acpi_sinfo.vector_width = 32; + + if (sleep_state >= ACPI_S_STATE_COUNT || + acpi_shutdown_map[sleep_state] == -1) { + pr_warn("unsupported sleep state 0x%x\n", sleep_state); + return -1; + } + + tboot_shutdown(acpi_shutdown_map[sleep_state]); + return 0; +} + +static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) +{ + if (!tboot_enabled()) + return 0; + + pr_warn("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)"); + return -ENODEV; +} + +static atomic_t ap_wfs_count; + +static int tboot_wait_for_aps(int num_aps) +{ + unsigned long timeout; + + timeout = AP_WAIT_TIMEOUT*HZ; + while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && + timeout) { + mdelay(1); + timeout--; + } + + if (timeout) + pr_warn("tboot wait for APs timeout\n"); + + return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); +} + +static int tboot_dying_cpu(unsigned int cpu) +{ + atomic_inc(&ap_wfs_count); + if (num_online_cpus() == 1) { + if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) + return -EBUSY; + } + return 0; +} + +#ifdef CONFIG_DEBUG_FS + +#define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ + 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } + +#define TBOOT_SERIAL_LOG_ADDR 0x60000 +#define TBOOT_SERIAL_LOG_SIZE 0x08000 +#define LOG_MAX_SIZE_OFF 16 +#define LOG_BUF_OFF 24 + +static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; + +static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) +{ + void __iomem *log_base; + u8 log_uuid[16]; + u32 max_size; + void *kbuf; + int ret = -EFAULT; + + log_base = ioremap(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); + if (!log_base) + return ret; + + memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); + if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) + goto err_iounmap; + + max_size = readl(log_base + LOG_MAX_SIZE_OFF); + if (*ppos >= max_size) { + ret = 0; + goto err_iounmap; + } + + if (*ppos + count > max_size) + count = max_size - *ppos; + + kbuf = kmalloc(count, GFP_KERNEL); + if (!kbuf) { + ret = -ENOMEM; + goto err_iounmap; + } + + memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); + if (copy_to_user(user_buf, kbuf, count)) + goto err_kfree; + + *ppos += count; + + ret = count; + +err_kfree: + kfree(kbuf); + +err_iounmap: + iounmap(log_base); + + return ret; +} + +static const struct file_operations tboot_log_fops = { + .read = tboot_log_read, + .llseek = default_llseek, +}; + +#endif /* CONFIG_DEBUG_FS */ + +static __init int tboot_late_init(void) +{ + if (!tboot_enabled()) + return 0; + + tboot_create_trampoline(); + + atomic_set(&ap_wfs_count, 0); + cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL, + tboot_dying_cpu); +#ifdef CONFIG_DEBUG_FS + debugfs_create_file("tboot_log", S_IRUSR, + arch_debugfs_dir, NULL, &tboot_log_fops); +#endif + + acpi_os_set_prepare_sleep(&tboot_sleep); + acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep); + return 0; +} + +late_initcall(tboot_late_init); + +/* + * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) + */ + +#define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 +#define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 + +/* # pages for each config regs space - used by fixmap */ +#define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ + TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) + +/* offsets from pub/priv config space */ +#define TXTCR_HEAP_BASE 0x0300 +#define TXTCR_HEAP_SIZE 0x0308 + +#define SHA1_SIZE 20 + +struct sha1_hash { + u8 hash[SHA1_SIZE]; +}; + +struct sinit_mle_data { + u32 version; /* currently 6 */ + struct sha1_hash bios_acm_id; + u32 edx_senter_flags; + u64 mseg_valid; + struct sha1_hash sinit_hash; + struct sha1_hash mle_hash; + struct sha1_hash stm_hash; + struct sha1_hash lcp_policy_hash; + u32 lcp_policy_control; + u32 rlp_wakeup_addr; + u32 reserved; + u32 num_mdrs; + u32 mdrs_off; + u32 num_vtd_dmars; + u32 vtd_dmars_off; +} __packed; + +struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) +{ + void *heap_base, *heap_ptr, *config; + + if (!tboot_enabled()) + return dmar_tbl; + + /* + * ACPI tables may not be DMA protected by tboot, so use DMAR copy + * SINIT saved in SinitMleData in TXT heap (which is DMA protected) + */ + + /* map config space in order to get heap addr */ + config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * + PAGE_SIZE); + if (!config) + return NULL; + + /* now map TXT heap */ + heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), + *(u64 *)(config + TXTCR_HEAP_SIZE)); + iounmap(config); + if (!heap_base) + return NULL; + + /* walk heap to SinitMleData */ + /* skip BiosData */ + heap_ptr = heap_base + *(u64 *)heap_base; + /* skip OsMleData */ + heap_ptr += *(u64 *)heap_ptr; + /* skip OsSinitData */ + heap_ptr += *(u64 *)heap_ptr; + /* now points to SinitMleDataSize; set to SinitMleData */ + heap_ptr += sizeof(u64); + /* get addr of DMAR table */ + dmar_tbl = (struct acpi_table_header *)(heap_ptr + + ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - + sizeof(u64)); + + /* don't unmap heap because dmar.c needs access to this */ + + return dmar_tbl; +} |