diff options
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 9 | ||||
| -rw-r--r-- | arch/arm64/mm/proc.S | 70 |
2 files changed, 66 insertions, 13 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index ed9670d8360c..bc5e4e569864 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1765,6 +1765,9 @@ static int __init __kpti_install_ng_mappings(void *__unused) pgd_t *kpti_ng_temp_pgd; u64 alloc = 0; + if (levels == 5 && !pgtable_l5_enabled()) + levels = 4; + remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings); if (!cpu) { @@ -1778,9 +1781,9 @@ static int __init __kpti_install_ng_mappings(void *__unused) // // The physical pages are laid out as follows: // - // +--------+-/-------+-/------ +-\\--------+ - // : PTE[] : | PMD[] : | PUD[] : || PGD[] : - // +--------+-\-------+-\------ +-//--------+ + // +--------+-/-------+-/------ +-/------ +-\\\--------+ + // : PTE[] : | PMD[] : | PUD[] : | P4D[] : ||| PGD[] : + // +--------+-\-------+-\------ +-\------ +-///--------+ // ^ // The first page is mapped into this hierarchy at a PMD_SHIFT // aligned virtual address, so that we can manipulate the PTE diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index d03434b7bca5..fa0d7c63f8d2 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -216,16 +216,15 @@ SYM_FUNC_ALIAS(__pi_idmap_cpu_replace_ttbr1, idmap_cpu_replace_ttbr1) .macro kpti_mk_tbl_ng, type, num_entries add end_\type\()p, cur_\type\()p, #\num_entries * 8 .Ldo_\type: - ldr \type, [cur_\type\()p] // Load the entry + ldr \type, [cur_\type\()p], #8 // Load the entry and advance tbz \type, #0, .Lnext_\type // Skip invalid and tbnz \type, #11, .Lnext_\type // non-global entries orr \type, \type, #PTE_NG // Same bit for blocks and pages - str \type, [cur_\type\()p] // Update the entry + str \type, [cur_\type\()p, #-8] // Update the entry .ifnc \type, pte tbnz \type, #1, .Lderef_\type .endif .Lnext_\type: - add cur_\type\()p, cur_\type\()p, #8 cmp cur_\type\()p, end_\type\()p b.ne .Ldo_\type .endm @@ -235,18 +234,18 @@ SYM_FUNC_ALIAS(__pi_idmap_cpu_replace_ttbr1, idmap_cpu_replace_ttbr1) * fixmap slot associated with the current level. */ .macro kpti_map_pgtbl, type, level - str xzr, [temp_pte, #8 * (\level + 1)] // break before make + str xzr, [temp_pte, #8 * (\level + 2)] // break before make dsb nshst - add pte, temp_pte, #PAGE_SIZE * (\level + 1) + add pte, temp_pte, #PAGE_SIZE * (\level + 2) lsr pte, pte, #12 tlbi vaae1, pte dsb nsh isb phys_to_pte pte, cur_\type\()p - add cur_\type\()p, temp_pte, #PAGE_SIZE * (\level + 1) + add cur_\type\()p, temp_pte, #PAGE_SIZE * (\level + 2) orr pte, pte, pte_flags - str pte, [temp_pte, #8 * (\level + 1)] + str pte, [temp_pte, #8 * (\level + 2)] dsb nshst .endm @@ -279,6 +278,8 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) end_ptep .req x15 pte .req x16 valid .req x17 + cur_p4dp .req x19 + end_p4dp .req x20 mov x5, x3 // preserve temp_pte arg mrs swapper_ttb, ttbr1_el1 @@ -286,6 +287,12 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) cbnz cpu, __idmap_kpti_secondary +#if CONFIG_PGTABLE_LEVELS > 4 + stp x29, x30, [sp, #-32]! + mov x29, sp + stp x19, x20, [sp, #16] +#endif + /* We're the boot CPU. Wait for the others to catch up */ sevl 1: wfe @@ -303,9 +310,32 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) mov_q pte_flags, KPTI_NG_PTE_FLAGS /* Everybody is enjoying the idmap, so we can rewrite swapper. */ + +#ifdef CONFIG_ARM64_LPA2 + /* + * If LPA2 support is configured, but 52-bit virtual addressing is not + * enabled at runtime, we will fall back to one level of paging less, + * and so we have to walk swapper_pg_dir as if we dereferenced its + * address from a PGD level entry, and terminate the PGD level loop + * right after. + */ + adrp pgd, swapper_pg_dir // walk &swapper_pg_dir at the next level + mov cur_pgdp, end_pgdp // must be equal to terminate the PGD loop +alternative_if_not ARM64_HAS_VA52 + b .Lderef_pgd // skip to the next level +alternative_else_nop_endif + /* + * LPA2 based 52-bit virtual addressing requires 52-bit physical + * addressing to be enabled as well. In this case, the shareability + * bits are repurposed as physical address bits, and should not be + * set in pte_flags. + */ + bic pte_flags, pte_flags, #PTE_SHARED +#endif + /* PGD */ adrp cur_pgdp, swapper_pg_dir - kpti_map_pgtbl pgd, 0 + kpti_map_pgtbl pgd, -1 kpti_mk_tbl_ng pgd, PTRS_PER_PGD /* Ensure all the updated entries are visible to secondary CPUs */ @@ -318,16 +348,33 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) /* Set the flag to zero to indicate that we're all done */ str wzr, [flag_ptr] +#if CONFIG_PGTABLE_LEVELS > 4 + ldp x19, x20, [sp, #16] + ldp x29, x30, [sp], #32 +#endif ret .Lderef_pgd: + /* P4D */ + .if CONFIG_PGTABLE_LEVELS > 4 + p4d .req x30 + pte_to_phys cur_p4dp, pgd + kpti_map_pgtbl p4d, 0 + kpti_mk_tbl_ng p4d, PTRS_PER_P4D + b .Lnext_pgd + .else /* CONFIG_PGTABLE_LEVELS <= 4 */ + p4d .req pgd + .set .Lnext_p4d, .Lnext_pgd + .endif + +.Lderef_p4d: /* PUD */ .if CONFIG_PGTABLE_LEVELS > 3 pud .req x10 - pte_to_phys cur_pudp, pgd + pte_to_phys cur_pudp, p4d kpti_map_pgtbl pud, 1 kpti_mk_tbl_ng pud, PTRS_PER_PUD - b .Lnext_pgd + b .Lnext_p4d .else /* CONFIG_PGTABLE_LEVELS <= 3 */ pud .req pgd .set .Lnext_pud, .Lnext_pgd @@ -371,6 +418,9 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) .unreq end_ptep .unreq pte .unreq valid + .unreq cur_p4dp + .unreq end_p4dp + .unreq p4d /* Secondary CPUs end up here */ __idmap_kpti_secondary: |