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-rw-r--r--arch/arm64/include/asm/fixmap.h4
-rw-r--r--arch/arm64/include/asm/pgtable.h1
-rw-r--r--arch/arm64/kernel/asm-offsets.c6
-rw-r--r--arch/arm64/mm/mmu.c23
4 files changed, 33 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h
index 4052ec39e8db..8119b49be98d 100644
--- a/arch/arm64/include/asm/fixmap.h
+++ b/arch/arm64/include/asm/fixmap.h
@@ -58,6 +58,10 @@ enum fixed_addresses {
FIX_APEI_GHES_NMI,
#endif /* CONFIG_ACPI_APEI_GHES */
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+ FIX_ENTRY_TRAMP_TEXT,
+#define TRAMP_VALIAS (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT))
+#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
__end_of_permanent_fixed_addresses,
/*
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 149d05fb9421..774003b247ad 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -680,6 +680,7 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm,
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
+extern pgd_t tramp_pg_dir[PTRS_PER_PGD];
/*
* Encode and decode a swap entry:
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 71bf088f1e4b..af247d10252f 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -24,6 +24,7 @@
#include <linux/kvm_host.h>
#include <linux/suspend.h>
#include <asm/cpufeature.h>
+#include <asm/fixmap.h>
#include <asm/thread_info.h>
#include <asm/memory.h>
#include <asm/smp_plat.h>
@@ -148,11 +149,14 @@ int main(void)
DEFINE(ARM_SMCCC_RES_X2_OFFS, offsetof(struct arm_smccc_res, a2));
DEFINE(ARM_SMCCC_QUIRK_ID_OFFS, offsetof(struct arm_smccc_quirk, id));
DEFINE(ARM_SMCCC_QUIRK_STATE_OFFS, offsetof(struct arm_smccc_quirk, state));
-
BLANK();
DEFINE(HIBERN_PBE_ORIG, offsetof(struct pbe, orig_address));
DEFINE(HIBERN_PBE_ADDR, offsetof(struct pbe, address));
DEFINE(HIBERN_PBE_NEXT, offsetof(struct pbe, next));
DEFINE(ARM64_FTR_SYSVAL, offsetof(struct arm64_ftr_reg, sys_val));
+ BLANK();
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+ DEFINE(TRAMP_VALIAS, TRAMP_VALIAS);
+#endif
return 0;
}
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 267d2b79d52d..fe68a48c64cb 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -525,6 +525,29 @@ static int __init parse_rodata(char *arg)
}
early_param("rodata", parse_rodata);
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+static int __init map_entry_trampoline(void)
+{
+ extern char __entry_tramp_text_start[];
+
+ pgprot_t prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
+ phys_addr_t pa_start = __pa_symbol(__entry_tramp_text_start);
+
+ /* The trampoline is always mapped and can therefore be global */
+ pgprot_val(prot) &= ~PTE_NG;
+
+ /* Map only the text into the trampoline page table */
+ memset(tramp_pg_dir, 0, PGD_SIZE);
+ __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE,
+ prot, pgd_pgtable_alloc, 0);
+
+ /* ...as well as the kernel page table */
+ __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot);
+ return 0;
+}
+core_initcall(map_entry_trampoline);
+#endif
+
/*
* Create fine-grained mappings for the kernel.
*/