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-rw-r--r--arch/x86/boot/compressed/eboot.c3
-rw-r--r--arch/x86/include/asm/efi.h26
-rw-r--r--arch/x86/mm/debug_pagetables.c6
-rw-r--r--arch/x86/platform/efi/efi_64.c60
-rw-r--r--arch/x86/platform/efi/efi_thunk_64.S2
-rw-r--r--arch/x86/platform/efi/quirks.c10
6 files changed, 56 insertions, 51 deletions
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 886a9115af62..47d3efff6805 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -421,9 +421,10 @@ static void retrieve_apple_device_properties(struct boot_params *boot_params)
}
}
+static const efi_char16_t apple[] = L"Apple";
+
static void setup_quirks(struct boot_params *boot_params)
{
- efi_char16_t const apple[] = { 'A', 'p', 'p', 'l', 'e', 0 };
efi_char16_t *fw_vendor = (efi_char16_t *)(unsigned long)
efi_table_attr(efi_system_table, fw_vendor, sys_table);
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index a399c1ebf6f0..cec5fae23eb3 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -7,6 +7,7 @@
#include <asm/processor-flags.h>
#include <asm/tlb.h>
#include <asm/nospec-branch.h>
+#include <asm/mmu_context.h>
/*
* We map the EFI regions needed for runtime services non-contiguously,
@@ -69,14 +70,13 @@ extern asmlinkage u64 efi_call(void *fp, ...);
#define efi_call_phys(f, args...) efi_call((f), args)
/*
- * Scratch space used for switching the pagetable in the EFI stub
+ * struct efi_scratch - Scratch space used while switching to/from efi_mm
+ * @phys_stack: stack used during EFI Mixed Mode
+ * @prev_mm: store/restore stolen mm_struct while switching to/from efi_mm
*/
struct efi_scratch {
- u64 r15;
- u64 prev_cr3;
- pgd_t *efi_pgt;
- bool use_pgd;
- u64 phys_stack;
+ u64 phys_stack;
+ struct mm_struct *prev_mm;
} __packed;
#define arch_efi_call_virt_setup() \
@@ -86,11 +86,8 @@ struct efi_scratch {
__kernel_fpu_begin(); \
firmware_restrict_branch_speculation_start(); \
\
- if (efi_scratch.use_pgd) { \
- efi_scratch.prev_cr3 = __read_cr3(); \
- write_cr3((unsigned long)efi_scratch.efi_pgt); \
- __flush_tlb_all(); \
- } \
+ if (!efi_enabled(EFI_OLD_MEMMAP)) \
+ efi_switch_mm(&efi_mm); \
})
#define arch_efi_call_virt(p, f, args...) \
@@ -98,10 +95,8 @@ struct efi_scratch {
#define arch_efi_call_virt_teardown() \
({ \
- if (efi_scratch.use_pgd) { \
- write_cr3(efi_scratch.prev_cr3); \
- __flush_tlb_all(); \
- } \
+ if (!efi_enabled(EFI_OLD_MEMMAP)) \
+ efi_switch_mm(efi_scratch.prev_mm); \
\
firmware_restrict_branch_speculation_end(); \
__kernel_fpu_end(); \
@@ -144,6 +139,7 @@ extern void __init efi_dump_pagetable(void);
extern void __init efi_apply_memmap_quirks(void);
extern int __init efi_reuse_config(u64 tables, int nr_tables);
extern void efi_delete_dummy_variable(void);
+extern void efi_switch_mm(struct mm_struct *mm);
struct efi_setup_data {
u64 fw_vendor;
diff --git a/arch/x86/mm/debug_pagetables.c b/arch/x86/mm/debug_pagetables.c
index 51a6f92da2bf..225fe2f0bfec 100644
--- a/arch/x86/mm/debug_pagetables.c
+++ b/arch/x86/mm/debug_pagetables.c
@@ -1,4 +1,5 @@
#include <linux/debugfs.h>
+#include <linux/efi.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <asm/pgtable.h>
@@ -73,13 +74,12 @@ static const struct file_operations ptdump_curusr_fops = {
#endif
#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
-extern pgd_t *efi_pgd;
static struct dentry *pe_efi;
static int ptdump_show_efi(struct seq_file *m, void *v)
{
- if (efi_pgd)
- ptdump_walk_pgd_level_debugfs(m, efi_pgd, false);
+ if (efi_mm.pgd)
+ ptdump_walk_pgd_level_debugfs(m, efi_mm.pgd, false);
return 0;
}
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 7f443bd1411d..bed7e7f4e44c 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -34,6 +34,7 @@
#include <linux/slab.h>
#include <linux/ucs2_string.h>
#include <linux/mem_encrypt.h>
+#include <linux/sched/task.h>
#include <asm/setup.h>
#include <asm/page.h>
@@ -82,9 +83,8 @@ pgd_t * __init efi_call_phys_prolog(void)
int n_pgds, i, j;
if (!efi_enabled(EFI_OLD_MEMMAP)) {
- save_pgd = (pgd_t *)__read_cr3();
- write_cr3((unsigned long)efi_scratch.efi_pgt);
- goto out;
+ efi_switch_mm(&efi_mm);
+ return NULL;
}
early_code_mapping_set_exec(1);
@@ -156,8 +156,7 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd)
pud_t *pud;
if (!efi_enabled(EFI_OLD_MEMMAP)) {
- write_cr3((unsigned long)save_pgd);
- __flush_tlb_all();
+ efi_switch_mm(efi_scratch.prev_mm);
return;
}
@@ -191,8 +190,7 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd)
early_code_mapping_set_exec(0);
}
-pgd_t *efi_pgd;
-EXPORT_SYMBOL_GPL(efi_pgd);
+EXPORT_SYMBOL_GPL(efi_mm);
/*
* We need our own copy of the higher levels of the page tables
@@ -205,7 +203,7 @@ EXPORT_SYMBOL_GPL(efi_pgd);
*/
int __init efi_alloc_page_tables(void)
{
- pgd_t *pgd;
+ pgd_t *pgd, *efi_pgd;
p4d_t *p4d;
pud_t *pud;
gfp_t gfp_mask;
@@ -233,6 +231,10 @@ int __init efi_alloc_page_tables(void)
return -ENOMEM;
}
+ efi_mm.pgd = efi_pgd;
+ mm_init_cpumask(&efi_mm);
+ init_new_context(NULL, &efi_mm);
+
return 0;
}
@@ -245,6 +247,7 @@ void efi_sync_low_kernel_mappings(void)
pgd_t *pgd_k, *pgd_efi;
p4d_t *p4d_k, *p4d_efi;
pud_t *pud_k, *pud_efi;
+ pgd_t *efi_pgd = efi_mm.pgd;
if (efi_enabled(EFI_OLD_MEMMAP))
return;
@@ -338,20 +341,12 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
unsigned long pfn, text, pf;
struct page *page;
unsigned npages;
- pgd_t *pgd;
+ pgd_t *pgd = efi_mm.pgd;
if (efi_enabled(EFI_OLD_MEMMAP))
return 0;
/*
- * Since the PGD is encrypted, set the encryption mask so that when
- * this value is loaded into cr3 the PGD will be decrypted during
- * the pagetable walk.
- */
- efi_scratch.efi_pgt = (pgd_t *)__sme_pa(efi_pgd);
- pgd = efi_pgd;
-
- /*
* It can happen that the physical address of new_memmap lands in memory
* which is not mapped in the EFI page table. Therefore we need to go
* and ident-map those pages containing the map before calling
@@ -364,8 +359,6 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
return 1;
}
- efi_scratch.use_pgd = true;
-
/*
* Certain firmware versions are way too sentimential and still believe
* they are exclusive and unquestionable owners of the first physical page,
@@ -419,7 +412,7 @@ static void __init __map_region(efi_memory_desc_t *md, u64 va)
{
unsigned long flags = _PAGE_RW;
unsigned long pfn;
- pgd_t *pgd = efi_pgd;
+ pgd_t *pgd = efi_mm.pgd;
if (!(md->attribute & EFI_MEMORY_WB))
flags |= _PAGE_PCD;
@@ -523,7 +516,7 @@ void __init parse_efi_setup(u64 phys_addr, u32 data_len)
static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
{
unsigned long pfn;
- pgd_t *pgd = efi_pgd;
+ pgd_t *pgd = efi_mm.pgd;
int err1, err2;
/* Update the 1:1 mapping */
@@ -620,10 +613,26 @@ void __init efi_dump_pagetable(void)
if (efi_enabled(EFI_OLD_MEMMAP))
ptdump_walk_pgd_level(NULL, swapper_pg_dir);
else
- ptdump_walk_pgd_level(NULL, efi_pgd);
+ ptdump_walk_pgd_level(NULL, efi_mm.pgd);
#endif
}
+/*
+ * Makes the calling thread switch to/from efi_mm context. Can be used
+ * for SetVirtualAddressMap() i.e. current->active_mm == init_mm as well
+ * as during efi runtime calls i.e current->active_mm == current_mm.
+ * We are not mm_dropping()/mm_grabbing() any mm, because we are not
+ * losing/creating any references.
+ */
+void efi_switch_mm(struct mm_struct *mm)
+{
+ task_lock(current);
+ efi_scratch.prev_mm = current->active_mm;
+ current->active_mm = mm;
+ switch_mm(efi_scratch.prev_mm, mm, NULL);
+ task_unlock(current);
+}
+
#ifdef CONFIG_EFI_MIXED
extern efi_status_t efi64_thunk(u32, ...);
@@ -677,16 +686,13 @@ efi_status_t efi_thunk_set_virtual_address_map(
efi_sync_low_kernel_mappings();
local_irq_save(flags);
- efi_scratch.prev_cr3 = __read_cr3();
- write_cr3((unsigned long)efi_scratch.efi_pgt);
- __flush_tlb_all();
+ efi_switch_mm(&efi_mm);
func = (u32)(unsigned long)phys_set_virtual_address_map;
status = efi64_thunk(func, memory_map_size, descriptor_size,
descriptor_version, virtual_map);
- write_cr3(efi_scratch.prev_cr3);
- __flush_tlb_all();
+ efi_switch_mm(efi_scratch.prev_mm);
local_irq_restore(flags);
return status;
diff --git a/arch/x86/platform/efi/efi_thunk_64.S b/arch/x86/platform/efi/efi_thunk_64.S
index 189b218da87c..46c58b08739c 100644
--- a/arch/x86/platform/efi/efi_thunk_64.S
+++ b/arch/x86/platform/efi/efi_thunk_64.S
@@ -33,7 +33,7 @@ ENTRY(efi64_thunk)
* Switch to 1:1 mapped 32-bit stack pointer.
*/
movq %rsp, efi_saved_sp(%rip)
- movq efi_scratch+25(%rip), %rsp
+ movq efi_scratch(%rip), %rsp
/*
* Calculate the physical address of the kernel text.
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 5b513ccffde4..36c1f8b9f7e0 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -75,7 +75,7 @@ struct quark_security_header {
u32 rsvd[2];
};
-static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
+static const efi_char16_t efi_dummy_name[] = L"DUMMY";
static bool efi_no_storage_paranoia;
@@ -105,7 +105,8 @@ early_param("efi_no_storage_paranoia", setup_storage_paranoia);
*/
void efi_delete_dummy_variable(void)
{
- efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ efi.set_variable((efi_char16_t *)efi_dummy_name,
+ &EFI_DUMMY_GUID,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
@@ -177,12 +178,13 @@ efi_status_t efi_query_variable_store(u32 attributes, unsigned long size,
* that by attempting to use more space than is available.
*/
unsigned long dummy_size = remaining_size + 1024;
- void *dummy = kzalloc(dummy_size, GFP_ATOMIC);
+ void *dummy = kzalloc(dummy_size, GFP_KERNEL);
if (!dummy)
return EFI_OUT_OF_RESOURCES;
- status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ status = efi.set_variable((efi_char16_t *)efi_dummy_name,
+ &EFI_DUMMY_GUID,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,