diff options
author | Ard Biesheuvel <ardb@kernel.org> | 2021-01-19 15:05:40 +0100 |
---|---|---|
committer | Ard Biesheuvel <ardb@kernel.org> | 2021-01-19 17:57:15 +0100 |
commit | 514b1a8477d25a157f65bf52a443f8ffcc2eb54e (patch) | |
tree | bad43c89baff36df8af5ede176d981114dc742bd | |
parent | 3e1e00c00e2b9b5c9a2f47f1c67720a5d430e4d0 (diff) | |
download | linux-514b1a8477d25a157f65bf52a443f8ffcc2eb54e.tar.bz2 |
efi: x86: clean up previous struct mm switching
EFI on x86_64 keeps track of the process's MM pointer by storing it
in a global struct called 'efi_scratch', which also used to contain
the mixed mode stack pointer. Let's clean this up a little bit, by
getting rid of the struct, and pushing the mm handling into the
callees entirely.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
-rw-r--r-- | arch/x86/include/asm/efi.h | 17 | ||||
-rw-r--r-- | arch/x86/platform/efi/efi_64.c | 27 |
2 files changed, 20 insertions, 24 deletions
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 5e37e6d63c63..1328b7959b72 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -95,20 +95,12 @@ extern asmlinkage u64 __efi_call(void *fp, ...); __efi_call(__VA_ARGS__); \ }) -/* - * struct efi_scratch - Scratch space used while switching to/from efi_mm - * @prev_mm: store/restore stolen mm_struct while switching to/from efi_mm - */ -struct efi_scratch { - struct mm_struct *prev_mm; -} __packed; - #define arch_efi_call_virt_setup() \ ({ \ efi_sync_low_kernel_mappings(); \ kernel_fpu_begin(); \ firmware_restrict_branch_speculation_start(); \ - efi_switch_mm(&efi_mm); \ + efi_enter_mm(); \ }) #define arch_efi_call_virt(p, f, args...) \ @@ -116,7 +108,7 @@ struct efi_scratch { #define arch_efi_call_virt_teardown() \ ({ \ - efi_switch_mm(efi_scratch.prev_mm); \ + efi_leave_mm(); \ firmware_restrict_branch_speculation_end(); \ kernel_fpu_end(); \ }) @@ -135,7 +127,6 @@ struct efi_scratch { #endif /* CONFIG_X86_32 */ -extern struct efi_scratch efi_scratch; extern int __init efi_memblock_x86_reserve_range(void); extern void __init efi_print_memmap(void); extern void __init efi_map_region(efi_memory_desc_t *md); @@ -148,10 +139,12 @@ 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); extern void efi_recover_from_page_fault(unsigned long phys_addr); extern void efi_free_boot_services(void); +void efi_enter_mm(void); +void efi_leave_mm(void); + /* kexec external ABI */ struct efi_setup_data { u64 fw_vendor; diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 1d904181e6a1..62a6c8650773 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -54,10 +54,7 @@ * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G. */ static u64 efi_va = EFI_VA_START; - -struct efi_scratch efi_scratch; - -EXPORT_SYMBOL_GPL(efi_mm); +static struct mm_struct *efi_prev_mm; /* * We need our own copy of the higher levels of the page tables @@ -481,11 +478,17 @@ void __init efi_dump_pagetable(void) * can not change under us. * It should be ensured that there are no concurent calls to this function. */ -void efi_switch_mm(struct mm_struct *mm) +void efi_enter_mm(void) +{ + efi_prev_mm = current->active_mm; + current->active_mm = &efi_mm; + switch_mm(efi_prev_mm, &efi_mm, NULL); +} + +void efi_leave_mm(void) { - efi_scratch.prev_mm = current->active_mm; - current->active_mm = mm; - switch_mm(efi_scratch.prev_mm, mm, NULL); + current->active_mm = efi_prev_mm; + switch_mm(&efi_mm, efi_prev_mm, NULL); } static DEFINE_SPINLOCK(efi_runtime_lock); @@ -549,12 +552,12 @@ efi_thunk_set_virtual_address_map(unsigned long memory_map_size, efi_sync_low_kernel_mappings(); local_irq_save(flags); - efi_switch_mm(&efi_mm); + efi_enter_mm(); status = __efi_thunk(set_virtual_address_map, memory_map_size, descriptor_size, descriptor_version, virtual_map); - efi_switch_mm(efi_scratch.prev_mm); + efi_leave_mm(); local_irq_restore(flags); return status; @@ -848,7 +851,7 @@ efi_set_virtual_address_map(unsigned long memory_map_size, descriptor_size, descriptor_version, virtual_map); - efi_switch_mm(&efi_mm); + efi_enter_mm(); kernel_fpu_begin(); @@ -864,7 +867,7 @@ efi_set_virtual_address_map(unsigned long memory_map_size, /* grab the virtually remapped EFI runtime services table pointer */ efi.runtime = READ_ONCE(systab->runtime); - efi_switch_mm(efi_scratch.prev_mm); + efi_leave_mm(); return status; } |