github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-30 10:04:04 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

efi/arm: Disable LPAE PAN when calling EFI runtime services

Browse Source 
EFI runtime services are remapped into the lower 1 GiB of virtual
address space at boot, so they are guaranteed to be able to co-exist
with the kernel virtual mappings without the need to allocate space for
them in the kernel's vmalloc region, which is rather small.

This means those mappings are covered by TTBR0 when LPAE PAN is enabled,
and so 'user' access must be enabled while such calls are in progress.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
This commit is contained in:
Ard Biesheuvel 2024-06-10 14:12:45 +02:00
parent 99280413a5
commit a1439d8948
1 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
arch/arm/include/asm/efi.h
View File

@ -14,6 +14,7 @@
#include <asm/mach/map.h>
#include <asm/mmu_context.h>
#include <asm/ptrace.h>
#include <asm/uaccess.h>
#ifdef CONFIG_EFI
void efi_init(void);
@ -25,6 +26,18 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md, boo
#define arch_efi_call_virt_setup() efi_virtmap_load()
#define arch_efi_call_virt_teardown() efi_virtmap_unload()
#ifdef CONFIG_CPU_TTBR0_PAN
#undef arch_efi_call_virt
#define arch_efi_call_virt(p, f, args...) ({ \
unsigned int flags = uaccess_save_and_enable(); \
efi_status_t res = _Generic((p)->f(args), \
efi_status_t: (p)->f(args), \
default: ((p)->f(args), EFI_ABORTED)); \
uaccess_restore(flags); \
res; \
})
#endif
#define ARCH_EFI_IRQ_FLAGS_MASK \
(PSR_J_BIT | PSR_E_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | \
PSR_T_BIT | MODE_MASK)