From: Joerg Roedel <jroedel@xxxxxxx> It marks the end of the address-space range reserved for the LDT. The LDT-code will use it when unmapping the LDT for user-space. Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> --- arch/x86/include/asm/pgtable_32_types.h | 2 ++ arch/x86/include/asm/pgtable_64_types.h | 1 + arch/x86/kernel/ldt.c | 2 +- 3 files changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/pgtable_32_types.h b/arch/x86/include/asm/pgtable_32_types.h index 7297810..b0bc0ff 100644 --- a/arch/x86/include/asm/pgtable_32_types.h +++ b/arch/x86/include/asm/pgtable_32_types.h @@ -53,6 +53,8 @@ extern bool __vmalloc_start_set; /* set once high_memory is set */ #define LDT_BASE_ADDR \ ((CPU_ENTRY_AREA_BASE - PAGE_SIZE) & PMD_MASK) +#define LDT_END_ADDR (LDT_BASE_ADDR + PMD_SIZE) + #define PKMAP_BASE \ ((LDT_BASE_ADDR - PAGE_SIZE) & PMD_MASK) diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index 066e0ab..04edd2d 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -115,6 +115,7 @@ extern unsigned int ptrs_per_p4d; #define LDT_PGD_ENTRY_L5 -112UL #define LDT_PGD_ENTRY (pgtable_l5_enabled() ? LDT_PGD_ENTRY_L5 : LDT_PGD_ENTRY_L4) #define LDT_BASE_ADDR (LDT_PGD_ENTRY << PGDIR_SHIFT) +#define LDT_END_ADDR (LDT_BASE_ADDR + PGDIR_SIZE) #define __VMALLOC_BASE_L4 0xffffc90000000000UL #define __VMALLOC_BASE_L5 0xffa0000000000000UL diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index c9b1402..e921b3d 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -206,7 +206,7 @@ static void free_ldt_pgtables(struct mm_struct *mm) #ifdef CONFIG_PAGE_TABLE_ISOLATION struct mmu_gather tlb; unsigned long start = LDT_BASE_ADDR; - unsigned long end = start + (1UL << PGDIR_SHIFT); + unsigned long end = LDT_END_ADDR; if (!static_cpu_has(X86_FEATURE_PTI)) return; -- 2.7.4
