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 | 2 ++
arch/x86/kernel/ldt.c | 2 +-
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/pgtable_32_types.h b/arch/x86/include/asm/pgtable_32_types.h
index eb2e97a..02bd445 100644
--- a/arch/x86/include/asm/pgtable_32_types.h
+++ b/arch/x86/include/asm/pgtable_32_types.h
@@ -51,6 +51,8 @@ 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 e57003a..15188baa 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -90,12 +90,14 @@ typedef struct { pteval_t pte; } pte_t;
# define __VMEMMAP_BASE _AC(0xffd4000000000000, UL)
# define LDT_PGD_ENTRY _AC(-112, UL)
# define LDT_BASE_ADDR (LDT_PGD_ENTRY << PGDIR_SHIFT)
+#define LDT_END_ADDR (LDT_BASE_ADDR + PGDIR_SIZE)
#else
# define VMALLOC_SIZE_TB _AC(32, UL)
# define __VMALLOC_BASE _AC(0xffffc90000000000, UL)
# define __VMEMMAP_BASE _AC(0xffffea0000000000, UL)
# define LDT_PGD_ENTRY _AC(-3, UL)
# define LDT_BASE_ADDR (LDT_PGD_ENTRY << PGDIR_SHIFT)
+#define LDT_END_ADDR (LDT_BASE_ADDR + PGDIR_SIZE)
#endif
#ifdef CONFIG_RANDOMIZE_MEMORY
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 26d713e..f3c2fbf 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -202,7 +202,7 @@ 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
