x86/ldt: Prevent LDT inheritance on exec

[mirror_ubuntu-disco-kernel.git] / arch / x86 / include / asm / mmu_context.h

diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 4fdbe5efe535f43275c8cfb838d2d817f9b97593..5e25423bf9bb6d15df74068ecac87db63a9818f5 100644 (file)
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -57,11 +57,17 @@ struct ldt_struct {
 /*
  * Used for LDT copy/destruction.
  */
-int init_new_context_ldt(struct task_struct *tsk, struct mm_struct *mm);
+static inline void init_new_context_ldt(struct mm_struct *mm)
+{
+       mm->context.ldt = NULL;
+       init_rwsem(&mm->context.ldt_usr_sem);
+}
+int ldt_dup_context(struct mm_struct *oldmm, struct mm_struct *mm);
 void destroy_context_ldt(struct mm_struct *mm);
 #else  /* CONFIG_MODIFY_LDT_SYSCALL */
-static inline int init_new_context_ldt(struct task_struct *tsk,
-                                      struct mm_struct *mm)
+static inline void init_new_context_ldt(struct mm_struct *mm) { }
+static inline int ldt_dup_context(struct mm_struct *oldmm,
+                                 struct mm_struct *mm)
 {
        return 0;
 }
@@ -137,15 +143,16 @@ static inline int init_new_context(struct task_struct *tsk,
        mm->context.ctx_id = atomic64_inc_return(&last_mm_ctx_id);
        atomic64_set(&mm->context.tlb_gen, 0);
 
-       #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
        if (cpu_feature_enabled(X86_FEATURE_OSPKE)) {
                /* pkey 0 is the default and always allocated */
                mm->context.pkey_allocation_map = 0x1;
                /* -1 means unallocated or invalid */
                mm->context.execute_only_pkey = -1;
        }
-       #endif
-       return init_new_context_ldt(tsk, mm);
+#endif
+       init_new_context_ldt(mm);
+       return 0;
 }
 static inline void destroy_context(struct mm_struct *mm)
 {
@@ -181,7 +188,7 @@ do {                                                \
 static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
 {
        paravirt_arch_dup_mmap(oldmm, mm);
-       return 0;
+       return ldt_dup_context(oldmm, mm);
 }
 
 static inline void arch_exit_mmap(struct mm_struct *mm)