[patch V2 1/2] arch: Allow arch_dup_mmap() to fail

[Thomas Gleixner]

In order to sanitize the LDT initialization on x86 arch_dup_mmap() must be
allowed to fail Fix up all instances.

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
---
 arch/powerpc/include/asm/mmu_context.h   |    5 +++--
 arch/um/include/asm/mmu_context.h        |    3 ++-
 arch/unicore32/include/asm/mmu_context.h |    5 +++--
 arch/x86/include/asm/mmu_context.h       |    4 ++--
 include/asm-generic/mm_hooks.h           |    5 +++--
 kernel/fork.c                            |    3 +--
 6 files changed, 14 insertions(+), 11 deletions(-)

--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -160,9 +160,10 @@ static inline void enter_lazy_tlb(struct
 #endif
 }
 
-static inline void arch_dup_mmap(struct mm_struct *oldmm,
-                                struct mm_struct *mm)
+static inline int arch_dup_mmap(struct mm_struct *oldmm,
+                               struct mm_struct *mm)
 {
+       return 0;
 }
 
 #ifndef CONFIG_PPC_BOOK3S_64
--- a/arch/um/include/asm/mmu_context.h
+++ b/arch/um/include/asm/mmu_context.h
@@ -15,9 +15,10 @@ extern void uml_setup_stubs(struct mm_st
 /*
  * Needed since we do not use the asm-generic/mm_hooks.h:
  */
-static inline void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
+static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
 {
        uml_setup_stubs(mm);
+       return 0;
 }
 extern void arch_exit_mmap(struct mm_struct *mm);
 static inline void arch_unmap(struct mm_struct *mm,
--- a/arch/unicore32/include/asm/mmu_context.h
+++ b/arch/unicore32/include/asm/mmu_context.h
@@ -81,9 +81,10 @@ do { \
        } \
 } while (0)
 
-static inline void arch_dup_mmap(struct mm_struct *oldmm,
-                                struct mm_struct *mm)
+static inline int arch_dup_mmap(struct mm_struct *oldmm,
+                               struct mm_struct *mm)
 {
+       return 0;
 }
 
 static inline void arch_unmap(struct mm_struct *mm,
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -176,10 +176,10 @@ do {                                              \
 } while (0)
 #endif
 
-static inline void arch_dup_mmap(struct mm_struct *oldmm,
-                                struct mm_struct *mm)
+static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
 {
        paravirt_arch_dup_mmap(oldmm, mm);
+       return 0;
 }
 
 static inline void arch_exit_mmap(struct mm_struct *mm)
--- a/include/asm-generic/mm_hooks.h
+++ b/include/asm-generic/mm_hooks.h
@@ -7,9 +7,10 @@
 #ifndef _ASM_GENERIC_MM_HOOKS_H
 #define _ASM_GENERIC_MM_HOOKS_H
 
-static inline void arch_dup_mmap(struct mm_struct *oldmm,
-                                struct mm_struct *mm)
+static inline int arch_dup_mmap(struct mm_struct *oldmm,
+                               struct mm_struct *mm)
 {
+       return 0;
 }
 
 static inline void arch_exit_mmap(struct mm_struct *mm)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -721,8 +721,7 @@ static __latent_entropy int dup_mmap(str
                        goto out;
        }
        /* a new mm has just been created */
-       arch_dup_mmap(oldmm, mm);
-       retval = 0;
+       retval = arch_dup_mmap(oldmm, mm);
 out:
        up_write(&mm->mmap_sem);
        flush_tlb_mm(oldmm);