Merge branch 'security-fixes' into fixes

3 files changed, 31 insertions, 28 deletions

diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index 9c9b30717fda..56211f2084ef 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -130,8 +130,10 @@ struct mm_struct;
 extern unsigned long arch_randomize_brk(struct mm_struct *mm);
 #define arch_randomize_brk arch_randomize_brk
 
+#ifdef CONFIG_MMU
 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 struct linux_binprm;
 int arch_setup_additional_pages(struct linux_binprm *, int);
+#endif
 
 #endif
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 16ed3f7c4980..536c85fe72a8 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -474,17 +474,18 @@ const char *arch_vma_name(struct vm_area_struct *vma)
                  "[sigpage]" : NULL;
 }
 
+static struct page *signal_page;
 extern struct page *get_signal_page(void);
 
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
         struct mm_struct *mm = current->mm;
-        struct page *page;
         unsigned long addr;
         int ret;
 
-        page = get_signal_page();
-        if (!page)
+        if (!signal_page)
+                signal_page = get_signal_page();
+        if (!signal_page)
                 return -ENOMEM;
 
         down_write(&mm->mmap_sem);
@@ -496,7 +497,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 
         ret = install_special_mapping(mm, addr, PAGE_SIZE,
                 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
-                &page);
+                &signal_page);
 
         if (ret == 0)
                 mm->context.sigpage = addr;
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 0f17e06d51e6..ab3304225272 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -402,7 +402,8 @@ setup_return(struct pt_regs *regs, struct ksignal *ksig,
                     __put_user(sigreturn_codes[idx+1], rc+1))
                         return 1;
 
-                if ((cpsr & MODE32_BIT) && !IS_ENABLED(CONFIG_ARM_MPU)) {
+#ifdef CONFIG_MMU
+                if (cpsr & MODE32_BIT) {
                         struct mm_struct *mm = current->mm;
 
                         /*
@@ -412,7 +413,9 @@ setup_return(struct pt_regs *regs, struct ksignal *ksig,
                          */
                         retcode = mm->context.sigpage + signal_return_offset +
                                   (idx << 2) + thumb;
-                } else {
+                } else
+#endif
+                {
                         /*
                          * Ensure that the instruction cache sees
                          * the return code written onto the stack.
@@ -614,35 +617,32 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
         return 0;
 }
 
-static struct page *signal_page;
-
 struct page *get_signal_page(void)
 {
-        if (!signal_page) {
-                unsigned long ptr;
-                unsigned offset;
-                void *addr;
+        unsigned long ptr;
+        unsigned offset;
+        struct page *page;
+        void *addr;
 
-                signal_page = alloc_pages(GFP_KERNEL, 0);
+        page = alloc_pages(GFP_KERNEL, 0);
 
-                if (!signal_page)
-                        return NULL;
+        if (!page)
+                return NULL;
 
-                addr = page_address(signal_page);
+        addr = page_address(page);
 
-                /* Give the signal return code some randomness */
-                offset = 0x200 + (get_random_int() & 0x7fc);
-                signal_return_offset = offset;
+        /* Give the signal return code some randomness */
+        offset = 0x200 + (get_random_int() & 0x7fc);
+        signal_return_offset = offset;
 
-                /*
-                 * Copy signal return handlers into the vector page, and
-                 * set sigreturn to be a pointer to these.
-                 */
-                memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes));
+        /*
+         * Copy signal return handlers into the vector page, and
+         * set sigreturn to be a pointer to these.
+         */
+        memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes));
 
-                ptr = (unsigned long)addr + offset;
-                flush_icache_range(ptr, ptr + sizeof(sigreturn_codes));
-        }
+        ptr = (unsigned long)addr + offset;
+        flush_icache_range(ptr, ptr + sizeof(sigreturn_codes));
 
-        return signal_page;
+        return page;
 }