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authorRussell King <rmk+kernel@arm.linux.org.uk>2013-08-01 20:51:13 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-08-01 20:51:13 +0100
commit24195cad3e00557da166d629c8b0fd2f984f2170 (patch)
treedf4353bd5f7d213310e8d4eef812b7c0c2ed4331 /arch/arm/kernel/process.c
parent2449189bb7c73b5fe55a18bc0d289e39bdcd4998 (diff)
parenta5463cd3435475386cbbe7b06e01292ac169d36f (diff)
Merge branch 'security-fixes' into fixes
Diffstat (limited to 'arch/arm/kernel/process.c')
-rw-r--r--arch/arm/kernel/process.c45
1 files changed, 42 insertions, 3 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 08b47ebd3144..16ed3f7c4980 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -429,10 +429,11 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
}
#ifdef CONFIG_MMU
+#ifdef CONFIG_KUSER_HELPERS
/*
* The vectors page is always readable from user space for the
- * atomic helpers and the signal restart code. Insert it into the
- * gate_vma so that it is visible through ptrace and /proc/<pid>/mem.
+ * atomic helpers. Insert it into the gate_vma so that it is visible
+ * through ptrace and /proc/<pid>/mem.
*/
static struct vm_area_struct gate_vma = {
.vm_start = 0xffff0000,
@@ -461,9 +462,47 @@ int in_gate_area_no_mm(unsigned long addr)
{
return in_gate_area(NULL, addr);
}
+#define is_gate_vma(vma) ((vma) = &gate_vma)
+#else
+#define is_gate_vma(vma) 0
+#endif
const char *arch_vma_name(struct vm_area_struct *vma)
{
- return (vma == &gate_vma) ? "[vectors]" : NULL;
+ return is_gate_vma(vma) ? "[vectors]" :
+ (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
+ "[sigpage]" : NULL;
+}
+
+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)
+ return -ENOMEM;
+
+ down_write(&mm->mmap_sem);
+ addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
+ if (IS_ERR_VALUE(addr)) {
+ ret = addr;
+ goto up_fail;
+ }
+
+ ret = install_special_mapping(mm, addr, PAGE_SIZE,
+ VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
+ &page);
+
+ if (ret == 0)
+ mm->context.sigpage = addr;
+
+ up_fail:
+ up_write(&mm->mmap_sem);
+ return ret;
}
#endif