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Diffstat (limited to 'arch/x86/mm/mpx.c')
-rw-r--r--arch/x86/mm/mpx.c33
1 files changed, 32 insertions, 1 deletions
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 1c34b767c84c..9ceaa955d2ba 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -355,10 +355,19 @@ int mpx_enable_management(void)
*/
bd_base = mpx_get_bounds_dir();
down_write(&mm->mmap_sem);
+
+ /* MPX doesn't support addresses above 47 bits yet. */
+ if (find_vma(mm, DEFAULT_MAP_WINDOW)) {
+ pr_warn_once("%s (%d): MPX cannot handle addresses "
+ "above 47-bits. Disabling.",
+ current->comm, current->pid);
+ ret = -ENXIO;
+ goto out;
+ }
mm->context.bd_addr = bd_base;
if (mm->context.bd_addr == MPX_INVALID_BOUNDS_DIR)
ret = -ENXIO;
-
+out:
up_write(&mm->mmap_sem);
return ret;
}
@@ -1030,3 +1039,25 @@ void mpx_notify_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
if (ret)
force_sig(SIGSEGV, current);
}
+
+/* MPX cannot handle addresses above 47 bits yet. */
+unsigned long mpx_unmapped_area_check(unsigned long addr, unsigned long len,
+ unsigned long flags)
+{
+ if (!kernel_managing_mpx_tables(current->mm))
+ return addr;
+ if (addr + len <= DEFAULT_MAP_WINDOW)
+ return addr;
+ if (flags & MAP_FIXED)
+ return -ENOMEM;
+
+ /*
+ * Requested len is larger than the whole area we're allowed to map in.
+ * Resetting hinting address wouldn't do much good -- fail early.
+ */
+ if (len > DEFAULT_MAP_WINDOW)
+ return -ENOMEM;
+
+ /* Look for unmap area within DEFAULT_MAP_WINDOW */
+ return 0;
+}