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-rw-r--r--arch/x86/kernel/ldt.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index a870910c8565..4d17bacf4030 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1992 Krishna Balasubramanian and Linus Torvalds
* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
@@ -21,6 +22,25 @@
#include <asm/mmu_context.h>
#include <asm/syscalls.h>
+static void refresh_ldt_segments(void)
+{
+#ifdef CONFIG_X86_64
+ unsigned short sel;
+
+ /*
+ * Make sure that the cached DS and ES descriptors match the updated
+ * LDT.
+ */
+ savesegment(ds, sel);
+ if ((sel & SEGMENT_TI_MASK) == SEGMENT_LDT)
+ loadsegment(ds, sel);
+
+ savesegment(es, sel);
+ if ((sel & SEGMENT_TI_MASK) == SEGMENT_LDT)
+ loadsegment(es, sel);
+#endif
+}
+
/* context.lock is held for us, so we don't need any locking. */
static void flush_ldt(void *__mm)
{
@@ -32,6 +52,8 @@ static void flush_ldt(void *__mm)
pc = &mm->context;
set_ldt(pc->ldt->entries, pc->ldt->nr_entries);
+
+ refresh_ldt_segments();
}
/* The caller must call finalize_ldt_struct on the result. LDT starts zeroed. */