The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b082f2dd80612015cd6d9d84e52099734ec9a0e1 Mon Sep 17 00:00:00 2001
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Date: Fri, 26 Oct 2018 15:28:56 +0300
Subject: [PATCH] x86/ldt: Remove unused variable in map_ldt_struct()
Splitting out the sanity check in map_ldt_struct() moved page table syncing
into a separate function, which made the pgd variable unused. Remove it.
[ tglx: Massaged changelog ]
Fixes: 9bae3197e15d ("x86/ldt: Split out sanity check in map_ldt_struct()")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: bp@xxxxxxxxx
Cc: hpa@xxxxxxxxx
Cc: dave.hansen@xxxxxxxxxxxxxxx
Cc: peterz@xxxxxxxxxxxxx
Cc: boris.ostrovsky@xxxxxxxxxx
Cc: jgross@xxxxxxxx
Cc: bhe@xxxxxxxxxx
Cc: willy@xxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20181026122856.66224-4-kirill.shutemov@xxxxxxxxxxxxxxx
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 18e4525c5933..6135ae8ce036 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -207,7 +207,6 @@ map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot)
bool is_vmalloc;
spinlock_t *ptl;
int i, nr_pages;
- pgd_t *pgd;
if (!static_cpu_has(X86_FEATURE_PTI))
return 0;
@@ -221,13 +220,6 @@ map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot)
/* Check if the current mappings are sane */
sanity_check_ldt_mapping(mm);
- /*
- * Did we already have the top level entry allocated? We can't
- * use pgd_none() for this because it doens't do anything on
- * 4-level page table kernels.
- */
- pgd = pgd_offset(mm, LDT_BASE_ADDR);
-
is_vmalloc = is_vmalloc_addr(ldt->entries);
nr_pages = DIV_ROUND_UP(ldt->nr_entries * LDT_ENTRY_SIZE, PAGE_SIZE);
