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@vger.kernel.org.

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@linux.intel.com 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@linux.intel.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Andy Lutomirski luto@kernel.org Cc: bp@alien8.de Cc: hpa@zytor.com Cc: dave.hansen@linux.intel.com Cc: peterz@infradead.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: bhe@redhat.com Cc: willy@infradead.org Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181026122856.66224-4-kirill.shutemov@linux.intel...

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);