[PATCH 4.4 103/105] Revert "x86/mm/pat: Ensure cpa->pfn only contains page frame numbers"

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 87e2bd898d3a79a8c609f183180adac47879a2a4 which is
commit edc3b9129cecd0f0857112136f5b8b1bc1d45918 upstream.

Turns there was too many other issues with this patch to make it viable
for the stable tree.

Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-efi@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Ghannam, Yazen" <Yazen.Ghannam@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/mm/pageattr.c         |   17 +++++++++++------
 arch/x86/platform/efi/efi_64.c |   16 ++++++----------
 2 files changed, 17 insertions(+), 16 deletions(-)

--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -911,10 +911,15 @@ static void populate_pte(struct cpa_data
 	pte = pte_offset_kernel(pmd, start);
 
 	while (num_pages-- && start < end) {
-		set_pte(pte, pfn_pte(cpa->pfn, pgprot));
+
+		/* deal with the NX bit */
+		if (!(pgprot_val(pgprot) & _PAGE_NX))
+			cpa->pfn &= ~_PAGE_NX;
+
+		set_pte(pte, pfn_pte(cpa->pfn >> PAGE_SHIFT, pgprot));
 
 		start	 += PAGE_SIZE;
-		cpa->pfn++;
+		cpa->pfn += PAGE_SIZE;
 		pte++;
 	}
 }
@@ -970,11 +975,11 @@ static int populate_pmd(struct cpa_data
 
 		pmd = pmd_offset(pud, start);
 
-		set_pmd(pmd, __pmd(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
+		set_pmd(pmd, __pmd(cpa->pfn | _PAGE_PSE |
 				   massage_pgprot(pmd_pgprot)));
 
 		start	  += PMD_SIZE;
-		cpa->pfn  += PMD_SIZE >> PAGE_SHIFT;
+		cpa->pfn  += PMD_SIZE;
 		cur_pages += PMD_SIZE >> PAGE_SHIFT;
 	}
 
@@ -1043,11 +1048,11 @@ static int populate_pud(struct cpa_data
 	 * Map everything starting from the Gb boundary, possibly with 1G pages
 	 */
 	while (end - start >= PUD_SIZE) {
-		set_pud(pud, __pud(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
+		set_pud(pud, __pud(cpa->pfn | _PAGE_PSE |
 				   massage_pgprot(pud_pgprot)));
 
 		start	  += PUD_SIZE;
-		cpa->pfn  += PUD_SIZE >> PAGE_SHIFT;
+		cpa->pfn  += PUD_SIZE;
 		cur_pages += PUD_SIZE >> PAGE_SHIFT;
 		pud++;
 	}
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -143,7 +143,7 @@ void efi_sync_low_kernel_mappings(void)
 
 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 {
-	unsigned long pfn, text;
+	unsigned long text;
 	struct page *page;
 	unsigned npages;
 	pgd_t *pgd;
@@ -160,8 +160,7 @@ int __init efi_setup_page_tables(unsigne
 	 * and ident-map those pages containing the map before calling
 	 * phys_efi_set_virtual_address_map().
 	 */
-	pfn = pa_memmap >> PAGE_SHIFT;
-	if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, _PAGE_NX)) {
+	if (kernel_map_pages_in_pgd(pgd, pa_memmap, pa_memmap, num_pages, _PAGE_NX)) {
 		pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
 		return 1;
 	}
@@ -186,9 +185,8 @@ int __init efi_setup_page_tables(unsigne
 
 	npages = (_end - _text) >> PAGE_SHIFT;
 	text = __pa(_text);
-	pfn = text >> PAGE_SHIFT;
 
-	if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, 0)) {
+	if (kernel_map_pages_in_pgd(pgd, text >> PAGE_SHIFT, text, npages, 0)) {
 		pr_err("Failed to map kernel text 1:1\n");
 		return 1;
 	}
@@ -206,14 +204,12 @@ void __init efi_cleanup_page_tables(unsi
 static void __init __map_region(efi_memory_desc_t *md, u64 va)
 {
 	pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
-	unsigned long flags = 0;
-	unsigned long pfn;
+	unsigned long pf = 0;
 
 	if (!(md->attribute & EFI_MEMORY_WB))
-		flags |= _PAGE_PCD;
+		pf |= _PAGE_PCD;
 
-	pfn = md->phys_addr >> PAGE_SHIFT;
-	if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
+	if (kernel_map_pages_in_pgd(pgd, md->phys_addr, va, md->num_pages, pf))
 		pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
 			   md->phys_addr, va);
 }