Merge android-4.4.111 (f851888) into msm-4.4

* refs/heads/tmp-f851888
  Linux 4.4.111
  Fix build error in vma.c
  Map the vsyscall page with _PAGE_USER
  proc: much faster /proc/vmstat
  module: Issue warnings when tainting kernel
  module: keep percpu symbols in module's symtab
  genksyms: Handle string literals with spaces in reference files
  x86/tlb: Drop the _GPL from the cpu_tlbstate export
  parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel
  x86/microcode/AMD: Add support for fam17h microcode loading
  Input: elantech - add new icbody type 15
  ARC: uaccess: dont use "l" gcc inline asm constraint modifier
  kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()
  kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals
  kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL
  kernel: make groups_sort calling a responsibility group_info allocators
  fscache: Fix the default for fscache_maybe_release_page()
  sunxi-rsb: Include OF based modalias in device uevent
  crypto: pcrypt - fix freeing pcrypt instances
  crypto: chacha20poly1305 - validate the digest size
  crypto: n2 - cure use after free
  kernel/acct.c: fix the acct->needcheck check in check_free_space()
  x86/kasan: Write protect kasan zero shadow
  clocksource: arch_timer: make virtual counter access configurable
  arm64: issue isb when trapping CNTVCT_EL0 access
  BACKPORT: arm64: Add CNTFRQ_EL0 trap handler
  BACKPORT: arm64: Add CNTVCT_EL0 trap handler
  ANDROID: sdcardfs: Fix missing break on default_normal
  ANDROID: usb: f_fs: Prevent gadget unbind if it is already unbound
  arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entry
  arm64: use RET instruction for exiting the trampoline
  FROMLIST: arm64: kaslr: Put kernel vectors address in separate data page
  FROMLIST: arm64: mm: Introduce TTBR_ASID_MASK for getting at the ASID in the TTBR
  FROMLIST: arm64: Kconfig: Add CONFIG_UNMAP_KERNEL_AT_EL0
  FROMLIST: arm64: entry: Add fake CPU feature for unmapping the kernel at EL0
  FROMLIST: arm64: tls: Avoid unconditional zeroing of tpidrro_el0 for native tasks
  FROMLIST: arm64: erratum: Work around Falkor erratum #E1003 in trampoline code
  FROMLIST: arm64: entry: Hook up entry trampoline to exception vectors
  FROMLIST: arm64: entry: Explicitly pass exception level to kernel_ventry macro
  FROMLIST: arm64: mm: Map entry trampoline into trampoline and kernel page tables
  FROMLIST: arm64: entry: Add exception trampoline page for exceptions from EL0
  FROMLIST: arm64: mm: Invalidate both kernel and user ASIDs when performing TLBI
  FROMLIST: arm64: mm: Add arm64_kernel_unmapped_at_el0 helper
  FROMLIST: arm64: mm: Allocate ASIDs in pairs
  FROMLIST: arm64: mm: Fix and re-enable ARM64_SW_TTBR0_PAN
  FROMLIST: arm64: mm: Move ASID from TTBR0 to TTBR1
  FROMLIST: arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN
  FROMLIST: arm64: mm: Use non-global mappings for kernel space
  UPSTREAM: arm64: factor out entry stack manipulation
  UPSTREAM: arm64: tlbflush.h: add __tlbi() macro

Conflicts:
	arch/arm64/include/asm/cpufeature.h
	arch/arm64/kernel/asm-offsets.c
	arch/arm64/kernel/cpufeature.c
	arch/arm64/kernel/entry.S
	arch/arm64/kernel/vmlinux.lds.S
	drivers/clocksource/Kconfig
	drivers/clocksource/arm_arch_timer.c
	drivers/usb/gadget/function/f_fs.c

Change-Id: I41e84762e30c9a7b1e283850c3f780f3dbe86f44
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>

1 files changed, 30 insertions, 4 deletions

diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c
index b0b3a69f1c7f..6a7a77929a8c 100644
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -20,6 +20,7 @@
 #include <asm/pgalloc.h>
 #include <asm/desc.h>
 #include <asm/cmdline.h>
+#include <asm/vsyscall.h>
 
 int kaiser_enabled __read_mostly = 1;
 EXPORT_SYMBOL(kaiser_enabled);	/* for inlined TLB flush functions */
@@ -111,12 +112,13 @@ static inline unsigned long get_pa_from_mapping(unsigned long vaddr)
  *
  * Returns a pointer to a PTE on success, or NULL on failure.
  */
-static pte_t *kaiser_pagetable_walk(unsigned long address)
+static pte_t *kaiser_pagetable_walk(unsigned long address, bool user)
 {
 	pmd_t *pmd;
 	pud_t *pud;
 	pgd_t *pgd = native_get_shadow_pgd(pgd_offset_k(address));
 	gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO);
+	unsigned long prot = _KERNPG_TABLE;
 
 	if (pgd_none(*pgd)) {
 		WARN_ONCE(1, "All shadow pgds should have been populated");
@@ -124,6 +126,17 @@ static pte_t *kaiser_pagetable_walk(unsigned long address)
 	}
 	BUILD_BUG_ON(pgd_large(*pgd) != 0);
 
+	if (user) {
+		/*
+		 * The vsyscall page is the only page that will have
+		 *  _PAGE_USER set. Catch everything else.
+		 */
+		BUG_ON(address != VSYSCALL_ADDR);
+
+		set_pgd(pgd, __pgd(pgd_val(*pgd) | _PAGE_USER));
+		prot = _PAGE_TABLE;
+	}
+
 	pud = pud_offset(pgd, address);
 	/* The shadow page tables do not use large mappings: */
 	if (pud_large(*pud)) {
@@ -136,7 +149,7 @@ static pte_t *kaiser_pagetable_walk(unsigned long address)
 			return NULL;
 		spin_lock(&shadow_table_allocation_lock);
 		if (pud_none(*pud)) {
-			set_pud(pud, __pud(_KERNPG_TABLE | __pa(new_pmd_page)));
+			set_pud(pud, __pud(prot | __pa(new_pmd_page)));
 			__inc_zone_page_state(virt_to_page((void *)
 						new_pmd_page), NR_KAISERTABLE);
 		} else
@@ -156,7 +169,7 @@ static pte_t *kaiser_pagetable_walk(unsigned long address)
 			return NULL;
 		spin_lock(&shadow_table_allocation_lock);
 		if (pmd_none(*pmd)) {
-			set_pmd(pmd, __pmd(_KERNPG_TABLE | __pa(new_pte_page)));
+			set_pmd(pmd, __pmd(prot | __pa(new_pte_page)));
 			__inc_zone_page_state(virt_to_page((void *)
 						new_pte_page), NR_KAISERTABLE);
 		} else
@@ -192,7 +205,7 @@ static int kaiser_add_user_map(const void *__start_addr, unsigned long size,
 			ret = -EIO;
 			break;
 		}
-		pte = kaiser_pagetable_walk(address);
+		pte = kaiser_pagetable_walk(address, flags & _PAGE_USER);
 		if (!pte) {
 			ret = -ENOMEM;
 			break;
@@ -319,6 +332,19 @@ void __init kaiser_init(void)
 
 	kaiser_init_all_pgds();
 
+	/*
+	 * Note that this sets _PAGE_USER and it needs to happen when the
+	 * pagetable hierarchy gets created, i.e., early. Otherwise
+	 * kaiser_pagetable_walk() will encounter initialized PTEs in the
+	 * hierarchy and not set the proper permissions, leading to the
+	 * pagefaults with page-protection violations when trying to read the
+	 * vsyscall page. For example.
+	 */
+	if (vsyscall_enabled())
+		kaiser_add_user_map_early((void *)VSYSCALL_ADDR,
+					  PAGE_SIZE,
+					   __PAGE_KERNEL_VSYSCALL);
+
 	for_each_possible_cpu(cpu) {
 		void *percpu_vaddr = __per_cpu_user_mapped_start +
 				     per_cpu_offset(cpu);