Merge branch 'x86-iopl-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 iopl updates from Ingo Molnar:
 "This implements a nice simplification of the iopl and ioperm code that
  Thomas Gleixner discovered: we can implement the IO privilege features
  of the iopl system call by using the IO permission bitmap in
  permissive mode, while trapping CLI/STI/POPF/PUSHF uses in user-space
  if they change the interrupt flag.

  This implements that feature, with testing facilities and related
  cleanups"

[ "Simplification" may be an over-statement. The main goal is to avoid
  the cli/sti of iopl by effectively implementing the IO port access
  parts of iopl in terms of ioperm.

  This may end up not workign well in case people actually depend on
  cli/sti being available, or if there are mixed uses of iopl and
  ioperm. We will see..       - Linus ]

* 'x86-iopl-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  x86/ioperm: Fix use of deprecated config option
  x86/entry/32: Clarify register saving in __switch_to_asm()
  selftests/x86/iopl: Extend test to cover IOPL emulation
  x86/ioperm: Extend IOPL config to control ioperm() as well
  x86/iopl: Remove legacy IOPL option
  x86/iopl: Restrict iopl() permission scope
  x86/iopl: Fixup misleading comment
  selftests/x86/ioperm: Extend testing so the shared bitmap is exercised
  x86/ioperm: Share I/O bitmap if identical
  x86/ioperm: Remove bitmap if all permissions dropped
  x86/ioperm: Move TSS bitmap update to exit to user work
  x86/ioperm: Add bitmap sequence number
  x86/ioperm: Move iobitmap data into a struct
  x86/tss: Move I/O bitmap data into a seperate struct
  x86/io: Speedup schedule out of I/O bitmap user
  x86/ioperm: Avoid bitmap allocation if no permissions are set
  x86/ioperm: Simplify first ioperm() invocation logic
  x86/iopl: Cleanup include maze
  x86/tss: Fix and move VMX BUILD_BUG_ON()
  x86/cpu: Unify cpu_init()
  ...

1 files changed, 80 insertions, 108 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 3103f2bfed85..baa2fed8deb6 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -53,10 +53,7 @@
 #include <asm/microcode_intel.h>
 #include <asm/intel-family.h>
 #include <asm/cpu_device_id.h>
-
-#ifdef CONFIG_X86_LOCAL_APIC
 #include <asm/uv/uv.h>
-#endif
 
 #include "cpu.h"
 
@@ -1781,7 +1778,7 @@ static void wait_for_master_cpu(int cpu)
 }
 
 #ifdef CONFIG_X86_64
-static void setup_getcpu(int cpu)
+static inline void setup_getcpu(int cpu)
 {
 	unsigned long cpudata = vdso_encode_cpunode(cpu, early_cpu_to_node(cpu));
 	struct desc_struct d = { };
@@ -1801,7 +1798,59 @@ static void setup_getcpu(int cpu)
 
 	write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_CPUNODE, &d, DESCTYPE_S);
 }
+
+static inline void ucode_cpu_init(int cpu)
+{
+	if (cpu)
+		load_ucode_ap();
+}
+
+static inline void tss_setup_ist(struct tss_struct *tss)
+{
+	/* Set up the per-CPU TSS IST stacks */
+	tss->x86_tss.ist[IST_INDEX_DF] = __this_cpu_ist_top_va(DF);
+	tss->x86_tss.ist[IST_INDEX_NMI] = __this_cpu_ist_top_va(NMI);
+	tss->x86_tss.ist[IST_INDEX_DB] = __this_cpu_ist_top_va(DB);
+	tss->x86_tss.ist[IST_INDEX_MCE] = __this_cpu_ist_top_va(MCE);
+}
+
+static inline void gdt_setup_doublefault_tss(int cpu) { }
+
+#else /* CONFIG_X86_64 */
+
+static inline void setup_getcpu(int cpu) { }
+
+static inline void ucode_cpu_init(int cpu)
+{
+	show_ucode_info_early();
+}
+
+static inline void tss_setup_ist(struct tss_struct *tss) { }
+
+static inline void gdt_setup_doublefault_tss(int cpu)
+{
+#ifdef CONFIG_DOUBLEFAULT
+	/* Set up the doublefault TSS pointer in the GDT */
+	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
+#endif
+}
+#endif /* !CONFIG_X86_64 */
+
+static inline void tss_setup_io_bitmap(struct tss_struct *tss)
+{
+	tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET_INVALID;
+
+#ifdef CONFIG_X86_IOPL_IOPERM
+	tss->io_bitmap.prev_max = 0;
+	tss->io_bitmap.prev_sequence = 0;
+	memset(tss->io_bitmap.bitmap, 0xff, sizeof(tss->io_bitmap.bitmap));
+	/*
+	 * Invalidate the extra array entry past the end of the all
+	 * permission bitmap as required by the hardware.
+	 */
+	tss->io_bitmap.mapall[IO_BITMAP_LONGS] = ~0UL;
 #endif
+}
 
 /*
  * cpu_init() initializes state that is per-CPU. Some data is already
@@ -1809,21 +1858,15 @@ static void setup_getcpu(int cpu)
  * and IDT. We reload them nevertheless, this function acts as a
  * 'CPU state barrier', nothing should get across.
  */
-#ifdef CONFIG_X86_64
-
 void cpu_init(void)
 {
+	struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw);
+	struct task_struct *cur = current;
 	int cpu = raw_smp_processor_id();
-	struct task_struct *me;
-	struct tss_struct *t;
-	int i;
 
 	wait_for_master_cpu(cpu);
 
-	if (cpu)
-		load_ucode_ap();
-
-	t = &per_cpu(cpu_tss_rw, cpu);
+	ucode_cpu_init(cpu);
 
 #ifdef CONFIG_NUMA
 	if (this_cpu_read(numa_node) == 0 &&
@@ -1832,63 +1875,47 @@ void cpu_init(void)
 #endif
 	setup_getcpu(cpu);
 
-	me = current;
-
 	pr_debug("Initializing CPU#%d\n", cpu);
 
-	cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
+	if (IS_ENABLED(CONFIG_X86_64) || cpu_feature_enabled(X86_FEATURE_VME) ||
+	    boot_cpu_has(X86_FEATURE_TSC) || boot_cpu_has(X86_FEATURE_DE))
+		cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
 
 	/*
 	 * Initialize the per-CPU GDT with the boot GDT,
 	 * and set up the GDT descriptor:
 	 */
-
 	switch_to_new_gdt(cpu);
-	loadsegment(fs, 0);
-
 	load_current_idt();
 
-	memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
-	syscall_init();
-
-	wrmsrl(MSR_FS_BASE, 0);
-	wrmsrl(MSR_KERNEL_GS_BASE, 0);
-	barrier();
+	if (IS_ENABLED(CONFIG_X86_64)) {
+		loadsegment(fs, 0);
+		memset(cur->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
+		syscall_init();
 
-	x86_configure_nx();
-	x2apic_setup();
+		wrmsrl(MSR_FS_BASE, 0);
+		wrmsrl(MSR_KERNEL_GS_BASE, 0);
+		barrier();
 
-	/*
-	 * set up and load the per-CPU TSS
-	 */
-	if (!t->x86_tss.ist[0]) {
-		t->x86_tss.ist[IST_INDEX_DF] = __this_cpu_ist_top_va(DF);
-		t->x86_tss.ist[IST_INDEX_NMI] = __this_cpu_ist_top_va(NMI);
-		t->x86_tss.ist[IST_INDEX_DB] = __this_cpu_ist_top_va(DB);
-		t->x86_tss.ist[IST_INDEX_MCE] = __this_cpu_ist_top_va(MCE);
+		x2apic_setup();
 	}
 
-	t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
-
-	/*
-	 * <= is required because the CPU will access up to
-	 * 8 bits beyond the end of the IO permission bitmap.
-	 */
-	for (i = 0; i <= IO_BITMAP_LONGS; i++)
-		t->io_bitmap[i] = ~0UL;
-
 	mmgrab(&init_mm);
-	me->active_mm = &init_mm;
-	BUG_ON(me->mm);
+	cur->active_mm = &init_mm;
+	BUG_ON(cur->mm);
 	initialize_tlbstate_and_flush();
-	enter_lazy_tlb(&init_mm, me);
+	enter_lazy_tlb(&init_mm, cur);
 
-	/*
-	 * Initialize the TSS.  sp0 points to the entry trampoline stack
-	 * regardless of what task is running.
-	 */
+	/* Initialize the TSS. */
+	tss_setup_ist(tss);
+	tss_setup_io_bitmap(tss);
 	set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
+
 	load_TR_desc();
+	/*
+	 * sp0 points to the entry trampoline stack regardless of what task
+	 * is running.
+	 */
 	load_sp0((unsigned long)(cpu_entry_stack(cpu) + 1));
 
 	load_mm_ldt(&init_mm);
@@ -1896,6 +1923,8 @@ void cpu_init(void)
 	clear_all_debug_regs();
 	dbg_restore_debug_regs();
 
+	gdt_setup_doublefault_tss(cpu);
+
 	fpu__init_cpu();
 
 	if (is_uv_system())
@@ -1904,63 +1933,6 @@ void cpu_init(void)
 	load_fixmap_gdt(cpu);
 }
 
-#else
-
-void cpu_init(void)
-{
-	int cpu = smp_processor_id();
-	struct task_struct *curr = current;
-	struct tss_struct *t = &per_cpu(cpu_tss_rw, cpu);
-
-	wait_for_master_cpu(cpu);
-
-	show_ucode_info_early();
-
-	pr_info("Initializing CPU#%d\n", cpu);
-
-	if (cpu_feature_enabled(X86_FEATURE_VME) ||
-	    boot_cpu_has(X86_FEATURE_TSC) ||
-	    boot_cpu_has(X86_FEATURE_DE))
-		cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
-
-	load_current_idt();
-	switch_to_new_gdt(cpu);
-
-	/*
-	 * Set up and load the per-CPU TSS and LDT
-	 */
-	mmgrab(&init_mm);
-	curr->active_mm = &init_mm;
-	BUG_ON(curr->mm);
-	initialize_tlbstate_and_flush();
-	enter_lazy_tlb(&init_mm, curr);
-
-	/*
-	 * Initialize the TSS.  sp0 points to the entry trampoline stack
-	 * regardless of what task is running.
-	 */
-	set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
-	load_TR_desc();
-	load_sp0((unsigned long)(cpu_entry_stack(cpu) + 1));
-
-	load_mm_ldt(&init_mm);
-
-	t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
-
-#ifdef CONFIG_DOUBLEFAULT
-	/* Set up doublefault TSS pointer in the GDT */
-	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
-#endif
-
-	clear_all_debug_regs();
-	dbg_restore_debug_regs();
-
-	fpu__init_cpu();
-
-	load_fixmap_gdt(cpu);
-}
-#endif
-
 /*
  * The microcode loader calls this upon late microcode load to recheck features,
  * only when microcode has been updated. Caller holds microcode_mutex and CPU