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

Pull x86 fixes from Ingo Molnar:
 "Misc fixes all across the map:

   - /proc/kcore vsyscall related fixes
   - LTO fix
   - build warning fix
   - CPU hotplug fix
   - Kconfig NR_CPUS cleanups
   - cpu_has() cleanups/robustification
   - .gitignore fix
   - memory-failure unmapping fix
   - UV platform fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages
  x86/error_inject: Make just_return_func() globally visible
  x86/platform/UV: Fix GAM Range Table entries less than 1GB
  x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore
  x86/smpboot: Fix uncore_pci_remove() indexing bug when hot-removing a physical CPU
  x86/mm/kcore: Add vsyscall page to /proc/kcore conditionally
  vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page
  x86/Kconfig: Further simplify the NR_CPUS config
  x86/Kconfig: Simplify NR_CPUS config
  x86/MCE: Fix build warning introduced by "x86: do not use print_symbol()"
  x86/cpufeature: Update _static_cpu_has() to use all named variables
  x86/cpufeature: Reindent _static_cpu_has()

arch/x86/.gitignore

@@ -1,6 +1,7 @@
 boot/compressed/vmlinux
 tools/test_get_len
 tools/insn_sanity
+tools/insn_decoder_test
 purgatory/kexec-purgatory.c
 purgatory/purgatory.ro
 

arch/x86/Kconfig

@@ -423,12 +423,6 @@ config X86_MPPARSE
 	  For old smp systems that do not have proper acpi support. Newer systems
 	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 
-config X86_BIGSMP
-	bool "Support for big SMP systems with more than 8 CPUs"
-	depends on X86_32 && SMP
-	---help---
-	  This option is needed for the systems that have more than 8 CPUs
-
 config GOLDFISH
        def_bool y
        depends on X86_GOLDFISH
@@ -460,6 +454,12 @@ config INTEL_RDT
 	  Say N if unsure.
 
 if X86_32
+config X86_BIGSMP
+	bool "Support for big SMP systems with more than 8 CPUs"
+	depends on SMP
+	---help---
+	  This option is needed for the systems that have more than 8 CPUs
+
 config X86_EXTENDED_PLATFORM
 	bool "Support for extended (non-PC) x86 platforms"
 	default y
@@ -949,25 +949,66 @@ config MAXSMP
 	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
 	  If unsure, say N.
 
+#
+# The maximum number of CPUs supported:
+#
+# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
+# and which can be configured interactively in the
+# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
+#
+# The ranges are different on 32-bit and 64-bit kernels, depending on
+# hardware capabilities and scalability features of the kernel.
+#
+# ( If MAXSMP is enabled we just use the highest possible value and disable
+#   interactive configuration. )
+#
+
+config NR_CPUS_RANGE_BEGIN
+	int
+	default NR_CPUS_RANGE_END if MAXSMP
+	default    1 if !SMP
+	default    2
+
+config NR_CPUS_RANGE_END
+	int
+	depends on X86_32
+	default   64 if  SMP &&  X86_BIGSMP
+	default    8 if  SMP && !X86_BIGSMP
+	default    1 if !SMP
+
+config NR_CPUS_RANGE_END
+	int
+	depends on X86_64
+	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
+	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
+	default    1 if !SMP
+
+config NR_CPUS_DEFAULT
+	int
+	depends on X86_32
+	default   32 if  X86_BIGSMP
+	default    8 if  SMP
+	default    1 if !SMP
+
+config NR_CPUS_DEFAULT
+	int
+	depends on X86_64
+	default 8192 if  MAXSMP
+	default   64 if  SMP
+	default    1 if !SMP
+
 config NR_CPUS
 	int "Maximum number of CPUs" if SMP && !MAXSMP
-	range 2 8 if SMP && X86_32 && !X86_BIGSMP
+	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
-	range 2 64 if SMP && X86_32 && X86_BIGSMP
+	default NR_CPUS_DEFAULT
-	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64
-	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
-	default "1" if !SMP
-	default "8192" if MAXSMP
-	default "32" if SMP && X86_BIGSMP
-	default "8" if SMP && X86_32
-	default "64" if SMP
 	---help---
 	  This allows you to specify the maximum number of CPUs which this
 	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
 	  supported value is 8192, otherwise the maximum value is 512.  The
 	  minimum value which makes sense is 2.
 
-	  This is purely to save memory - each supported CPU adds
+	  This is purely to save memory: each supported CPU adds about 8KB
-	  approximately eight kilobytes to the kernel image.
+	  to the kernel image.
 
 config SCHED_SMT
 	bool "SMT (Hyperthreading) scheduler support"

arch/x86/include/asm/cpufeature.h

@@ -156,7 +156,7 @@ static __always_inline __pure bool _static_cpu_has(u16 bit)
 		 ".section .altinstructions,\"a\"\n"
 		 " .long 1b - .\n"		/* src offset */
 		 " .long 4f - .\n"		/* repl offset */
-			 " .word %P1\n"			/* always replace */
+		 " .word %P[always]\n"		/* always replace */
 		 " .byte 3b - 1b\n"		/* src len */
 		 " .byte 5f - 4f\n"		/* repl len */
 		 " .byte 3b - 2b\n"		/* pad len */
@@ -168,7 +168,7 @@ static __always_inline __pure bool _static_cpu_has(u16 bit)
 		 ".section .altinstructions,\"a\"\n"
 		 " .long 1b - .\n"		/* src offset */
 		 " .long 0\n"			/* no replacement */
-			 " .word %P0\n"			/* feature bit */
+		 " .word %P[feature]\n"		/* feature bit */
 		 " .byte 3b - 1b\n"		/* src len */
 		 " .byte 0\n"			/* repl len */
 		 " .byte 0\n"			/* pad len */
@@ -179,13 +179,14 @@ static __always_inline __pure bool _static_cpu_has(u16 bit)
 		 " jnz %l[t_yes]\n"
 		 " jmp %l[t_no]\n"
 		 ".previous\n"
-			 : : "i" (bit), "i" (X86_FEATURE_ALWAYS),
+		 : : [feature]  "i" (bit),
+		     [always]   "i" (X86_FEATURE_ALWAYS),
 		     [bitnum]   "i" (1 << (bit & 7)),
 		     [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
 		 : : t_yes, t_no);
-	t_yes:
+t_yes:
 	return true;
-	t_no:
+t_no:
 	return false;
 }
 

arch/x86/include/asm/page_64.h

@@ -52,10 +52,6 @@ static inline void clear_page(void *page)
 
 void copy_page(void *to, void *from);
 
-#ifdef CONFIG_X86_MCE
-#define arch_unmap_kpfn arch_unmap_kpfn
-#endif
-
 #endif	/* !__ASSEMBLY__ */
 
 #ifdef CONFIG_X86_VSYSCALL_EMULATION

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -1176,16 +1176,25 @@ static void __init decode_gam_rng_tbl(unsigned long ptr)
 
 	uv_gre_table = gre;
 	for (; gre->type != UV_GAM_RANGE_TYPE_UNUSED; gre++) {
+		unsigned long size = ((unsigned long)(gre->limit - lgre)
+					<< UV_GAM_RANGE_SHFT);
+		int order = 0;
+		char suffix[] = " KMGTPE";
+
+		while (size > 9999 && order < sizeof(suffix)) {
+			size /= 1024;
+			order++;
+		}
+
 		if (!index) {
 			pr_info("UV: GAM Range Table...\n");
 			pr_info("UV:  # %20s %14s %5s %4s %5s %3s %2s\n", "Range", "", "Size", "Type", "NASID", "SID", "PN");
 		}
-		pr_info("UV: %2d: 0x%014lx-0x%014lx %5luG %3d   %04x  %02x %02x\n",
+		pr_info("UV: %2d: 0x%014lx-0x%014lx %5lu%c %3d   %04x  %02x %02x\n",
 			index++,
 			(unsigned long)lgre << UV_GAM_RANGE_SHFT,
 			(unsigned long)gre->limit << UV_GAM_RANGE_SHFT,
-			((unsigned long)(gre->limit - lgre)) >>
+			size, suffix[order],
-				(30 - UV_GAM_RANGE_SHFT), /* 64M -> 1G */
 			gre->type, gre->nasid, gre->sockid, gre->pnode);
 
 		lgre = gre->limit;

arch/x86/kernel/cpu/mcheck/mce-internal.h

@@ -115,4 +115,19 @@ static inline void mce_unregister_injector_chain(struct notifier_block *nb)	{ }
 
 extern struct mca_config mca_cfg;
 
+#ifndef CONFIG_X86_64
+/*
+ * On 32-bit systems it would be difficult to safely unmap a poison page
+ * from the kernel 1:1 map because there are no non-canonical addresses that
+ * we can use to refer to the address without risking a speculative access.
+ * However, this isn't much of an issue because:
+ * 1) Few unmappable pages are in the 1:1 map. Most are in HIGHMEM which
+ *    are only mapped into the kernel as needed
+ * 2) Few people would run a 32-bit kernel on a machine that supports
+ *    recoverable errors because they have too much memory to boot 32-bit.
+ */
+static inline void mce_unmap_kpfn(unsigned long pfn) {}
+#define mce_unmap_kpfn mce_unmap_kpfn
+#endif
+
 #endif /* __X86_MCE_INTERNAL_H__ */

arch/x86/kernel/cpu/mcheck/mce.c

@@ -105,6 +105,10 @@ static struct irq_work mce_irq_work;
 
 static void (*quirk_no_way_out)(int bank, struct mce *m, struct pt_regs *regs);
 
+#ifndef mce_unmap_kpfn
+static void mce_unmap_kpfn(unsigned long pfn);
+#endif
+
 /*
  * CPU/chipset specific EDAC code can register a notifier call here to print
  * MCE errors in a human-readable form.
@@ -234,7 +238,7 @@ static void __print_mce(struct mce *m)
 			m->cs, m->ip);
 
 		if (m->cs == __KERNEL_CS)
-			pr_cont("{%pS}", (void *)m->ip);
+			pr_cont("{%pS}", (void *)(unsigned long)m->ip);
 		pr_cont("\n");
 	}
 
@@ -590,7 +594,8 @@ static int srao_decode_notifier(struct notifier_block *nb, unsigned long val,
 
 	if (mce_usable_address(mce) && (mce->severity == MCE_AO_SEVERITY)) {
 		pfn = mce->addr >> PAGE_SHIFT;
-		memory_failure(pfn, 0);
+		if (!memory_failure(pfn, 0))
+			mce_unmap_kpfn(pfn);
 	}
 
 	return NOTIFY_OK;
@@ -1057,12 +1062,13 @@ static int do_memory_failure(struct mce *m)
 	ret = memory_failure(m->addr >> PAGE_SHIFT, flags);
 	if (ret)
 		pr_err("Memory error not recovered");
+	else
+		mce_unmap_kpfn(m->addr >> PAGE_SHIFT);
 	return ret;
 }
 
-#if defined(arch_unmap_kpfn) && defined(CONFIG_MEMORY_FAILURE)
+#ifndef mce_unmap_kpfn
-
+static void mce_unmap_kpfn(unsigned long pfn)
-void arch_unmap_kpfn(unsigned long pfn)
 {
 	unsigned long decoy_addr;
 
@@ -1073,7 +1079,7 @@ void arch_unmap_kpfn(unsigned long pfn)
 	 * We would like to just call:
 	 *	set_memory_np((unsigned long)pfn_to_kaddr(pfn), 1);
 	 * but doing that would radically increase the odds of a
-	 * speculative access to the posion page because we'd have
+	 * speculative access to the poison page because we'd have
 	 * the virtual address of the kernel 1:1 mapping sitting
 	 * around in registers.
 	 * Instead we get tricky.  We create a non-canonical address
@@ -1098,7 +1104,6 @@ void arch_unmap_kpfn(unsigned long pfn)
 
 	if (set_memory_np(decoy_addr, 1))
 		pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
-
 }
 #endif
 

arch/x86/kernel/smpboot.c

@@ -1430,7 +1430,6 @@ static void remove_siblinginfo(int cpu)
 	cpumask_clear(cpu_llc_shared_mask(cpu));
 	cpumask_clear(topology_sibling_cpumask(cpu));
 	cpumask_clear(topology_core_cpumask(cpu));
-	c->phys_proc_id = 0;
 	c->cpu_core_id = 0;
 	cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
 	recompute_smt_state();

arch/x86/lib/error-inject.c

@@ -7,6 +7,7 @@ asmlinkage void just_return_func(void);
 
 asm(
 	".type just_return_func, @function\n"
+	".globl just_return_func\n"
 	"just_return_func:\n"
 	"	ret\n"
 	".size just_return_func, .-just_return_func\n"

arch/x86/mm/init_64.c

@@ -1193,8 +1193,8 @@ void __init mem_init(void)
 	register_page_bootmem_info();
 
 	/* Register memory areas for /proc/kcore */
-	kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
+	if (get_gate_vma(&init_mm))
-			 PAGE_SIZE, KCORE_OTHER);
+		kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
 
 	mem_init_print_info(NULL);
 }

fs/proc/kcore.c

@@ -510,6 +510,10 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
 			/* we have to zero-fill user buffer even if no read */
 			if (copy_to_user(buffer, buf, tsz))
 				return -EFAULT;
+		} else if (m->type == KCORE_USER) {
+			/* User page is handled prior to normal kernel page: */
+			if (copy_to_user(buffer, (char *)start, tsz))
+				return -EFAULT;
 		} else {
 			if (kern_addr_valid(start)) {
 				/*

include/linux/kcore.h

@@ -10,6 +10,7 @@ enum kcore_type {
 	KCORE_VMALLOC,
 	KCORE_RAM,
 	KCORE_VMEMMAP,
+	KCORE_USER,
 	KCORE_OTHER,
 };
 

include/linux/mm_inline.h

@@ -127,10 +127,4 @@ static __always_inline enum lru_list page_lru(struct page *page)
 
 #define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
 
-#ifdef arch_unmap_kpfn
-extern void arch_unmap_kpfn(unsigned long pfn);
-#else
-static __always_inline void arch_unmap_kpfn(unsigned long pfn) { }
-#endif
-
 #endif

mm/memory-failure.c

@@ -1139,8 +1139,6 @@ int memory_failure(unsigned long pfn, int flags)
 		return 0;
 	}
 
-	arch_unmap_kpfn(pfn);
-
 	orig_head = hpage = compound_head(p);
 	num_poisoned_pages_inc();