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()

14 files changed, 146 insertions, 81 deletions

diff --git a/arch/x86/.gitignore b/arch/x86/.gitignore
index aff152c87cf4..5a82bac5e0bc 100644
--- a/arch/x86/.gitignore
+++ b/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
 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 63bf349b2b24..a528c14d45a5 100644
--- a/arch/x86/Kconfig
+++ b/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 2 64 if SMP && X86_32 && X86_BIGSMP
-        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
+        range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
+        default NR_CPUS_DEFAULT
         ---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
-          approximately eight kilobytes to the kernel image.
+          This is purely to save memory: each supported CPU adds about 8KB
+          to the kernel image.
 
 config SCHED_SMT
         bool "SMT (Hyperthreading) scheduler support"
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 70eddb3922ff..736771c9822e 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -148,45 +148,46 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
  */
 static __always_inline __pure bool _static_cpu_has(u16 bit)
 {
-                asm_volatile_goto("1: jmp 6f\n"
-                         "2:\n"
-                         ".skip -(((5f-4f) - (2b-1b)) > 0) * "
-                                 "((5f-4f) - (2b-1b)),0x90\n"
-                         "3:\n"
-                         ".section .altinstructions,\"a\"\n"
-                         " .long 1b - .\n"              /* src offset */
-                         " .long 4f - .\n"              /* repl offset */
-                         " .word %P1\n"                 /* always replace */
-                         " .byte 3b - 1b\n"             /* src len */
-                         " .byte 5f - 4f\n"             /* repl len */
-                         " .byte 3b - 2b\n"             /* pad len */
-                         ".previous\n"
-                         ".section .altinstr_replacement,\"ax\"\n"
-                         "4: jmp %l[t_no]\n"
-                         "5:\n"
-                         ".previous\n"
-                         ".section .altinstructions,\"a\"\n"
-                         " .long 1b - .\n"              /* src offset */
-                         " .long 0\n"                   /* no replacement */
-                         " .word %P0\n"                 /* feature bit */
-                         " .byte 3b - 1b\n"             /* src len */
-                         " .byte 0\n"                   /* repl len */
-                         " .byte 0\n"                   /* pad len */
-                         ".previous\n"
-                         ".section .altinstr_aux,\"ax\"\n"
-                         "6:\n"
-                         " testb %[bitnum],%[cap_byte]\n"
-                         " jnz %l[t_yes]\n"
-                         " jmp %l[t_no]\n"
-                         ".previous\n"
-                         : : "i" (bit), "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:
-                return true;
-        t_no:
-                return false;
+        asm_volatile_goto("1: jmp 6f\n"
+                 "2:\n"
+                 ".skip -(((5f-4f) - (2b-1b)) > 0) * "
+                         "((5f-4f) - (2b-1b)),0x90\n"
+                 "3:\n"
+                 ".section .altinstructions,\"a\"\n"
+                 " .long 1b - .\n"              /* src offset */
+                 " .long 4f - .\n"              /* repl offset */
+                 " .word %P[always]\n"          /* always replace */
+                 " .byte 3b - 1b\n"             /* src len */
+                 " .byte 5f - 4f\n"             /* repl len */
+                 " .byte 3b - 2b\n"             /* pad len */
+                 ".previous\n"
+                 ".section .altinstr_replacement,\"ax\"\n"
+                 "4: jmp %l[t_no]\n"
+                 "5:\n"
+                 ".previous\n"
+                 ".section .altinstructions,\"a\"\n"
+                 " .long 1b - .\n"              /* src offset */
+                 " .long 0\n"                   /* no replacement */
+                 " .word %P[feature]\n"         /* feature bit */
+                 " .byte 3b - 1b\n"             /* src len */
+                 " .byte 0\n"                   /* repl len */
+                 " .byte 0\n"                   /* pad len */
+                 ".previous\n"
+                 ".section .altinstr_aux,\"ax\"\n"
+                 "6:\n"
+                 " testb %[bitnum],%[cap_byte]\n"
+                 " jnz %l[t_yes]\n"
+                 " jmp %l[t_no]\n"
+                 ".previous\n"
+                 : : [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:
+        return true;
+t_no:
+        return false;
 }
 
 #define static_cpu_has(bit)                                     \
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 4baa6bceb232..d652a3808065 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/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
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 46b675aaf20b..f11910b44638 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/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)) >>
-                                (30 - UV_GAM_RANGE_SHFT), /* 64M -> 1G */
+                        size, suffix[order],
                         gre->type, gre->nasid, gre->sockid, gre->pnode);
 
                 lgre = gre->limit;
diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index aa0d5df9dc60..e956eb267061 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/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__ */
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 3a8e88a611eb..8ff94d1e2dce 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/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)
-
-void arch_unmap_kpfn(unsigned long pfn)
+#ifndef mce_unmap_kpfn
+static void mce_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
 
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 6f27facbaa9b..cfc61e1d45e2 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/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();
diff --git a/arch/x86/lib/error-inject.c b/arch/x86/lib/error-inject.c
index 7b881d03d0dd..3cdf06128d13 100644
--- a/arch/x86/lib/error-inject.c
+++ b/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"
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index fecb0c0a6077..8b72923f1d35 100644
--- a/arch/x86/mm/init_64.c
+++ b/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,
-                         PAGE_SIZE, KCORE_OTHER);
+        if (get_gate_vma(&init_mm))
+                kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER);
 
         mem_init_print_info(NULL);
 }
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index e8a93bc8285d..d1e82761de81 100644
--- a/fs/proc/kcore.c
+++ b/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)) {
                                 /*
diff --git a/include/linux/kcore.h b/include/linux/kcore.h
index 7ff25a808fef..80db19d3a505 100644
--- a/include/linux/kcore.h
+++ b/include/linux/kcore.h
@@ -10,6 +10,7 @@ enum kcore_type {
         KCORE_VMALLOC,
         KCORE_RAM,
         KCORE_VMEMMAP,
+        KCORE_USER,
         KCORE_OTHER,
 };
 
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index c30b32e3c862..10191c28fc04 100644
--- a/include/linux/mm_inline.h
+++ b/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
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 4b80ccee4535..8291b75f42c8 100644
--- a/mm/memory-failure.c
+++ b/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();