[GIT PULL] x86 fixes

Ingo Molnar
2018-02-15T00:45:58Z

Linus,

Please pull the latest x86-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

# HEAD: fd0e786d9d09024f67bd71ec094b110237dc3840 x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages

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

out-of-topic modifications in x86-urgent-for-linus:
-----------------------------------------------------
fs/proc/kcore.c # 595dd46ebfc1: vfs/proc/kcore, x86/mm/kcore
include/linux/kcore.h # 595dd46ebfc1: vfs/proc/kcore, x86/mm/kcore
include/linux/mm_inline.h # fd0e786d9d09: x86/mm, mm/hwpoison: Don't u
mm/memory-failure.c # fd0e786d9d09: x86/mm, mm/hwpoison: Don't u

Thanks,

Ingo

------------------>
Arnd Bergmann (1):
x86/error_inject: Make just_return_func() globally visible

Borislav Petkov (1):
x86/MCE: Fix build warning introduced by "x86: do not use print_symbol()"

Ingo Molnar (1):
x86/Kconfig: Further simplify the NR_CPUS config

Jia Zhang (2):
vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page
x86/mm/kcore: Add vsyscall page to /proc/kcore conditionally

Masayoshi Mizuma (1):
x86/smpboot: Fix uncore_pci_remove() indexing bug when hot-removing a physical CPU

Peter Zijlstra (2):
x86/cpufeature: Reindent _static_cpu_has()
x86/cpufeature: Update _static_cpu_has() to use all named variables

Progyan Bhattacharya (1):
x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore

Randy Dunlap (1):
x86/Kconfig: Simplify NR_CPUS config

Tony Luck (1):
x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages

mike.travis@hpe.com (1):
x86/platform/UV: Fix GAM Range Table entries less than 1GB

arch/x86/.gitignore | 1 +
arch/x86/Kconfig | 75 ++++++++++++++++++++++-------
arch/x86/include/asm/cpufeature.h | 79 ++++++++++++++++---------------
arch/x86/include/asm/page_64.h | 4 --
arch/x86/kernel/apic/x2apic_uv_x.c | 15 ++++--
arch/x86/kernel/cpu/mcheck/mce-internal.h | 15 ++++++
arch/x86/kernel/cpu/mcheck/mce.c | 19 +++++---
arch/x86/kernel/smpboot.c | 1 -
arch/x86/lib/error-inject.c | 1 +
arch/x86/mm/init_64.c | 4 +-
fs/proc/kcore.c | 4 ++
include/linux/kcore.h | 1 +
include/linux/mm_inline.h | 6 ---
mm/memory-failure.c | 2 -
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 1ab42c852069..8ba9c3128947 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();