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

A set of fixes for x86:

  - Prevent an out-of-bounds access in mtrr_write()

  - Break a circular dependency in the new hyperv IPI acceleration code

  - Address the build breakage related to inline functions by enforcing
    gnu_inline and explicitely bringing native_save_fl() out of line, which
    also adds a set of _ARM_ARG macros which provide 32/64bit safety.

  - Initialize the shadow CR4 per cpu variable before using it.

Thanks,

        tglx

------------------>
H. Peter Anvin (1):
      x86/asm: Add _ASM_ARG* constants for argument registers to <asm/asm.h>

Jann Horn (1):
      x86/mtrr: Don't copy out-of-bounds data in mtrr_write

K. Y. Srinivasan (1):
      x86/hyper-v: Fix the circular dependency in IPI enlightenment

Nick Desaulniers (2):
      compiler-gcc.h: Add __attribute__((gnu_inline)) to all inline declarations
      x86/paravirt: Make native_save_fl() extern inline

Zhenzhong Duan (1):
      x86/mm/32: Initialize the CR4 shadow before __flush_tlb_all()


 arch/x86/hyperv/hv_apic.c       |  5 ++++
 arch/x86/hyperv/hv_init.c       |  5 +++-
 arch/x86/include/asm/asm.h      | 59 +++++++++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/irqflags.h |  2 +-
 arch/x86/include/asm/mshyperv.h |  5 +++-
 arch/x86/kernel/Makefile        |  1 +
 arch/x86/kernel/cpu/mtrr/if.c   |  3 ++-
 arch/x86/kernel/irqflags.S      | 26 ++++++++++++++++++
 arch/x86/kernel/smpboot.c       |  5 ++++
 include/linux/compiler-gcc.h    | 29 +++++++++++++++-----
 10 files changed, 129 insertions(+), 11 deletions(-)
 create mode 100644 arch/x86/kernel/irqflags.S

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index f68855499391..402338365651 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -114,6 +114,8 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, 
int vector)
                ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K;
                nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask);
        }
+       if (nr_bank < 0)
+               goto ipi_mask_ex_done;
        if (!nr_bank)
                ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
 
@@ -158,6 +160,9 @@ static bool __send_ipi_mask(const struct cpumask *mask, int 
vector)
 
        for_each_cpu(cur_cpu, mask) {
                vcpu = hv_cpu_number_to_vp_number(cur_cpu);
+               if (vcpu == VP_INVAL)
+                       goto ipi_mask_done;
+
                /*
                 * This particular version of the IPI hypercall can
                 * only target upto 64 CPUs.
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 4c431e1c1eff..1ff420217298 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -265,7 +265,7 @@ void __init hyperv_init(void)
 {
        u64 guest_id, required_msrs;
        union hv_x64_msr_hypercall_contents hypercall_msr;
-       int cpuhp;
+       int cpuhp, i;
 
        if (x86_hyper_type != X86_HYPER_MS_HYPERV)
                return;
@@ -293,6 +293,9 @@ void __init hyperv_init(void)
        if (!hv_vp_index)
                return;
 
+       for (i = 0; i < num_possible_cpus(); i++)
+               hv_vp_index[i] = VP_INVAL;
+
        hv_vp_assist_page = kcalloc(num_possible_cpus(),
                                    sizeof(*hv_vp_assist_page), GFP_KERNEL);
        if (!hv_vp_assist_page) {
diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 219faaec51df..990770f9e76b 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -46,6 +46,65 @@
 #define _ASM_SI                __ASM_REG(si)
 #define _ASM_DI                __ASM_REG(di)
 
+#ifndef __x86_64__
+/* 32 bit */
+
+#define _ASM_ARG1      _ASM_AX
+#define _ASM_ARG2      _ASM_DX
+#define _ASM_ARG3      _ASM_CX
+
+#define _ASM_ARG1L     eax
+#define _ASM_ARG2L     edx
+#define _ASM_ARG3L     ecx
+
+#define _ASM_ARG1W     ax
+#define _ASM_ARG2W     dx
+#define _ASM_ARG3W     cx
+
+#define _ASM_ARG1B     al
+#define _ASM_ARG2B     dl
+#define _ASM_ARG3B     cl
+
+#else
+/* 64 bit */
+
+#define _ASM_ARG1      _ASM_DI
+#define _ASM_ARG2      _ASM_SI
+#define _ASM_ARG3      _ASM_DX
+#define _ASM_ARG4      _ASM_CX
+#define _ASM_ARG5      r8
+#define _ASM_ARG6      r9
+
+#define _ASM_ARG1Q     rdi
+#define _ASM_ARG2Q     rsi
+#define _ASM_ARG3Q     rdx
+#define _ASM_ARG4Q     rcx
+#define _ASM_ARG5Q     r8
+#define _ASM_ARG6Q     r9
+
+#define _ASM_ARG1L     edi
+#define _ASM_ARG2L     esi
+#define _ASM_ARG3L     edx
+#define _ASM_ARG4L     ecx
+#define _ASM_ARG5L     r8d
+#define _ASM_ARG6L     r9d
+
+#define _ASM_ARG1W     di
+#define _ASM_ARG2W     si
+#define _ASM_ARG3W     dx
+#define _ASM_ARG4W     cx
+#define _ASM_ARG5W     r8w
+#define _ASM_ARG6W     r9w
+
+#define _ASM_ARG1B     dil
+#define _ASM_ARG2B     sil
+#define _ASM_ARG3B     dl
+#define _ASM_ARG4B     cl
+#define _ASM_ARG5B     r8b
+#define _ASM_ARG6B     r9b
+
+#endif
+
 /*
  * Macros to generate condition code outputs from inline assembly,
  * The output operand must be type "bool".
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 89f08955fff7..c4fc17220df9 100644
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -13,7 +13,7 @@
  * Interrupt control:
  */
 
-static inline unsigned long native_save_fl(void)
+extern inline unsigned long native_save_fl(void)
 {
        unsigned long flags;
 
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 3cd14311edfa..5a7375ed5f7c 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -9,6 +9,8 @@
 #include <asm/hyperv-tlfs.h>
 #include <asm/nospec-branch.h>
 
+#define VP_INVAL       U32_MAX
+
 struct ms_hyperv_info {
        u32 features;
        u32 misc_features;
@@ -20,7 +22,6 @@ struct ms_hyperv_info {
 
 extern struct ms_hyperv_info ms_hyperv;
 
-
 /*
  * Generate the guest ID.
  */
@@ -281,6 +282,8 @@ static inline int cpumask_to_vpset(struct hv_vpset *vpset,
         */
        for_each_cpu(cpu, cpus) {
                vcpu = hv_cpu_number_to_vp_number(cpu);
+               if (vcpu == VP_INVAL)
+                       return -1;
                vcpu_bank = vcpu / 64;
                vcpu_offset = vcpu % 64;
                __set_bit(vcpu_offset, (unsigned long *)
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 02d6f5cf4e70..8824d01c0c35 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -61,6 +61,7 @@ obj-y                 += alternative.o i8253.o hw_breakpoint.o
 obj-y                  += tsc.o tsc_msr.o io_delay.o rtc.o
 obj-y                  += pci-iommu_table.o
 obj-y                  += resource.o
+obj-y                  += irqflags.o
 
 obj-y                          += process.o
 obj-y                          += fpu/
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index 4021d3859499..40eee6cc4124 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -106,7 +106,8 @@ mtrr_write(struct file *file, const char __user *buf, 
size_t len, loff_t * ppos)
 
        memset(line, 0, LINE_SIZE);
 
-       length = strncpy_from_user(line, buf, LINE_SIZE - 1);
+       len = min_t(size_t, len, LINE_SIZE - 1);
+       length = strncpy_from_user(line, buf, len);
        if (length < 0)
                return length;
 
diff --git a/arch/x86/kernel/irqflags.S b/arch/x86/kernel/irqflags.S
new file mode 100644
index 000000000000..ddeeaac8adda
--- /dev/null
+++ b/arch/x86/kernel/irqflags.S
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <asm/asm.h>
+#include <asm/export.h>
+#include <linux/linkage.h>
+
+/*
+ * unsigned long native_save_fl(void)
+ */
+ENTRY(native_save_fl)
+       pushf
+       pop %_ASM_AX
+       ret
+ENDPROC(native_save_fl)
+EXPORT_SYMBOL(native_save_fl)
+
+/*
+ * void native_restore_fl(unsigned long flags)
+ * %eax/%rdi: flags
+ */
+ENTRY(native_restore_fl)
+       push %_ASM_ARG1
+       popf
+       ret
+ENDPROC(native_restore_fl)
+EXPORT_SYMBOL(native_restore_fl)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index c2f7d1d2a5c3..db9656e13ea0 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -221,6 +221,11 @@ static void notrace start_secondary(void *unused)
 #ifdef CONFIG_X86_32
        /* switch away from the initial page table */
        load_cr3(swapper_pg_dir);
+       /*
+        * Initialize the CR4 shadow before doing anything that could
+        * try to read it.
+        */
+       cr4_init_shadow();
        __flush_tlb_all();
 #endif
        load_current_idt();
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index fd282c7d3e5e..573f5a7d42d4 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -65,6 +65,18 @@
 #define __must_be_array(a)     BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
 #endif
 
+/*
+ * Feature detection for gnu_inline (gnu89 extern inline semantics). Either
+ * __GNUC_STDC_INLINE__ is defined (not using gnu89 extern inline semantics,
+ * and we opt in to the gnu89 semantics), or __GNUC_STDC_INLINE__ is not
+ * defined so the gnu89 semantics are the default.
+ */
+#ifdef __GNUC_STDC_INLINE__
+# define __gnu_inline  __attribute__((gnu_inline))
+#else
+# define __gnu_inline
+#endif
+
 /*
  * Force always-inline if the user requests it so via the .config,
  * or if gcc is too old.
@@ -72,19 +84,22 @@
  * -Wunused-function.  This turns out to avoid the need for complex #ifdef
  * directives.  Suppress the warning in clang as well by using "unused"
  * function attribute, which is redundant but not harmful for gcc.
+ * Prefer gnu_inline, so that extern inline functions do not emit an
+ * externally visible function. This makes extern inline behave as per gnu89
+ * semantics rather than c99. This prevents multiple symbol definition errors
+ * of extern inline functions at link time.
+ * A lot of inline functions can cause havoc with function tracing.
  */
 #if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) ||               \
     !defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
-#define inline inline          __attribute__((always_inline,unused)) notrace
-#define __inline__ __inline__  __attribute__((always_inline,unused)) notrace
-#define __inline __inline      __attribute__((always_inline,unused)) notrace
+#define inline \
+       inline __attribute__((always_inline, unused)) notrace __gnu_inline
 #else
-/* A lot of inline functions can cause havoc with function tracing */
-#define inline inline          __attribute__((unused)) notrace
-#define __inline__ __inline__  __attribute__((unused)) notrace
-#define __inline __inline      __attribute__((unused)) notrace
+#define inline inline          __attribute__((unused)) notrace __gnu_inline
 #endif
 
+#define __inline__ inline
+#define __inline inline
 #define __always_inline        inline __attribute__((always_inline))
 #define  noinline      __attribute__((noinline))
 

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