From 4fb5f58e8d191f7c81637ad81284e4848afb4244 Mon Sep 17 00:00:00 2001 From: Zhenzhong Duan Date: Mon, 2 Jul 2018 23:49:54 -0700 Subject: x86/mm/32: Initialize the CR4 shadow before __flush_tlb_all() On 32-bit kernels, __flush_tlb_all() may have read the CR4 shadow before the initialization of CR4 shadow in cpu_init(). Fix it by adding an explicit cr4_init_shadow() call into start_secondary() which is the first function called on non-boot SMP CPUs - ahead of the __flush_tlb_all() call. ( This is somewhat of a layering violation, but start_secondary() does CR4 bootstrap in the PCID case anyway. ) Signed-off-by: Zhenzhong Duan Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: "H. Peter Anvin" Link: http://lkml.kernel.org/r/b07b6ae9-4b57-4b40-b9bc-50c2c67f1d91@default Signed-off-by: Ingo Molnar --- arch/x86/kernel/smpboot.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch') 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(); -- cgit v1.2.3 From 0e2e160033283e20f688d8bad5b89460cc5bfcc4 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Thu, 21 Jun 2018 09:23:23 -0700 Subject: x86/asm: Add _ASM_ARG* constants for argument registers to i386 and x86-64 uses different registers for arguments; make them available so we don't have to #ifdef in the actual code. Native size and specified size (q, l, w, b) versions are provided. Signed-off-by: H. Peter Anvin Signed-off-by: Nick Desaulniers Reviewed-by: Sedat Dilek Acked-by: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: acme@redhat.com Cc: akataria@vmware.com Cc: akpm@linux-foundation.org Cc: andrea.parri@amarulasolutions.com Cc: ard.biesheuvel@linaro.org Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: astrachan@google.com Cc: boris.ostrovsky@oracle.com Cc: brijesh.singh@amd.com Cc: caoj.fnst@cn.fujitsu.com Cc: geert@linux-m68k.org Cc: ghackmann@google.com Cc: gregkh@linuxfoundation.org Cc: jan.kiszka@siemens.com Cc: jarkko.sakkinen@linux.intel.com Cc: joe@perches.com Cc: jpoimboe@redhat.com Cc: keescook@google.com Cc: kirill.shutemov@linux.intel.com Cc: kstewart@linuxfoundation.org Cc: linux-efi@vger.kernel.org Cc: linux-kbuild@vger.kernel.org Cc: manojgupta@google.com Cc: mawilcox@microsoft.com Cc: michal.lkml@markovi.net Cc: mjg59@google.com Cc: mka@chromium.org Cc: pombredanne@nexb.com Cc: rientjes@google.com Cc: rostedt@goodmis.org Cc: thomas.lendacky@amd.com Cc: tstellar@redhat.com Cc: tweek@google.com Cc: virtualization@lists.linux-foundation.org Cc: will.deacon@arm.com Cc: yamada.masahiro@socionext.com Link: http://lkml.kernel.org/r/20180621162324.36656-3-ndesaulniers@google.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/asm.h | 59 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) (limited to 'arch') 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". -- cgit v1.2.3 From d0a8d9378d16eb3c69bd8e6d23779fbdbee3a8c7 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Thu, 21 Jun 2018 09:23:24 -0700 Subject: x86/paravirt: Make native_save_fl() extern inline native_save_fl() is marked static inline, but by using it as a function pointer in arch/x86/kernel/paravirt.c, it MUST be outlined. paravirt's use of native_save_fl() also requires that no GPRs other than %rax are clobbered. Compilers have different heuristics which they use to emit stack guard code, the emittance of which can break paravirt's callee saved assumption by clobbering %rcx. Marking a function definition extern inline means that if this version cannot be inlined, then the out-of-line version will be preferred. By having the out-of-line version be implemented in assembly, it cannot be instrumented with a stack protector, which might violate custom calling conventions that code like paravirt rely on. The semantics of extern inline has changed since gnu89. This means that folks using GCC versions >= 5.1 may see symbol redefinition errors at link time for subdirs that override KBUILD_CFLAGS (making the C standard used implicit) regardless of this patch. This has been cleaned up earlier in the patch set, but is left as a note in the commit message for future travelers. Reports: https://lkml.org/lkml/2018/5/7/534 https://github.com/ClangBuiltLinux/linux/issues/16 Discussion: https://bugs.llvm.org/show_bug.cgi?id=37512 https://lkml.org/lkml/2018/5/24/1371 Thanks to the many folks that participated in the discussion. Debugged-by: Alistair Strachan Debugged-by: Matthias Kaehlcke Suggested-by: Arnd Bergmann Suggested-by: H. Peter Anvin Suggested-by: Tom Stellar Reported-by: Sedat Dilek Tested-by: Sedat Dilek Signed-off-by: Nick Desaulniers Acked-by: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: acme@redhat.com Cc: akataria@vmware.com Cc: akpm@linux-foundation.org Cc: andrea.parri@amarulasolutions.com Cc: ard.biesheuvel@linaro.org Cc: aryabinin@virtuozzo.com Cc: astrachan@google.com Cc: boris.ostrovsky@oracle.com Cc: brijesh.singh@amd.com Cc: caoj.fnst@cn.fujitsu.com Cc: geert@linux-m68k.org Cc: ghackmann@google.com Cc: gregkh@linuxfoundation.org Cc: jan.kiszka@siemens.com Cc: jarkko.sakkinen@linux.intel.com Cc: joe@perches.com Cc: jpoimboe@redhat.com Cc: keescook@google.com Cc: kirill.shutemov@linux.intel.com Cc: kstewart@linuxfoundation.org Cc: linux-efi@vger.kernel.org Cc: linux-kbuild@vger.kernel.org Cc: manojgupta@google.com Cc: mawilcox@microsoft.com Cc: michal.lkml@markovi.net Cc: mjg59@google.com Cc: mka@chromium.org Cc: pombredanne@nexb.com Cc: rientjes@google.com Cc: rostedt@goodmis.org Cc: thomas.lendacky@amd.com Cc: tweek@google.com Cc: virtualization@lists.linux-foundation.org Cc: will.deacon@arm.com Cc: yamada.masahiro@socionext.com Link: http://lkml.kernel.org/r/20180621162324.36656-4-ndesaulniers@google.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/irqflags.h | 2 +- arch/x86/kernel/Makefile | 1 + arch/x86/kernel/irqflags.S | 26 ++++++++++++++++++++++++++ 3 files changed, 28 insertions(+), 1 deletion(-) create mode 100644 arch/x86/kernel/irqflags.S (limited to 'arch') 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/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/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 +#include +#include + +/* + * 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) -- cgit v1.2.3 From 1268ed0c474a5c8f165ef386f3310521b5e00e27 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Tue, 3 Jul 2018 16:01:55 -0700 Subject: x86/hyper-v: Fix the circular dependency in IPI enlightenment The IPI hypercalls depend on being able to map the Linux notion of CPU ID to the hypervisor's notion of the CPU ID. The array hv_vp_index[] provides this mapping. Code for populating this array depends on the IPI functionality. Break this circular dependency. [ tglx: Use a proper define instead of '-1' with a u32 variable as pointed out by Vitaly ] Fixes: 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments") Signed-off-by: K. Y. Srinivasan Signed-off-by: Thomas Gleixner Tested-by: Michael Kelley Cc: gregkh@linuxfoundation.org Cc: devel@linuxdriverproject.org Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: jasowang@redhat.com Cc: hpa@zytor.com Cc: sthemmin@microsoft.com Cc: Michael.H.Kelley@microsoft.com Cc: vkuznets@redhat.com Link: https://lkml.kernel.org/r/20180703230155.15160-1-kys@linuxonhyperv.com --- arch/x86/hyperv/hv_apic.c | 5 +++++ arch/x86/hyperv/hv_init.c | 5 ++++- arch/x86/include/asm/mshyperv.h | 5 ++++- 3 files changed, 13 insertions(+), 2 deletions(-) (limited to 'arch') 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/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 #include +#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 *) -- cgit v1.2.3 From 15279df6f26cf2013d713904b4a0c957ae8abb96 Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Fri, 6 Jul 2018 23:50:03 +0200 Subject: x86/mtrr: Don't copy out-of-bounds data in mtrr_write Don't access the provided buffer out of bounds - this can cause a kernel out-of-bounds read when invoked through sys_splice() or other things that use kernel_write()/__kernel_write(). Fixes: 7f8ec5a4f01a ("x86/mtrr: Convert to use strncpy_from_user() helper") Signed-off-by: Jann Horn Signed-off-by: Thomas Gleixner Cc: Andy Shevchenko Cc: "H. Peter Anvin" Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180706215003.156702-1-jannh@google.com --- arch/x86/kernel/cpu/mtrr/if.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch') 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; -- cgit v1.2.3