diff options
author | 2020-08-15 10:38:03 -0700 | |
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committer | 2020-08-15 10:38:03 -0700 | |
commit | 50f6c7dbd973092d8e5f3c89f29eb4bea19fdebd (patch) | |
tree | 99b5a8715e371e0009968b0d7b1c23a67aa6ab58 | |
parent | Merge tag 'sched-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/ker... (diff) | |
parent | x86/alternatives: Acquire pte lock with interrupts enabled (diff) | |
download | linux-50f6c7dbd973092d8e5f3c89f29eb4bea19fdebd.tar.gz linux-50f6c7dbd973092d8e5f3c89f29eb4bea19fdebd.tar.bz2 linux-50f6c7dbd973092d8e5f3c89f29eb4bea19fdebd.zip |
Merge tag 'x86-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc fixes and small updates all around the place:
- Fix mitigation state sysfs output
- Fix an FPU xstate/sxave code assumption bug triggered by
Architectural LBR support
- Fix Lightning Mountain SoC TSC frequency enumeration bug
- Fix kexec debug output
- Fix kexec memory range assumption bug
- Fix a boundary condition in the crash kernel code
- Optimize porgatory.ro generation a bit
- Enable ACRN guests to use X2APIC mode
- Reduce a __text_poke() IRQs-off critical section for the benefit of
PREEMPT_RT"
* tag 'x86-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/alternatives: Acquire pte lock with interrupts enabled
x86/bugs/multihit: Fix mitigation reporting when VMX is not in use
x86/fpu/xstate: Fix an xstate size check warning with architectural LBRs
x86/purgatory: Don't generate debug info for purgatory.ro
x86/tsr: Fix tsc frequency enumeration bug on Lightning Mountain SoC
kexec_file: Correctly output debugging information for the PT_LOAD ELF header
kexec: Improve & fix crash_exclude_mem_range() to handle overlapping ranges
x86/crash: Correct the address boundary of function parameters
x86/acrn: Remove redundant chars from ACRN signature
x86/acrn: Allow ACRN guest to use X2APIC mode
-rw-r--r-- | Documentation/admin-guide/hw-vuln/multihit.rst | 4 | ||||
-rw-r--r-- | arch/x86/kernel/alternative.c | 6 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/acrn.c | 12 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 8 | ||||
-rw-r--r-- | arch/x86/kernel/crash.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 33 | ||||
-rw-r--r-- | arch/x86/kernel/tsc_msr.c | 9 | ||||
-rw-r--r-- | arch/x86/purgatory/Makefile | 5 | ||||
-rw-r--r-- | kernel/kexec_file.c | 41 |
9 files changed, 88 insertions, 32 deletions
diff --git a/Documentation/admin-guide/hw-vuln/multihit.rst b/Documentation/admin-guide/hw-vuln/multihit.rst index ba9988d8bce5..140e4cec38c3 100644 --- a/Documentation/admin-guide/hw-vuln/multihit.rst +++ b/Documentation/admin-guide/hw-vuln/multihit.rst @@ -80,6 +80,10 @@ The possible values in this file are: - The processor is not vulnerable. * - KVM: Mitigation: Split huge pages - Software changes mitigate this issue. + * - KVM: Mitigation: VMX unsupported + - KVM is not vulnerable because Virtual Machine Extensions (VMX) is not supported. + * - KVM: Mitigation: VMX disabled + - KVM is not vulnerable because Virtual Machine Extensions (VMX) is disabled. * - KVM: Vulnerable - The processor is vulnerable, but no mitigation enabled diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index d1175533d125..c3daf0aaa0ee 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -875,8 +875,6 @@ static void *__text_poke(void *addr, const void *opcode, size_t len) */ BUG_ON(!pages[0] || (cross_page_boundary && !pages[1])); - local_irq_save(flags); - /* * Map the page without the global bit, as TLB flushing is done with * flush_tlb_mm_range(), which is intended for non-global PTEs. @@ -893,6 +891,8 @@ static void *__text_poke(void *addr, const void *opcode, size_t len) */ VM_BUG_ON(!ptep); + local_irq_save(flags); + pte = mk_pte(pages[0], pgprot); set_pte_at(poking_mm, poking_addr, ptep, pte); @@ -942,8 +942,8 @@ static void *__text_poke(void *addr, const void *opcode, size_t len) */ BUG_ON(memcmp(addr, opcode, len)); - pte_unmap_unlock(ptep, ptl); local_irq_restore(flags); + pte_unmap_unlock(ptep, ptl); return addr; } diff --git a/arch/x86/kernel/cpu/acrn.c b/arch/x86/kernel/cpu/acrn.c index 1da9b1c9a2db..0b2c03943ac6 100644 --- a/arch/x86/kernel/cpu/acrn.c +++ b/arch/x86/kernel/cpu/acrn.c @@ -11,14 +11,15 @@ #include <linux/interrupt.h> #include <asm/apic.h> +#include <asm/cpufeatures.h> #include <asm/desc.h> #include <asm/hypervisor.h> #include <asm/idtentry.h> #include <asm/irq_regs.h> -static uint32_t __init acrn_detect(void) +static u32 __init acrn_detect(void) { - return hypervisor_cpuid_base("ACRNACRNACRN\0\0", 0); + return hypervisor_cpuid_base("ACRNACRNACRN", 0); } static void __init acrn_init_platform(void) @@ -29,12 +30,7 @@ static void __init acrn_init_platform(void) static bool acrn_x2apic_available(void) { - /* - * x2apic is not supported for now. Future enablement will have to check - * X86_FEATURE_X2APIC to determine whether x2apic is supported in the - * guest. - */ - return false; + return boot_cpu_has(X86_FEATURE_X2APIC); } static void (*acrn_intr_handler)(void); diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index f0b743a2fe9c..d3f0db463f96 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -31,6 +31,7 @@ #include <asm/intel-family.h> #include <asm/e820/api.h> #include <asm/hypervisor.h> +#include <asm/tlbflush.h> #include "cpu.h" @@ -1549,7 +1550,12 @@ static ssize_t l1tf_show_state(char *buf) static ssize_t itlb_multihit_show_state(char *buf) { - if (itlb_multihit_kvm_mitigation) + if (!boot_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) || + !boot_cpu_has(X86_FEATURE_VMX)) + return sprintf(buf, "KVM: Mitigation: VMX unsupported\n"); + else if (!(cr4_read_shadow() & X86_CR4_VMXE)) + return sprintf(buf, "KVM: Mitigation: VMX disabled\n"); + else if (itlb_multihit_kvm_mitigation) return sprintf(buf, "KVM: Mitigation: Split huge pages\n"); else return sprintf(buf, "KVM: Vulnerable\n"); diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index fd87b59452a3..a8f3af257e26 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -230,7 +230,7 @@ static int elf_header_exclude_ranges(struct crash_mem *cmem) int ret = 0; /* Exclude the low 1M because it is always reserved */ - ret = crash_exclude_mem_range(cmem, 0, 1<<20); + ret = crash_exclude_mem_range(cmem, 0, (1<<20)-1); if (ret) return ret; diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 7a2bf884fede..038e19c0019e 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -611,6 +611,10 @@ static void check_xstate_against_struct(int nr) * This essentially double-checks what the cpu told us about * how large the XSAVE buffer needs to be. We are recalculating * it to be safe. + * + * Dynamic XSAVE features allocate their own buffers and are not + * covered by these checks. Only the size of the buffer for task->fpu + * is checked here. */ static void do_extra_xstate_size_checks(void) { @@ -673,6 +677,33 @@ static unsigned int __init get_xsaves_size(void) return ebx; } +/* + * Get the total size of the enabled xstates without the dynamic supervisor + * features. + */ +static unsigned int __init get_xsaves_size_no_dynamic(void) +{ + u64 mask = xfeatures_mask_dynamic(); + unsigned int size; + + if (!mask) + return get_xsaves_size(); + + /* Disable dynamic features. */ + wrmsrl(MSR_IA32_XSS, xfeatures_mask_supervisor()); + + /* + * Ask the hardware what size is required of the buffer. + * This is the size required for the task->fpu buffer. + */ + size = get_xsaves_size(); + + /* Re-enable dynamic features so XSAVES will work on them again. */ + wrmsrl(MSR_IA32_XSS, xfeatures_mask_supervisor() | mask); + + return size; +} + static unsigned int __init get_xsave_size(void) { unsigned int eax, ebx, ecx, edx; @@ -710,7 +741,7 @@ static int __init init_xstate_size(void) xsave_size = get_xsave_size(); if (boot_cpu_has(X86_FEATURE_XSAVES)) - possible_xstate_size = get_xsaves_size(); + possible_xstate_size = get_xsaves_size_no_dynamic(); else possible_xstate_size = xsave_size; diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c index 46c72f2ec32f..6555a857a1e6 100644 --- a/arch/x86/kernel/tsc_msr.c +++ b/arch/x86/kernel/tsc_msr.c @@ -134,10 +134,15 @@ static const struct freq_desc freq_desc_ann = { .mask = 0x0f, }; -/* 24 MHz crystal? : 24 * 13 / 4 = 78 MHz */ +/* + * 24 MHz crystal? : 24 * 13 / 4 = 78 MHz + * Frequency step for Lightning Mountain SoC is fixed to 78 MHz, + * so all the frequency entries are 78000. + */ static const struct freq_desc freq_desc_lgm = { .use_msr_plat = true, - .freqs = { 78000, 78000, 78000, 78000, 78000, 78000, 78000, 78000 }, + .freqs = { 78000, 78000, 78000, 78000, 78000, 78000, 78000, 78000, + 78000, 78000, 78000, 78000, 78000, 78000, 78000, 78000 }, .mask = 0x0f, }; diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index 183ac60e5990..95ea17a9d20c 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -32,7 +32,7 @@ KCOV_INSTRUMENT := n # make up the standalone purgatory.ro PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel -PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss +PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss -g0 PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING PURGATORY_CFLAGS += -fno-stack-protector @@ -64,6 +64,9 @@ CFLAGS_sha256.o += $(PURGATORY_CFLAGS) CFLAGS_REMOVE_string.o += $(PURGATORY_CFLAGS_REMOVE) CFLAGS_string.o += $(PURGATORY_CFLAGS) +AFLAGS_REMOVE_setup-x86_$(BITS).o += -Wa,-gdwarf-2 +AFLAGS_REMOVE_entry64.o += -Wa,-gdwarf-2 + $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE $(call if_changed,ld) diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 78c0837bfd7b..ca40bef75a61 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -1169,24 +1169,26 @@ int crash_exclude_mem_range(struct crash_mem *mem, unsigned long long mstart, unsigned long long mend) { int i, j; - unsigned long long start, end; + unsigned long long start, end, p_start, p_end; struct crash_mem_range temp_range = {0, 0}; for (i = 0; i < mem->nr_ranges; i++) { start = mem->ranges[i].start; end = mem->ranges[i].end; + p_start = mstart; + p_end = mend; if (mstart > end || mend < start) continue; /* Truncate any area outside of range */ if (mstart < start) - mstart = start; + p_start = start; if (mend > end) - mend = end; + p_end = end; /* Found completely overlapping range */ - if (mstart == start && mend == end) { + if (p_start == start && p_end == end) { mem->ranges[i].start = 0; mem->ranges[i].end = 0; if (i < mem->nr_ranges - 1) { @@ -1197,20 +1199,29 @@ int crash_exclude_mem_range(struct crash_mem *mem, mem->ranges[j].end = mem->ranges[j+1].end; } + + /* + * Continue to check if there are another overlapping ranges + * from the current position because of shifting the above + * mem ranges. + */ + i--; + mem->nr_ranges--; + continue; } mem->nr_ranges--; return 0; } - if (mstart > start && mend < end) { + if (p_start > start && p_end < end) { /* Split original range */ - mem->ranges[i].end = mstart - 1; - temp_range.start = mend + 1; + mem->ranges[i].end = p_start - 1; + temp_range.start = p_end + 1; temp_range.end = end; - } else if (mstart != start) - mem->ranges[i].end = mstart - 1; + } else if (p_start != start) + mem->ranges[i].end = p_start - 1; else - mem->ranges[i].start = mend + 1; + mem->ranges[i].start = p_end + 1; break; } @@ -1247,7 +1258,7 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, unsigned long long notes_addr; unsigned long mstart, mend; - /* extra phdr for vmcoreinfo elf note */ + /* extra phdr for vmcoreinfo ELF note */ nr_phdr = nr_cpus + 1; nr_phdr += mem->nr_ranges; @@ -1255,7 +1266,7 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, * kexec-tools creates an extra PT_LOAD phdr for kernel text mapping * area (for example, ffffffff80000000 - ffffffffa0000000 on x86_64). * I think this is required by tools like gdb. So same physical - * memory will be mapped in two elf headers. One will contain kernel + * memory will be mapped in two ELF headers. One will contain kernel * text virtual addresses and other will have __va(physical) addresses. */ @@ -1282,7 +1293,7 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, ehdr->e_ehsize = sizeof(Elf64_Ehdr); ehdr->e_phentsize = sizeof(Elf64_Phdr); - /* Prepare one phdr of type PT_NOTE for each present cpu */ + /* Prepare one phdr of type PT_NOTE for each present CPU */ for_each_present_cpu(cpu) { phdr->p_type = PT_NOTE; notes_addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpu)); @@ -1324,10 +1335,10 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, phdr->p_filesz = phdr->p_memsz = mend - mstart + 1; phdr->p_align = 0; ehdr->e_phnum++; - phdr++; - pr_debug("Crash PT_LOAD elf header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n", + pr_debug("Crash PT_LOAD ELF header. phdr=%p vaddr=0x%llx, paddr=0x%llx, sz=0x%llx e_phnum=%d p_offset=0x%llx\n", phdr, phdr->p_vaddr, phdr->p_paddr, phdr->p_filesz, ehdr->e_phnum, phdr->p_offset); + phdr++; } *addr = buf; |