diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/extable_fixup_types.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/word-at-a-time.h | 46 | ||||
| -rw-r--r-- | arch/x86/include/asm/xen/cpuid.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/xen/events.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 10 | ||||
| -rw-r--r-- | arch/x86/mm/extable.c | 55 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten.c | 2 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten_hvm.c | 24 | ||||
| -rw-r--r-- | arch/x86/xen/suspend_hvm.c | 10 |
9 files changed, 98 insertions, 56 deletions
diff --git a/arch/x86/include/asm/extable_fixup_types.h b/arch/x86/include/asm/extable_fixup_types.h index 503622627400..991e31cfde94 100644 --- a/arch/x86/include/asm/extable_fixup_types.h +++ b/arch/x86/include/asm/extable_fixup_types.h @@ -64,4 +64,6 @@ #define EX_TYPE_UCOPY_LEN4 (EX_TYPE_UCOPY_LEN | EX_DATA_IMM(4)) #define EX_TYPE_UCOPY_LEN8 (EX_TYPE_UCOPY_LEN | EX_DATA_IMM(8)) +#define EX_TYPE_ZEROPAD 20 /* longword load with zeropad on fault */ + #endif diff --git a/arch/x86/include/asm/word-at-a-time.h b/arch/x86/include/asm/word-at-a-time.h index 8338b0432b50..46b4f1f7f354 100644 --- a/arch/x86/include/asm/word-at-a-time.h +++ b/arch/x86/include/asm/word-at-a-time.h @@ -77,58 +77,18 @@ static inline unsigned long find_zero(unsigned long mask) * and the next page not being mapped, take the exception and * return zeroes in the non-existing part. */ -#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT - static inline unsigned long load_unaligned_zeropad(const void *addr) { - unsigned long offset, data; unsigned long ret; - asm_volatile_goto( + asm volatile( "1: mov %[mem], %[ret]\n" - - _ASM_EXTABLE(1b, %l[do_exception]) - - : [ret] "=r" (ret) - : [mem] "m" (*(unsigned long *)addr) - : : do_exception); - - return ret; - -do_exception: - offset = (unsigned long)addr & (sizeof(long) - 1); - addr = (void *)((unsigned long)addr & ~(sizeof(long) - 1)); - data = *(unsigned long *)addr; - ret = data >> offset * 8; - - return ret; -} - -#else /* !CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ - -static inline unsigned long load_unaligned_zeropad(const void *addr) -{ - unsigned long offset, data; - unsigned long ret, err = 0; - - asm( "1: mov %[mem], %[ret]\n" "2:\n" - - _ASM_EXTABLE_FAULT(1b, 2b) - - : [ret] "=&r" (ret), "+a" (err) + _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_ZEROPAD) + : [ret] "=r" (ret) : [mem] "m" (*(unsigned long *)addr)); - if (unlikely(err)) { - offset = (unsigned long)addr & (sizeof(long) - 1); - addr = (void *)((unsigned long)addr & ~(sizeof(long) - 1)); - data = *(unsigned long *)addr; - ret = data >> offset * 8; - } - return ret; } -#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ - #endif /* _ASM_WORD_AT_A_TIME_H */ diff --git a/arch/x86/include/asm/xen/cpuid.h b/arch/x86/include/asm/xen/cpuid.h index 78e667a31d6c..6daa9b0c8d11 100644 --- a/arch/x86/include/asm/xen/cpuid.h +++ b/arch/x86/include/asm/xen/cpuid.h @@ -107,6 +107,8 @@ * ID field from 8 to 15 bits, allowing to target APIC IDs up 32768. */ #define XEN_HVM_CPUID_EXT_DEST_ID (1u << 5) +/* Per-vCPU event channel upcalls */ +#define XEN_HVM_CPUID_UPCALL_VECTOR (1u << 6) /* * Leaf 6 (0x40000x05) diff --git a/arch/x86/include/asm/xen/events.h b/arch/x86/include/asm/xen/events.h index 068d9b067c83..62bdceb594f1 100644 --- a/arch/x86/include/asm/xen/events.h +++ b/arch/x86/include/asm/xen/events.h @@ -23,7 +23,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) /* No need for a barrier -- XCHG is a barrier on x86. */ #define xchg_xen_ulong(ptr, val) xchg((ptr), (val)) -extern int xen_have_vector_callback; +extern bool xen_have_vector_callback; /* * Events delivered via platform PCI interrupts are always @@ -34,4 +34,5 @@ static inline bool xen_support_evtchn_rebind(void) return (!xen_hvm_domain() || xen_have_vector_callback); } +extern bool xen_percpu_upcall; #endif /* _ASM_X86_XEN_EVENTS_H */ diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 9f7e751b91df..510d85261132 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -152,7 +152,7 @@ void __init check_bugs(void) /* * spectre_v2_user_select_mitigation() relies on the state set by * retbleed_select_mitigation(); specifically the STIBP selection is - * forced for UNRET. + * forced for UNRET or IBPB. */ spectre_v2_user_select_mitigation(); ssb_select_mitigation(); @@ -1179,7 +1179,8 @@ spectre_v2_user_select_mitigation(void) boot_cpu_has(X86_FEATURE_AMD_STIBP_ALWAYS_ON)) mode = SPECTRE_V2_USER_STRICT_PREFERRED; - if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET) { + if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET || + retbleed_mitigation == RETBLEED_MITIGATION_IBPB) { if (mode != SPECTRE_V2_USER_STRICT && mode != SPECTRE_V2_USER_STRICT_PREFERRED) pr_info("Selecting STIBP always-on mode to complement retbleed mitigation\n"); @@ -2360,10 +2361,11 @@ static ssize_t srbds_show_state(char *buf) static ssize_t retbleed_show_state(char *buf) { - if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET) { + if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET || + retbleed_mitigation == RETBLEED_MITIGATION_IBPB) { if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD && boot_cpu_data.x86_vendor != X86_VENDOR_HYGON) - return sprintf(buf, "Vulnerable: untrained return thunk on non-Zen uarch\n"); + return sprintf(buf, "Vulnerable: untrained return thunk / IBPB on non-AMD based uarch\n"); return sprintf(buf, "%s; SMT %s\n", retbleed_strings[retbleed_mitigation], diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 331310c29349..60814e110a54 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -41,6 +41,59 @@ static bool ex_handler_default(const struct exception_table_entry *e, return true; } +/* + * This is the *very* rare case where we do a "load_unaligned_zeropad()" + * and it's a page crosser into a non-existent page. + * + * This happens when we optimistically load a pathname a word-at-a-time + * and the name is less than the full word and the next page is not + * mapped. Typically that only happens for CONFIG_DEBUG_PAGEALLOC. + * + * NOTE! The faulting address is always a 'mov mem,reg' type instruction + * of size 'long', and the exception fixup must always point to right + * after the instruction. + */ +static bool ex_handler_zeropad(const struct exception_table_entry *e, + struct pt_regs *regs, + unsigned long fault_addr) +{ + struct insn insn; + const unsigned long mask = sizeof(long) - 1; + unsigned long offset, addr, next_ip, len; + unsigned long *reg; + + next_ip = ex_fixup_addr(e); + len = next_ip - regs->ip; + if (len > MAX_INSN_SIZE) + return false; + + if (insn_decode(&insn, (void *) regs->ip, len, INSN_MODE_KERN)) + return false; + if (insn.length != len) + return false; + + if (insn.opcode.bytes[0] != 0x8b) + return false; + if (insn.opnd_bytes != sizeof(long)) + return false; + + addr = (unsigned long) insn_get_addr_ref(&insn, regs); + if (addr == ~0ul) + return false; + + offset = addr & mask; + addr = addr & ~mask; + if (fault_addr != addr + sizeof(long)) + return false; + + reg = insn_get_modrm_reg_ptr(&insn, regs); + if (!reg) + return false; + + *reg = *(unsigned long *)addr >> (offset * 8); + return ex_handler_default(e, regs); +} + static bool ex_handler_fault(const struct exception_table_entry *fixup, struct pt_regs *regs, int trapnr) { @@ -217,6 +270,8 @@ int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code, return ex_handler_sgx(e, regs, trapnr); case EX_TYPE_UCOPY_LEN: return ex_handler_ucopy_len(e, regs, trapnr, reg, imm); + case EX_TYPE_ZEROPAD: + return ex_handler_zeropad(e, regs, fault_addr); } BUG(); } diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 30c6e986a6cd..b8db2148c07d 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -51,7 +51,7 @@ EXPORT_SYMBOL_GPL(xen_start_info); struct shared_info xen_dummy_shared_info; -__read_mostly int xen_have_vector_callback; +__read_mostly bool xen_have_vector_callback = true; EXPORT_SYMBOL_GPL(xen_have_vector_callback); /* diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index 28762f800596..1c1ac418484b 100644 --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -8,6 +8,8 @@ #include <xen/features.h> #include <xen/events.h> +#include <xen/hvm.h> +#include <xen/interface/hvm/hvm_op.h> #include <xen/interface/memory.h> #include <asm/apic.h> @@ -31,6 +33,9 @@ static unsigned long shared_info_pfn; +__ro_after_init bool xen_percpu_upcall; +EXPORT_SYMBOL_GPL(xen_percpu_upcall); + void xen_hvm_init_shared_info(void) { struct xen_add_to_physmap xatp; @@ -126,6 +131,9 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback) { struct pt_regs *old_regs = set_irq_regs(regs); + if (xen_percpu_upcall) + ack_APIC_irq(); + inc_irq_stat(irq_hv_callback_count); xen_hvm_evtchn_do_upcall(); @@ -169,6 +177,15 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu) if (!xen_have_vector_callback) return 0; + if (xen_percpu_upcall) { + rc = xen_set_upcall_vector(cpu); + if (rc) { + WARN(1, "HVMOP_set_evtchn_upcall_vector" + " for CPU %d failed: %d\n", cpu, rc); + return rc; + } + } + if (xen_feature(XENFEAT_hvm_safe_pvclock)) xen_setup_timer(cpu); @@ -189,8 +206,6 @@ static int xen_cpu_dead_hvm(unsigned int cpu) return 0; } -static bool no_vector_callback __initdata; - static void __init xen_hvm_guest_init(void) { if (xen_pv_domain()) @@ -213,9 +228,6 @@ static void __init xen_hvm_guest_init(void) xen_panic_handler_init(); - if (!no_vector_callback && xen_feature(XENFEAT_hvm_callback_vector)) - xen_have_vector_callback = 1; - xen_hvm_smp_init(); WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm)); xen_unplug_emulated_devices(); @@ -241,7 +253,7 @@ early_param("xen_nopv", xen_parse_nopv); static __init int xen_parse_no_vector_callback(char *arg) { - no_vector_callback = true; + xen_have_vector_callback = false; return 0; } early_param("xen_no_vector_callback", xen_parse_no_vector_callback); diff --git a/arch/x86/xen/suspend_hvm.c b/arch/x86/xen/suspend_hvm.c index 9d548b0c772f..0c4f7554b7cc 100644 --- a/arch/x86/xen/suspend_hvm.c +++ b/arch/x86/xen/suspend_hvm.c @@ -5,6 +5,7 @@ #include <xen/hvm.h> #include <xen/features.h> #include <xen/interface/features.h> +#include <xen/events.h> #include "xen-ops.h" @@ -14,6 +15,13 @@ void xen_hvm_post_suspend(int suspend_cancelled) xen_hvm_init_shared_info(); xen_vcpu_restore(); } - xen_setup_callback_vector(); + if (xen_percpu_upcall) { + unsigned int cpu; + + for_each_online_cpu(cpu) + BUG_ON(xen_set_upcall_vector(cpu)); + } else { + xen_setup_callback_vector(); + } xen_unplug_emulated_devices(); } |