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-rw-r--r--arch/x86/entry/entry_fred.c294
1 files changed, 294 insertions, 0 deletions
diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c
new file mode 100644
index 0000000000..89c1476fcd
--- /dev/null
+++ b/arch/x86/entry/entry_fred.c
@@ -0,0 +1,294 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * The FRED specific kernel/user entry functions which are invoked from
+ * assembly code and dispatch to the associated handlers.
+ */
+#include <linux/kernel.h>
+#include <linux/kdebug.h>
+#include <linux/nospec.h>
+
+#include <asm/desc.h>
+#include <asm/fred.h>
+#include <asm/idtentry.h>
+#include <asm/syscall.h>
+#include <asm/trapnr.h>
+#include <asm/traps.h>
+
+/* FRED EVENT_TYPE_OTHER vector numbers */
+#define FRED_SYSCALL 1
+#define FRED_SYSENTER 2
+
+static noinstr void fred_bad_type(struct pt_regs *regs, unsigned long error_code)
+{
+ irqentry_state_t irq_state = irqentry_nmi_enter(regs);
+
+ instrumentation_begin();
+
+ /* Panic on events from a high stack level */
+ if (regs->fred_cs.sl > 0) {
+ pr_emerg("PANIC: invalid or fatal FRED event; event type %u "
+ "vector %u error 0x%lx aux 0x%lx at %04x:%016lx\n",
+ regs->fred_ss.type, regs->fred_ss.vector, error_code,
+ fred_event_data(regs), regs->cs, regs->ip);
+ die("invalid or fatal FRED event", regs, error_code);
+ panic("invalid or fatal FRED event");
+ } else {
+ unsigned long flags = oops_begin();
+ int sig = SIGKILL;
+
+ pr_alert("BUG: invalid or fatal FRED event; event type %u "
+ "vector %u error 0x%lx aux 0x%lx at %04x:%016lx\n",
+ regs->fred_ss.type, regs->fred_ss.vector, error_code,
+ fred_event_data(regs), regs->cs, regs->ip);
+
+ if (__die("Invalid or fatal FRED event", regs, error_code))
+ sig = 0;
+
+ oops_end(flags, regs, sig);
+ }
+
+ instrumentation_end();
+ irqentry_nmi_exit(regs, irq_state);
+}
+
+static noinstr void fred_intx(struct pt_regs *regs)
+{
+ switch (regs->fred_ss.vector) {
+ /* Opcode 0xcd, 0x3, NOT INT3 (opcode 0xcc) */
+ case X86_TRAP_BP:
+ return exc_int3(regs);
+
+ /* Opcode 0xcd, 0x4, NOT INTO (opcode 0xce) */
+ case X86_TRAP_OF:
+ return exc_overflow(regs);
+
+#ifdef CONFIG_IA32_EMULATION
+ /* INT80 */
+ case IA32_SYSCALL_VECTOR:
+ if (ia32_enabled())
+ return fred_int80_emulation(regs);
+ fallthrough;
+#endif
+
+ default:
+ return exc_general_protection(regs, 0);
+ }
+}
+
+static __always_inline void fred_other(struct pt_regs *regs)
+{
+ /* The compiler can fold these conditions into a single test */
+ if (likely(regs->fred_ss.vector == FRED_SYSCALL && regs->fred_ss.lm)) {
+ regs->orig_ax = regs->ax;
+ regs->ax = -ENOSYS;
+ do_syscall_64(regs, regs->orig_ax);
+ return;
+ } else if (ia32_enabled() &&
+ likely(regs->fred_ss.vector == FRED_SYSENTER && !regs->fred_ss.lm)) {
+ regs->orig_ax = regs->ax;
+ regs->ax = -ENOSYS;
+ do_fast_syscall_32(regs);
+ return;
+ } else {
+ exc_invalid_op(regs);
+ return;
+ }
+}
+
+#define SYSVEC(_vector, _function) [_vector - FIRST_SYSTEM_VECTOR] = fred_sysvec_##_function
+
+static idtentry_t sysvec_table[NR_SYSTEM_VECTORS] __ro_after_init = {
+ SYSVEC(ERROR_APIC_VECTOR, error_interrupt),
+ SYSVEC(SPURIOUS_APIC_VECTOR, spurious_apic_interrupt),
+ SYSVEC(LOCAL_TIMER_VECTOR, apic_timer_interrupt),
+ SYSVEC(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi),
+
+ SYSVEC(RESCHEDULE_VECTOR, reschedule_ipi),
+ SYSVEC(CALL_FUNCTION_SINGLE_VECTOR, call_function_single),
+ SYSVEC(CALL_FUNCTION_VECTOR, call_function),
+ SYSVEC(REBOOT_VECTOR, reboot),
+
+ SYSVEC(THRESHOLD_APIC_VECTOR, threshold),
+ SYSVEC(DEFERRED_ERROR_VECTOR, deferred_error),
+ SYSVEC(THERMAL_APIC_VECTOR, thermal),
+
+ SYSVEC(IRQ_WORK_VECTOR, irq_work),
+
+ SYSVEC(POSTED_INTR_VECTOR, kvm_posted_intr_ipi),
+ SYSVEC(POSTED_INTR_WAKEUP_VECTOR, kvm_posted_intr_wakeup_ipi),
+ SYSVEC(POSTED_INTR_NESTED_VECTOR, kvm_posted_intr_nested_ipi),
+};
+
+static bool fred_setup_done __initdata;
+
+void __init fred_install_sysvec(unsigned int sysvec, idtentry_t handler)
+{
+ if (WARN_ON_ONCE(sysvec < FIRST_SYSTEM_VECTOR))
+ return;
+
+ if (WARN_ON_ONCE(fred_setup_done))
+ return;
+
+ if (!WARN_ON_ONCE(sysvec_table[sysvec - FIRST_SYSTEM_VECTOR]))
+ sysvec_table[sysvec - FIRST_SYSTEM_VECTOR] = handler;
+}
+
+static noinstr void fred_handle_spurious_interrupt(struct pt_regs *regs)
+{
+ spurious_interrupt(regs, regs->fred_ss.vector);
+}
+
+void __init fred_complete_exception_setup(void)
+{
+ unsigned int vector;
+
+ for (vector = 0; vector < FIRST_EXTERNAL_VECTOR; vector++)
+ set_bit(vector, system_vectors);
+
+ for (vector = 0; vector < NR_SYSTEM_VECTORS; vector++) {
+ if (sysvec_table[vector])
+ set_bit(vector + FIRST_SYSTEM_VECTOR, system_vectors);
+ else
+ sysvec_table[vector] = fred_handle_spurious_interrupt;
+ }
+ fred_setup_done = true;
+}
+
+static noinstr void fred_extint(struct pt_regs *regs)
+{
+ unsigned int vector = regs->fred_ss.vector;
+ unsigned int index = array_index_nospec(vector - FIRST_SYSTEM_VECTOR,
+ NR_SYSTEM_VECTORS);
+
+ if (WARN_ON_ONCE(vector < FIRST_EXTERNAL_VECTOR))
+ return;
+
+ if (likely(vector >= FIRST_SYSTEM_VECTOR)) {
+ irqentry_state_t state = irqentry_enter(regs);
+
+ instrumentation_begin();
+ sysvec_table[index](regs);
+ instrumentation_end();
+ irqentry_exit(regs, state);
+ } else {
+ common_interrupt(regs, vector);
+ }
+}
+
+static noinstr void fred_hwexc(struct pt_regs *regs, unsigned long error_code)
+{
+ /* Optimize for #PF. That's the only exception which matters performance wise */
+ if (likely(regs->fred_ss.vector == X86_TRAP_PF))
+ return exc_page_fault(regs, error_code);
+
+ switch (regs->fred_ss.vector) {
+ case X86_TRAP_DE: return exc_divide_error(regs);
+ case X86_TRAP_DB: return fred_exc_debug(regs);
+ case X86_TRAP_BR: return exc_bounds(regs);
+ case X86_TRAP_UD: return exc_invalid_op(regs);
+ case X86_TRAP_NM: return exc_device_not_available(regs);
+ case X86_TRAP_DF: return exc_double_fault(regs, error_code);
+ case X86_TRAP_TS: return exc_invalid_tss(regs, error_code);
+ case X86_TRAP_NP: return exc_segment_not_present(regs, error_code);
+ case X86_TRAP_SS: return exc_stack_segment(regs, error_code);
+ case X86_TRAP_GP: return exc_general_protection(regs, error_code);
+ case X86_TRAP_MF: return exc_coprocessor_error(regs);
+ case X86_TRAP_AC: return exc_alignment_check(regs, error_code);
+ case X86_TRAP_XF: return exc_simd_coprocessor_error(regs);
+
+#ifdef CONFIG_X86_MCE
+ case X86_TRAP_MC: return fred_exc_machine_check(regs);
+#endif
+#ifdef CONFIG_INTEL_TDX_GUEST
+ case X86_TRAP_VE: return exc_virtualization_exception(regs);
+#endif
+#ifdef CONFIG_X86_CET
+ case X86_TRAP_CP: return exc_control_protection(regs, error_code);
+#endif
+ default: return fred_bad_type(regs, error_code);
+ }
+
+}
+
+static noinstr void fred_swexc(struct pt_regs *regs, unsigned long error_code)
+{
+ switch (regs->fred_ss.vector) {
+ case X86_TRAP_BP: return exc_int3(regs);
+ case X86_TRAP_OF: return exc_overflow(regs);
+ default: return fred_bad_type(regs, error_code);
+ }
+}
+
+__visible noinstr void fred_entry_from_user(struct pt_regs *regs)
+{
+ unsigned long error_code = regs->orig_ax;
+
+ /* Invalidate orig_ax so that syscall_get_nr() works correctly */
+ regs->orig_ax = -1;
+
+ switch (regs->fred_ss.type) {
+ case EVENT_TYPE_EXTINT:
+ return fred_extint(regs);
+ case EVENT_TYPE_NMI:
+ if (likely(regs->fred_ss.vector == X86_TRAP_NMI))
+ return fred_exc_nmi(regs);
+ break;
+ case EVENT_TYPE_HWEXC:
+ return fred_hwexc(regs, error_code);
+ case EVENT_TYPE_SWINT:
+ return fred_intx(regs);
+ case EVENT_TYPE_PRIV_SWEXC:
+ if (likely(regs->fred_ss.vector == X86_TRAP_DB))
+ return fred_exc_debug(regs);
+ break;
+ case EVENT_TYPE_SWEXC:
+ return fred_swexc(regs, error_code);
+ case EVENT_TYPE_OTHER:
+ return fred_other(regs);
+ default: break;
+ }
+
+ return fred_bad_type(regs, error_code);
+}
+
+__visible noinstr void fred_entry_from_kernel(struct pt_regs *regs)
+{
+ unsigned long error_code = regs->orig_ax;
+
+ /* Invalidate orig_ax so that syscall_get_nr() works correctly */
+ regs->orig_ax = -1;
+
+ switch (regs->fred_ss.type) {
+ case EVENT_TYPE_EXTINT:
+ return fred_extint(regs);
+ case EVENT_TYPE_NMI:
+ if (likely(regs->fred_ss.vector == X86_TRAP_NMI))
+ return fred_exc_nmi(regs);
+ break;
+ case EVENT_TYPE_HWEXC:
+ return fred_hwexc(regs, error_code);
+ case EVENT_TYPE_PRIV_SWEXC:
+ if (likely(regs->fred_ss.vector == X86_TRAP_DB))
+ return fred_exc_debug(regs);
+ break;
+ case EVENT_TYPE_SWEXC:
+ return fred_swexc(regs, error_code);
+ default: break;
+ }
+
+ return fred_bad_type(regs, error_code);
+}
+
+#if IS_ENABLED(CONFIG_KVM_INTEL)
+__visible noinstr void __fred_entry_from_kvm(struct pt_regs *regs)
+{
+ switch (regs->fred_ss.type) {
+ case EVENT_TYPE_EXTINT:
+ return fred_extint(regs);
+ case EVENT_TYPE_NMI:
+ return fred_exc_nmi(regs);
+ default:
+ WARN_ON_ONCE(1);
+ }
+}
+#endif