/*- * Copyright (C) 1994, David Greenman * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * the University of Utah, and William Jolitz. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)trap.c 7.4 (Berkeley) 5/13/91 */ #include __FBSDID("$FreeBSD$"); /* * 386 Trap and System call handling */ #include "opt_clock.h" #include "opt_cpu.h" #include "opt_hwpmc_hooks.h" #include "opt_isa.h" #include "opt_kdb.h" #include "opt_stack.h" #include "opt_trap.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HWPMC_HOOKS #include PMC_SOFT_DEFINE( , , page_fault, all); PMC_SOFT_DEFINE( , , page_fault, read); PMC_SOFT_DEFINE( , , page_fault, write); #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef SMP #include #endif #include #include #include #ifdef POWERFAIL_NMI #include #include #endif #ifdef KDTRACE_HOOKS #include #endif extern void trap(struct trapframe *frame); extern void syscall(struct trapframe *frame); static int trap_pfault(struct trapframe *, int, vm_offset_t); static void trap_fatal(struct trapframe *, vm_offset_t); void dblfault_handler(void); extern inthand_t IDTVEC(lcall_syscall); #define MAX_TRAP_MSG 32 static char *trap_msg[] = { "", /* 0 unused */ "privileged instruction fault", /* 1 T_PRIVINFLT */ "", /* 2 unused */ "breakpoint instruction fault", /* 3 T_BPTFLT */ "", /* 4 unused */ "", /* 5 unused */ "arithmetic trap", /* 6 T_ARITHTRAP */ "", /* 7 unused */ "", /* 8 unused */ "general protection fault", /* 9 T_PROTFLT */ "trace trap", /* 10 T_TRCTRAP */ "", /* 11 unused */ "page fault", /* 12 T_PAGEFLT */ "", /* 13 unused */ "alignment fault", /* 14 T_ALIGNFLT */ "", /* 15 unused */ "", /* 16 unused */ "", /* 17 unused */ "integer divide fault", /* 18 T_DIVIDE */ "non-maskable interrupt trap", /* 19 T_NMI */ "overflow trap", /* 20 T_OFLOW */ "FPU bounds check fault", /* 21 T_BOUND */ "FPU device not available", /* 22 T_DNA */ "double fault", /* 23 T_DOUBLEFLT */ "FPU operand fetch fault", /* 24 T_FPOPFLT */ "invalid TSS fault", /* 25 T_TSSFLT */ "segment not present fault", /* 26 T_SEGNPFLT */ "stack fault", /* 27 T_STKFLT */ "machine check trap", /* 28 T_MCHK */ "SIMD floating-point exception", /* 29 T_XMMFLT */ "reserved (unknown) fault", /* 30 T_RESERVED */ "", /* 31 unused (reserved) */ "DTrace pid return trap", /* 32 T_DTRACE_RET */ }; #if defined(I586_CPU) && !defined(NO_F00F_HACK) int has_f00f_bug = 0; /* Initialized so that it can be patched. */ #endif static int prot_fault_translation = 0; SYSCTL_INT(_machdep, OID_AUTO, prot_fault_translation, CTLFLAG_RW, &prot_fault_translation, 0, "Select signal to deliver on protection fault"); static int uprintf_signal; SYSCTL_INT(_machdep, OID_AUTO, uprintf_signal, CTLFLAG_RW, &uprintf_signal, 0, "Print debugging information on trap signal to ctty"); /* * Exception, fault, and trap interface to the FreeBSD kernel. * This common code is called from assembly language IDT gate entry * routines that prepare a suitable stack frame, and restore this * frame after the exception has been processed. */ void trap(struct trapframe *frame) { #ifdef KDTRACE_HOOKS struct reg regs; #endif struct thread *td = curthread; struct proc *p = td->td_proc; #ifdef KDB register_t dr6; #endif int i = 0, ucode = 0; u_int type; register_t addr = 0; vm_offset_t eva; ksiginfo_t ksi; #ifdef POWERFAIL_NMI static int lastalert = 0; #endif PCPU_INC(cnt.v_trap); type = frame->tf_trapno; #ifdef SMP /* Handler for NMI IPIs used for stopping CPUs. */ if (type == T_NMI) { if (ipi_nmi_handler() == 0) goto out; } #endif /* SMP */ #ifdef KDB if (kdb_active) { kdb_reenter(); goto out; } #endif if (type == T_RESERVED) { trap_fatal(frame, 0); goto out; } if (type == T_NMI) { #ifdef HWPMC_HOOKS /* * CPU PMCs interrupt using an NMI so we check for that first. * If the HWPMC module is active, 'pmc_hook' will point to * the function to be called. A non-zero return value from the * hook means that the NMI was consumed by it and that we can * return immediately. */ if (pmc_intr != NULL && (*pmc_intr)(PCPU_GET(cpuid), frame) != 0) goto out; #endif #ifdef STACK if (stack_nmi_handler(frame) != 0) goto out; #endif } if (type == T_MCHK) { mca_intr(); goto out; } #ifdef KDTRACE_HOOKS /* * A trap can occur while DTrace executes a probe. Before * executing the probe, DTrace blocks re-scheduling and sets * a flag in its per-cpu flags to indicate that it doesn't * want to fault. On returning from the probe, the no-fault * flag is cleared and finally re-scheduling is enabled. */ if ((type == T_PROTFLT || type == T_PAGEFLT) && dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type)) goto out; #endif if ((frame->tf_eflags & PSL_I) == 0) { /* * Buggy application or kernel code has disabled * interrupts and then trapped. Enabling interrupts * now is wrong, but it is better than running with * interrupts disabled until they are accidentally * enabled later. */ if (TRAPF_USERMODE(frame) && (curpcb->pcb_flags & PCB_VM86CALL) == 0) uprintf( "pid %ld (%s): trap %d with interrupts disabled\n", (long)curproc->p_pid, curthread->td_name, type); else if (type != T_NMI && type != T_BPTFLT && type != T_TRCTRAP && frame->tf_eip != (int)cpu_switch_load_gs) { /* * XXX not quite right, since this may be for a * multiple fault in user mode. */ printf("kernel trap %d with interrupts disabled\n", type); /* * Page faults need interrupts disabled until later, * and we shouldn't enable interrupts while holding * a spin lock. */ if (type != T_PAGEFLT && td->td_md.md_spinlock_count == 0) enable_intr(); } } eva = 0; if (type == T_PAGEFLT) { /* * For some Cyrix CPUs, %cr2 is clobbered by * interrupts. This problem is worked around by using * an interrupt gate for the pagefault handler. We * are finally ready to read %cr2 and conditionally * reenable interrupts. If we hold a spin lock, then * we must not reenable interrupts. This might be a * spurious page fault. */ eva = rcr2(); if (td->td_md.md_spinlock_count == 0) enable_intr(); } if (TRAPF_USERMODE(frame) && (curpcb->pcb_flags & PCB_VM86CALL) == 0) { /* user trap */ td->td_pticks = 0; td->td_frame = frame; addr = frame->tf_eip; if (td->td_cowgen != p->p_cowgen) thread_cow_update(td); switch (type) { case T_PRIVINFLT: /* privileged instruction fault */ i = SIGILL; ucode = ILL_PRVOPC; break; case T_BPTFLT: /* bpt instruction fault */ case T_TRCTRAP: /* trace trap */ enable_intr(); #ifdef KDTRACE_HOOKS if (type == T_BPTFLT) { fill_frame_regs(frame, ®s); if (dtrace_pid_probe_ptr != NULL && dtrace_pid_probe_ptr(®s) == 0) goto out; } #endif user_trctrap_out: frame->tf_eflags &= ~PSL_T; i = SIGTRAP; ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT); break; case T_ARITHTRAP: /* arithmetic trap */ ucode = npxtrap_x87(); if (ucode == -1) goto userout; i = SIGFPE; break; /* * The following two traps can happen in * vm86 mode, and, if so, we want to handle * them specially. */ case T_PROTFLT: /* general protection fault */ case T_STKFLT: /* stack fault */ if (frame->tf_eflags & PSL_VM) { i = vm86_emulate((struct vm86frame *)frame); if (i == SIGTRAP) { type = T_TRCTRAP; load_dr6(rdr6() | 0x4000); goto user_trctrap_out; } if (i == 0) goto user; break; } i = SIGBUS; ucode = (type == T_PROTFLT) ? BUS_OBJERR : BUS_ADRERR; break; case T_SEGNPFLT: /* segment not present fault */ i = SIGBUS; ucode = BUS_ADRERR; break; case T_TSSFLT: /* invalid TSS fault */ i = SIGBUS; ucode = BUS_OBJERR; break; case T_ALIGNFLT: i = SIGBUS; ucode = BUS_ADRALN; break; case T_DOUBLEFLT: /* double fault */ default: i = SIGBUS; ucode = BUS_OBJERR; break; case T_PAGEFLT: /* page fault */ i = trap_pfault(frame, TRUE, eva); #if defined(I586_CPU) && !defined(NO_F00F_HACK) if (i == -2) { /* * The f00f hack workaround has triggered, so * treat the fault as an illegal instruction * (T_PRIVINFLT) instead of a page fault. */ type = frame->tf_trapno = T_PRIVINFLT; /* Proceed as in that case. */ ucode = ILL_PRVOPC; i = SIGILL; break; } #endif if (i == -1) goto userout; if (i == 0) goto user; if (i == SIGSEGV) ucode = SEGV_MAPERR; else { if (prot_fault_translation == 0) { /* * Autodetect. * This check also covers the images * without the ABI-tag ELF note. */ if (SV_CURPROC_ABI() == SV_ABI_FREEBSD && p->p_osrel >= P_OSREL_SIGSEGV) { i = SIGSEGV; ucode = SEGV_ACCERR; } else { i = SIGBUS; ucode = BUS_PAGE_FAULT; } } else if (prot_fault_translation == 1) { /* * Always compat mode. */ i = SIGBUS; ucode = BUS_PAGE_FAULT; } else { /* * Always SIGSEGV mode. */ i = SIGSEGV; ucode = SEGV_ACCERR; } } addr = eva; break; case T_DIVIDE: /* integer divide fault */ ucode = FPE_INTDIV; i = SIGFPE; break; #ifdef DEV_ISA case T_NMI: #ifdef POWERFAIL_NMI #ifndef TIMER_FREQ # define TIMER_FREQ 1193182 #endif if (time_second - lastalert > 10) { log(LOG_WARNING, "NMI: power fail\n"); sysbeep(880, hz); lastalert = time_second; } goto userout; #else /* !POWERFAIL_NMI */ nmi_handle_intr(type, frame); goto out; #endif /* POWERFAIL_NMI */ #endif /* DEV_ISA */ case T_OFLOW: /* integer overflow fault */ ucode = FPE_INTOVF; i = SIGFPE; break; case T_BOUND: /* bounds check fault */ ucode = FPE_FLTSUB; i = SIGFPE; break; case T_DNA: KASSERT(PCB_USER_FPU(td->td_pcb), ("kernel FPU ctx has leaked")); /* transparent fault (due to context switch "late") */ if (npxdna()) goto userout; uprintf("pid %d killed due to lack of floating point\n", p->p_pid); i = SIGKILL; ucode = 0; break; case T_FPOPFLT: /* FPU operand fetch fault */ ucode = ILL_COPROC; i = SIGILL; break; case T_XMMFLT: /* SIMD floating-point exception */ ucode = npxtrap_sse(); if (ucode == -1) goto userout; i = SIGFPE; break; #ifdef KDTRACE_HOOKS case T_DTRACE_RET: enable_intr(); fill_frame_regs(frame, ®s); if (dtrace_return_probe_ptr != NULL && dtrace_return_probe_ptr(®s) == 0) goto out; goto userout; #endif } } else { /* kernel trap */ KASSERT(cold || td->td_ucred != NULL, ("kernel trap doesn't have ucred")); switch (type) { case T_PAGEFLT: /* page fault */ (void) trap_pfault(frame, FALSE, eva); goto out; case T_DNA: if (PCB_USER_FPU(td->td_pcb)) panic("Unregistered use of FPU in kernel"); if (npxdna()) goto out; break; case T_ARITHTRAP: /* arithmetic trap */ case T_XMMFLT: /* SIMD floating-point exception */ case T_FPOPFLT: /* FPU operand fetch fault */ /* * XXXKIB for now disable any FPU traps in kernel * handler registration seems to be overkill */ trap_fatal(frame, 0); goto out; /* * The following two traps can happen in * vm86 mode, and, if so, we want to handle * them specially. */ case T_PROTFLT: /* general protection fault */ case T_STKFLT: /* stack fault */ if (frame->tf_eflags & PSL_VM) { i = vm86_emulate((struct vm86frame *)frame); if (i == SIGTRAP) { type = T_TRCTRAP; load_dr6(rdr6() | 0x4000); goto kernel_trctrap; } if (i != 0) /* * returns to original process */ vm86_trap((struct vm86frame *)frame); goto out; } if (type == T_STKFLT) break; /* FALL THROUGH */ case T_SEGNPFLT: /* segment not present fault */ if (curpcb->pcb_flags & PCB_VM86CALL) break; /* * Invalid %fs's and %gs's can be created using * procfs or PT_SETREGS or by invalidating the * underlying LDT entry. This causes a fault * in kernel mode when the kernel attempts to * switch contexts. Lose the bad context * (XXX) so that we can continue, and generate * a signal. */ if (frame->tf_eip == (int)cpu_switch_load_gs) { curpcb->pcb_gs = 0; #if 0 PROC_LOCK(p); kern_psignal(p, SIGBUS); PROC_UNLOCK(p); #endif goto out; } if (td->td_intr_nesting_level != 0) break; /* * Invalid segment selectors and out of bounds * %eip's and %esp's can be set up in user mode. * This causes a fault in kernel mode when the * kernel tries to return to user mode. We want * to get this fault so that we can fix the * problem here and not have to check all the * selectors and pointers when the user changes * them. */ if (frame->tf_eip == (int)doreti_iret) { frame->tf_eip = (int)doreti_iret_fault; goto out; } if (frame->tf_eip == (int)doreti_popl_ds) { frame->tf_eip = (int)doreti_popl_ds_fault; goto out; } if (frame->tf_eip == (int)doreti_popl_es) { frame->tf_eip = (int)doreti_popl_es_fault; goto out; } if (frame->tf_eip == (int)doreti_popl_fs) { frame->tf_eip = (int)doreti_popl_fs_fault; goto out; } if (curpcb->pcb_onfault != NULL) { frame->tf_eip = (int)curpcb->pcb_onfault; goto out; } break; case T_TSSFLT: /* * PSL_NT can be set in user mode and isn't cleared * automatically when the kernel is entered. This * causes a TSS fault when the kernel attempts to * `iret' because the TSS link is uninitialized. We * want to get this fault so that we can fix the * problem here and not every time the kernel is * entered. */ if (frame->tf_eflags & PSL_NT) { frame->tf_eflags &= ~PSL_NT; goto out; } break; case T_TRCTRAP: /* trace trap */ kernel_trctrap: if (frame->tf_eip == (int)IDTVEC(lcall_syscall)) { /* * We've just entered system mode via the * syscall lcall. Continue single stepping * silently until the syscall handler has * saved the flags. */ goto out; } if (frame->tf_eip == (int)IDTVEC(lcall_syscall) + 1) { /* * The syscall handler has now saved the * flags. Stop single stepping it. */ frame->tf_eflags &= ~PSL_T; goto out; } /* * Ignore debug register trace traps due to * accesses in the user's address space, which * can happen under several conditions such as * if a user sets a watchpoint on a buffer and * then passes that buffer to a system call. * We still want to get TRCTRAPS for addresses * in kernel space because that is useful when * debugging the kernel. */ if (user_dbreg_trap() && !(curpcb->pcb_flags & PCB_VM86CALL)) { /* * Reset breakpoint bits because the * processor doesn't */ load_dr6(rdr6() & ~0xf); goto out; } /* * FALLTHROUGH (TRCTRAP kernel mode, kernel address) */ case T_BPTFLT: /* * If KDB is enabled, let it handle the debugger trap. * Otherwise, debugger traps "can't happen". */ #ifdef KDB /* XXX %dr6 is not quite reentrant. */ dr6 = rdr6(); load_dr6(dr6 & ~0x4000); if (kdb_trap(type, dr6, frame)) goto out; #endif break; #ifdef DEV_ISA case T_NMI: #ifdef POWERFAIL_NMI if (time_second - lastalert > 10) { log(LOG_WARNING, "NMI: power fail\n"); sysbeep(880, hz); lastalert = time_second; } goto out; #else /* !POWERFAIL_NMI */ nmi_handle_intr(type, frame); goto out; #endif /* POWERFAIL_NMI */ #endif /* DEV_ISA */ } trap_fatal(frame, eva); goto out; } /* Translate fault for emulators (e.g. Linux) */ if (*p->p_sysent->sv_transtrap) i = (*p->p_sysent->sv_transtrap)(i, type); ksiginfo_init_trap(&ksi); ksi.ksi_signo = i; ksi.ksi_code = ucode; ksi.ksi_addr = (void *)addr; ksi.ksi_trapno = type; if (uprintf_signal) { uprintf("pid %d comm %s: signal %d err %x code %d type %d " "addr 0x%x esp 0x%08x eip 0x%08x " "<%02x %02x %02x %02x %02x %02x %02x %02x>\n", p->p_pid, p->p_comm, i, frame->tf_err, ucode, type, addr, frame->tf_esp, frame->tf_eip, fubyte((void *)(frame->tf_eip + 0)), fubyte((void *)(frame->tf_eip + 1)), fubyte((void *)(frame->tf_eip + 2)), fubyte((void *)(frame->tf_eip + 3)), fubyte((void *)(frame->tf_eip + 4)), fubyte((void *)(frame->tf_eip + 5)), fubyte((void *)(frame->tf_eip + 6)), fubyte((void *)(frame->tf_eip + 7))); } KASSERT((read_eflags() & PSL_I) != 0, ("interrupts disabled")); trapsignal(td, &ksi); #ifdef DEBUG if (type <= MAX_TRAP_MSG) { uprintf("fatal process exception: %s", trap_msg[type]); if ((type == T_PAGEFLT) || (type == T_PROTFLT)) uprintf(", fault VA = 0x%lx", (u_long)eva); uprintf("\n"); } #endif user: userret(td, frame); KASSERT(PCB_USER_FPU(td->td_pcb), ("Return from trap with kernel FPU ctx leaked")); userout: out: return; } static int trap_pfault(frame, usermode, eva) struct trapframe *frame; int usermode; vm_offset_t eva; { vm_offset_t va; vm_map_t map; int rv = 0; vm_prot_t ftype; struct thread *td = curthread; struct proc *p = td->td_proc; if (__predict_false((td->td_pflags & TDP_NOFAULTING) != 0)) { /* * Due to both processor errata and lazy TLB invalidation when * access restrictions are removed from virtual pages, memory * accesses that are allowed by the physical mapping layer may * nonetheless cause one spurious page fault per virtual page. * When the thread is executing a "no faulting" section that * is bracketed by vm_fault_{disable,enable}_pagefaults(), * every page fault is treated as a spurious page fault, * unless it accesses the same virtual address as the most * recent page fault within the same "no faulting" section. */ if (td->td_md.md_spurflt_addr != eva || (td->td_pflags & TDP_RESETSPUR) != 0) { /* * Do nothing to the TLB. A stale TLB entry is * flushed automatically by a page fault. */ td->td_md.md_spurflt_addr = eva; td->td_pflags &= ~TDP_RESETSPUR; return (0); } } else { /* * If we get a page fault while in a critical section, then * it is most likely a fatal kernel page fault. The kernel * is already going to panic trying to get a sleep lock to * do the VM lookup, so just consider it a fatal trap so the * kernel can print out a useful trap message and even get * to the debugger. * * If we get a page fault while holding a non-sleepable * lock, then it is most likely a fatal kernel page fault. * If WITNESS is enabled, then it's going to whine about * bogus LORs with various VM locks, so just skip to the * fatal trap handling directly. */ if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL, "Kernel page fault") != 0) { trap_fatal(frame, eva); return (-1); } } va = trunc_page(eva); if (va >= KERNBASE) { /* * Don't allow user-mode faults in kernel address space. * An exception: if the faulting address is the invalid * instruction entry in the IDT, then the Intel Pentium * F00F bug workaround was triggered, and we need to * treat it is as an illegal instruction, and not a page * fault. */ #if defined(I586_CPU) && !defined(NO_F00F_HACK) if ((eva == (unsigned int)&idt[6]) && has_f00f_bug) return (-2); #endif if (usermode) goto nogo; map = kernel_map; } else { map = &p->p_vmspace->vm_map; /* * When accessing a user-space address, kernel must be * ready to accept the page fault, and provide a * handling routine. Since accessing the address * without the handler is a bug, do not try to handle * it normally, and panic immediately. */ if (!usermode && (td->td_intr_nesting_level != 0 || curpcb->pcb_onfault == NULL)) { trap_fatal(frame, eva); return (-1); } } /* * If the trap was caused by errant bits in the PTE then panic. */ if (frame->tf_err & PGEX_RSV) { trap_fatal(frame, eva); return (-1); } /* * PGEX_I is defined only if the execute disable bit capability is * supported and enabled. */ if (frame->tf_err & PGEX_W) ftype = VM_PROT_WRITE; #if defined(PAE) || defined(PAE_TABLES) else if ((frame->tf_err & PGEX_I) && pg_nx != 0) ftype = VM_PROT_EXECUTE; #endif else ftype = VM_PROT_READ; /* Fault in the page. */ rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); if (rv == KERN_SUCCESS) { #ifdef HWPMC_HOOKS if (ftype == VM_PROT_READ || ftype == VM_PROT_WRITE) { PMC_SOFT_CALL_TF( , , page_fault, all, frame); if (ftype == VM_PROT_READ) PMC_SOFT_CALL_TF( , , page_fault, read, frame); else PMC_SOFT_CALL_TF( , , page_fault, write, frame); } #endif return (0); } nogo: if (!usermode) { if (td->td_intr_nesting_level == 0 && curpcb->pcb_onfault != NULL) { frame->tf_eip = (int)curpcb->pcb_onfault; return (0); } trap_fatal(frame, eva); return (-1); } return ((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV); } static void trap_fatal(frame, eva) struct trapframe *frame; vm_offset_t eva; { int code, ss, esp; u_int type; struct soft_segment_descriptor softseg; char *msg; code = frame->tf_err; type = frame->tf_trapno; sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg); if (type <= MAX_TRAP_MSG) msg = trap_msg[type]; else msg = "UNKNOWN"; printf("\n\nFatal trap %d: %s while in %s mode\n", type, msg, frame->tf_eflags & PSL_VM ? "vm86" : ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel"); #ifdef SMP /* two separate prints in case of a trap on an unmapped page */ printf("cpuid = %d; ", PCPU_GET(cpuid)); printf("apic id = %02x\n", PCPU_GET(apic_id)); #endif if (type == T_PAGEFLT) { printf("fault virtual address = 0x%x\n", eva); printf("fault code = %s %s%s, %s\n", code & PGEX_U ? "user" : "supervisor", code & PGEX_W ? "write" : "read", #if defined(PAE) || defined(PAE_TABLES) pg_nx != 0 ? (code & PGEX_I ? " instruction" : " data") : #endif "", code & PGEX_RSV ? "reserved bits in PTE" : code & PGEX_P ? "protection violation" : "page not present"); } printf("instruction pointer = 0x%x:0x%x\n", frame->tf_cs & 0xffff, frame->tf_eip); if (TF_HAS_STACKREGS(frame)) { ss = frame->tf_ss & 0xffff; esp = frame->tf_esp; } else { ss = GSEL(GDATA_SEL, SEL_KPL); esp = (int)&frame->tf_esp; } printf("stack pointer = 0x%x:0x%x\n", ss, esp); printf("frame pointer = 0x%x:0x%x\n", ss, frame->tf_ebp); printf("code segment = base 0x%x, limit 0x%x, type 0x%x\n", softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type); printf(" = DPL %d, pres %d, def32 %d, gran %d\n", softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_def32, softseg.ssd_gran); printf("processor eflags = "); if (frame->tf_eflags & PSL_T) printf("trace trap, "); if (frame->tf_eflags & PSL_I) printf("interrupt enabled, "); if (frame->tf_eflags & PSL_NT) printf("nested task, "); if (frame->tf_eflags & PSL_RF) printf("resume, "); if (frame->tf_eflags & PSL_VM) printf("vm86, "); printf("IOPL = %d\n", (frame->tf_eflags & PSL_IOPL) >> 12); printf("current process = %d (%s)\n", curproc->p_pid, curthread->td_name); #ifdef KDB if (debugger_on_panic || kdb_active) { frame->tf_err = eva; /* smuggle fault address to ddb */ if (kdb_trap(type, 0, frame)) { frame->tf_err = code; /* restore error code */ return; } frame->tf_err = code; /* restore error code */ } #endif printf("trap number = %d\n", type); if (type <= MAX_TRAP_MSG) panic("%s", trap_msg[type]); else panic("unknown/reserved trap"); } /* * Double fault handler. Called when a fault occurs while writing * a frame for a trap/exception onto the stack. This usually occurs * when the stack overflows (such is the case with infinite recursion, * for example). * * XXX Note that the current PTD gets replaced by IdlePTD when the * task switch occurs. This means that the stack that was active at * the time of the double fault is not available at unless * the machine was idle when the double fault occurred. The downside * of this is that "trace " in ddb won't work. */ void dblfault_handler() { #ifdef KDTRACE_HOOKS if (dtrace_doubletrap_func != NULL) (*dtrace_doubletrap_func)(); #endif printf("\nFatal double fault:\n"); printf("eip = 0x%x\n", PCPU_GET(common_tss.tss_eip)); printf("esp = 0x%x\n", PCPU_GET(common_tss.tss_esp)); printf("ebp = 0x%x\n", PCPU_GET(common_tss.tss_ebp)); #ifdef SMP /* two separate prints in case of a trap on an unmapped page */ printf("cpuid = %d; ", PCPU_GET(cpuid)); printf("apic id = %02x\n", PCPU_GET(apic_id)); #endif panic("double fault"); } int cpu_fetch_syscall_args(struct thread *td) { struct proc *p; struct trapframe *frame; struct syscall_args *sa; caddr_t params; long tmp; int error; p = td->td_proc; frame = td->td_frame; sa = &td->td_sa; params = (caddr_t)frame->tf_esp + sizeof(int); sa->code = frame->tf_eax; /* * Need to check if this is a 32 bit or 64 bit syscall. */ if (sa->code == SYS_syscall) { /* * Code is first argument, followed by actual args. */ error = fueword(params, &tmp); if (error == -1) return (EFAULT); sa->code = tmp; params += sizeof(int); } else if (sa->code == SYS___syscall) { /* * Like syscall, but code is a quad, so as to maintain * quad alignment for the rest of the arguments. */ error = fueword(params, &tmp); if (error == -1) return (EFAULT); sa->code = tmp; params += sizeof(quad_t); } if (p->p_sysent->sv_mask) sa->code &= p->p_sysent->sv_mask; if (sa->code >= p->p_sysent->sv_size) sa->callp = &p->p_sysent->sv_table[0]; else sa->callp = &p->p_sysent->sv_table[sa->code]; sa->narg = sa->callp->sy_narg; if (params != NULL && sa->narg != 0) error = copyin(params, (caddr_t)sa->args, (u_int)(sa->narg * sizeof(int))); else error = 0; if (error == 0) { td->td_retval[0] = 0; td->td_retval[1] = frame->tf_edx; } return (error); } #include "../../kern/subr_syscall.c" /* * syscall - system call request C handler. A system call is * essentially treated as a trap by reusing the frame layout. */ void syscall(struct trapframe *frame) { struct thread *td; register_t orig_tf_eflags; int error; ksiginfo_t ksi; #ifdef DIAGNOSTIC if (!(TRAPF_USERMODE(frame) && (curpcb->pcb_flags & PCB_VM86CALL) == 0)) { panic("syscall"); /* NOT REACHED */ } #endif orig_tf_eflags = frame->tf_eflags; td = curthread; td->td_frame = frame; error = syscallenter(td); /* * Traced syscall. */ if ((orig_tf_eflags & PSL_T) && !(orig_tf_eflags & PSL_VM)) { frame->tf_eflags &= ~PSL_T; ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGTRAP; ksi.ksi_code = TRAP_TRACE; ksi.ksi_addr = (void *)frame->tf_eip; trapsignal(td, &ksi); } KASSERT(PCB_USER_FPU(td->td_pcb), ("System call %s returning with kernel FPU ctx leaked", syscallname(td->td_proc, td->td_sa.code))); KASSERT(td->td_pcb->pcb_save == get_pcb_user_save_td(td), ("System call %s returning with mangled pcb_save", syscallname(td->td_proc, td->td_sa.code))); syscallret(td, error); }