From cbc88996c619bc138b998f7e31c069ea60dcdefc Mon Sep 17 00:00:00 2001 From: jhb Date: Fri, 29 Jun 2001 19:51:37 +0000 Subject: Move ast() and userret() to sys/kern/subr_trap.c now that they are MI. --- sys/kern/subr_trap.c | 1179 +------------------------------------------------- 1 file changed, 17 insertions(+), 1162 deletions(-) (limited to 'sys/kern/subr_trap.c') diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c index f6a9e0c..7ffc5ec 100644 --- a/sys/kern/subr_trap.c +++ b/sys/kern/subr_trap.c @@ -38,131 +38,27 @@ * $FreeBSD$ */ -/* - * 386 Trap and System call handling - */ - -#include "opt_clock.h" -#include "opt_cpu.h" -#include "opt_ddb.h" -#include "opt_isa.h" -#include "opt_ktrace.h" +#ifdef __i386__ #include "opt_npx.h" -#include "opt_trap.h" +#endif #include #include -#include -#include -#include #include -#include +#include #include +#include #include #include -#include -#include -#include -#include +#include #include -#ifdef KTRACE -#include -#endif - -#include -#include -#include -#include -#include -#include -#include -#include - #include -#include #include -#ifdef SMP -#include -#endif -#include - -#include -#include - -#ifdef POWERFAIL_NMI -#include -#include -#endif - -#include - -#include - -#include - -int (*pmath_emulate) __P((struct trapframe *)); - -extern void trap __P((struct trapframe frame)); -extern int trapwrite __P((unsigned addr)); -extern void syscall __P((struct trapframe frame)); -extern void ast __P((struct trapframe *framep)); - -static int trap_pfault __P((struct trapframe *, int, vm_offset_t)); -static void trap_fatal __P((struct trapframe *, vm_offset_t)); -void dblfault_handler __P((void)); - -extern inthand_t IDTVEC(lcall_syscall); - -#define MAX_TRAP_MSG 28 -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 */ -}; - -#if defined(I586_CPU) && !defined(NO_F00F_HACK) -extern int has_f00f_bug; -#endif - -#ifdef DDB -static int ddb_on_nmi = 1; -SYSCTL_INT(_machdep, OID_AUTO, ddb_on_nmi, CTLFLAG_RW, - &ddb_on_nmi, 0, "Go to DDB on NMI"); -#endif -static int panic_on_nmi = 1; -SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW, - &panic_on_nmi, 0, "Panic on NMI"); - -#ifdef WITNESS -extern char *syscallnames[]; -#endif +/* + * Define the code needed before returning to user mode, for + * trap and syscall. + */ void userret(p, frame, oticks) struct proc *p; @@ -180,12 +76,12 @@ userret(p, frame, oticks) p->p_pri.pri_level = p->p_pri.pri_user; if (resched_wanted(p)) { /* - * Since we are curproc, clock will normally just change - * our priority without moving us from one queue to another - * (since the running process is not on a queue.) - * If that happened after we setrunqueue ourselves but before we - * mi_switch()'ed, we might not be on the queue indicated by - * our priority. + * Since we are curproc, a clock interrupt could + * change our priority without changing run queues + * (the running process is not kept on a run queue). + * If this happened after we setrunqueue ourselves but + * before we switch()'ed, we might not be on the queue + * indicated by our priority. */ DROP_GIANT_NOSWITCH(); setrunqueue(p); @@ -212,1050 +108,9 @@ userret(p, frame, oticks) } /* - * 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(frame) - struct trapframe frame; -{ - struct proc *p = curproc; - u_quad_t sticks = 0; - int i = 0, ucode = 0, type, code; - vm_offset_t eva; -#ifdef POWERFAIL_NMI - static int lastalert = 0; -#endif - - atomic_add_int(&cnt.v_trap, 1); - - 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. XXX This is really bad if we trap - * while holding a spin lock. - */ - type = frame.tf_trapno; - if (ISPL(frame.tf_cs) == SEL_UPL || (frame.tf_eflags & PSL_VM)) - printf( - "pid %ld (%s): trap %d with interrupts disabled\n", - (long)curproc->p_pid, curproc->p_comm, type); - else if (type != T_BPTFLT && type != T_TRCTRAP) { - /* - * XXX not quite right, since this may be for a - * multiple fault in user mode. - */ - printf("kernel trap %d with interrupts disabled\n", - type); - /* - * We should walk p_heldmtx here and see if any are - * spin mutexes, and not do this if so. - */ - enable_intr(); - } - } - - eva = 0; - -#if defined(I586_CPU) && !defined(NO_F00F_HACK) -restart: -#endif - - type = frame.tf_trapno; - code = frame.tf_err; - - if ((ISPL(frame.tf_cs) == SEL_UPL) || - ((frame.tf_eflags & PSL_VM) && !in_vm86call)) { - /* user trap */ - - mtx_lock_spin(&sched_lock); - sticks = p->p_sticks; - mtx_unlock_spin(&sched_lock); - p->p_frame = &frame; - - switch (type) { - case T_PRIVINFLT: /* privileged instruction fault */ - ucode = type; - i = SIGILL; - break; - - case T_BPTFLT: /* bpt instruction fault */ - case T_TRCTRAP: /* trace trap */ - frame.tf_eflags &= ~PSL_T; - i = SIGTRAP; - break; - - case T_ARITHTRAP: /* arithmetic trap */ -#ifdef DEV_NPX - ucode = npxtrap(); - if (ucode == -1) - return; -#else - ucode = code; -#endif - 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) { - mtx_lock(&Giant); - i = vm86_emulate((struct vm86frame *)&frame); - mtx_unlock(&Giant); - if (i == 0) - goto user; - break; - } - /* FALL THROUGH */ - - case T_SEGNPFLT: /* segment not present fault */ - case T_TSSFLT: /* invalid TSS fault */ - case T_DOUBLEFLT: /* double fault */ - default: - ucode = code + BUS_SEGM_FAULT ; - i = SIGBUS; - break; - - case T_PAGEFLT: /* page fault */ - /* - * 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 then must - * reenable interrupts. - */ - eva = rcr2(); - enable_intr(); - mtx_lock(&Giant); - i = trap_pfault(&frame, TRUE, eva); - mtx_unlock(&Giant); -#if defined(I586_CPU) && !defined(NO_F00F_HACK) - if (i == -2) { - /* - * f00f hack workaround has triggered, treat - * as illegal instruction not page fault. - */ - frame.tf_trapno = T_PRIVINFLT; - goto restart; - } -#endif - if (i == -1) - goto out; - if (i == 0) - goto user; - - ucode = T_PAGEFLT; - 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 - mtx_lock(&Giant); - if (time_second - lastalert > 10) { - log(LOG_WARNING, "NMI: power fail\n"); - sysbeep(TIMER_FREQ/880, hz); - lastalert = time_second; - } - mtx_unlock(&Giant); - goto out; -#else /* !POWERFAIL_NMI */ - /* machine/parity/power fail/"kitchen sink" faults */ - /* XXX Giant */ - if (isa_nmi(code) == 0) { -#ifdef DDB - /* - * NMI can be hooked up to a pushbutton - * for debugging. - */ - if (ddb_on_nmi) { - printf ("NMI ... going to debugger\n"); - kdb_trap (type, 0, &frame); - } -#endif /* DDB */ - goto out; - } else if (panic_on_nmi) - panic("NMI indicates hardware failure"); - break; -#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: -#ifdef DEV_NPX - /* transparent fault (due to context switch "late") */ - if (npxdna()) - goto out; -#endif - if (!pmath_emulate) { - i = SIGFPE; - ucode = FPE_FPU_NP_TRAP; - break; - } - mtx_lock(&Giant); - i = (*pmath_emulate)(&frame); - mtx_unlock(&Giant); - if (i == 0) { - if (!(frame.tf_eflags & PSL_T)) - goto out; - frame.tf_eflags &= ~PSL_T; - i = SIGTRAP; - } - /* else ucode = emulator_only_knows() XXX */ - break; - - case T_FPOPFLT: /* FPU operand fetch fault */ - ucode = T_FPOPFLT; - i = SIGILL; - break; - } - } else { - /* kernel trap */ - - switch (type) { - case T_PAGEFLT: /* page fault */ - /* - * 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 then must - * reenable interrupts. - */ - eva = rcr2(); - enable_intr(); - mtx_lock(&Giant); - (void) trap_pfault(&frame, FALSE, eva); - mtx_unlock(&Giant); - goto out; - - case T_DNA: -#ifdef DEV_NPX - /* - * The kernel is apparently using npx for copying. - * XXX this should be fatal unless the kernel has - * registered such use. - */ - if (npxdna()) - goto out; -#endif - 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) { - mtx_lock(&Giant); - i = vm86_emulate((struct vm86frame *)&frame); - mtx_unlock(&Giant); - 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 (in_vm86call) - break; - - if (p->p_intr_nesting_level != 0) - 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) { - PCPU_GET(curpcb)->pcb_gs = 0; - PROC_LOCK(p); - psignal(p, SIGBUS); - PROC_UNLOCK(p); - goto out; - } - - /* - * 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 (PCPU_GET(curpcb) != NULL && - PCPU_GET(curpcb)->pcb_onfault != NULL) { - frame.tf_eip = - (int)PCPU_GET(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 */ - 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. - */ - /* XXX Giant */ - if (user_dbreg_trap() && !in_vm86call) { - /* - * Reset breakpoint bits because the - * processor doesn't - */ - load_dr6(rdr6() & 0xfffffff0); - goto out; - } - /* - * Fall through (TRCTRAP kernel mode, kernel address) - */ - case T_BPTFLT: - /* - * If DDB is enabled, let it handle the debugger trap. - * Otherwise, debugger traps "can't happen". - */ -#ifdef DDB - /* XXX Giant */ - if (kdb_trap (type, 0, &frame)) - goto out; -#endif - break; - -#ifdef DEV_ISA - case T_NMI: -#ifdef POWERFAIL_NMI - mtx_lock(&Giant); - if (time_second - lastalert > 10) { - log(LOG_WARNING, "NMI: power fail\n"); - sysbeep(TIMER_FREQ/880, hz); - lastalert = time_second; - } - mtx_unlock(&Giant); - goto out; -#else /* !POWERFAIL_NMI */ - /* XXX Giant */ - /* machine/parity/power fail/"kitchen sink" faults */ - if (isa_nmi(code) == 0) { -#ifdef DDB - /* - * NMI can be hooked up to a pushbutton - * for debugging. - */ - if (ddb_on_nmi) { - printf ("NMI ... going to debugger\n"); - kdb_trap (type, 0, &frame); - } -#endif /* DDB */ - goto out; - } else if (panic_on_nmi == 0) - goto out; - /* FALL THROUGH */ -#endif /* POWERFAIL_NMI */ -#endif /* DEV_ISA */ - } - - trap_fatal(&frame, eva); - goto out; - } - - mtx_lock(&Giant); - /* Translate fault for emulators (e.g. Linux) */ - if (*p->p_sysent->sv_transtrap) - i = (*p->p_sysent->sv_transtrap)(i, type); - - trapsignal(p, i, ucode); - -#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 - mtx_unlock(&Giant); - -user: - userret(p, &frame, sticks); - if (mtx_owned(&Giant)) - mtx_unlock(&Giant); -out: - return; -} - -#ifdef notyet -/* - * This version doesn't allow a page fault to user space while - * in the kernel. The rest of the kernel needs to be made "safe" - * before this can be used. I think the only things remaining - * to be made safe are the iBCS2 code and the process tracing/ - * debugging code. + * Process an asynchronous software trap. + * This is relatively easy. */ -static int -trap_pfault(frame, usermode, eva) - struct trapframe *frame; - int usermode; - vm_offset_t eva; -{ - vm_offset_t va; - struct vmspace *vm = NULL; - vm_map_t map = 0; - int rv = 0; - vm_prot_t ftype; - struct proc *p = curproc; - - if (frame->tf_err & PGEX_W) - ftype = VM_PROT_WRITE; - else - ftype = VM_PROT_READ; - - va = trunc_page(eva); - if (va < VM_MIN_KERNEL_ADDRESS) { - vm_offset_t v; - vm_page_t mpte; - - if (p == NULL || - (!usermode && va < VM_MAXUSER_ADDRESS && - (p->p_intr_nesting_level != 0 || - PCPU_GET(curpcb) == NULL || - PCPU_GET(curpcb)->pcb_onfault == NULL))) { - trap_fatal(frame, eva); - return (-1); - } - - /* - * This is a fault on non-kernel virtual memory. - * vm is initialized above to NULL. If curproc is NULL - * or curproc->p_vmspace is NULL the fault is fatal. - */ - vm = p->p_vmspace; - if (vm == NULL) - goto nogo; - - map = &vm->vm_map; - - /* - * Keep swapout from messing with us during this - * critical time. - */ - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - - /* - * Grow the stack if necessary - */ - /* grow_stack returns false only if va falls into - * a growable stack region and the stack growth - * fails. It returns true if va was not within - * a growable stack region, or if the stack - * growth succeeded. - */ - if (!grow_stack (p, va)) - rv = KERN_FAILURE; - else - /* Fault in the user page: */ - rv = vm_fault(map, va, ftype, - (ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY - : VM_FAULT_NORMAL); - - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); - } else { - /* - * Don't allow user-mode faults in kernel address space. - */ - if (usermode) - goto nogo; - - /* - * Since we know that kernel virtual address addresses - * always have pte pages mapped, we just have to fault - * the page. - */ - rv = vm_fault(kernel_map, va, ftype, VM_FAULT_NORMAL); - } - - if (rv == KERN_SUCCESS) - return (0); -nogo: - if (!usermode) { - if (p->p_intr_nesting_level == 0 && - PCPU_GET(curpcb) != NULL && - PCPU_GET(curpcb)->pcb_onfault != NULL) { - frame->tf_eip = (int)PCPU_GET(curpcb)->pcb_onfault; - return (0); - } - trap_fatal(frame, eva); - return (-1); - } - - /* kludge to pass faulting virtual address to sendsig */ - frame->tf_err = eva; - - return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV); -} -#endif - -int -trap_pfault(frame, usermode, eva) - struct trapframe *frame; - int usermode; - vm_offset_t eva; -{ - vm_offset_t va; - struct vmspace *vm = NULL; - vm_map_t map = 0; - int rv = 0; - vm_prot_t ftype; - struct proc *p = curproc; - - 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 { - /* - * This is a fault on non-kernel virtual memory. - * vm is initialized above to NULL. If curproc is NULL - * or curproc->p_vmspace is NULL the fault is fatal. - */ - if (p != NULL) - vm = p->p_vmspace; - - if (vm == NULL) - goto nogo; - - map = &vm->vm_map; - } - - if (frame->tf_err & PGEX_W) - ftype = VM_PROT_WRITE; - else - ftype = VM_PROT_READ; - - if (map != kernel_map) { - /* - * Keep swapout from messing with us during this - * critical time. - */ - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - - /* - * Grow the stack if necessary - */ - /* grow_stack returns false only if va falls into - * a growable stack region and the stack growth - * fails. It returns true if va was not within - * a growable stack region, or if the stack - * growth succeeded. - */ - if (!grow_stack (p, va)) - rv = KERN_FAILURE; - else - /* Fault in the user page: */ - rv = vm_fault(map, va, ftype, - (ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY - : VM_FAULT_NORMAL); - - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); - } else { - /* - * Don't have to worry about process locking or stacks in the - * kernel. - */ - rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); - } - - if (rv == KERN_SUCCESS) - return (0); -nogo: - if (!usermode) { - if (p->p_intr_nesting_level == 0 && - PCPU_GET(curpcb) != NULL && - PCPU_GET(curpcb)->pcb_onfault != NULL) { - frame->tf_eip = (int)PCPU_GET(curpcb)->pcb_onfault; - return (0); - } - trap_fatal(frame, eva); - return (-1); - } - - /* kludge to pass faulting virtual address to sendsig */ - frame->tf_err = eva; - - return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV); -} - -static void -trap_fatal(frame, eva) - struct trapframe *frame; - vm_offset_t eva; -{ - int code, type, ss, esp; - struct soft_segment_descriptor softseg; - - code = frame->tf_err; - type = frame->tf_trapno; - sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg); - - if (type <= MAX_TRAP_MSG) - printf("\n\nFatal trap %d: %s while in %s mode\n", - type, trap_msg[type], - 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("lapic.id = %08x\n", lapic.id); -#endif - if (type == T_PAGEFLT) { - printf("fault virtual address = 0x%x\n", eva); - printf("fault code = %s %s, %s\n", - code & PGEX_U ? "user" : "supervisor", - code & PGEX_W ? "write" : "read", - code & PGEX_P ? "protection violation" : "page not present"); - } - printf("instruction pointer = 0x%x:0x%x\n", - frame->tf_cs & 0xffff, frame->tf_eip); - if ((ISPL(frame->tf_cs) == SEL_UPL) || (frame->tf_eflags & PSL_VM)) { - 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 = "); - if (curproc) { - printf("%lu (%s)\n", - (u_long)curproc->p_pid, curproc->p_comm ? - curproc->p_comm : ""); - } else { - printf("Idle\n"); - } - -#ifdef KDB - if (kdb_trap(&psl)) - return; -#endif -#ifdef DDB - if ((debugger_on_panic || db_active) && kdb_trap(type, 0, frame)) - return; -#endif - printf("trap number = %d\n", type); - if (type <= MAX_TRAP_MSG) - panic(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() -{ - 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("lapic.id = %08x\n", lapic.id); -#endif - panic("double fault"); -} - -/* - * Compensate for 386 brain damage (missing URKR). - * This is a little simpler than the pagefault handler in trap() because - * it the page tables have already been faulted in and high addresses - * are thrown out early for other reasons. - */ -int trapwrite(addr) - unsigned addr; -{ - struct proc *p; - vm_offset_t va; - struct vmspace *vm; - int rv; - - va = trunc_page((vm_offset_t)addr); - /* - * XXX - MAX is END. Changed > to >= for temp. fix. - */ - if (va >= VM_MAXUSER_ADDRESS) - return (1); - - p = curproc; - vm = p->p_vmspace; - - PROC_LOCK(p); - ++p->p_lock; - PROC_UNLOCK(p); - - if (!grow_stack (p, va)) - rv = KERN_FAILURE; - else - /* - * fault the data page - */ - rv = vm_fault(&vm->vm_map, va, VM_PROT_WRITE, VM_FAULT_DIRTY); - - PROC_LOCK(p); - --p->p_lock; - PROC_UNLOCK(p); - - if (rv != KERN_SUCCESS) - return 1; - - return (0); -} - -/* - * syscall - MP aware system call request C handler - * - * A system call is essentially treated as a trap except that the - * MP lock is not held on entry or return. We are responsible for - * obtaining the MP lock if necessary and for handling ASTs - * (e.g. a task switch) prior to return. - * - * In general, only simple access and manipulation of curproc and - * the current stack is allowed without having to hold MP lock. - */ -void -syscall(frame) - struct trapframe frame; -{ - caddr_t params; - int i; - struct sysent *callp; - struct proc *p = curproc; - u_quad_t sticks; - int error; - int narg; - int args[8]; - u_int code; - - atomic_add_int(&cnt.v_syscall, 1); - -#ifdef DIAGNOSTIC - if (ISPL(frame.tf_cs) != SEL_UPL) { - mtx_lock(&Giant); - panic("syscall"); - /* NOT REACHED */ - } -#endif - - mtx_lock_spin(&sched_lock); - sticks = p->p_sticks; - mtx_unlock_spin(&sched_lock); - - p->p_frame = &frame; - params = (caddr_t)frame.tf_esp + sizeof(int); - code = frame.tf_eax; - - if (p->p_sysent->sv_prepsyscall) { - /* - * The prep code is not MP aware. - */ - mtx_lock(&Giant); - (*p->p_sysent->sv_prepsyscall)(&frame, args, &code, ¶ms); - mtx_unlock(&Giant); - } else { - /* - * Need to check if this is a 32 bit or 64 bit syscall. - * fuword is MP aware. - */ - if (code == SYS_syscall) { - /* - * Code is first argument, followed by actual args. - */ - code = fuword(params); - params += sizeof(int); - } else if (code == SYS___syscall) { - /* - * Like syscall, but code is a quad, so as to maintain - * quad alignment for the rest of the arguments. - */ - code = fuword(params); - params += sizeof(quad_t); - } - } - - if (p->p_sysent->sv_mask) - code &= p->p_sysent->sv_mask; - - if (code >= p->p_sysent->sv_size) - callp = &p->p_sysent->sv_table[0]; - else - callp = &p->p_sysent->sv_table[code]; - - narg = callp->sy_narg & SYF_ARGMASK; - - /* - * copyin is MP aware, but the tracing code is not - */ - if (params && (i = narg * sizeof(int)) && - (error = copyin(params, (caddr_t)args, (u_int)i))) { - mtx_lock(&Giant); -#ifdef KTRACE - if (KTRPOINT(p, KTR_SYSCALL)) - ktrsyscall(p->p_tracep, code, narg, args); -#endif - goto bad; - } - - /* - * Try to run the syscall without the MP lock if the syscall - * is MP safe. - */ - if ((callp->sy_narg & SYF_MPSAFE) == 0) { - mtx_lock(&Giant); - } - -#ifdef KTRACE - /* - * We have to obtain the MP lock no matter what if - * we are ktracing - */ - if (KTRPOINT(p, KTR_SYSCALL)) { - if (!mtx_owned(&Giant)) - mtx_lock(&Giant); - ktrsyscall(p->p_tracep, code, narg, args); - } -#endif - p->p_retval[0] = 0; - p->p_retval[1] = frame.tf_edx; - - STOPEVENT(p, S_SCE, narg); /* MP aware */ - - error = (*callp->sy_call)(p, args); - - /* - * MP SAFE (we may or may not have the MP lock at this point) - */ - switch (error) { - case 0: - frame.tf_eax = p->p_retval[0]; - frame.tf_edx = p->p_retval[1]; - frame.tf_eflags &= ~PSL_C; - break; - - case ERESTART: - /* - * Reconstruct pc, assuming lcall $X,y is 7 bytes, - * int 0x80 is 2 bytes. We saved this in tf_err. - */ - frame.tf_eip -= frame.tf_err; - break; - - case EJUSTRETURN: - break; - - default: -bad: - if (p->p_sysent->sv_errsize) { - if (error >= p->p_sysent->sv_errsize) - error = -1; /* XXX */ - else - error = p->p_sysent->sv_errtbl[error]; - } - frame.tf_eax = error; - frame.tf_eflags |= PSL_C; - break; - } - - /* - * Traced syscall. trapsignal() is not MP aware. - */ - if ((frame.tf_eflags & PSL_T) && !(frame.tf_eflags & PSL_VM)) { - if (!mtx_owned(&Giant)) - mtx_lock(&Giant); - frame.tf_eflags &= ~PSL_T; - trapsignal(p, SIGTRAP, 0); - } - - /* - * Handle reschedule and other end-of-syscall issues - */ - userret(p, &frame, sticks); - -#ifdef KTRACE - if (KTRPOINT(p, KTR_SYSRET)) { - if (!mtx_owned(&Giant)) - mtx_lock(&Giant); - ktrsysret(p->p_tracep, code, error, p->p_retval[0]); - } -#endif - - /* - * Release Giant if we had to get it - */ - if (mtx_owned(&Giant)) - mtx_unlock(&Giant); - - /* - * This works because errno is findable through the - * register set. If we ever support an emulation where this - * is not the case, this code will need to be revisited. - */ - STOPEVENT(p, S_SCX, code); - -#ifdef WITNESS - if (witness_list(p)) { - panic("system call %s returning with mutex(s) held\n", - syscallnames[code]); - } -#endif - mtx_assert(&sched_lock, MA_NOTOWNED); - mtx_assert(&Giant, MA_NOTOWNED); -} - void ast(framep) struct trapframe *framep; -- cgit v1.1