The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/trap.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (C) 1994, David Greenman
    3  * Copyright (c) 1990, 1993
    4  *      The Regents of the University of California.  All rights reserved.
    5  *
    6  * This code is derived from software contributed to Berkeley by
    7  * the University of Utah, and William Jolitz.
    8  *
    9  * Redistribution and use in source and binary forms, with or without
   10  * modification, are permitted provided that the following conditions
   11  * are met:
   12  * 1. Redistributions of source code must retain the above copyright
   13  *    notice, this list of conditions and the following disclaimer.
   14  * 2. Redistributions in binary form must reproduce the above copyright
   15  *    notice, this list of conditions and the following disclaimer in the
   16  *    documentation and/or other materials provided with the distribution.
   17  * 3. All advertising materials mentioning features or use of this software
   18  *    must display the following acknowledgement:
   19  *      This product includes software developed by the University of
   20  *      California, Berkeley and its contributors.
   21  * 4. Neither the name of the University nor the names of its contributors
   22  *    may be used to endorse or promote products derived from this software
   23  *    without specific prior written permission.
   24  *
   25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   35  * SUCH DAMAGE.
   36  *
   37  *      from: @(#)trap.c        7.4 (Berkeley) 5/13/91
   38  */
   39 
   40 #include <sys/cdefs.h>
   41 __FBSDID("$FreeBSD: releng/9.1/sys/i386/i386/trap.c 236238 2012-05-29 14:50:21Z fabient $");
   42 
   43 /*
   44  * 386 Trap and System call handling
   45  */
   46 
   47 #include "opt_clock.h"
   48 #include "opt_cpu.h"
   49 #include "opt_hwpmc_hooks.h"
   50 #include "opt_isa.h"
   51 #include "opt_kdb.h"
   52 #include "opt_kdtrace.h"
   53 #include "opt_npx.h"
   54 #include "opt_trap.h"
   55 
   56 #include <sys/param.h>
   57 #include <sys/bus.h>
   58 #include <sys/systm.h>
   59 #include <sys/proc.h>
   60 #include <sys/pioctl.h>
   61 #include <sys/ptrace.h>
   62 #include <sys/kdb.h>
   63 #include <sys/kernel.h>
   64 #include <sys/ktr.h>
   65 #include <sys/lock.h>
   66 #include <sys/mutex.h>
   67 #include <sys/resourcevar.h>
   68 #include <sys/signalvar.h>
   69 #include <sys/syscall.h>
   70 #include <sys/sysctl.h>
   71 #include <sys/sysent.h>
   72 #include <sys/uio.h>
   73 #include <sys/vmmeter.h>
   74 #ifdef HWPMC_HOOKS
   75 #include <sys/pmckern.h>
   76 PMC_SOFT_DEFINE( , , page_fault, all);
   77 PMC_SOFT_DEFINE( , , page_fault, read);
   78 PMC_SOFT_DEFINE( , , page_fault, write);
   79 #endif
   80 #include <security/audit/audit.h>
   81 
   82 #include <vm/vm.h>
   83 #include <vm/vm_param.h>
   84 #include <vm/pmap.h>
   85 #include <vm/vm_kern.h>
   86 #include <vm/vm_map.h>
   87 #include <vm/vm_page.h>
   88 #include <vm/vm_extern.h>
   89 
   90 #include <machine/cpu.h>
   91 #include <machine/intr_machdep.h>
   92 #include <x86/mca.h>
   93 #include <machine/md_var.h>
   94 #include <machine/pcb.h>
   95 #ifdef SMP
   96 #include <machine/smp.h>
   97 #endif
   98 #include <machine/tss.h>
   99 #include <machine/vm86.h>
  100 
  101 #ifdef POWERFAIL_NMI
  102 #include <sys/syslog.h>
  103 #include <machine/clock.h>
  104 #endif
  105 
  106 #ifdef KDTRACE_HOOKS
  107 #include <sys/dtrace_bsd.h>
  108 
  109 /*
  110  * This is a hook which is initialised by the dtrace module
  111  * to handle traps which might occur during DTrace probe
  112  * execution.
  113  */
  114 dtrace_trap_func_t      dtrace_trap_func;
  115 
  116 dtrace_doubletrap_func_t        dtrace_doubletrap_func;
  117 
  118 /*
  119  * This is a hook which is initialised by the systrace module
  120  * when it is loaded. This keeps the DTrace syscall provider
  121  * implementation opaque. 
  122  */
  123 systrace_probe_func_t   systrace_probe_func;
  124 
  125 /*
  126  * These hooks are necessary for the pid, usdt and fasttrap providers.
  127  */
  128 dtrace_fasttrap_probe_ptr_t     dtrace_fasttrap_probe_ptr;
  129 dtrace_pid_probe_ptr_t          dtrace_pid_probe_ptr;
  130 dtrace_return_probe_ptr_t       dtrace_return_probe_ptr;
  131 #endif
  132 
  133 extern void trap(struct trapframe *frame);
  134 extern void syscall(struct trapframe *frame);
  135 
  136 static int trap_pfault(struct trapframe *, int, vm_offset_t);
  137 static void trap_fatal(struct trapframe *, vm_offset_t);
  138 void dblfault_handler(void);
  139 
  140 extern inthand_t IDTVEC(lcall_syscall);
  141 
  142 #define MAX_TRAP_MSG            33
  143 static char *trap_msg[] = {
  144         "",                                     /*  0 unused */
  145         "privileged instruction fault",         /*  1 T_PRIVINFLT */
  146         "",                                     /*  2 unused */
  147         "breakpoint instruction fault",         /*  3 T_BPTFLT */
  148         "",                                     /*  4 unused */
  149         "",                                     /*  5 unused */
  150         "arithmetic trap",                      /*  6 T_ARITHTRAP */
  151         "",                                     /*  7 unused */
  152         "",                                     /*  8 unused */
  153         "general protection fault",             /*  9 T_PROTFLT */
  154         "trace trap",                           /* 10 T_TRCTRAP */
  155         "",                                     /* 11 unused */
  156         "page fault",                           /* 12 T_PAGEFLT */
  157         "",                                     /* 13 unused */
  158         "alignment fault",                      /* 14 T_ALIGNFLT */
  159         "",                                     /* 15 unused */
  160         "",                                     /* 16 unused */
  161         "",                                     /* 17 unused */
  162         "integer divide fault",                 /* 18 T_DIVIDE */
  163         "non-maskable interrupt trap",          /* 19 T_NMI */
  164         "overflow trap",                        /* 20 T_OFLOW */
  165         "FPU bounds check fault",               /* 21 T_BOUND */
  166         "FPU device not available",             /* 22 T_DNA */
  167         "double fault",                         /* 23 T_DOUBLEFLT */
  168         "FPU operand fetch fault",              /* 24 T_FPOPFLT */
  169         "invalid TSS fault",                    /* 25 T_TSSFLT */
  170         "segment not present fault",            /* 26 T_SEGNPFLT */
  171         "stack fault",                          /* 27 T_STKFLT */
  172         "machine check trap",                   /* 28 T_MCHK */
  173         "SIMD floating-point exception",        /* 29 T_XMMFLT */
  174         "reserved (unknown) fault",             /* 30 T_RESERVED */
  175         "",                                     /* 31 unused (reserved) */
  176         "DTrace pid return trap",               /* 32 T_DTRACE_RET */
  177         "DTrace fasttrap probe trap",           /* 33 T_DTRACE_PROBE */
  178 
  179 };
  180 
  181 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
  182 extern int has_f00f_bug;
  183 #endif
  184 
  185 #ifdef KDB
  186 static int kdb_on_nmi = 1;
  187 SYSCTL_INT(_machdep, OID_AUTO, kdb_on_nmi, CTLFLAG_RW,
  188         &kdb_on_nmi, 0, "Go to KDB on NMI");
  189 TUNABLE_INT("machdep.kdb_on_nmi", &kdb_on_nmi);
  190 #endif
  191 static int panic_on_nmi = 1;
  192 SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
  193         &panic_on_nmi, 0, "Panic on NMI");
  194 TUNABLE_INT("machdep.panic_on_nmi", &panic_on_nmi);
  195 static int prot_fault_translation = 0;
  196 SYSCTL_INT(_machdep, OID_AUTO, prot_fault_translation, CTLFLAG_RW,
  197         &prot_fault_translation, 0, "Select signal to deliver on protection fault");
  198 
  199 /*
  200  * Exception, fault, and trap interface to the FreeBSD kernel.
  201  * This common code is called from assembly language IDT gate entry
  202  * routines that prepare a suitable stack frame, and restore this
  203  * frame after the exception has been processed.
  204  */
  205 
  206 void
  207 trap(struct trapframe *frame)
  208 {
  209         struct thread *td = curthread;
  210         struct proc *p = td->td_proc;
  211         int i = 0, ucode = 0, code;
  212         u_int type;
  213         register_t addr = 0;
  214         vm_offset_t eva;
  215         ksiginfo_t ksi;
  216 #ifdef POWERFAIL_NMI
  217         static int lastalert = 0;
  218 #endif
  219 
  220         PCPU_INC(cnt.v_trap);
  221         type = frame->tf_trapno;
  222 
  223 #ifdef SMP
  224         /* Handler for NMI IPIs used for stopping CPUs. */
  225         if (type == T_NMI) {
  226                  if (ipi_nmi_handler() == 0)
  227                            goto out;
  228         }
  229 #endif /* SMP */
  230 
  231 #ifdef KDB
  232         if (kdb_active) {
  233                 kdb_reenter();
  234                 goto out;
  235         }
  236 #endif
  237 
  238         if (type == T_RESERVED) {
  239                 trap_fatal(frame, 0);
  240                 goto out;
  241         }
  242 
  243 #ifdef  HWPMC_HOOKS
  244         /*
  245          * CPU PMCs interrupt using an NMI so we check for that first.
  246          * If the HWPMC module is active, 'pmc_hook' will point to
  247          * the function to be called.  A return value of '1' from the
  248          * hook means that the NMI was handled by it and that we can
  249          * return immediately.
  250          */
  251         if (type == T_NMI && pmc_intr &&
  252             (*pmc_intr)(PCPU_GET(cpuid), frame))
  253             goto out;
  254 #endif
  255 
  256         if (type == T_MCHK) {
  257                 mca_intr();
  258                 goto out;
  259         }
  260 
  261 #ifdef KDTRACE_HOOKS
  262         /*
  263          * A trap can occur while DTrace executes a probe. Before
  264          * executing the probe, DTrace blocks re-scheduling and sets
  265          * a flag in it's per-cpu flags to indicate that it doesn't
  266          * want to fault. On returning from the probe, the no-fault
  267          * flag is cleared and finally re-scheduling is enabled.
  268          *
  269          * If the DTrace kernel module has registered a trap handler,
  270          * call it and if it returns non-zero, assume that it has
  271          * handled the trap and modified the trap frame so that this
  272          * function can return normally.
  273          */
  274         if (type == T_DTRACE_PROBE || type == T_DTRACE_RET ||
  275             type == T_BPTFLT) {
  276                 struct reg regs;
  277 
  278                 fill_frame_regs(frame, &regs);
  279                 if (type == T_DTRACE_PROBE &&
  280                     dtrace_fasttrap_probe_ptr != NULL &&
  281                     dtrace_fasttrap_probe_ptr(&regs) == 0)
  282                         goto out;
  283                 if (type == T_BPTFLT &&
  284                     dtrace_pid_probe_ptr != NULL &&
  285                     dtrace_pid_probe_ptr(&regs) == 0)
  286                         goto out;
  287                 if (type == T_DTRACE_RET &&
  288                     dtrace_return_probe_ptr != NULL &&
  289                     dtrace_return_probe_ptr(&regs) == 0)
  290                         goto out;
  291         }
  292         if ((type == T_PROTFLT || type == T_PAGEFLT) &&
  293             dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type))
  294                 goto out;
  295 #endif
  296 
  297         if ((frame->tf_eflags & PSL_I) == 0) {
  298                 /*
  299                  * Buggy application or kernel code has disabled
  300                  * interrupts and then trapped.  Enabling interrupts
  301                  * now is wrong, but it is better than running with
  302                  * interrupts disabled until they are accidentally
  303                  * enabled later.
  304                  */
  305                 if (ISPL(frame->tf_cs) == SEL_UPL || (frame->tf_eflags & PSL_VM))
  306                         uprintf(
  307                             "pid %ld (%s): trap %d with interrupts disabled\n",
  308                             (long)curproc->p_pid, curthread->td_name, type);
  309                 else if (type != T_BPTFLT && type != T_TRCTRAP &&
  310                          frame->tf_eip != (int)cpu_switch_load_gs) {
  311                         /*
  312                          * XXX not quite right, since this may be for a
  313                          * multiple fault in user mode.
  314                          */
  315                         printf("kernel trap %d with interrupts disabled\n",
  316                             type);
  317                         /*
  318                          * Page faults need interrupts disabled until later,
  319                          * and we shouldn't enable interrupts while holding
  320                          * a spin lock or if servicing an NMI.
  321                          */
  322                         if (type != T_NMI && type != T_PAGEFLT &&
  323                             td->td_md.md_spinlock_count == 0)
  324                                 enable_intr();
  325                 }
  326         }
  327         eva = 0;
  328         code = frame->tf_err;
  329         if (type == T_PAGEFLT) {
  330                 /*
  331                  * For some Cyrix CPUs, %cr2 is clobbered by
  332                  * interrupts.  This problem is worked around by using
  333                  * an interrupt gate for the pagefault handler.  We
  334                  * are finally ready to read %cr2 and conditionally
  335                  * reenable interrupts.  If we hold a spin lock, then
  336                  * we must not reenable interrupts.  This might be a
  337                  * spurious page fault.
  338                  */
  339                 eva = rcr2();
  340                 if (td->td_md.md_spinlock_count == 0)
  341                         enable_intr();
  342         }
  343 
  344         if ((ISPL(frame->tf_cs) == SEL_UPL) ||
  345             ((frame->tf_eflags & PSL_VM) && 
  346                 !(PCPU_GET(curpcb)->pcb_flags & PCB_VM86CALL))) {
  347                 /* user trap */
  348 
  349                 td->td_pticks = 0;
  350                 td->td_frame = frame;
  351                 addr = frame->tf_eip;
  352                 if (td->td_ucred != p->p_ucred) 
  353                         cred_update_thread(td);
  354 
  355                 switch (type) {
  356                 case T_PRIVINFLT:       /* privileged instruction fault */
  357                         i = SIGILL;
  358                         ucode = ILL_PRVOPC;
  359                         break;
  360 
  361                 case T_BPTFLT:          /* bpt instruction fault */
  362                 case T_TRCTRAP:         /* trace trap */
  363                         enable_intr();
  364                         frame->tf_eflags &= ~PSL_T;
  365                         i = SIGTRAP;
  366                         ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT);
  367                         break;
  368 
  369                 case T_ARITHTRAP:       /* arithmetic trap */
  370 #ifdef DEV_NPX
  371                         ucode = npxtrap();
  372                         if (ucode == -1)
  373                                 goto userout;
  374 #else
  375                         ucode = 0;
  376 #endif
  377                         i = SIGFPE;
  378                         break;
  379 
  380                         /*
  381                          * The following two traps can happen in
  382                          * vm86 mode, and, if so, we want to handle
  383                          * them specially.
  384                          */
  385                 case T_PROTFLT:         /* general protection fault */
  386                 case T_STKFLT:          /* stack fault */
  387                         if (frame->tf_eflags & PSL_VM) {
  388                                 i = vm86_emulate((struct vm86frame *)frame);
  389                                 if (i == 0)
  390                                         goto user;
  391                                 break;
  392                         }
  393                         i = SIGBUS;
  394                         ucode = (type == T_PROTFLT) ? BUS_OBJERR : BUS_ADRERR;
  395                         break;
  396                 case T_SEGNPFLT:        /* segment not present fault */
  397                         i = SIGBUS;
  398                         ucode = BUS_ADRERR;
  399                         break;
  400                 case T_TSSFLT:          /* invalid TSS fault */
  401                         i = SIGBUS;
  402                         ucode = BUS_OBJERR;
  403                         break;
  404                 case T_DOUBLEFLT:       /* double fault */
  405                 default:
  406                         i = SIGBUS;
  407                         ucode = BUS_OBJERR;
  408                         break;
  409 
  410                 case T_PAGEFLT:         /* page fault */
  411 
  412                         i = trap_pfault(frame, TRUE, eva);
  413 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
  414                         if (i == -2) {
  415                                 /*
  416                                  * The f00f hack workaround has triggered, so
  417                                  * treat the fault as an illegal instruction 
  418                                  * (T_PRIVINFLT) instead of a page fault.
  419                                  */
  420                                 type = frame->tf_trapno = T_PRIVINFLT;
  421 
  422                                 /* Proceed as in that case. */
  423                                 ucode = ILL_PRVOPC;
  424                                 i = SIGILL;
  425                                 break;
  426                         }
  427 #endif
  428                         if (i == -1)
  429                                 goto userout;
  430                         if (i == 0)
  431                                 goto user;
  432 
  433                         if (i == SIGSEGV)
  434                                 ucode = SEGV_MAPERR;
  435                         else {
  436                                 if (prot_fault_translation == 0) {
  437                                         /*
  438                                          * Autodetect.
  439                                          * This check also covers the images
  440                                          * without the ABI-tag ELF note.
  441                                          */
  442                                         if (SV_CURPROC_ABI() == SV_ABI_FREEBSD
  443                                             && p->p_osrel >= P_OSREL_SIGSEGV) {
  444                                                 i = SIGSEGV;
  445                                                 ucode = SEGV_ACCERR;
  446                                         } else {
  447                                                 i = SIGBUS;
  448                                                 ucode = BUS_PAGE_FAULT;
  449                                         }
  450                                 } else if (prot_fault_translation == 1) {
  451                                         /*
  452                                          * Always compat mode.
  453                                          */
  454                                         i = SIGBUS;
  455                                         ucode = BUS_PAGE_FAULT;
  456                                 } else {
  457                                         /*
  458                                          * Always SIGSEGV mode.
  459                                          */
  460                                         i = SIGSEGV;
  461                                         ucode = SEGV_ACCERR;
  462                                 }
  463                         }
  464                         addr = eva;
  465                         break;
  466 
  467                 case T_DIVIDE:          /* integer divide fault */
  468                         ucode = FPE_INTDIV;
  469                         i = SIGFPE;
  470                         break;
  471 
  472 #ifdef DEV_ISA
  473                 case T_NMI:
  474 #ifdef POWERFAIL_NMI
  475 #ifndef TIMER_FREQ
  476 #  define TIMER_FREQ 1193182
  477 #endif
  478                         if (time_second - lastalert > 10) {
  479                                 log(LOG_WARNING, "NMI: power fail\n");
  480                                 sysbeep(880, hz);
  481                                 lastalert = time_second;
  482                         }
  483                         goto userout;
  484 #else /* !POWERFAIL_NMI */
  485                         /* machine/parity/power fail/"kitchen sink" faults */
  486                         if (isa_nmi(code) == 0) {
  487 #ifdef KDB
  488                                 /*
  489                                  * NMI can be hooked up to a pushbutton
  490                                  * for debugging.
  491                                  */
  492                                 if (kdb_on_nmi) {
  493                                         printf ("NMI ... going to debugger\n");
  494                                         kdb_trap(type, 0, frame);
  495                                 }
  496 #endif /* KDB */
  497                                 goto userout;
  498                         } else if (panic_on_nmi)
  499                                 panic("NMI indicates hardware failure");
  500                         break;
  501 #endif /* POWERFAIL_NMI */
  502 #endif /* DEV_ISA */
  503 
  504                 case T_OFLOW:           /* integer overflow fault */
  505                         ucode = FPE_INTOVF;
  506                         i = SIGFPE;
  507                         break;
  508 
  509                 case T_BOUND:           /* bounds check fault */
  510                         ucode = FPE_FLTSUB;
  511                         i = SIGFPE;
  512                         break;
  513 
  514                 case T_DNA:
  515 #ifdef DEV_NPX
  516                         KASSERT(PCB_USER_FPU(td->td_pcb),
  517                             ("kernel FPU ctx has leaked"));
  518                         /* transparent fault (due to context switch "late") */
  519                         if (npxdna())
  520                                 goto userout;
  521 #endif
  522                         uprintf("pid %d killed due to lack of floating point\n",
  523                                 p->p_pid);
  524                         i = SIGKILL;
  525                         ucode = 0;
  526                         break;
  527 
  528                 case T_FPOPFLT:         /* FPU operand fetch fault */
  529                         ucode = ILL_COPROC;
  530                         i = SIGILL;
  531                         break;
  532 
  533                 case T_XMMFLT:          /* SIMD floating-point exception */
  534                         ucode = 0; /* XXX */
  535                         i = SIGFPE;
  536                         break;
  537                 }
  538         } else {
  539                 /* kernel trap */
  540 
  541                 KASSERT(cold || td->td_ucred != NULL,
  542                     ("kernel trap doesn't have ucred"));
  543                 switch (type) {
  544                 case T_PAGEFLT:                 /* page fault */
  545                         (void) trap_pfault(frame, FALSE, eva);
  546                         goto out;
  547 
  548                 case T_DNA:
  549 #ifdef DEV_NPX
  550                         KASSERT(!PCB_USER_FPU(td->td_pcb),
  551                             ("Unregistered use of FPU in kernel"));
  552                         if (npxdna())
  553                                 goto out;
  554 #endif
  555                         break;
  556 
  557                 case T_ARITHTRAP:       /* arithmetic trap */
  558                 case T_XMMFLT:          /* SIMD floating-point exception */
  559                 case T_FPOPFLT:         /* FPU operand fetch fault */
  560                         /*
  561                          * XXXKIB for now disable any FPU traps in kernel
  562                          * handler registration seems to be overkill
  563                          */
  564                         trap_fatal(frame, 0);
  565                         goto out;
  566 
  567                         /*
  568                          * The following two traps can happen in
  569                          * vm86 mode, and, if so, we want to handle
  570                          * them specially.
  571                          */
  572                 case T_PROTFLT:         /* general protection fault */
  573                 case T_STKFLT:          /* stack fault */
  574                         if (frame->tf_eflags & PSL_VM) {
  575                                 i = vm86_emulate((struct vm86frame *)frame);
  576                                 if (i != 0)
  577                                         /*
  578                                          * returns to original process
  579                                          */
  580                                         vm86_trap((struct vm86frame *)frame);
  581                                 goto out;
  582                         }
  583                         if (type == T_STKFLT)
  584                                 break;
  585 
  586                         /* FALL THROUGH */
  587 
  588                 case T_SEGNPFLT:        /* segment not present fault */
  589                         if (PCPU_GET(curpcb)->pcb_flags & PCB_VM86CALL)
  590                                 break;
  591 
  592                         /*
  593                          * Invalid %fs's and %gs's can be created using
  594                          * procfs or PT_SETREGS or by invalidating the
  595                          * underlying LDT entry.  This causes a fault
  596                          * in kernel mode when the kernel attempts to
  597                          * switch contexts.  Lose the bad context
  598                          * (XXX) so that we can continue, and generate
  599                          * a signal.
  600                          */
  601                         if (frame->tf_eip == (int)cpu_switch_load_gs) {
  602                                 PCPU_GET(curpcb)->pcb_gs = 0;
  603 #if 0                           
  604                                 PROC_LOCK(p);
  605                                 kern_psignal(p, SIGBUS);
  606                                 PROC_UNLOCK(p);
  607 #endif                          
  608                                 goto out;
  609                         }
  610 
  611                         if (td->td_intr_nesting_level != 0)
  612                                 break;
  613 
  614                         /*
  615                          * Invalid segment selectors and out of bounds
  616                          * %eip's and %esp's can be set up in user mode.
  617                          * This causes a fault in kernel mode when the
  618                          * kernel tries to return to user mode.  We want
  619                          * to get this fault so that we can fix the
  620                          * problem here and not have to check all the
  621                          * selectors and pointers when the user changes
  622                          * them.
  623                          */
  624                         if (frame->tf_eip == (int)doreti_iret) {
  625                                 frame->tf_eip = (int)doreti_iret_fault;
  626                                 goto out;
  627                         }
  628                         if (frame->tf_eip == (int)doreti_popl_ds) {
  629                                 frame->tf_eip = (int)doreti_popl_ds_fault;
  630                                 goto out;
  631                         }
  632                         if (frame->tf_eip == (int)doreti_popl_es) {
  633                                 frame->tf_eip = (int)doreti_popl_es_fault;
  634                                 goto out;
  635                         }
  636                         if (frame->tf_eip == (int)doreti_popl_fs) {
  637                                 frame->tf_eip = (int)doreti_popl_fs_fault;
  638                                 goto out;
  639                         }
  640                         if (PCPU_GET(curpcb)->pcb_onfault != NULL) {
  641                                 frame->tf_eip =
  642                                     (int)PCPU_GET(curpcb)->pcb_onfault;
  643                                 goto out;
  644                         }
  645                         break;
  646 
  647                 case T_TSSFLT:
  648                         /*
  649                          * PSL_NT can be set in user mode and isn't cleared
  650                          * automatically when the kernel is entered.  This
  651                          * causes a TSS fault when the kernel attempts to
  652                          * `iret' because the TSS link is uninitialized.  We
  653                          * want to get this fault so that we can fix the
  654                          * problem here and not every time the kernel is
  655                          * entered.
  656                          */
  657                         if (frame->tf_eflags & PSL_NT) {
  658                                 frame->tf_eflags &= ~PSL_NT;
  659                                 goto out;
  660                         }
  661                         break;
  662 
  663                 case T_TRCTRAP:  /* trace trap */
  664                         if (frame->tf_eip == (int)IDTVEC(lcall_syscall)) {
  665                                 /*
  666                                  * We've just entered system mode via the
  667                                  * syscall lcall.  Continue single stepping
  668                                  * silently until the syscall handler has
  669                                  * saved the flags.
  670                                  */
  671                                 goto out;
  672                         }
  673                         if (frame->tf_eip == (int)IDTVEC(lcall_syscall) + 1) {
  674                                 /*
  675                                  * The syscall handler has now saved the
  676                                  * flags.  Stop single stepping it.
  677                                  */
  678                                 frame->tf_eflags &= ~PSL_T;
  679                                 goto out;
  680                         }
  681                         /*
  682                          * Ignore debug register trace traps due to
  683                          * accesses in the user's address space, which
  684                          * can happen under several conditions such as
  685                          * if a user sets a watchpoint on a buffer and
  686                          * then passes that buffer to a system call.
  687                          * We still want to get TRCTRAPS for addresses
  688                          * in kernel space because that is useful when
  689                          * debugging the kernel.
  690                          */
  691                         if (user_dbreg_trap() && 
  692                            !(PCPU_GET(curpcb)->pcb_flags & PCB_VM86CALL)) {
  693                                 /*
  694                                  * Reset breakpoint bits because the
  695                                  * processor doesn't
  696                                  */
  697                                 load_dr6(rdr6() & 0xfffffff0);
  698                                 goto out;
  699                         }
  700                         /*
  701                          * FALLTHROUGH (TRCTRAP kernel mode, kernel address)
  702                          */
  703                 case T_BPTFLT:
  704                         /*
  705                          * If KDB is enabled, let it handle the debugger trap.
  706                          * Otherwise, debugger traps "can't happen".
  707                          */
  708 #ifdef KDB
  709                         if (kdb_trap(type, 0, frame))
  710                                 goto out;
  711 #endif
  712                         break;
  713 
  714 #ifdef DEV_ISA
  715                 case T_NMI:
  716 #ifdef POWERFAIL_NMI
  717                         if (time_second - lastalert > 10) {
  718                                 log(LOG_WARNING, "NMI: power fail\n");
  719                                 sysbeep(880, hz);
  720                                 lastalert = time_second;
  721                         }
  722                         goto out;
  723 #else /* !POWERFAIL_NMI */
  724                         /* machine/parity/power fail/"kitchen sink" faults */
  725                         if (isa_nmi(code) == 0) {
  726 #ifdef KDB
  727                                 /*
  728                                  * NMI can be hooked up to a pushbutton
  729                                  * for debugging.
  730                                  */
  731                                 if (kdb_on_nmi) {
  732                                         printf ("NMI ... going to debugger\n");
  733                                         kdb_trap(type, 0, frame);
  734                                 }
  735 #endif /* KDB */
  736                                 goto out;
  737                         } else if (panic_on_nmi == 0)
  738                                 goto out;
  739                         /* FALLTHROUGH */
  740 #endif /* POWERFAIL_NMI */
  741 #endif /* DEV_ISA */
  742                 }
  743 
  744                 trap_fatal(frame, eva);
  745                 goto out;
  746         }
  747 
  748         /* Translate fault for emulators (e.g. Linux) */
  749         if (*p->p_sysent->sv_transtrap)
  750                 i = (*p->p_sysent->sv_transtrap)(i, type);
  751 
  752         ksiginfo_init_trap(&ksi);
  753         ksi.ksi_signo = i;
  754         ksi.ksi_code = ucode;
  755         ksi.ksi_addr = (void *)addr;
  756         ksi.ksi_trapno = type;
  757         trapsignal(td, &ksi);
  758 
  759 #ifdef DEBUG
  760         if (type <= MAX_TRAP_MSG) {
  761                 uprintf("fatal process exception: %s",
  762                         trap_msg[type]);
  763                 if ((type == T_PAGEFLT) || (type == T_PROTFLT))
  764                         uprintf(", fault VA = 0x%lx", (u_long)eva);
  765                 uprintf("\n");
  766         }
  767 #endif
  768 
  769 user:
  770         userret(td, frame);
  771         mtx_assert(&Giant, MA_NOTOWNED);
  772         KASSERT(PCB_USER_FPU(td->td_pcb),
  773             ("Return from trap with kernel FPU ctx leaked"));
  774 userout:
  775 out:
  776         return;
  777 }
  778 
  779 static int
  780 trap_pfault(frame, usermode, eva)
  781         struct trapframe *frame;
  782         int usermode;
  783         vm_offset_t eva;
  784 {
  785         vm_offset_t va;
  786         struct vmspace *vm = NULL;
  787         vm_map_t map;
  788         int rv = 0;
  789         vm_prot_t ftype;
  790         struct thread *td = curthread;
  791         struct proc *p = td->td_proc;
  792 
  793         if (__predict_false((td->td_pflags & TDP_NOFAULTING) != 0)) {
  794                 /*
  795                  * Due to both processor errata and lazy TLB invalidation when
  796                  * access restrictions are removed from virtual pages, memory
  797                  * accesses that are allowed by the physical mapping layer may
  798                  * nonetheless cause one spurious page fault per virtual page. 
  799                  * When the thread is executing a "no faulting" section that
  800                  * is bracketed by vm_fault_{disable,enable}_pagefaults(),
  801                  * every page fault is treated as a spurious page fault,
  802                  * unless it accesses the same virtual address as the most
  803                  * recent page fault within the same "no faulting" section.
  804                  */
  805                 if (td->td_md.md_spurflt_addr != eva ||
  806                     (td->td_pflags & TDP_RESETSPUR) != 0) {
  807                         /*
  808                          * Do nothing to the TLB.  A stale TLB entry is
  809                          * flushed automatically by a page fault.
  810                          */
  811                         td->td_md.md_spurflt_addr = eva;
  812                         td->td_pflags &= ~TDP_RESETSPUR;
  813                         return (0);
  814                 }
  815         } else {
  816                 /*
  817                  * If we get a page fault while in a critical section, then
  818                  * it is most likely a fatal kernel page fault.  The kernel
  819                  * is already going to panic trying to get a sleep lock to
  820                  * do the VM lookup, so just consider it a fatal trap so the
  821                  * kernel can print out a useful trap message and even get
  822                  * to the debugger.
  823                  *
  824                  * If we get a page fault while holding a non-sleepable
  825                  * lock, then it is most likely a fatal kernel page fault.
  826                  * If WITNESS is enabled, then it's going to whine about
  827                  * bogus LORs with various VM locks, so just skip to the
  828                  * fatal trap handling directly.
  829                  */
  830                 if (td->td_critnest != 0 ||
  831                     WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL,
  832                     "Kernel page fault") != 0) {
  833                         trap_fatal(frame, eva);
  834                         return (-1);
  835                 }
  836         }
  837         va = trunc_page(eva);
  838         if (va >= KERNBASE) {
  839                 /*
  840                  * Don't allow user-mode faults in kernel address space.
  841                  * An exception:  if the faulting address is the invalid
  842                  * instruction entry in the IDT, then the Intel Pentium
  843                  * F00F bug workaround was triggered, and we need to
  844                  * treat it is as an illegal instruction, and not a page
  845                  * fault.
  846                  */
  847 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
  848                 if ((eva == (unsigned int)&idt[6]) && has_f00f_bug)
  849                         return -2;
  850 #endif
  851                 if (usermode)
  852                         goto nogo;
  853 
  854                 map = kernel_map;
  855         } else {
  856                 /*
  857                  * This is a fault on non-kernel virtual memory.
  858                  * vm is initialized above to NULL. If curproc is NULL
  859                  * or curproc->p_vmspace is NULL the fault is fatal.
  860                  */
  861                 if (p != NULL)
  862                         vm = p->p_vmspace;
  863 
  864                 if (vm == NULL)
  865                         goto nogo;
  866 
  867                 map = &vm->vm_map;
  868                 if (!usermode && (td->td_intr_nesting_level != 0 ||
  869                     PCPU_GET(curpcb)->pcb_onfault == NULL)) {
  870                         trap_fatal(frame, eva);
  871                         return (-1);
  872                 }
  873         }
  874 
  875         /*
  876          * PGEX_I is defined only if the execute disable bit capability is
  877          * supported and enabled.
  878          */
  879         if (frame->tf_err & PGEX_W)
  880                 ftype = VM_PROT_WRITE;
  881 #ifdef PAE
  882         else if ((frame->tf_err & PGEX_I) && pg_nx != 0)
  883                 ftype = VM_PROT_EXECUTE;
  884 #endif
  885         else
  886                 ftype = VM_PROT_READ;
  887 
  888         if (map != kernel_map) {
  889                 /*
  890                  * Keep swapout from messing with us during this
  891                  *      critical time.
  892                  */
  893                 PROC_LOCK(p);
  894                 ++p->p_lock;
  895                 PROC_UNLOCK(p);
  896 
  897                 /* Fault in the user page: */
  898                 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
  899 
  900                 PROC_LOCK(p);
  901                 --p->p_lock;
  902                 PROC_UNLOCK(p);
  903         } else {
  904                 /*
  905                  * Don't have to worry about process locking or stacks in the
  906                  * kernel.
  907                  */
  908                 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
  909         }
  910         if (rv == KERN_SUCCESS) {
  911 #ifdef HWPMC_HOOKS
  912                 if (ftype == VM_PROT_READ || ftype == VM_PROT_WRITE) {
  913                         PMC_SOFT_CALL_TF( , , page_fault, all, frame);
  914                         if (ftype == VM_PROT_READ)
  915                                 PMC_SOFT_CALL_TF( , , page_fault, read,
  916                                     frame);
  917                         else
  918                                 PMC_SOFT_CALL_TF( , , page_fault, write,
  919                                     frame);
  920                 }
  921 #endif
  922                 return (0);
  923         }
  924 nogo:
  925         if (!usermode) {
  926                 if (td->td_intr_nesting_level == 0 &&
  927                     PCPU_GET(curpcb)->pcb_onfault != NULL) {
  928                         frame->tf_eip = (int)PCPU_GET(curpcb)->pcb_onfault;
  929                         return (0);
  930                 }
  931                 trap_fatal(frame, eva);
  932                 return (-1);
  933         }
  934 
  935         return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
  936 }
  937 
  938 static void
  939 trap_fatal(frame, eva)
  940         struct trapframe *frame;
  941         vm_offset_t eva;
  942 {
  943         int code, ss, esp;
  944         u_int type;
  945         struct soft_segment_descriptor softseg;
  946         char *msg;
  947 
  948         code = frame->tf_err;
  949         type = frame->tf_trapno;
  950         sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg);
  951 
  952         if (type <= MAX_TRAP_MSG)
  953                 msg = trap_msg[type];
  954         else
  955                 msg = "UNKNOWN";
  956         printf("\n\nFatal trap %d: %s while in %s mode\n", type, msg,
  957             frame->tf_eflags & PSL_VM ? "vm86" :
  958             ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
  959 #ifdef SMP
  960         /* two separate prints in case of a trap on an unmapped page */
  961         printf("cpuid = %d; ", PCPU_GET(cpuid));
  962         printf("apic id = %02x\n", PCPU_GET(apic_id));
  963 #endif
  964         if (type == T_PAGEFLT) {
  965                 printf("fault virtual address   = 0x%x\n", eva);
  966                 printf("fault code              = %s %s, %s\n",
  967                         code & PGEX_U ? "user" : "supervisor",
  968                         code & PGEX_W ? "write" : "read",
  969                         code & PGEX_P ? "protection violation" : "page not present");
  970         }
  971         printf("instruction pointer     = 0x%x:0x%x\n",
  972                frame->tf_cs & 0xffff, frame->tf_eip);
  973         if ((ISPL(frame->tf_cs) == SEL_UPL) || (frame->tf_eflags & PSL_VM)) {
  974                 ss = frame->tf_ss & 0xffff;
  975                 esp = frame->tf_esp;
  976         } else {
  977                 ss = GSEL(GDATA_SEL, SEL_KPL);
  978                 esp = (int)&frame->tf_esp;
  979         }
  980         printf("stack pointer           = 0x%x:0x%x\n", ss, esp);
  981         printf("frame pointer           = 0x%x:0x%x\n", ss, frame->tf_ebp);
  982         printf("code segment            = base 0x%x, limit 0x%x, type 0x%x\n",
  983                softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type);
  984         printf("                        = DPL %d, pres %d, def32 %d, gran %d\n",
  985                softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_def32,
  986                softseg.ssd_gran);
  987         printf("processor eflags        = ");
  988         if (frame->tf_eflags & PSL_T)
  989                 printf("trace trap, ");
  990         if (frame->tf_eflags & PSL_I)
  991                 printf("interrupt enabled, ");
  992         if (frame->tf_eflags & PSL_NT)
  993                 printf("nested task, ");
  994         if (frame->tf_eflags & PSL_RF)
  995                 printf("resume, ");
  996         if (frame->tf_eflags & PSL_VM)
  997                 printf("vm86, ");
  998         printf("IOPL = %d\n", (frame->tf_eflags & PSL_IOPL) >> 12);
  999         printf("current process         = ");
 1000         if (curproc) {
 1001                 printf("%lu (%s)\n", (u_long)curproc->p_pid, curthread->td_name);
 1002         } else {
 1003                 printf("Idle\n");
 1004         }
 1005 
 1006 #ifdef KDB
 1007         if (debugger_on_panic || kdb_active) {
 1008                 frame->tf_err = eva;    /* smuggle fault address to ddb */
 1009                 if (kdb_trap(type, 0, frame)) {
 1010                         frame->tf_err = code;   /* restore error code */
 1011                         return;
 1012                 }
 1013                 frame->tf_err = code;           /* restore error code */
 1014         }
 1015 #endif
 1016         printf("trap number             = %d\n", type);
 1017         if (type <= MAX_TRAP_MSG)
 1018                 panic("%s", trap_msg[type]);
 1019         else
 1020                 panic("unknown/reserved trap");
 1021 }
 1022 
 1023 /*
 1024  * Double fault handler. Called when a fault occurs while writing
 1025  * a frame for a trap/exception onto the stack. This usually occurs
 1026  * when the stack overflows (such is the case with infinite recursion,
 1027  * for example).
 1028  *
 1029  * XXX Note that the current PTD gets replaced by IdlePTD when the
 1030  * task switch occurs. This means that the stack that was active at
 1031  * the time of the double fault is not available at <kstack> unless
 1032  * the machine was idle when the double fault occurred. The downside
 1033  * of this is that "trace <ebp>" in ddb won't work.
 1034  */
 1035 void
 1036 dblfault_handler()
 1037 {
 1038 #ifdef KDTRACE_HOOKS
 1039         if (dtrace_doubletrap_func != NULL)
 1040                 (*dtrace_doubletrap_func)();
 1041 #endif
 1042         printf("\nFatal double fault:\n");
 1043         printf("eip = 0x%x\n", PCPU_GET(common_tss.tss_eip));
 1044         printf("esp = 0x%x\n", PCPU_GET(common_tss.tss_esp));
 1045         printf("ebp = 0x%x\n", PCPU_GET(common_tss.tss_ebp));
 1046 #ifdef SMP
 1047         /* two separate prints in case of a trap on an unmapped page */
 1048         printf("cpuid = %d; ", PCPU_GET(cpuid));
 1049         printf("apic id = %02x\n", PCPU_GET(apic_id));
 1050 #endif
 1051         panic("double fault");
 1052 }
 1053 
 1054 int
 1055 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
 1056 {
 1057         struct proc *p;
 1058         struct trapframe *frame;
 1059         caddr_t params;
 1060         int error;
 1061 
 1062         p = td->td_proc;
 1063         frame = td->td_frame;
 1064 
 1065         params = (caddr_t)frame->tf_esp + sizeof(int);
 1066         sa->code = frame->tf_eax;
 1067 
 1068         /*
 1069          * Need to check if this is a 32 bit or 64 bit syscall.
 1070          */
 1071         if (sa->code == SYS_syscall) {
 1072                 /*
 1073                  * Code is first argument, followed by actual args.
 1074                  */
 1075                 sa->code = fuword(params);
 1076                 params += sizeof(int);
 1077         } else if (sa->code == SYS___syscall) {
 1078                 /*
 1079                  * Like syscall, but code is a quad, so as to maintain
 1080                  * quad alignment for the rest of the arguments.
 1081                  */
 1082                 sa->code = fuword(params);
 1083                 params += sizeof(quad_t);
 1084         }
 1085 
 1086         if (p->p_sysent->sv_mask)
 1087                 sa->code &= p->p_sysent->sv_mask;
 1088         if (sa->code >= p->p_sysent->sv_size)
 1089                 sa->callp = &p->p_sysent->sv_table[0];
 1090         else
 1091                 sa->callp = &p->p_sysent->sv_table[sa->code];
 1092         sa->narg = sa->callp->sy_narg;
 1093 
 1094         if (params != NULL && sa->narg != 0)
 1095                 error = copyin(params, (caddr_t)sa->args,
 1096                     (u_int)(sa->narg * sizeof(int)));
 1097         else
 1098                 error = 0;
 1099 
 1100         if (error == 0) {
 1101                 td->td_retval[0] = 0;
 1102                 td->td_retval[1] = frame->tf_edx;
 1103         }
 1104                 
 1105         return (error);
 1106 }
 1107 
 1108 #include "../../kern/subr_syscall.c"
 1109 
 1110 /*
 1111  * syscall - system call request C handler.  A system call is
 1112  * essentially treated as a trap by reusing the frame layout.
 1113  */
 1114 void
 1115 syscall(struct trapframe *frame)
 1116 {
 1117         struct thread *td;
 1118         struct syscall_args sa;
 1119         register_t orig_tf_eflags;
 1120         int error;
 1121         ksiginfo_t ksi;
 1122 
 1123 #ifdef DIAGNOSTIC
 1124         if (ISPL(frame->tf_cs) != SEL_UPL) {
 1125                 panic("syscall");
 1126                 /* NOT REACHED */
 1127         }
 1128 #endif
 1129         orig_tf_eflags = frame->tf_eflags;
 1130 
 1131         td = curthread;
 1132         td->td_frame = frame;
 1133 
 1134         error = syscallenter(td, &sa);
 1135 
 1136         /*
 1137          * Traced syscall.
 1138          */
 1139         if ((orig_tf_eflags & PSL_T) && !(orig_tf_eflags & PSL_VM)) {
 1140                 frame->tf_eflags &= ~PSL_T;
 1141                 ksiginfo_init_trap(&ksi);
 1142                 ksi.ksi_signo = SIGTRAP;
 1143                 ksi.ksi_code = TRAP_TRACE;
 1144                 ksi.ksi_addr = (void *)frame->tf_eip;
 1145                 trapsignal(td, &ksi);
 1146         }
 1147 
 1148         KASSERT(PCB_USER_FPU(td->td_pcb),
 1149             ("System call %s returning with kernel FPU ctx leaked",
 1150              syscallname(td->td_proc, sa.code)));
 1151         KASSERT(td->td_pcb->pcb_save == &td->td_pcb->pcb_user_save,
 1152             ("System call %s returning with mangled pcb_save",
 1153              syscallname(td->td_proc, sa.code)));
 1154 
 1155         syscallret(td, error, &sa);
 1156 }

Cache object: 56f841e2d5b4430eafde27731139db51


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.