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/kern/subr_trap.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
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  * Copyright (c) 2007 The FreeBSD Foundation
    6  *
    7  * This code is derived from software contributed to Berkeley by
    8  * the University of Utah, and William Jolitz.
    9  *
   10  * Portions of this software were developed by A. Joseph Koshy under
   11  * sponsorship from the FreeBSD Foundation and Google, Inc.
   12  *
   13  * Redistribution and use in source and binary forms, with or without
   14  * modification, are permitted provided that the following conditions
   15  * are met:
   16  * 1. Redistributions of source code must retain the above copyright
   17  *    notice, this list of conditions and the following disclaimer.
   18  * 2. Redistributions in binary form must reproduce the above copyright
   19  *    notice, this list of conditions and the following disclaimer in the
   20  *    documentation and/or other materials provided with the distribution.
   21  * 3. All advertising materials mentioning features or use of this software
   22  *    must display the following acknowledgement:
   23  *      This product includes software developed by the University of
   24  *      California, Berkeley and its contributors.
   25  * 4. Neither the name of the University nor the names of its contributors
   26  *    may be used to endorse or promote products derived from this software
   27  *    without specific prior written permission.
   28  *
   29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   39  * SUCH DAMAGE.
   40  *
   41  *      from: @(#)trap.c        7.4 (Berkeley) 5/13/91
   42  */
   43 
   44 #include <sys/cdefs.h>
   45 __FBSDID("$FreeBSD: releng/10.2/sys/kern/subr_trap.c 284665 2015-06-21 06:28:26Z trasz $");
   46 
   47 #include "opt_hwpmc_hooks.h"
   48 #include "opt_ktrace.h"
   49 #include "opt_kdtrace.h"
   50 #include "opt_sched.h"
   51 
   52 #include <sys/param.h>
   53 #include <sys/bus.h>
   54 #include <sys/capsicum.h>
   55 #include <sys/kernel.h>
   56 #include <sys/lock.h>
   57 #include <sys/mutex.h>
   58 #include <sys/pmckern.h>
   59 #include <sys/proc.h>
   60 #include <sys/ktr.h>
   61 #include <sys/pioctl.h>
   62 #include <sys/ptrace.h>
   63 #include <sys/racct.h>
   64 #include <sys/resourcevar.h>
   65 #include <sys/sched.h>
   66 #include <sys/signalvar.h>
   67 #include <sys/syscall.h>
   68 #include <sys/syscallsubr.h>
   69 #include <sys/sysent.h>
   70 #include <sys/systm.h>
   71 #include <sys/vmmeter.h>
   72 #ifdef KTRACE
   73 #include <sys/uio.h>
   74 #include <sys/ktrace.h>
   75 #endif
   76 #include <security/audit/audit.h>
   77 
   78 #include <machine/cpu.h>
   79 
   80 #ifdef VIMAGE
   81 #include <net/vnet.h>
   82 #endif
   83 
   84 #ifdef XEN
   85 #include <vm/vm.h>
   86 #include <vm/vm_param.h>
   87 #include <vm/pmap.h>
   88 #endif
   89 
   90 #ifdef  HWPMC_HOOKS
   91 #include <sys/pmckern.h>
   92 #endif
   93 
   94 #include <security/mac/mac_framework.h>
   95 
   96 void (*softdep_ast_cleanup)(void);
   97 
   98 /*
   99  * Define the code needed before returning to user mode, for trap and
  100  * syscall.
  101  */
  102 void
  103 userret(struct thread *td, struct trapframe *frame)
  104 {
  105         struct proc *p = td->td_proc;
  106 
  107         CTR3(KTR_SYSC, "userret: thread %p (pid %d, %s)", td, p->p_pid,
  108             td->td_name);
  109         KASSERT((p->p_flag & P_WEXIT) == 0,
  110             ("Exiting process returns to usermode"));
  111 #if 0
  112 #ifdef DIAGNOSTIC
  113         /* Check that we called signotify() enough. */
  114         PROC_LOCK(p);
  115         thread_lock(td);
  116         if (SIGPENDING(td) && ((td->td_flags & TDF_NEEDSIGCHK) == 0 ||
  117             (td->td_flags & TDF_ASTPENDING) == 0))
  118                 printf("failed to set signal flags properly for ast()\n");
  119         thread_unlock(td);
  120         PROC_UNLOCK(p);
  121 #endif
  122 #endif
  123 #ifdef KTRACE
  124         KTRUSERRET(td);
  125 #endif
  126         if (softdep_ast_cleanup != NULL)
  127                 softdep_ast_cleanup();
  128 
  129         /*
  130          * If this thread tickled GEOM, we need to wait for the giggling to
  131          * stop before we return to userland
  132          */
  133         if (td->td_pflags & TDP_GEOM)
  134                 g_waitidle();
  135 
  136         /*
  137          * Charge system time if profiling.
  138          */
  139         if (p->p_flag & P_PROFIL)
  140                 addupc_task(td, TRAPF_PC(frame), td->td_pticks * psratio);
  141         /*
  142          * Let the scheduler adjust our priority etc.
  143          */
  144         sched_userret(td);
  145 #ifdef XEN
  146         PT_UPDATES_FLUSH();
  147 #endif
  148 
  149         /*
  150          * Check for misbehavior.
  151          *
  152          * In case there is a callchain tracing ongoing because of
  153          * hwpmc(4), skip the scheduler pinning check.
  154          * hwpmc(4) subsystem, infact, will collect callchain informations
  155          * at ast() checkpoint, which is past userret().
  156          */
  157         WITNESS_WARN(WARN_PANIC, NULL, "userret: returning");
  158         KASSERT(td->td_critnest == 0,
  159             ("userret: Returning in a critical section"));
  160         KASSERT(td->td_locks == 0,
  161             ("userret: Returning with %d locks held", td->td_locks));
  162         KASSERT((td->td_pflags & TDP_NOFAULTING) == 0,
  163             ("userret: Returning with pagefaults disabled"));
  164         KASSERT(td->td_no_sleeping == 0,
  165             ("userret: Returning with sleep disabled"));
  166         KASSERT(td->td_pinned == 0 || (td->td_pflags & TDP_CALLCHAIN) != 0,
  167             ("userret: Returning with with pinned thread"));
  168         KASSERT(td->td_vp_reserv == 0,
  169             ("userret: Returning while holding vnode reservation"));
  170         KASSERT((td->td_flags & TDF_SBDRY) == 0,
  171             ("userret: Returning with stop signals deferred"));
  172         KASSERT(td->td_su == NULL,
  173             ("userret: Returning with SU cleanup request not handled"));
  174 #ifdef VIMAGE
  175         /* Unfortunately td_vnet_lpush needs VNET_DEBUG. */
  176         VNET_ASSERT(curvnet == NULL,
  177             ("%s: Returning on td %p (pid %d, %s) with vnet %p set in %s",
  178             __func__, td, p->p_pid, td->td_name, curvnet,
  179             (td->td_vnet_lpush != NULL) ? td->td_vnet_lpush : "N/A"));
  180 #endif
  181 #ifdef RACCT
  182         if (racct_enable) {
  183                 PROC_LOCK(p);
  184                 while (p->p_throttled == 1)
  185                         msleep(p->p_racct, &p->p_mtx, 0, "racct", 0);
  186                 PROC_UNLOCK(p);
  187         }
  188 #endif
  189 }
  190 
  191 /*
  192  * Process an asynchronous software trap.
  193  * This is relatively easy.
  194  * This function will return with preemption disabled.
  195  */
  196 void
  197 ast(struct trapframe *framep)
  198 {
  199         struct thread *td;
  200         struct proc *p;
  201         int flags;
  202         int sig;
  203 
  204         td = curthread;
  205         p = td->td_proc;
  206 
  207         CTR3(KTR_SYSC, "ast: thread %p (pid %d, %s)", td, p->p_pid,
  208             p->p_comm);
  209         KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode"));
  210         WITNESS_WARN(WARN_PANIC, NULL, "Returning to user mode");
  211         mtx_assert(&Giant, MA_NOTOWNED);
  212         THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
  213         td->td_frame = framep;
  214         td->td_pticks = 0;
  215 
  216         /*
  217          * This updates the td_flag's for the checks below in one
  218          * "atomic" operation with turning off the astpending flag.
  219          * If another AST is triggered while we are handling the
  220          * AST's saved in flags, the astpending flag will be set and
  221          * ast() will be called again.
  222          */
  223         thread_lock(td);
  224         flags = td->td_flags;
  225         td->td_flags &= ~(TDF_ASTPENDING | TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK |
  226             TDF_NEEDRESCHED | TDF_ALRMPEND | TDF_PROFPEND | TDF_MACPEND);
  227         thread_unlock(td);
  228         PCPU_INC(cnt.v_trap);
  229 
  230         if (td->td_ucred != p->p_ucred) 
  231                 cred_update_thread(td);
  232         if (td->td_pflags & TDP_OWEUPC && p->p_flag & P_PROFIL) {
  233                 addupc_task(td, td->td_profil_addr, td->td_profil_ticks);
  234                 td->td_profil_ticks = 0;
  235                 td->td_pflags &= ~TDP_OWEUPC;
  236         }
  237 #ifdef HWPMC_HOOKS
  238         /* Handle Software PMC callchain capture. */
  239         if (PMC_IS_PENDING_CALLCHAIN(td))
  240                 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_USER_CALLCHAIN_SOFT, (void *) framep);
  241 #endif
  242         if (flags & TDF_ALRMPEND) {
  243                 PROC_LOCK(p);
  244                 kern_psignal(p, SIGVTALRM);
  245                 PROC_UNLOCK(p);
  246         }
  247         if (flags & TDF_PROFPEND) {
  248                 PROC_LOCK(p);
  249                 kern_psignal(p, SIGPROF);
  250                 PROC_UNLOCK(p);
  251         }
  252 #ifdef MAC
  253         if (flags & TDF_MACPEND)
  254                 mac_thread_userret(td);
  255 #endif
  256         if (flags & TDF_NEEDRESCHED) {
  257 #ifdef KTRACE
  258                 if (KTRPOINT(td, KTR_CSW))
  259                         ktrcsw(1, 1, __func__);
  260 #endif
  261                 thread_lock(td);
  262                 sched_prio(td, td->td_user_pri);
  263                 mi_switch(SW_INVOL | SWT_NEEDRESCHED, NULL);
  264                 thread_unlock(td);
  265 #ifdef KTRACE
  266                 if (KTRPOINT(td, KTR_CSW))
  267                         ktrcsw(0, 1, __func__);
  268 #endif
  269         }
  270 
  271         /*
  272          * Check for signals. Unlocked reads of p_pendingcnt or
  273          * p_siglist might cause process-directed signal to be handled
  274          * later.
  275          */
  276         if (flags & TDF_NEEDSIGCHK || p->p_pendingcnt > 0 ||
  277             !SIGISEMPTY(p->p_siglist)) {
  278                 PROC_LOCK(p);
  279                 mtx_lock(&p->p_sigacts->ps_mtx);
  280                 while ((sig = cursig(td)) != 0)
  281                         postsig(sig);
  282                 mtx_unlock(&p->p_sigacts->ps_mtx);
  283                 PROC_UNLOCK(p);
  284         }
  285         /*
  286          * We need to check to see if we have to exit or wait due to a
  287          * single threading requirement or some other STOP condition.
  288          */
  289         if (flags & TDF_NEEDSUSPCHK) {
  290                 PROC_LOCK(p);
  291                 thread_suspend_check(0);
  292                 PROC_UNLOCK(p);
  293         }
  294 
  295         if (td->td_pflags & TDP_OLDMASK) {
  296                 td->td_pflags &= ~TDP_OLDMASK;
  297                 kern_sigprocmask(td, SIG_SETMASK, &td->td_oldsigmask, NULL, 0);
  298         }
  299 
  300         userret(td, framep);
  301 }
  302 
  303 const char *
  304 syscallname(struct proc *p, u_int code)
  305 {
  306         static const char unknown[] = "unknown";
  307         struct sysentvec *sv;
  308 
  309         sv = p->p_sysent;
  310         if (sv->sv_syscallnames == NULL || code >= sv->sv_size)
  311                 return (unknown);
  312         return (sv->sv_syscallnames[code]);
  313 }

Cache object: c67e6db47d74db421b036e8230bf902c


[ 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.