/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright 2019 Joyent, Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include int syscalltrace = 0; #ifdef SYSCALLTRACE static kmutex_t systrace_lock; /* syscall tracing lock */ #endif /* SYSCALLTRACE */ static krwlock_t *lock_syscall(struct sysent *, uint_t); #ifdef _SYSCALL32_IMPL static struct sysent * lwp_getsysent(klwp_t *lwp) { if (lwp_getdatamodel(lwp) == DATAMODEL_NATIVE) return (sysent); return (sysent32); } #define LWP_GETSYSENT(lwp) (lwp_getsysent(lwp)) #else #define LWP_GETSYSENT(lwp) (sysent) #endif /* * Called to restore the lwp's register window just before * returning to user level (only if the registers have been * fetched or modified through /proc). */ /*ARGSUSED1*/ void xregrestore(klwp_t *lwp, int shared) { /* * If locals+ins were modified by /proc copy them out. * Also copy to the shared window, if necessary. */ if (lwp->lwp_pcb.pcb_xregstat == XREGMODIFIED) { struct machpcb *mpcb = lwptompcb(lwp); caddr_t sp = (caddr_t)lwptoregs(lwp)->r_sp; size_t rwinsize; caddr_t rwp; int is64; if (lwp_getdatamodel(lwp) == DATAMODEL_LP64) { rwinsize = sizeof (struct rwindow); rwp = sp + STACK_BIAS; is64 = 1; } else { rwinsize = sizeof (struct rwindow32); sp = (caddr_t)(uintptr_t)(caddr32_t)(uintptr_t)sp; rwp = sp; is64 = 0; } if (is64) (void) copyout_nowatch(&lwp->lwp_pcb.pcb_xregs, rwp, rwinsize); else { struct rwindow32 rwindow32; int watched; watched = watch_disable_addr(rwp, rwinsize, S_WRITE); rwindow_nto32(&lwp->lwp_pcb.pcb_xregs, &rwindow32); (void) copyout(&rwindow32, rwp, rwinsize); if (watched) watch_enable_addr(rwp, rwinsize, S_WRITE); } /* also copy to the user return window */ mpcb->mpcb_rsp[0] = sp; mpcb->mpcb_rsp[1] = NULL; bcopy(&lwp->lwp_pcb.pcb_xregs, &mpcb->mpcb_rwin[0], sizeof (lwp->lwp_pcb.pcb_xregs)); } lwp->lwp_pcb.pcb_xregstat = XREGNONE; } /* * Get the arguments to the current system call. * lwp->lwp_ap normally points to the out regs in the reg structure. * If the user is going to change the out registers and might want to * get the args (for /proc tracing), it must copy the args elsewhere * via save_syscall_args(). */ uint_t get_syscall_args(klwp_t *lwp, long *argp, int *nargsp) { kthread_t *t = lwptot(lwp); uint_t code = t->t_sysnum; long mask; long *ap; int nargs; if (lwptoproc(lwp)->p_model == DATAMODEL_ILP32) mask = (uint32_t)0xffffffffU; else mask = 0xffffffffffffffff; if (code != 0 && code < NSYSCALL) { nargs = LWP_GETSYSENT(lwp)[code].sy_narg; ASSERT(nargs <= MAXSYSARGS); *nargsp = nargs; ap = lwp->lwp_ap; while (nargs-- > 0) *argp++ = *ap++ & mask; } else { *nargsp = 0; } return (code); } #ifdef _SYSCALL32_IMPL /* * Get the arguments to the current 32-bit system call. */ uint_t get_syscall32_args(klwp_t *lwp, int *argp, int *nargsp) { long args[MAXSYSARGS]; uint_t i, code; code = get_syscall_args(lwp, args, nargsp); for (i = 0; i != *nargsp; i++) *argp++ = (int)args[i]; return (code); } #endif /* * Save the system call arguments in a safe place. * lwp->lwp_ap normally points to the out regs in the reg structure. * If the user is going to change the out registers, g1, or the stack, * and might want to get the args (for /proc tracing), it must copy * the args elsewhere via save_syscall_args(). * * This may be called from stop() even when we're not in a system call. * Since there's no easy way to tell, this must be safe (not panic). * If the copyins get data faults, return non-zero. */ int save_syscall_args() { kthread_t *t = curthread; klwp_t *lwp = ttolwp(t); struct regs *rp = lwptoregs(lwp); uint_t code = t->t_sysnum; uint_t nargs; int i; caddr_t ua; model_t datamodel; if (lwp->lwp_argsaved || code == 0) return (0); /* args already saved or not needed */ if (code >= NSYSCALL) { nargs = 0; /* illegal syscall */ } else { struct sysent *se = LWP_GETSYSENT(lwp); struct sysent *callp = se + code; nargs = callp->sy_narg; if (LOADABLE_SYSCALL(callp) && nargs == 0) { krwlock_t *module_lock; /* * Find out how many arguments the system * call uses. * * We have the property that loaded syscalls * never change the number of arguments they * use after they've been loaded once. This * allows us to stop for /proc tracing without * holding the module lock. * /proc is assured that sy_narg is valid. */ module_lock = lock_syscall(se, code); nargs = callp->sy_narg; rw_exit(module_lock); } } /* * Fetch the system call arguments. */ if (nargs == 0) goto out; ASSERT(nargs <= MAXSYSARGS); if ((datamodel = lwp_getdatamodel(lwp)) == DATAMODEL_ILP32) { if (rp->r_g1 == 0) { /* indirect syscall */ lwp->lwp_arg[0] = (uint32_t)rp->r_o1; lwp->lwp_arg[1] = (uint32_t)rp->r_o2; lwp->lwp_arg[2] = (uint32_t)rp->r_o3; lwp->lwp_arg[3] = (uint32_t)rp->r_o4; lwp->lwp_arg[4] = (uint32_t)rp->r_o5; if (nargs > 5) { ua = (caddr_t)(uintptr_t)(caddr32_t)(uintptr_t) (rp->r_sp + MINFRAME32); for (i = 5; i < nargs; i++) { uint32_t a; if (fuword32(ua, &a) != 0) return (-1); lwp->lwp_arg[i] = a; ua += sizeof (a); } } } else { lwp->lwp_arg[0] = (uint32_t)rp->r_o0; lwp->lwp_arg[1] = (uint32_t)rp->r_o1; lwp->lwp_arg[2] = (uint32_t)rp->r_o2; lwp->lwp_arg[3] = (uint32_t)rp->r_o3; lwp->lwp_arg[4] = (uint32_t)rp->r_o4; lwp->lwp_arg[5] = (uint32_t)rp->r_o5; if (nargs > 6) { ua = (caddr_t)(uintptr_t)(caddr32_t)(uintptr_t) (rp->r_sp + MINFRAME32); for (i = 6; i < nargs; i++) { uint32_t a; if (fuword32(ua, &a) != 0) return (-1); lwp->lwp_arg[i] = a; ua += sizeof (a); } } } } else { ASSERT(datamodel == DATAMODEL_LP64); lwp->lwp_arg[0] = rp->r_o0; lwp->lwp_arg[1] = rp->r_o1; lwp->lwp_arg[2] = rp->r_o2; lwp->lwp_arg[3] = rp->r_o3; lwp->lwp_arg[4] = rp->r_o4; lwp->lwp_arg[5] = rp->r_o5; if (nargs > 6) { ua = (caddr_t)rp->r_sp + MINFRAME + STACK_BIAS; for (i = 6; i < nargs; i++) { unsigned long a; if (fulword(ua, &a) != 0) return (-1); lwp->lwp_arg[i] = a; ua += sizeof (a); } } } out: lwp->lwp_ap = lwp->lwp_arg; lwp->lwp_argsaved = 1; t->t_post_sys = 1; /* so lwp_ap will be reset */ return (0); } void reset_syscall_args(void) { klwp_t *lwp = ttolwp(curthread); lwp->lwp_ap = (long *)&lwptoregs(lwp)->r_o0; lwp->lwp_argsaved = 0; } /* * nonexistent system call-- signal lwp (may want to handle it) * flag error if lwp won't see signal immediately * This works for old or new calling sequence. */ int64_t nosys(void) { tsignal(curthread, SIGSYS); return ((int64_t)set_errno(ENOSYS)); } int nosys32(void) { return (nosys()); } /* * Perform pre-system-call processing, including stopping for tracing, * auditing, microstate-accounting, etc. * * This routine is called only if the t_pre_sys flag is set. Any condition * requiring pre-syscall handling must set the t_pre_sys flag. If the * condition is persistent, this routine will repost t_pre_sys. */ int pre_syscall(int arg0) { unsigned int code; kthread_t *t = curthread; proc_t *p = ttoproc(t); klwp_t *lwp = ttolwp(t); struct regs *rp = lwptoregs(lwp); int repost; t->t_pre_sys = repost = 0; /* clear pre-syscall processing flag */ ASSERT(t->t_schedflag & TS_DONT_SWAP); syscall_mstate(LMS_USER, LMS_SYSTEM); /* * The syscall arguments in the out registers should be pointed to * by lwp_ap. If the args need to be copied so that the outs can * be changed without losing the ability to get the args for /proc, * they can be saved by save_syscall_args(), and lwp_ap will be * restored by post_syscall(). */ ASSERT(lwp->lwp_ap == (long *)&rp->r_o0); /* * Make sure the thread is holding the latest credentials for the * process. The credentials in the process right now apply to this * thread for the entire system call. */ if (t->t_cred != p->p_cred) { cred_t *oldcred = t->t_cred; /* * DTrace accesses t_cred in probe context. t_cred must * always be either NULL, or point to a valid, allocated cred * structure. */ t->t_cred = crgetcred(); crfree(oldcred); } /* * Undo special arrangements to single-step the lwp * so that a debugger will see valid register contents. * Also so that the pc is valid for syncfpu(). * Also so that a syscall like exec() can be stepped. */ if (lwp->lwp_pcb.pcb_step != STEP_NONE) { (void) prundostep(); repost = 1; } /* * Check for indirect system call in case we stop for tracing. * Don't allow multiple indirection. */ code = t->t_sysnum; if (code == 0 && arg0 != 0) { /* indirect syscall */ code = arg0; t->t_sysnum = arg0; } /* * From the proc(4) manual page: * When entry to a system call is being traced, the traced process * stops after having begun the call to the system but before the * system call arguments have been fetched from the process. * If proc changes the args we must refetch them after starting. */ if (PTOU(p)->u_systrap) { if (prismember(&PTOU(p)->u_entrymask, code)) { /* * Recheck stop condition, now that lock is held. */ mutex_enter(&p->p_lock); if (PTOU(p)->u_systrap && prismember(&PTOU(p)->u_entrymask, code)) { stop(PR_SYSENTRY, code); /* * Must refetch args since they were * possibly modified by /proc. Indicate * that the valid copy is in the * registers. */ lwp->lwp_argsaved = 0; lwp->lwp_ap = (long *)&rp->r_o0; } mutex_exit(&p->p_lock); } repost = 1; } if (lwp->lwp_sysabort) { /* * lwp_sysabort may have been set via /proc while the process * was stopped on PR_SYSENTRY. If so, abort the system call. * Override any error from the copyin() of the arguments. */ lwp->lwp_sysabort = 0; (void) set_errno(EINTR); /* sets post-sys processing */ t->t_pre_sys = 1; /* repost anyway */ return (1); /* don't do system call, return EINTR */ } /* begin auditing for this syscall */ if (audit_active == C2AUDIT_LOADED) { uint32_t auditing = au_zone_getstate(NULL); if (auditing & AU_AUDIT_MASK) { int error; if (error = audit_start(T_SYSCALL, code, auditing, \ 0, lwp)) { t->t_pre_sys = 1; /* repost anyway */ lwp->lwp_error = 0; /* for old drivers */ return (error); } repost = 1; } } #ifndef NPROBE /* Kernel probe */ if (tnf_tracing_active) { TNF_PROBE_1(syscall_start, "syscall thread", /* CSTYLED */, tnf_sysnum, sysnum, t->t_sysnum); t->t_post_sys = 1; /* make sure post_syscall runs */ repost = 1; } #endif /* NPROBE */ #ifdef SYSCALLTRACE if (syscalltrace) { int i; long *ap; char *cp; char *sysname; struct sysent *callp; if (code >= NSYSCALL) callp = &nosys_ent; /* nosys has no args */ else callp = LWP_GETSYSENT(lwp) + code; (void) save_syscall_args(); mutex_enter(&systrace_lock); printf("%d: ", p->p_pid); if (code >= NSYSCALL) printf("0x%x", code); else { sysname = mod_getsysname(code); printf("%s[0x%x]", sysname == NULL ? "NULL" : sysname, code); } cp = "("; for (i = 0, ap = lwp->lwp_ap; i < callp->sy_narg; i++, ap++) { printf("%s%lx", cp, *ap); cp = ", "; } if (i) printf(")"); printf(" %s id=0x%p\n", PTOU(p)->u_comm, curthread); mutex_exit(&systrace_lock); } #endif /* SYSCALLTRACE */ /* * If there was a continuing reason for pre-syscall processing, * set the t_pre_sys flag for the next system call. */ if (repost) t->t_pre_sys = 1; lwp->lwp_error = 0; /* for old drivers */ lwp->lwp_badpriv = PRIV_NONE; /* for privilege tracing */ return (0); } /* * Post-syscall processing. Perform abnormal system call completion * actions such as /proc tracing, profiling, signals, preemption, etc. * * This routine is called only if t_post_sys, t_sig_check, or t_astflag is set. * Any condition requiring pre-syscall handling must set one of these. * If the condition is persistent, this routine will repost t_post_sys. */ void post_syscall(long rval1, long rval2) { kthread_t *t = curthread; proc_t *p = curproc; klwp_t *lwp = ttolwp(t); struct regs *rp = lwptoregs(lwp); uint_t error; int code = t->t_sysnum; int repost = 0; int proc_stop = 0; /* non-zero if stopping for /proc */ int sigprof = 0; /* non-zero if sending SIGPROF */ t->t_post_sys = 0; error = lwp->lwp_errno; /* * Code can be zero if this is a new LWP returning after a forkall(), * other than the one which matches the one in the parent which called * forkall(). In these LWPs, skip most of post-syscall activity. */ if (code == 0) goto sig_check; /* put out audit record for this syscall */ if (AU_AUDITING()) { rval_t rval; /* fix audit_finish() someday */ /* XX64 -- truncation of 64-bit return values? */ rval.r_val1 = (int)rval1; rval.r_val2 = (int)rval2; audit_finish(T_SYSCALL, code, error, &rval); repost = 1; } if (curthread->t_pdmsg != NULL) { char *m = curthread->t_pdmsg; uprintf("%s", m); kmem_free(m, strlen(m) + 1); curthread->t_pdmsg = NULL; } /* * If we're going to stop for /proc tracing, set the flag and * save the arguments so that the return values don't smash them. */ if (PTOU(p)->u_systrap) { if (prismember(&PTOU(p)->u_exitmask, code)) { proc_stop = 1; (void) save_syscall_args(); } repost = 1; } /* * Similarly check to see if SIGPROF might be sent. */ if (curthread->t_rprof != NULL && curthread->t_rprof->rp_anystate != 0) { (void) save_syscall_args(); sigprof = 1; } if (lwp->lwp_eosys == NORMALRETURN) { if (error == 0) { #ifdef SYSCALLTRACE if (syscalltrace) { mutex_enter(&systrace_lock); printf( "%d: r_val1=0x%lx, r_val2=0x%lx, id 0x%p\n", p->p_pid, rval1, rval2, curthread); mutex_exit(&systrace_lock); } #endif /* SYSCALLTRACE */ rp->r_tstate &= ~TSTATE_IC; rp->r_o0 = rval1; rp->r_o1 = rval2; } else { int sig; #ifdef SYSCALLTRACE if (syscalltrace) { mutex_enter(&systrace_lock); printf("%d: error=%d, id 0x%p\n", p->p_pid, error, curthread); mutex_exit(&systrace_lock); } #endif /* SYSCALLTRACE */ if (error == EINTR && t->t_activefd.a_stale) error = EBADF; if (error == EINTR && (sig = lwp->lwp_cursig) != 0 && sigismember(&PTOU(p)->u_sigrestart, sig) && PTOU(p)->u_signal[sig - 1] != SIG_DFL && PTOU(p)->u_signal[sig - 1] != SIG_IGN) error = ERESTART; rp->r_o0 = error; rp->r_tstate |= TSTATE_IC; } /* * The default action is to redo the trap instruction. * We increment the pc and npc past it for NORMALRETURN. * JUSTRETURN has set up a new pc and npc already. * If we are a cloned thread of forkall(), don't * adjust here because we have already inherited * the adjusted values from our clone. */ if (!(t->t_flag & T_FORKALL)) { rp->r_pc = rp->r_npc; rp->r_npc += 4; } } /* * From the proc(4) manual page: * When exit from a system call is being traced, the traced process * stops on completion of the system call just prior to checking for * signals and returning to user level. At this point all return * values have been stored into the traced process's saved registers. */ if (proc_stop) { mutex_enter(&p->p_lock); if (PTOU(p)->u_systrap && prismember(&PTOU(p)->u_exitmask, code)) stop(PR_SYSEXIT, code); mutex_exit(&p->p_lock); } /* * If we are the parent returning from a successful * vfork, wait for the child to exec or exit. * This code must be here and not in the bowels of the system * so that /proc can intercept exit from vfork in a timely way. */ if (t->t_flag & T_VFPARENT) { ASSERT(code == SYS_vfork || code == SYS_forksys); ASSERT(rp->r_o1 == 0 && error == 0); vfwait((pid_t)rval1); t->t_flag &= ~T_VFPARENT; } /* * If profiling is active, bill the current PC in user-land * and keep reposting until profiling is disabled. */ if (p->p_prof.pr_scale) { if (lwp->lwp_oweupc) profil_tick(rp->r_pc); repost = 1; } sig_check: /* * Reset flag for next time. * We must do this after stopping on PR_SYSEXIT * because /proc uses the information in lwp_eosys. */ lwp->lwp_eosys = NORMALRETURN; clear_stale_fd(); t->t_flag &= ~T_FORKALL; if (t->t_astflag | t->t_sig_check) { /* * Turn off the AST flag before checking all the conditions that * may have caused an AST. This flag is on whenever a signal or * unusual condition should be handled after the next trap or * syscall. */ astoff(t); t->t_sig_check = 0; /* * The following check is legal for the following reasons: * 1) The thread we are checking, is ourselves, so there is * no way the proc can go away. * 2) The only time we need to be protected by the * lock is if the binding is changed. * * Note we will still take the lock and check the binding * if the condition was true without the lock held. This * prevents lock contention among threads owned by the * same proc. */ if (curthread->t_proc_flag & TP_CHANGEBIND) { mutex_enter(&p->p_lock); if (curthread->t_proc_flag & TP_CHANGEBIND) { timer_lwpbind(); curthread->t_proc_flag &= ~TP_CHANGEBIND; } mutex_exit(&p->p_lock); } /* * for kaio requests on the special kaio poll queue, * copyout their results to user memory. */ if (p->p_aio) aio_cleanup(0); /* * If this LWP was asked to hold, call holdlwp(), which will * stop. holdlwps() sets this up and calls pokelwps() which * sets the AST flag. * * Also check TP_EXITLWP, since this is used by fresh new LWPs * through lwp_rtt(). That flag is set if the lwp_create(2) * syscall failed after creating the LWP. */ if (ISHOLD(p) || (t->t_proc_flag & TP_EXITLWP)) holdlwp(); /* * All code that sets signals and makes ISSIG_PENDING * evaluate true must set t_sig_check afterwards. */ if (ISSIG_PENDING(t, lwp, p)) { if (issig(FORREAL)) psig(); t->t_sig_check = 1; /* recheck next time */ } if (sigprof) { int nargs = (code > 0 && code < NSYSCALL)? LWP_GETSYSENT(lwp)[code].sy_narg : 0; realsigprof(code, nargs, error); t->t_sig_check = 1; /* recheck next time */ } /* * If a performance counter overflow interrupt was * delivered *during* the syscall, then re-enable the * AST so that we take a trip through trap() to cause * the SIGEMT to be delivered. */ if (lwp->lwp_pcb.pcb_flags & CPC_OVERFLOW) aston(t); /* * If an asynchronous hardware error is pending, turn AST flag * back on. AST will be checked again before we return to user * mode and we'll come back through trap() to handle the error. */ if (lwp->lwp_pcb.pcb_flags & ASYNC_HWERR) aston(t); } /* * Restore register window if a debugger modified it. * Set up to perform a single-step if a debugger requested it. */ if (lwp->lwp_pcb.pcb_xregstat != XREGNONE) xregrestore(lwp, 1); lwp->lwp_errno = 0; /* clear error for next time */ #ifndef NPROBE /* Kernel probe */ if (tnf_tracing_active) { TNF_PROBE_3(syscall_end, "syscall thread", /* CSTYLED */, tnf_long, rval1, rval1, tnf_long, rval2, rval2, tnf_long, errno, (long)error); repost = 1; } #endif /* NPROBE */ /* * Set state to LWP_USER here so preempt won't give us a kernel * priority if it occurs after this point. Call CL_TRAPRET() to * restore the user-level priority. * * It is important that no locks (other than spinlocks) be entered * after this point before returning to user mode (unless lwp_state * is set back to LWP_SYS). * * Sampled times past this point are charged to the user. */ lwp->lwp_state = LWP_USER; if (t->t_trapret) { t->t_trapret = 0; thread_lock(t); CL_TRAPRET(t); thread_unlock(t); } if (CPU->cpu_runrun || t->t_schedflag & TS_ANYWAITQ) preempt(); prunstop(); /* * t_post_sys will be set if pcb_step is active. */ if (lwp->lwp_pcb.pcb_step != STEP_NONE) { prdostep(); repost = 1; } t->t_sysnum = 0; /* no longer in a system call */ /* * In case the args were copied to the lwp, reset the * pointer so the next syscall will have the right lwp_ap pointer. */ lwp->lwp_ap = (long *)&rp->r_o0; lwp->lwp_argsaved = 0; /* * If there was a continuing reason for post-syscall processing, * set the t_post_sys flag for the next system call. */ if (repost) t->t_post_sys = 1; /* * If there is a ustack registered for this lwp, and the stack rlimit * has been altered, read in the ustack. If the saved stack rlimit * matches the bounds of the ustack, update the ustack to reflect * the new rlimit. If the new stack rlimit is RLIM_INFINITY, disable * stack checking by setting the size to 0. */ if (lwp->lwp_ustack != 0 && lwp->lwp_old_stk_ctl != 0) { rlim64_t new_size; model_t model; caddr_t top; struct rlimit64 rl; mutex_enter(&p->p_lock); new_size = p->p_stk_ctl; model = p->p_model; top = p->p_usrstack; (void) rctl_rlimit_get(rctlproc_legacy[RLIMIT_STACK], p, &rl); mutex_exit(&p->p_lock); if (rl.rlim_cur == RLIM64_INFINITY) new_size = 0; if (model == DATAMODEL_NATIVE) { stack_t stk; if (copyin((stack_t *)lwp->lwp_ustack, &stk, sizeof (stack_t)) == 0 && (stk.ss_size == lwp->lwp_old_stk_ctl || stk.ss_size == 0) && stk.ss_sp == top - stk.ss_size) { stk.ss_sp = (void *)((uintptr_t)stk.ss_sp + stk.ss_size - new_size); stk.ss_size = new_size; (void) copyout(&stk, (stack_t *)lwp->lwp_ustack, sizeof (stack_t)); } } else { stack32_t stk32; if (copyin((stack32_t *)lwp->lwp_ustack, &stk32, sizeof (stack32_t)) == 0 && (stk32.ss_size == lwp->lwp_old_stk_ctl || stk32.ss_size == 0) && stk32.ss_sp == (caddr32_t)(uintptr_t)(top - stk32.ss_size)) { stk32.ss_sp += stk32.ss_size - new_size; stk32.ss_size = new_size; (void) copyout(&stk32, (stack32_t *)lwp->lwp_ustack, sizeof (stack32_t)); } } lwp->lwp_old_stk_ctl = 0; } syscall_mstate(LMS_SYSTEM, LMS_USER); } /* * Call a system call which takes a pointer to the user args struct and * a pointer to the return values. This is a bit slower than the standard * C arg-passing method in some cases. */ int64_t syscall_ap() { uint_t error; struct sysent *callp; rval_t rval; klwp_t *lwp = ttolwp(curthread); struct regs *rp = lwptoregs(lwp); callp = LWP_GETSYSENT(lwp) + curthread->t_sysnum; /* * If the arguments don't fit in registers %o0 - o5, make sure they * have been copied to the lwp_arg array. */ if (callp->sy_narg > 6 && save_syscall_args()) return ((int64_t)set_errno(EFAULT)); rval.r_val1 = 0; rval.r_val2 = (int)rp->r_o1; lwp->lwp_error = 0; /* for old drivers */ error = (*(callp->sy_call))(lwp->lwp_ap, &rval); if (error) return ((int64_t)set_errno(error)); return (rval.r_vals); } /* * Load system call module. * Returns with pointer to held read lock for module. */ static krwlock_t * lock_syscall(struct sysent *table, uint_t code) { krwlock_t *module_lock; struct modctl *modp; int id; struct sysent *callp; module_lock = table[code].sy_lock; callp = &table[code]; /* * Optimization to only call modload if we don't have a loaded * syscall. */ rw_enter(module_lock, RW_READER); if (LOADED_SYSCALL(callp)) return (module_lock); rw_exit(module_lock); for (;;) { if ((id = modload("sys", syscallnames[code])) == -1) break; /* * If we loaded successfully at least once, the modctl * will still be valid, so we try to grab it by filename. * If this call fails, it's because the mod_filename * was changed after the call to modload() (mod_hold_by_name() * is the likely culprit). We can safely just take * another lap if this is the case; the modload() will * change the mod_filename back to one by which we can * find the modctl. */ modp = mod_find_by_filename("sys", syscallnames[code]); if (modp == NULL) continue; mutex_enter(&mod_lock); if (!modp->mod_installed) { mutex_exit(&mod_lock); continue; } break; } rw_enter(module_lock, RW_READER); if (id != -1) mutex_exit(&mod_lock); return (module_lock); } /* * Loadable syscall support. * If needed, load the module, then reserve it by holding a read * lock for the duration of the call. * Later, if the syscall is not unloadable, it could patch the vector. */ /*ARGSUSED*/ int64_t loadable_syscall( long a0, long a1, long a2, long a3, long a4, long a5, long a6, long a7) { int64_t rval; struct sysent *callp; struct sysent *se = LWP_GETSYSENT(ttolwp(curthread)); krwlock_t *module_lock; int code; code = curthread->t_sysnum; callp = se + code; /* * Try to autoload the system call if necessary. */ module_lock = lock_syscall(se, code); /* * we've locked either the loaded syscall or nosys */ if (callp->sy_flags & SE_ARGC) { int64_t (*sy_call)(); sy_call = (int64_t (*)())callp->sy_call; rval = (*sy_call)(a0, a1, a2, a3, a4, a5); } else { rval = syscall_ap(); } rw_exit(module_lock); return (rval); } /* * Handle indirect system calls. * This interface should be deprecated. The library can handle * this more efficiently, but keep this implementation for old binaries. * * XX64 Needs some work. */ int64_t indir(int code, long a0, long a1, long a2, long a3, long a4) { klwp_t *lwp = ttolwp(curthread); struct sysent *callp; if (code <= 0 || code >= NSYSCALL) return (nosys()); ASSERT(lwp->lwp_ap != NULL); curthread->t_sysnum = code; callp = LWP_GETSYSENT(lwp) + code; /* * Handle argument setup, unless already done in pre_syscall(). */ if (callp->sy_narg > 5) { if (save_syscall_args()) /* move args to LWP array */ return ((int64_t)set_errno(EFAULT)); } else if (!lwp->lwp_argsaved) { long *ap; ap = lwp->lwp_ap; /* args haven't been saved */ lwp->lwp_ap = ap + 1; /* advance arg pointer */ curthread->t_post_sys = 1; /* so lwp_ap will be reset */ } return ((*callp->sy_callc)(a0, a1, a2, a3, a4, lwp->lwp_arg[5])); } /* * set_errno - set an error return from the current system call. * This could be a macro. * This returns the value it is passed, so that the caller can * use tail-recursion-elimination and do return (set_errno(ERRNO)); */ uint_t set_errno(uint_t error) { ASSERT(error != 0); /* must not be used to clear errno */ curthread->t_post_sys = 1; /* have post_syscall do error return */ return (ttolwp(curthread)->lwp_errno = error); } /* * set_proc_pre_sys - Set pre-syscall processing for entire process. */ void set_proc_pre_sys(proc_t *p) { kthread_t *t; kthread_t *first; ASSERT(MUTEX_HELD(&p->p_lock)); t = first = p->p_tlist; do { t->t_pre_sys = 1; } while ((t = t->t_forw) != first); } /* * set_proc_post_sys - Set post-syscall processing for entire process. */ void set_proc_post_sys(proc_t *p) { kthread_t *t; kthread_t *first; ASSERT(MUTEX_HELD(&p->p_lock)); t = first = p->p_tlist; do { t->t_post_sys = 1; } while ((t = t->t_forw) != first); } /* * set_proc_sys - Set pre- and post-syscall processing for entire process. */ void set_proc_sys(proc_t *p) { kthread_t *t; kthread_t *first; ASSERT(MUTEX_HELD(&p->p_lock)); t = first = p->p_tlist; do { t->t_pre_sys = 1; t->t_post_sys = 1; } while ((t = t->t_forw) != first); } /* * set_all_proc_sys - set pre- and post-syscall processing flags for all * user processes. * * This is needed when auditing, tracing, or other facilities which affect * all processes are turned on. */ void set_all_proc_sys() { kthread_t *t; kthread_t *first; mutex_enter(&pidlock); t = first = curthread; do { t->t_pre_sys = 1; t->t_post_sys = 1; } while ((t = t->t_next) != first); mutex_exit(&pidlock); } /* * set_all_zone_usr_proc_sys - set pre- and post-syscall processing flags for * all user processes running in the zone of the current process * * This is needed when auditing is turned on. */ void set_all_zone_usr_proc_sys(zoneid_t zoneid) { proc_t *p; kthread_t *t; mutex_enter(&pidlock); for (p = practive; p != NULL; p = p->p_next) { /* skip kernel processes */ if (p->p_exec == NULLVP || p->p_as == &kas || p->p_stat == SIDL || p->p_stat == SZOMB || (p->p_flag & (SSYS | SEXITING | SEXITLWPS))) continue; /* * Only processes in the given zone (eventually in * all zones) are taken into account */ if (zoneid == ALL_ZONES || p->p_zone->zone_id == zoneid) { mutex_enter(&p->p_lock); if ((t = p->p_tlist) == NULL) { mutex_exit(&p->p_lock); continue; } /* * Set pre- and post-syscall processing flags * for all threads of the process */ do { t->t_pre_sys = 1; t->t_post_sys = 1; } while (p->p_tlist != (t = t->t_forw)); mutex_exit(&p->p_lock); } } mutex_exit(&pidlock); } /* * set_proc_ast - Set asynchronous service trap (AST) flag for all * threads in process. */ void set_proc_ast(proc_t *p) { kthread_t *t; kthread_t *first; ASSERT(MUTEX_HELD(&p->p_lock)); t = first = p->p_tlist; do { aston(t); } while ((t = t->t_forw) != first); }