/*- * Copyright (C) 1994, David Greenman * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * the University of Utah, and William Jolitz. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); /* * 386 Trap and System call handling */ #include "opt_clock.h" #include "opt_cpu.h" #include "opt_isa.h" #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #include #include #include #include #include #include #include #include #include #define IDTVEC(name) __CONCAT(X,name) extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(rsvd); extern const char *freebsd32_syscallnames[]; void ia32_syscall(struct trapframe *frame); /* Called from asm code */ void ia32_syscall(struct trapframe *frame) { caddr_t params; int i; struct sysent *callp; struct thread *td = curthread; struct proc *p = td->td_proc; register_t orig_tf_rflags; int error; int narg; u_int32_t args[8]; u_int64_t args64[8]; u_int code; ksiginfo_t ksi; /* * note: PCPU_INC() can only be used if we can afford * occassional inaccuracy in the count. */ PCPU_INC(cnt.v_syscall); td->td_pticks = 0; td->td_frame = frame; if (td->td_ucred != p->p_ucred) cred_update_thread(td); params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t); code = frame->tf_rax; orig_tf_rflags = frame->tf_rflags; if (p->p_sysent->sv_prepsyscall) { /* * The prep code is MP aware. */ (*p->p_sysent->sv_prepsyscall)(frame, args, &code, ¶ms); } else { /* * Need to check if this is a 32 bit or 64 bit syscall. * fuword is MP aware. */ if (code == SYS_syscall) { /* * Code is first argument, followed by actual args. */ code = fuword32(params); params += sizeof(int); } else if (code == SYS___syscall) { /* * Like syscall, but code is a quad, so as to maintain * quad alignment for the rest of the arguments. * We use a 32-bit fetch in case params is not * aligned. */ code = fuword32(params); params += sizeof(quad_t); } } if (p->p_sysent->sv_mask) code &= p->p_sysent->sv_mask; if (code >= p->p_sysent->sv_size) callp = &p->p_sysent->sv_table[0]; else callp = &p->p_sysent->sv_table[code]; narg = callp->sy_narg; /* * copyin and the ktrsyscall()/ktrsysret() code is MP-aware */ if (params != NULL && narg != 0) error = copyin(params, (caddr_t)args, (u_int)(narg * sizeof(int))); else error = 0; for (i = 0; i < narg; i++) args64[i] = args[i]; #ifdef KTRACE if (KTRPOINT(td, KTR_SYSCALL)) ktrsyscall(code, narg, args64); #endif CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td, td->td_proc->p_pid, td->td_proc->p_comm, code); if (error == 0) { td->td_retval[0] = 0; td->td_retval[1] = frame->tf_rdx; STOPEVENT(p, S_SCE, narg); PTRACESTOP_SC(p, td, S_PT_SCE); AUDIT_SYSCALL_ENTER(code, td); error = (*callp->sy_call)(td, args64); AUDIT_SYSCALL_EXIT(error, td); } switch (error) { case 0: frame->tf_rax = td->td_retval[0]; frame->tf_rdx = td->td_retval[1]; frame->tf_rflags &= ~PSL_C; break; case ERESTART: /* * Reconstruct pc, assuming lcall $X,y is 7 bytes, * int 0x80 is 2 bytes. We saved this in tf_err. */ frame->tf_rip -= frame->tf_err; break; case EJUSTRETURN: break; default: if (p->p_sysent->sv_errsize) { if (error >= p->p_sysent->sv_errsize) error = -1; /* XXX */ else error = p->p_sysent->sv_errtbl[error]; } frame->tf_rax = error; frame->tf_rflags |= PSL_C; break; } /* * Traced syscall. */ if (orig_tf_rflags & PSL_T) { frame->tf_rflags &= ~PSL_T; ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGTRAP; ksi.ksi_code = TRAP_TRACE; ksi.ksi_addr = (void *)frame->tf_rip; trapsignal(td, &ksi); } /* * Check for misbehavior. */ WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning", (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???"); KASSERT(td->td_critnest == 0, ("System call %s returning in a critical section", (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???")); KASSERT(td->td_locks == 0, ("System call %s returning with %d locks held", (code >= 0 && code < SYS_MAXSYSCALL) ? freebsd32_syscallnames[code] : "???", td->td_locks)); /* * Handle reschedule and other end-of-syscall issues */ userret(td, frame); CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td, td->td_proc->p_pid, td->td_proc->p_comm, code); #ifdef KTRACE if (KTRPOINT(td, KTR_SYSRET)) ktrsysret(code, error, td->td_retval[0]); #endif /* * This works because errno is findable through the * register set. If we ever support an emulation where this * is not the case, this code will need to be revisited. */ STOPEVENT(p, S_SCX, code); PTRACESTOP_SC(p, td, S_PT_SCX); } static void ia32_syscall_enable(void *dummy) { setidt(IDT_SYSCALL, &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0); } static void ia32_syscall_disable(void *dummy) { setidt(IDT_SYSCALL, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0); } SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL); SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL);