/*- * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * 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. * * $FreeBSD: src/sys/i386/i386/exception.s,v 1.65.2.3 2001/08/15 01:23:49 peter Exp $ * $DragonFly: src/sys/platform/pc32/i386/exception.s,v 1.2 2003/06/17 04:28:35 dillon Exp $ */ #include "npx.h" #include #include #include #include #include #ifdef SMP #include /** various SMP options */ #endif #include "assym.s" #ifdef SMP #define MOVL_KPSEL_EAX movl $KPSEL,%eax #else #define MOVL_KPSEL_EAX #endif #define SEL_RPL_MASK 0x0003 .text /*****************************************************************************/ /* Trap handling */ /*****************************************************************************/ /* * Trap and fault vector routines. * * Most traps are 'trap gates', SDT_SYS386TGT. A trap gate pushes state on * the stack that mostly looks like an interrupt, but does not disable * interrupts. A few of the traps we are use are interrupt gates, * SDT_SYS386IGT, which are nearly the same thing except interrupts are * disabled on entry. * * The cpu will push a certain amount of state onto the kernel stack for * the current process. The amount of state depends on the type of trap * and whether the trap crossed rings or not. See i386/include/frame.h. * At the very least the current EFLAGS (status register, which includes * the interrupt disable state prior to the trap), the code segment register, * and the return instruction pointer are pushed by the cpu. The cpu * will also push an 'error' code for certain traps. We push a dummy * error code for those traps where the cpu doesn't in order to maintain * a consistent frame. We also push a contrived 'trap number'. * * The cpu does not push the general registers, we must do that, and we * must restore them prior to calling 'iret'. The cpu adjusts the %cs and * %ss segment registers, but does not mess with %ds, %es, or %fs. Thus we * must load them with appropriate values for supervisor mode operation. * * On entry to a trap or interrupt WE DO NOT OWN THE MP LOCK. This means * that we must be careful in regards to accessing global variables. We * save (push) the current cpl (our software interrupt disable mask), call * the trap function, then call _doreti to restore the cpl and deal with * ASTs (software interrupts). _doreti will determine if the restoration * of the cpl unmasked any pending interrupts and will issue those interrupts * synchronously prior to doing the iret. * * At the moment we must own the MP lock to do any cpl manipulation, which * means we must own it prior to calling _doreti. The syscall case attempts * to avoid this by handling a reduced set of cases itself and iret'ing. */ #define IDTVEC(name) ALIGN_TEXT; .globl __CONCAT(_X,name); \ .type __CONCAT(_X,name),@function; __CONCAT(_X,name): #define TRAP(a) pushl $(a) ; jmp _alltraps #ifdef BDE_DEBUGGER #define BDBTRAP(name) \ ss ; \ cmpb $0,_bdb_exists ; \ je 1f ; \ testb $SEL_RPL_MASK,4(%esp) ; \ jne 1f ; \ ss ; \ .globl __CONCAT(__CONCAT(bdb_,name),_ljmp); \ __CONCAT(__CONCAT(bdb_,name),_ljmp): \ ljmp $0,$0 ; \ 1: #else #define BDBTRAP(name) #endif #define BPTTRAP(a) testl $PSL_I,4+8(%esp) ; je 1f ; sti ; 1: ; TRAP(a) MCOUNT_LABEL(user) MCOUNT_LABEL(btrap) IDTVEC(div) pushl $0; TRAP(T_DIVIDE) IDTVEC(dbg) BDBTRAP(dbg) pushl $0; BPTTRAP(T_TRCTRAP) IDTVEC(nmi) pushl $0; TRAP(T_NMI) IDTVEC(bpt) BDBTRAP(bpt) pushl $0; BPTTRAP(T_BPTFLT) IDTVEC(ofl) pushl $0; TRAP(T_OFLOW) IDTVEC(bnd) pushl $0; TRAP(T_BOUND) IDTVEC(ill) pushl $0; TRAP(T_PRIVINFLT) IDTVEC(dna) pushl $0; TRAP(T_DNA) IDTVEC(fpusegm) pushl $0; TRAP(T_FPOPFLT) IDTVEC(tss) TRAP(T_TSSFLT) IDTVEC(missing) TRAP(T_SEGNPFLT) IDTVEC(stk) TRAP(T_STKFLT) IDTVEC(prot) TRAP(T_PROTFLT) IDTVEC(page) TRAP(T_PAGEFLT) IDTVEC(mchk) pushl $0; TRAP(T_MCHK) IDTVEC(rsvd) pushl $0; TRAP(T_RESERVED) IDTVEC(fpu) #if NNPX > 0 /* * Handle like an interrupt (except for accounting) so that we can * call npx_intr to clear the error. It would be better to handle * npx interrupts as traps. Nested interrupts would probably have * to be converted to ASTs. */ pushl $0 /* dummy error code */ pushl $0 /* dummy trap type */ pushal pushl %ds pushl %es /* now stack frame is a trap frame */ pushl %fs mov $KDSEL,%ax mov %ax,%ds mov %ax,%es MOVL_KPSEL_EAX mov %ax,%fs FAKE_MCOUNT(13*4(%esp)) #ifdef SMP MPLOCKED incl _cnt+V_TRAP MP_LOCK movl _cpl,%eax pushl %eax /* save original cpl */ pushl $0 /* dummy unit to finish intr frame */ #else /* SMP */ movl _cpl,%eax pushl %eax pushl $0 /* dummy unit to finish intr frame */ incl _cnt+V_TRAP #endif /* SMP */ call _npx_intr incb _intr_nesting_level MEXITCOUNT jmp _doreti #else /* NNPX > 0 */ pushl $0; TRAP(T_ARITHTRAP) #endif /* NNPX > 0 */ IDTVEC(align) TRAP(T_ALIGNFLT) IDTVEC(xmm) pushl $0; TRAP(T_XMMFLT) /* * _alltraps entry point. Interrupts are enabled if this was a trap * gate (TGT), else disabled if this was an interrupt gate (IGT). * Note that int0x80_syscall is a trap gate. Only page faults * use an interrupt gate. * * Note that all calls to MP_LOCK must occur with interrupts enabled * in order to be able to take IPI's while waiting for the lock. */ SUPERALIGN_TEXT .globl _alltraps .type _alltraps,@function _alltraps: pushal pushl %ds pushl %es pushl %fs alltraps_with_regs_pushed: mov $KDSEL,%ax mov %ax,%ds mov %ax,%es MOVL_KPSEL_EAX mov %ax,%fs FAKE_MCOUNT(13*4(%esp)) calltrap: FAKE_MCOUNT(_btrap) /* init "from" _btrap -> calltrap */ MPLOCKED incl _cnt+V_TRAP MP_LOCK movl _cpl,%ebx /* keep orig. cpl here during trap() */ call _trap /* * Return via _doreti to handle ASTs. Have to change trap frame * to interrupt frame. */ pushl %ebx /* cpl to restore */ subl $4,%esp /* dummy unit to finish intr frame */ incb _intr_nesting_level MEXITCOUNT jmp _doreti /* * SYSCALL CALL GATE (old entry point for a.out binaries) * * The intersegment call has been set up to specify one dummy parameter. * * This leaves a place to put eflags so that the call frame can be * converted to a trap frame. Note that the eflags is (semi-)bogusly * pushed into (what will be) tf_err and then copied later into the * final spot. It has to be done this way because esp can't be just * temporarily altered for the pushfl - an interrupt might come in * and clobber the saved cs/eip. * * We do not obtain the MP lock, but the call to syscall2 might. If it * does it will release the lock prior to returning. */ SUPERALIGN_TEXT IDTVEC(syscall) pushfl /* save eflags in tf_err for now */ subl $4,%esp /* skip over tf_trapno */ pushal pushl %ds pushl %es pushl %fs mov $KDSEL,%ax /* switch to kernel segments */ mov %ax,%ds mov %ax,%es MOVL_KPSEL_EAX mov %ax,%fs movl TF_ERR(%esp),%eax /* copy saved eflags to final spot */ movl %eax,TF_EFLAGS(%esp) movl $7,TF_ERR(%esp) /* sizeof "lcall 7,0" */ FAKE_MCOUNT(13*4(%esp)) MPLOCKED incl _cnt+V_SYSCALL call _syscall2 MEXITCOUNT cli /* atomic astpending access */ cmpl $0,_astpending je doreti_syscall_ret #ifdef SMP MP_LOCK #endif pushl $0 /* cpl to restore */ subl $4,%esp /* dummy unit for interrupt frame */ movb $1,_intr_nesting_level jmp _doreti /* * Call gate entry for FreeBSD ELF and Linux/NetBSD syscall (int 0x80) * * Even though the name says 'int0x80', this is actually a TGT (trap gate) * rather then an IGT (interrupt gate). Thus interrupts are enabled on * entry just as they are for a normal syscall. * * We do not obtain the MP lock, but the call to syscall2 might. If it * does it will release the lock prior to returning. */ SUPERALIGN_TEXT IDTVEC(int0x80_syscall) subl $8,%esp /* skip over tf_trapno and tf_err */ pushal pushl %ds pushl %es pushl %fs mov $KDSEL,%ax /* switch to kernel segments */ mov %ax,%ds mov %ax,%es MOVL_KPSEL_EAX mov %ax,%fs movl $2,TF_ERR(%esp) /* sizeof "int 0x80" */ FAKE_MCOUNT(13*4(%esp)) MPLOCKED incl _cnt+V_SYSCALL call _syscall2 MEXITCOUNT cli /* atomic astpending access */ cmpl $0,_astpending je doreti_syscall_ret #ifdef SMP MP_LOCK #endif pushl $0 /* cpl to restore */ subl $4,%esp /* dummy unit for interrupt frame */ movb $1,_intr_nesting_level jmp _doreti ENTRY(fork_trampoline) call _spl0 #ifdef SMP cmpl $0,_switchtime jne 1f movl $gd_switchtime,%eax addl %fs:0,%eax pushl %eax call _microuptime popl %edx movl _ticks,%eax movl %eax,_switchticks 1: #endif /* * cpu_set_fork_handler intercepts this function call to * have this call a non-return function to stay in kernel mode. * initproc has its own fork handler, but it does return. */ pushl %ebx /* arg1 */ call *%esi /* function */ addl $4,%esp /* cut from syscall */ /* * Return via _doreti to handle ASTs. */ pushl $0 /* cpl to restore */ subl $4,%esp /* dummy unit to finish intr frame */ movb $1,_intr_nesting_level MEXITCOUNT jmp _doreti /* * Include vm86 call routines, which want to call _doreti. */ #include "i386/i386/vm86bios.s" /* * Include what was once config+isa-dependent code. * XXX it should be in a stand-alone file. It's still icu-dependent and * belongs in i386/isa. */ #include "i386/isa/vector.s" /* * Include what was once icu-dependent code. * XXX it should be merged into this file (also move the definition of * imen to vector.s or isa.c). * Before including it, set up a normal asm environment so that vector.s * doesn't have to know that stuff is included after it. */ .data ALIGN_DATA .text SUPERALIGN_TEXT #include "i386/isa/ipl.s"