Date: Fri, 20 Sep 2002 19:33:49 -0700 (PDT) From: Peter Wemm <peter@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 17806 for review Message-ID: <200209210233.g8L2Xnkf091881@freefall.freebsd.org>
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http://people.freebsd.org/~peter/p4db/chv.cgi?CH=17806 Change 17806 by peter@peter_daintree on 2002/09/20 19:33:42 remove vm86 process signal sending and receiving Affected files ... .. //depot/projects/hammer/sys/x86_64/include/psl.h#2 edit .. //depot/projects/hammer/sys/x86_64/x86_64/machdep.c#4 edit Differences ... ==== //depot/projects/hammer/sys/x86_64/include/psl.h#2 (text+ko) ==== @@ -55,10 +55,10 @@ #define PSL_IOPL 0x00003000 /* i/o privilege level */ #define PSL_NT 0x00004000 /* nested task bit */ #define PSL_RF 0x00010000 /* resume flag bit */ -#define PSL_VM 0x00020000 /* virtual 8086 mode bit */ +/* #define PSL_VM 0x00020000 */ /* virtual 8086 mode bit */ #define PSL_AC 0x00040000 /* alignment checking */ -#define PSL_VIF 0x00080000 /* virtual interrupt enable */ -#define PSL_VIP 0x00100000 /* virtual interrupt pending */ +/* #define PSL_VIF 0x00080000 */ /* virtual interrupt enable */ +/* #define PSL_VIP 0x00100000 */ /* virtual interrupt pending */ #define PSL_ID 0x00200000 /* identification bit */ /* ==== //depot/projects/hammer/sys/x86_64/x86_64/machdep.c#4 (text+ko) ==== @@ -348,35 +348,6 @@ PROC_UNLOCK(p); /* - * If we're a vm86 process, we want to save the segment registers. - * We also change eflags to be our emulated eflags, not the actual - * eflags. - */ - if (regs->tf_eflags & PSL_VM) { - struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs; - struct vm86_kernel *vm86 = &td->td_pcb->pcb_ext->ext_vm86; - - sf.sf_uc.uc_mcontext.mc_gs = tf->tf_vm86_gs; - sf.sf_uc.uc_mcontext.mc_fs = tf->tf_vm86_fs; - sf.sf_uc.uc_mcontext.mc_es = tf->tf_vm86_es; - sf.sf_uc.uc_mcontext.mc_ds = tf->tf_vm86_ds; - - if (vm86->vm86_has_vme == 0) - sf.sf_uc.uc_mcontext.mc_eflags = - (tf->tf_eflags & ~(PSL_VIF | PSL_VIP)) | - (vm86->vm86_eflags & (PSL_VIF | PSL_VIP)); - - /* - * Clear PSL_NT to inhibit T_TSSFLT faults on return from - * syscalls made by the signal handler. This just avoids - * wasting time for our lazy fixup of such faults. PSL_NT - * does nothing in vm86 mode, but vm86 programs can set it - * almost legitimately in probes for old cpu types. - */ - tf->tf_eflags &= ~(PSL_VM | PSL_NT | PSL_VIF | PSL_VIP); - } - - /* * Copy the sigframe out to the user's stack. */ if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { @@ -428,77 +399,40 @@ ucp = &uc; regs = td->td_frame; eflags = ucp->uc_mcontext.mc_eflags; - if (eflags & PSL_VM) { - struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs; - struct vm86_kernel *vm86; + /* + * Don't allow users to change privileged or reserved flags. + */ + /* + * XXX do allow users to change the privileged flag PSL_RF. + * The cpu sets PSL_RF in tf_eflags for faults. Debuggers + * should sometimes set it there too. tf_eflags is kept in + * the signal context during signal handling and there is no + * other place to remember it, so the PSL_RF bit may be + * corrupted by the signal handler without us knowing. + * Corruption of the PSL_RF bit at worst causes one more or + * one less debugger trap, so allowing it is fairly harmless. + */ + if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_eflags & ~PSL_RF)) { + printf("sigreturn: eflags = 0x%x\n", eflags); + return (EINVAL); + } - /* - * if pcb_ext == 0 or vm86_inited == 0, the user hasn't - * set up the vm86 area, and we can't enter vm86 mode. - */ - if (td->td_pcb->pcb_ext == 0) - return (EINVAL); - vm86 = &td->td_pcb->pcb_ext->ext_vm86; - if (vm86->vm86_inited == 0) - return (EINVAL); + /* + * Don't allow users to load a valid privileged %cs. Let the + * hardware check for invalid selectors, excess privilege in + * other selectors, invalid %eip's and invalid %esp's. + */ + cs = ucp->uc_mcontext.mc_cs; + if (!CS_SECURE(cs)) { + printf("sigreturn: cs = 0x%x\n", cs); + trapsignal(p, SIGBUS, T_PROTFLT); + return (EINVAL); + } - /* Go back to user mode if both flags are set. */ - if ((eflags & PSL_VIP) && (eflags & PSL_VIF)) - trapsignal(p, SIGBUS, 0); - - if (vm86->vm86_has_vme) { - eflags = (tf->tf_eflags & ~VME_USERCHANGE) | - (eflags & VME_USERCHANGE) | PSL_VM; - } else { - vm86->vm86_eflags = eflags; /* save VIF, VIP */ - eflags = (tf->tf_eflags & ~VM_USERCHANGE) | - (eflags & VM_USERCHANGE) | PSL_VM; - } - bcopy(&ucp->uc_mcontext.mc_fs, tf, sizeof(struct trapframe)); - tf->tf_eflags = eflags; - tf->tf_vm86_ds = tf->tf_ds; - tf->tf_vm86_es = tf->tf_es; - tf->tf_vm86_fs = tf->tf_fs; - tf->tf_vm86_gs = ucp->uc_mcontext.mc_gs; - tf->tf_ds = _udatasel; - tf->tf_es = _udatasel; - tf->tf_fs = _udatasel; - } else { - /* - * Don't allow users to change privileged or reserved flags. - */ - /* - * XXX do allow users to change the privileged flag PSL_RF. - * The cpu sets PSL_RF in tf_eflags for faults. Debuggers - * should sometimes set it there too. tf_eflags is kept in - * the signal context during signal handling and there is no - * other place to remember it, so the PSL_RF bit may be - * corrupted by the signal handler without us knowing. - * Corruption of the PSL_RF bit at worst causes one more or - * one less debugger trap, so allowing it is fairly harmless. - */ - if (!EFL_SECURE(eflags & ~PSL_RF, regs->tf_eflags & ~PSL_RF)) { - printf("sigreturn: eflags = 0x%x\n", eflags); - return (EINVAL); - } - - /* - * Don't allow users to load a valid privileged %cs. Let the - * hardware check for invalid selectors, excess privilege in - * other selectors, invalid %eip's and invalid %esp's. - */ - cs = ucp->uc_mcontext.mc_cs; - if (!CS_SECURE(cs)) { - printf("sigreturn: cs = 0x%x\n", cs); - trapsignal(p, SIGBUS, T_PROTFLT); - return (EINVAL); - } - - ret = set_fpcontext(td, &ucp->uc_mcontext); - if (ret != 0) - return (ret); - bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(*regs)); - } + ret = set_fpcontext(td, &ucp->uc_mcontext); + if (ret != 0) + return (ret); + bcopy(&ucp->uc_mcontext.mc_fs, regs, sizeof(*regs)); PROC_LOCK(p); #if defined(COMPAT_43) || defined(COMPAT_SUNOS) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe p4-projects" in the body of the message
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