diff options
| -rw-r--r-- | sys/arch/amd64/amd64/locore.S | 28 | ||||
| -rw-r--r-- | sys/arch/amd64/amd64/trap.c | 38 | ||||
| -rw-r--r-- | sys/arch/amd64/amd64/vector.S | 59 | ||||
| -rw-r--r-- | sys/arch/amd64/include/frameasm.h | 14 |
4 files changed, 85 insertions, 54 deletions
diff --git a/sys/arch/amd64/amd64/locore.S b/sys/arch/amd64/amd64/locore.S index db5ae42f520..8d4459f86c9 100644 --- a/sys/arch/amd64/amd64/locore.S +++ b/sys/arch/amd64/amd64/locore.S @@ -1,4 +1,4 @@ -/* $OpenBSD: locore.S,v 1.39 2009/06/09 02:56:38 krw Exp $ */ +/* $OpenBSD: locore.S,v 1.40 2010/09/28 03:53:14 guenther Exp $ */ /* $NetBSD: locore.S,v 1.13 2004/03/25 18:33:17 drochner Exp $ */ /* @@ -1049,12 +1049,28 @@ _C_LABEL(osyscall_return): jmp 2b iret_return: -#ifndef DIAGNOSTIC -1: INTRFASTEXIT -#else /* DIAGNOSTIC */ -1: cmpl $IPL_NONE,CPUVAR(ILEVEL) +1: +#ifdef DIAGNOSTIC + cmpl $IPL_NONE,CPUVAR(ILEVEL) jne 3f - INTRFASTEXIT +#endif /* DIAGNOSTIC */ + .globl intr_fast_exit +intr_fast_exit: + INTR_RESTORE_GPRS + testq $SEL_UPL,56(%rsp) + je 5f + cli + swapgs + movw 0(%rsp),%gs + movw 8(%rsp),%fs + movw 16(%rsp),%es + movw 24(%rsp),%ds +5: addq $48,%rsp + .globl _C_LABEL(doreti_iret) +_C_LABEL(doreti_iret): + iretq + +#ifdef DIAGNOSTIC 3: sti movabsq $4f, %rdi xorq %rax,%rax diff --git a/sys/arch/amd64/amd64/trap.c b/sys/arch/amd64/amd64/trap.c index 1dccaf218cf..8f358769fc8 100644 --- a/sys/arch/amd64/amd64/trap.c +++ b/sys/arch/amd64/amd64/trap.c @@ -1,4 +1,4 @@ -/* $OpenBSD: trap.c,v 1.18 2010/05/06 21:33:51 nicm Exp $ */ +/* $OpenBSD: trap.c,v 1.19 2010/09/28 03:53:14 guenther Exp $ */ /* $NetBSD: trap.c,v 1.2 2003/05/04 23:51:56 fvdl Exp $ */ /*- @@ -150,12 +150,10 @@ trap(struct trapframe *frame) struct proc *p = curproc; int type = (int)frame->tf_trapno; struct pcb *pcb; - extern char resume_iret[], IDTVEC(oosyscall)[]; + extern char doreti_iret[], resume_iret[], IDTVEC(oosyscall)[]; #if 0 extern char resume_pop_ds[], resume_pop_es[]; #endif - struct trapframe *vframe; - void *resume; caddr_t onfault; int error; uint64_t cr2; @@ -235,34 +233,14 @@ copyfault: /* * Check for failure during return to user mode. - * - * XXXfvdl check for rex prefix? - * - * We do this by looking at the instruction we faulted on. The - * specific instructions we recognize only happen when - * returning from a trap, syscall, or interrupt. - * - * XXX - * The heuristic used here will currently fail for the case of - * one of the 2 pop instructions faulting when returning from a - * a fast interrupt. This should not be possible. It can be - * fixed by rearranging the trap frame so that the stack format - * at this point is the same as on exit from a `slow' - * interrupt. + * We do this by looking at the address of the + * instruction that faulted. */ - switch (*(u_char *)frame->tf_rip) { - case 0xcf: /* iret */ - vframe = (void *)((u_int64_t)&frame->tf_rsp - 44); - resume = resume_iret; - break; - default: - goto we_re_toast; + if (frame->tf_rip == (u_int64_t)doreti_iret) { + frame->tf_rip = (u_int64_t)resume_iret; + return; } - if (KERNELMODE(vframe->tf_cs, vframe->tf_rflags)) - goto we_re_toast; - - frame->tf_rip = (u_int64_t)resume; - return; + goto we_re_toast; case T_PROTFLT|T_USER: /* protection fault */ case T_TSSFLT|T_USER: diff --git a/sys/arch/amd64/amd64/vector.S b/sys/arch/amd64/amd64/vector.S index 2f90fb7545e..be7ebb39deb 100644 --- a/sys/arch/amd64/amd64/vector.S +++ b/sys/arch/amd64/amd64/vector.S @@ -1,4 +1,4 @@ -/* $OpenBSD: vector.S,v 1.25 2010/04/05 19:04:32 kettenis Exp $ */ +/* $OpenBSD: vector.S,v 1.26 2010/09/28 03:53:14 guenther Exp $ */ /* $NetBSD: vector.S,v 1.5 2004/06/28 09:13:11 fvdl Exp $ */ /* @@ -137,8 +137,46 @@ IDTVEC(trap0b) TRAP(T_SEGNPFLT) IDTVEC(trap0c) TRAP(T_STKFLT) + + /* + * If iretq faults, we'll get a trap at doreti_iret with CPL==0 but + * the user's GS.base, which INTRENTRY wouldn't handle correctly + * (it would skip the swapgs), so locally expand both it and + * INTR_SAVE_GPRS, but add an extra test comparing %rip to doreti_iret + * so that we can do the necessary swapgs in that case. + */ IDTVEC(trap0d) - TRAP(T_PROTFLT) + subq $TF_ERR,%rsp + movl $T_PROTFLT,TF_TRAPNO(%rsp) + movq %rdi,TF_RDI(%rsp) + leaq _C_LABEL(doreti_iret)(%rip),%rdi + cmpq %rdi,TF_RIP(%rsp) + je 1f + testq $SEL_UPL,TF_CS(%rsp) + jz 2f +1: swapgs +2: movw %gs,TF_GS(%rsp) + movw %fs,TF_FS(%rsp) + movw %es,TF_ES(%rsp) + movw %ds,TF_DS(%rsp) + movq %r15,TF_R15(%rsp) + movq %r14,TF_R14(%rsp) + movq %r13,TF_R13(%rsp) + movq %r12,TF_R12(%rsp) + movq %r11,TF_R11(%rsp) + movq %r10,TF_R10(%rsp) + movq %r9,TF_R9(%rsp) + movq %r8,TF_R8(%rsp) + /*movq %rdi,TF_RDI(%rsp) done above */ + movq %rsi,TF_RSI(%rsp) + movq %rbp,TF_RBP(%rsp) + movq %rbx,TF_RBX(%rsp) + movq %rdx,TF_RDX(%rsp) + movq %rcx,TF_RCX(%rsp) + movq %rax,TF_RAX(%rsp) + sti + jmp calltrap + IDTVEC(trap0e) TRAP(T_PAGEFLT) IDTVEC(intrspurious) @@ -187,12 +225,21 @@ IDTVEC(exceptions) /* * If an error is detected during trap, syscall, or interrupt exit, trap() will - * change %eip to point to one of these labels. We clean up the stack, if - * necessary, and resume as if we were handling a general protection fault. - * This will cause the process to get a SIGBUS. + * change %rip to point to this label. At that point, we'll be running with + * the kernel GS.base, but the trap frame will be from CPL==3, so we can't + * go through INTRENTRY as it would do the swapgs that we don't want/need. + * So, locally expand INTRENTRY but without the swapgs: manually + * clean up the stack and resume as if we were handling a general + * protection fault. This will cause the process to get a SIGBUS. */ NENTRY(resume_iret) - ZTRAP(T_PROTFLT) + pushq $0 + pushq $T_PROTFLT + subq $32,%rsp + INTR_SAVE_GPRS + sti + jmp calltrap + /* * All traps go through here. Call the generic trap handler, and * check for ASTs afterwards. diff --git a/sys/arch/amd64/include/frameasm.h b/sys/arch/amd64/include/frameasm.h index c23b0e65a4d..5e1fa6145e1 100644 --- a/sys/arch/amd64/include/frameasm.h +++ b/sys/arch/amd64/include/frameasm.h @@ -1,4 +1,4 @@ -/* $OpenBSD: frameasm.h,v 1.1 2004/01/28 01:39:39 mickey Exp $ */ +/* $OpenBSD: frameasm.h,v 1.2 2010/09/28 03:53:14 guenther Exp $ */ /* $NetBSD: frameasm.h,v 1.1 2003/04/26 18:39:40 fvdl Exp $ */ #ifndef _AMD64_MACHINE_FRAMEASM_H @@ -60,17 +60,7 @@ 98: INTR_SAVE_GPRS #define INTRFASTEXIT \ - INTR_RESTORE_GPRS ; \ - testq $SEL_UPL,56(%rsp) ; \ - je 99f ; \ - cli ; \ - swapgs ; \ - movw 0(%rsp),%gs ; \ - movw 8(%rsp),%fs ; \ - movw 16(%rsp),%es ; \ - movw 24(%rsp),%ds ; \ -99: addq $48,%rsp ; \ - iretq + jmp intr_fast_exit #define INTR_RECURSE_HWFRAME \ movq %rsp,%r10 ; \ |