diff options
Diffstat (limited to 'sys/cddl/dev/dtrace/amd64/dtrace_asm.S')
| -rw-r--r-- | sys/cddl/dev/dtrace/amd64/dtrace_asm.S | 53 |
1 files changed, 49 insertions, 4 deletions
diff --git a/sys/cddl/dev/dtrace/amd64/dtrace_asm.S b/sys/cddl/dev/dtrace/amd64/dtrace_asm.S index 9a83c87dda02..0c8cd9a83d01 100644 --- a/sys/cddl/dev/dtrace/amd64/dtrace_asm.S +++ b/sys/cddl/dev/dtrace/amd64/dtrace_asm.S @@ -20,8 +20,6 @@ * * Portions Copyright 2008 John Birrell <jb@freebsd.org> * - * $FreeBSD$ - * */ /* * Copyright 2007 Sun Microsystems, Inc. All rights reserved. @@ -58,6 +56,8 @@ swapgs; \ 1: addq $TF_RIP,%rsp; +.globl dtrace_invop_callsite +.type dtrace_invop_callsite,@function ENTRY(dtrace_invop_start) @@ -69,11 +69,22 @@ movq TF_RIP(%rsp), %rdi decq %rdi movq %rsp, %rsi - movq TF_RAX(%rsp), %rdx + + /* + * Allocate some scratch space to let the invop handler return a value. + * This is needed when emulating "call" instructions. + */ + subq $16, %rsp + movq %rsp, %rdx + call dtrace_invop - ENTRY(dtrace_invop_callsite) +dtrace_invop_callsite: + addq $16, %rsp + cmpl $DTRACE_INVOP_PUSHL_EBP, %eax je bp_push + cmpl $DTRACE_INVOP_CALL, %eax + je bp_call cmpl $DTRACE_INVOP_LEAVE, %eax je bp_leave cmpl $DTRACE_INVOP_NOP, %eax @@ -109,6 +120,40 @@ bp_push: iretq /* return from interrupt */ /*NOTREACHED*/ +bp_call: + /* + * Emulate a "call" instruction. The invop handler must have already + * updated the saved copy of %rip in the register set. It's our job to + * pull the hardware-saved registers down to make space for the return + * address, which is provided by the invop handler in our scratch + * space. + */ + INTR_POP + subq $16, %rsp /* make room for %rbp */ + pushq %rax /* push temp */ + pushq %rbx /* push temp */ + + movq 32(%rsp), %rax /* load calling RIP */ + movq %rax, 16(%rsp) /* store calling RIP */ + movq 40(%rsp), %rax /* load calling CS */ + movq %rax, 24(%rsp) /* store calling CS */ + movq 48(%rsp), %rax /* load calling RFLAGS */ + movq %rax, 32(%rsp) /* store calling RFLAGS */ + movq 56(%rsp), %rax /* load calling RSP */ + subq $8, %rax /* make room for return address */ + movq %rax, 40(%rsp) /* store calling RSP */ + movq 64(%rsp), %rax /* load calling SS */ + movq %rax, 48(%rsp) /* store calling SS */ + + movq -(TF_RIP - 16)(%rsp), %rax /* load return address */ + movq 40(%rsp), %rbx /* reload calling RSP */ + movq %rax, (%rbx) /* store return address */ + + popq %rbx /* pop temp */ + popq %rax /* pop temp */ + iretq /* return from interrupt */ + /*NOTREACHED*/ + bp_leave: /* * We must emulate a "leave", which is the same as a "movq %rbp, %rsp" |