freebsd-nq/sys/amd64/include/asmacros.h
Konstantin Belousov 7f12ebe583 Do not leave stray qword on top of stack for interrupts and exceptions
without error code.  Doing so it mis-aligned the stack.

Since the only consumer of the SSE instructions with the alignment
requirements is AES-NI module, and since the FPU context cannot be
accessed in interrupts, the only situation where the alignment matter
are the compat32 syscalls, as reported in the PR.

PR:	229222
Reported and tested by:	 dewayne@heuristicsystems.com.au
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2018-06-25 11:29:04 +00:00

320 lines
10 KiB
C

/* -*- mode: asm -*- */
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1993 The Regents of the University of California.
* All rights reserved.
*
* Copyright (c) 2018 The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed by
* Konstantin Belousov <kib@FreeBSD.org> under sponsorship from
* the FreeBSD Foundation.
*
* 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. 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.
*
* $FreeBSD$
*/
#ifndef _MACHINE_ASMACROS_H_
#define _MACHINE_ASMACROS_H_
#include <sys/cdefs.h>
/* XXX too much duplication in various asm*.h's. */
/*
* CNAME is used to manage the relationship between symbol names in C
* and the equivalent assembly language names. CNAME is given a name as
* it would be used in a C program. It expands to the equivalent assembly
* language name.
*/
#define CNAME(csym) csym
#define ALIGN_DATA .p2align 3 /* 8 byte alignment, zero filled */
#ifdef GPROF
#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
#else
#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
#endif
#define SUPERALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
#define GEN_ENTRY(name) ALIGN_TEXT; .globl CNAME(name); \
.type CNAME(name),@function; CNAME(name):
#define NON_GPROF_ENTRY(name) GEN_ENTRY(name)
#define NON_GPROF_RET .byte 0xc3 /* opcode for `ret' */
#define END(name) .size name, . - name
#ifdef GPROF
/*
* __mcount is like [.]mcount except that doesn't require its caller to set
* up a frame pointer. It must be called before pushing anything onto the
* stack. gcc should eventually generate code to call __mcount in most
* cases. This would make -pg in combination with -fomit-frame-pointer
* useful. gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
* allow profiling before setting up the frame pointer, but this is
* inadequate for good handling of special cases, e.g., -fpic works best
* with profiling after the prologue.
*
* [.]mexitcount is a new function to support non-statistical profiling if an
* accurate clock is available. For C sources, calls to it are generated
* by the FreeBSD extension `-mprofiler-epilogue' to gcc. It is best to
* call [.]mexitcount at the end of a function like the MEXITCOUNT macro does,
* but gcc currently generates calls to it at the start of the epilogue to
* avoid problems with -fpic.
*
* [.]mcount and __mcount may clobber the call-used registers and %ef.
* [.]mexitcount may clobber %ecx and %ef.
*
* Cross-jumping makes non-statistical profiling timing more complicated.
* It is handled in many cases by calling [.]mexitcount before jumping. It
* is handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
* It is handled for some fault-handling jumps by not sharing the exit
* routine.
*
* ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
* the main entry point. Note that alt entries are counted twice. They
* have to be counted as ordinary entries for gprof to get the call times
* right for the ordinary entries.
*
* High local labels are used in macros to avoid clashes with local labels
* in functions.
*
* Ordinary `ret' is used instead of a macro `RET' because there are a lot
* of `ret's. 0xc3 is the opcode for `ret' (`#define ret ... ret' can't
* be used because this file is sometimes preprocessed in traditional mode).
* `ret' clobbers eflags but this doesn't matter.
*/
#define ALTENTRY(name) GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
#define CROSSJUMP(jtrue, label, jfalse) \
jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
#define CROSSJUMPTARGET(label) \
ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
#define ENTRY(name) GEN_ENTRY(name) ; 9: ; MCOUNT
#define FAKE_MCOUNT(caller) pushq caller ; call __mcount ; popq %rcx
#define MCOUNT call __mcount
#define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT
#ifdef GUPROF
#define MEXITCOUNT call .mexitcount
#define ret MEXITCOUNT ; NON_GPROF_RET
#else
#define MEXITCOUNT
#endif
#else /* !GPROF */
/*
* ALTENTRY() has to align because it is before a corresponding ENTRY().
* ENTRY() has to align to because there may be no ALTENTRY() before it.
* If there is a previous ALTENTRY() then the alignment code for ENTRY()
* is empty.
*/
#define ALTENTRY(name) GEN_ENTRY(name)
#define CROSSJUMP(jtrue, label, jfalse) jtrue label
#define CROSSJUMPTARGET(label)
#define ENTRY(name) GEN_ENTRY(name)
#define FAKE_MCOUNT(caller)
#define MCOUNT
#define MCOUNT_LABEL(name)
#define MEXITCOUNT
#endif /* GPROF */
/*
* Convenience for adding frame pointers to hand-coded ASM. Useful for
* DTrace, HWPMC, and KDB.
*/
#define PUSH_FRAME_POINTER \
pushq %rbp ; \
movq %rsp, %rbp ;
#define POP_FRAME_POINTER \
popq %rbp
#ifdef LOCORE
/*
* Access per-CPU data.
*/
#define PCPU(member) %gs:PC_ ## member
#define PCPU_ADDR(member, reg) \
movq %gs:PC_PRVSPACE, reg ; \
addq $PC_ ## member, reg
/*
* Convenience macro for declaring interrupt entry points.
*/
#define IDTVEC(name) ALIGN_TEXT; .globl __CONCAT(X,name); \
.type __CONCAT(X,name),@function; __CONCAT(X,name):
.macro SAVE_SEGS
movw %fs,TF_FS(%rsp)
movw %gs,TF_GS(%rsp)
movw %es,TF_ES(%rsp)
movw %ds,TF_DS(%rsp)
.endm
.macro MOVE_STACKS qw
.L.offset=0
.rept \qw
movq .L.offset(%rsp),%rdx
movq %rdx,.L.offset(%rax)
.L.offset=.L.offset+8
.endr
.endm
.macro PTI_UUENTRY has_err
movq PCPU(KCR3),%rax
movq %rax,%cr3
movq PCPU(RSP0),%rax
subq $PTI_SIZE - 8 * (1 - \has_err),%rax
MOVE_STACKS ((PTI_SIZE / 8) - 1 + \has_err)
movq %rax,%rsp
popq %rdx
popq %rax
.endm
.macro PTI_UENTRY has_err
swapgs
cmpq $~0,PCPU(UCR3)
je 1f
pushq %rax
pushq %rdx
PTI_UUENTRY \has_err
1:
.endm
.macro PTI_ENTRY name, cont, has_err=0
ALIGN_TEXT
.globl X\name\()_pti
.type X\name\()_pti,@function
X\name\()_pti:
/* %rax, %rdx and possibly err not yet pushed */
testb $SEL_RPL_MASK,PTI_CS-(2+1-\has_err)*8(%rsp)
jz \cont
PTI_UENTRY \has_err
swapgs
jmp \cont
.endm
.macro PTI_INTRENTRY vec_name
SUPERALIGN_TEXT
.globl X\vec_name\()_pti
.type X\vec_name\()_pti,@function
X\vec_name\()_pti:
testb $SEL_RPL_MASK,PTI_CS-3*8(%rsp) /* err, %rax, %rdx not pushed */
jz .L\vec_name\()_u
PTI_UENTRY has_err=0
jmp .L\vec_name\()_u
.endm
.macro INTR_PUSH_FRAME vec_name
SUPERALIGN_TEXT
.globl X\vec_name
.type X\vec_name,@function
X\vec_name:
testb $SEL_RPL_MASK,PTI_CS-3*8(%rsp) /* come from kernel? */
jz .L\vec_name\()_u /* Yes, dont swapgs again */
swapgs
.L\vec_name\()_u:
subq $TF_RIP,%rsp /* skip dummy tf_err and tf_trapno */
movq %rdi,TF_RDI(%rsp)
movq %rsi,TF_RSI(%rsp)
movq %rdx,TF_RDX(%rsp)
movq %rcx,TF_RCX(%rsp)
movq %r8,TF_R8(%rsp)
movq %r9,TF_R9(%rsp)
movq %rax,TF_RAX(%rsp)
movq %rbx,TF_RBX(%rsp)
movq %rbp,TF_RBP(%rsp)
movq %r10,TF_R10(%rsp)
movq %r11,TF_R11(%rsp)
movq %r12,TF_R12(%rsp)
movq %r13,TF_R13(%rsp)
movq %r14,TF_R14(%rsp)
movq %r15,TF_R15(%rsp)
SAVE_SEGS
movl $TF_HASSEGS,TF_FLAGS(%rsp)
cld
testb $SEL_RPL_MASK,TF_CS(%rsp) /* come from kernel ? */
jz 1f /* yes, leave PCB_FULL_IRET alone */
movq PCPU(CURPCB),%r8
andl $~PCB_FULL_IRET,PCB_FLAGS(%r8)
call handle_ibrs_entry
1:
.endm
.macro INTR_HANDLER vec_name
.text
PTI_INTRENTRY \vec_name
INTR_PUSH_FRAME \vec_name
.endm
.macro RESTORE_REGS
movq TF_RDI(%rsp),%rdi
movq TF_RSI(%rsp),%rsi
movq TF_RDX(%rsp),%rdx
movq TF_RCX(%rsp),%rcx
movq TF_R8(%rsp),%r8
movq TF_R9(%rsp),%r9
movq TF_RAX(%rsp),%rax
movq TF_RBX(%rsp),%rbx
movq TF_RBP(%rsp),%rbp
movq TF_R10(%rsp),%r10
movq TF_R11(%rsp),%r11
movq TF_R12(%rsp),%r12
movq TF_R13(%rsp),%r13
movq TF_R14(%rsp),%r14
movq TF_R15(%rsp),%r15
.endm
#endif /* LOCORE */
#ifdef __STDC__
#define ELFNOTE(name, type, desctype, descdata...) \
.pushsection .note.name ; \
.align 4 ; \
.long 2f - 1f /* namesz */ ; \
.long 4f - 3f /* descsz */ ; \
.long type ; \
1:.asciz #name ; \
2:.align 4 ; \
3:desctype descdata ; \
4:.align 4 ; \
.popsection
#else /* !__STDC__, i.e. -traditional */
#define ELFNOTE(name, type, desctype, descdata) \
.pushsection .note.name ; \
.align 4 ; \
.long 2f - 1f /* namesz */ ; \
.long 4f - 3f /* descsz */ ; \
.long type ; \
1:.asciz "name" ; \
2:.align 4 ; \
3:desctype descdata ; \
4:.align 4 ; \
.popsection
#endif /* __STDC__ */
#endif /* !_MACHINE_ASMACROS_H_ */