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amd64: wrap 64bit sigtramp into vdso

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Reviewed by:	emaste
Discussed with:	jrtc27
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Differential revision:	https://reviews.freebsd.org/D32960
This commit is contained in:
Konstantin Belousov 2021-11-05 10:07:24 +02:00
parent 9b135747a3
commit ab4524b3d7
9 changed files with 245 additions and 25 deletions
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20
sys/amd64/amd64/elf_machdep.c
View File

@ -49,14 +49,21 @@ __FBSDID("$FreeBSD$");
#include <machine/fpu.h>
#include <machine/md_var.h>
#include "vdso_offsets.h"
extern const char _binary_elf_vdso_so_1_start[];
extern const char _binary_elf_vdso_so_1_end[];
extern char _binary_elf_vdso_so_1_size;
struct sysentvec elf64_freebsd_sysvec_la48 = {
.sv_size = SYS_MAXSYSCALL,
.sv_table = sysent,
.sv_transtrap = NULL,
.sv_fixup = __elfN(freebsd_fixup),
.sv_sendsig = sendsig,
.sv_sigcode = sigcode,
.sv_szsigcode = &szsigcode,
.sv_sigcode = _binary_elf_vdso_so_1_start,
.sv_szsigcode = (int *)&_binary_elf_vdso_so_1_size,
.sv_sigcodeoff = VDSO_SIGCODE_OFFSET,
.sv_name = "FreeBSD ELF64",
.sv_coredump = __elfN(coredump),
.sv_elf_core_osabi = ELFOSABI_FREEBSD,
@ -75,7 +82,7 @@ struct sysentvec elf64_freebsd_sysvec_la48 = {
.sv_fixlimit = NULL,
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_LP64 | SV_SHP |
SV_TIMEKEEP | SV_RNG_SEED_VER,
SV_TIMEKEEP | SV_RNG_SEED_VER | SV_DSO_SIG,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = cpu_fetch_syscall_args,
.sv_syscallnames = syscallnames,
@ -96,8 +103,9 @@ struct sysentvec elf64_freebsd_sysvec_la57 = {
.sv_transtrap = NULL,
.sv_fixup = __elfN(freebsd_fixup),
.sv_sendsig = sendsig,
.sv_sigcode = sigcode,
.sv_szsigcode = &szsigcode,
.sv_sigcode = _binary_elf_vdso_so_1_start,
.sv_szsigcode = (int *)&_binary_elf_vdso_so_1_size,
.sv_sigcodeoff = VDSO_SIGCODE_OFFSET,
.sv_name = "FreeBSD ELF64",
.sv_coredump = __elfN(coredump),
.sv_elf_core_osabi = ELFOSABI_FREEBSD,
@ -116,7 +124,7 @@ struct sysentvec elf64_freebsd_sysvec_la57 = {
.sv_fixlimit = NULL,
.sv_maxssiz = NULL,
.sv_flags = SV_ABI_FREEBSD | SV_ASLR | SV_LP64 | SV_SHP |
SV_TIMEKEEP | SV_RNG_SEED_VER,
SV_TIMEKEEP | SV_RNG_SEED_VER | SV_DSO_SIG,
.sv_set_syscall_retval = cpu_set_syscall_retval,
.sv_fetch_syscall_args = cpu_fetch_syscall_args,
.sv_syscallnames = syscallnames,

18
sys/amd64/amd64/sigtramp.S
View File

@ -27,18 +27,15 @@
*/
#include <sys/syscall.h>
#include <machine/asmacros.h>
#include "assym.inc"
.text
/**********************************************************************
*
* Signal trampoline, copied to top of user stack
*
/*
* Signal trampoline, mapped as vdso into shared page.
*/
ENTRY(sigcode)
ENTRY(__vdso_sigcode)
call *SIGF_HANDLER(%rsp) /* call signal handler */
lea SIGF_UC(%rsp),%rdi /* get ucontext_t */
pushq $0 /* junk to fake return addr. */
@ -46,11 +43,6 @@ ENTRY(sigcode)
syscall /* enter kernel with args */
0: hlt /* trap priviliged instruction */
jmp 0b
END(__vdso_sigcode)
ALIGN_TEXT
esigcode:
.data
.globl szsigcode
szsigcode:
.long esigcode-sigcode
.section .note.GNU-stack,"",%progbits

7
sys/conf/files.amd64
View File

@ -12,6 +12,12 @@ include "conf/files.x86"
# dependency lines other than the first are silently ignored.
#
#
elf-vdso.so.o standard \
dependency "$S/amd64/amd64/sigtramp.S assym.inc $S/tools/amd64_vdso.sh" \
compile-with "env AWK='${AWK}' NM='${NM}' LD='${LD}' CC='${CC}' OBJCOPY='${OBJCOPY}' S='${S}' sh $S/tools/amd64_vdso.sh" \
no-implicit-rule before-depend \
clean "elf-vdso.so.o elf-vdso.so.1 vdso_offsets.h sigtramp.pico"
#
ia32_genassym.o standard \
dependency "$S/compat/ia32/ia32_genassym.c offset.inc" \
compile-with "${CC} ${CFLAGS:N-flto:N-fno-common} -fcommon -c ${.IMPSRC}" \
@ -75,7 +81,6 @@ amd64/amd64/mp_machdep.c optional smp
amd64/amd64/mpboot.S optional smp
amd64/amd64/pmap.c standard
amd64/amd64/ptrace_machdep.c standard
amd64/amd64/sigtramp.S standard
amd64/amd64/support.S standard
amd64/amd64/sys_machdep.c standard
amd64/amd64/trap.c standard

89
sys/conf/vdso_amd64.ldscript Normal file
View File

@ -0,0 +1,89 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2021 The FreeBSD Foundation
*
* This software was 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
/*
* Linker script for amd64 vdso.
*/
PHDRS
{
text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
dynamic PT_DYNAMIC FLAGS(5);
eh_frame_hdr PT_GNU_EH_FRAME FLAGS(5);
}
SECTIONS
{
. = . + SIZEOF_HEADERS;
.hash : { *(.hash) } :text
.gnu.hash : { *(.gnu.hash) } :text
.dynsym : { *(.dynsym) } :text
.dynstr : { *(.dynstr) } :text
.gnu.version : { *(.gnu.version) } :text
.gnu.version_d : { *(.gnu.version_d) } :text
.gnu.version_r : { *(.gnu.version_r) } :text
.eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
.eh_frame : { KEEP (*(.eh_frame)) } :text
.dynamic : { *(.dynamic) } :text :dynamic
.rodata : { *(.rodata*) } :text
.data : {
*(.got.plt) *(.got)
} :text
/DISCARD/ /* .data */: {
*(.data*)
*(.sdata*)
*(.gnu.linkonce.d.*)
*(.bss*)
*(.dynbss*)
*(.gnu.linkonce.b.*)
*(.ctors)
*(.dtors)
*(.jcr)
*(.init_array)
*(.init)
*(.fini)
*(.debug*)
*(.comment)
}
. = ALIGN(0x10);
.text : { *(.text .text*) } :text =0x90909090
}
VERSION
{
FBSD_1.7 {
global:
__vdso_sigcode;
local:
*;
};
}

7
sys/kern/kern_proc.c
View File

@ -3099,7 +3099,9 @@ sysctl_kern_proc_sigtramp(SYSCTL_HANDLER_ARGS)
if (sv->sv_sigcode_base != 0) {
kst32.ksigtramp_start = sv->sv_sigcode_base;
kst32.ksigtramp_end = sv->sv_sigcode_base +
*sv->sv_szsigcode;
((sv->sv_flags & SV_DSO_SIG) == 0 ?
*sv->sv_szsigcode :
(uintptr_t)sv->sv_szsigcode);
} else {
kst32.ksigtramp_start = sv->sv_psstrings -
*sv->sv_szsigcode;
@ -3115,7 +3117,8 @@ sysctl_kern_proc_sigtramp(SYSCTL_HANDLER_ARGS)
if (sv->sv_sigcode_base != 0) {
kst.ksigtramp_start = (char *)sv->sv_sigcode_base;
kst.ksigtramp_end = (char *)sv->sv_sigcode_base +
*sv->sv_szsigcode;
((sv->sv_flags & SV_DSO_SIG) == 0 ? *sv->sv_szsigcode :
(uintptr_t)sv->sv_szsigcode);
} else {
kst.ksigtramp_start = (char *)sv->sv_psstrings -
*sv->sv_szsigcode;

18
sys/kern/kern_sharedpage.c
View File

@ -305,10 +305,12 @@ void
exec_sysvec_init(void *param)
{
struct sysentvec *sv;
vm_offset_t sb;
#ifdef RANDOM_FENESTRASX
ptrdiff_t base;
#endif
u_int flags;
int res;
sv = param;
flags = sv->sv_flags;
@ -319,8 +321,20 @@ exec_sysvec_init(void *param)
sv->sv_shared_page_obj = shared_page_obj;
if ((flags & SV_ABI_MASK) == SV_ABI_FREEBSD) {
sv->sv_sigcode_base = sv->sv_shared_page_base +
shared_page_fill(*(sv->sv_szsigcode), 16, sv->sv_sigcode);
if ((flags & SV_DSO_SIG) != 0) {
sb = sv->sv_shared_page_base;
res = shared_page_fill((uintptr_t)sv->sv_szsigcode,
16, sv->sv_sigcode);
if (res == -1)
panic("copying sigtramp to shared page");
sb += res;
sb += sv->sv_sigcodeoff;
sv->sv_sigcode_base = sb;
} else {
sv->sv_sigcode_base = sv->sv_shared_page_base +
shared_page_fill(*(sv->sv_szsigcode), 16,
sv->sv_sigcode);
}
}
if ((flags & SV_TIMEKEEP) != 0) {
#ifdef COMPAT_FREEBSD32

4
sys/sys/sysent.h
View File

@ -109,8 +109,9 @@ struct sysentvec {
/* stack fixup function */
void (*sv_sendsig)(void (*)(int), struct ksiginfo *, struct __sigset *);
/* send signal */
char *sv_sigcode; /* start of sigtramp code */
const char *sv_sigcode; /* start of sigtramp code */
int *sv_szsigcode; /* size of sigtramp code */
int sv_sigcodeoff;
char *sv_name; /* name of binary type */
int (*sv_coredump)(struct thread *, struct vnode *, off_t, int);
/* function to dump core, or NULL */
@ -171,6 +172,7 @@ struct sysentvec {
#define SV_RNG_SEED_VER 0x100000 /* random(4) reseed generation. */
#define SV_SIG_DISCIGN 0x200000 /* Do not discard ignored signals */
#define SV_SIG_WAITNDQ 0x400000 /* Wait does not dequeue SIGCHLD */
#define SV_DSO_SIG 0x800000 /* Signal trampoline packed in dso */
#define SV_ABI_MASK 0xff
#define SV_PROC_FLAG(p, x) ((p)->p_sysent->sv_flags & (x))

59
sys/tools/amd64_vdso.sh Normal file
View File

@ -0,0 +1,59 @@
#!/bin/sh
# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
#
# Copyright (c) 2021 The FreeBSD Foundation
# All rights reserved.
#
# This software was 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.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
set -e
${CC} -x assembler-with-cpp -DLOCORE -fPIC -nostdinc -c \
-o sigtramp.pico -I. -I"${S}" -include opt_global.h \
"${S}"/amd64/amd64/sigtramp.S
# We need to make vdso as compact as possible, for it to leave space
# for other things in the shared page. For this, we pack everything
# into single loadable segment.
#
# -z rodynamic is undocumented lld-specific option, seemingly required
# for lld to avoid putting dynamic into dedicated writeable segment,
# despite ldscript placement. It is ignored by ld.bfd but ldscript
# alone is enough there.
#
${LD} --shared -Bsymbolic -soname="elf-vdso.so.1" \
-T "${S}"/conf/vdso_amd64.ldscript \
--eh-frame-hdr --no-undefined -z rodynamic -z norelro -nmagic \
--hash-style=sysv --fatal-warnings --strip-all \
-o elf-vdso.so.1 sigtramp.pico
${CC} -x assembler-with-cpp -DLOCORE -fPIC -nostdinc -c \
-o elf-vdso.so.o -I. -I"${S}" -include opt_global.h \
-DVDSO_NAME=elf_vdso_so_1 -DVDSO_FILE=elf-vdso.so.1 \
"${S}"/tools/vdso_wrap.S
${NM} -D elf-vdso.so.1 | \
awk '/__vdso_sigcode/{printf "#define VDSO_SIGCODE_OFFSET 0x%s\n",$1}' \
>vdso_offsets.h

48
sys/tools/vdso_wrap.S Normal file
View File

@ -0,0 +1,48 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2021 The FreeBSD Foundation
*
* This software was 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
#define VDSO_BLOB_START(S) __CONCAT(_binary_, __CONCAT(S, _start))
#define VDSO_BLOB_END(S) __CONCAT(_binary_, __CONCAT(S, _end))
#define VDSO_BLOB_SIZE(S) __CONCAT(_binary_, __CONCAT(S, _size))
.section .rodata, "a", %progbits
.globl VDSO_BLOB_START(VDSO_NAME)
.type VDSO_BLOB_START(VDSO_NAME), %object
.size VDSO_BLOB_START(VDSO_NAME), 0
VDSO_BLOB_START(VDSO_NAME):
.incbin __XSTRING(VDSO_FILE)
.globl VDSO_BLOB_END(VDSO_NAME)
.type VDSO_BLOB_END(VDSO_NAME), %object
.size VDSO_BLOB_END(VDSO_NAME), 0
VDSO_BLOB_END(VDSO_NAME):
.globl VDSO_BLOB_SIZE(VDSO_NAME)
.set VDSO_BLOB_SIZE(VDSO_NAME), . - VDSO_BLOB_START(VDSO_NAME)