Add very preliminary support for CloudABI for ARMv6.

In order to make CloudABI work on ARMv6, start off by copying over the
sysvec for ARM64 and adjust it to use 32-bit registers. Also add code
for fetching arguments from the stack if needed, as there are fewer
register than on ARM64.

Also import the vDSO that is needed to invoke system calls. This vDSO
uses the intra procedure call register (ip) to store the system call
number. This is a bit simpler than what native FreeBSD does, as FreeBSD
uses r7, while preserving the original r7 into ip.

This sysvec seems to be complete enough to start CloudABI processes.
These processes are capable of linking in the vDSO and are therefore
capable of executing (most?) system calls successfully. Unfortunately,
the biggest show stopper is still that TLS is completely broken:

- The linker used by CloudABI, LLD, still has troubles with some of the
  relocations needed for TLS. See LLVM bug 30218 for more details.

- Whereas FreeBSD uses the tpidruro register for TLS, for CloudABI I
  want to make use of tpidrurw, so that userspace can modify the base
  address directly. This is needed for efficient emulation.
  Unfortunately, this register doesn't seem to be preserved across
  context switches yet.

Obtained from:	https://github.com/NuxiNL/cloudabi (the vDSO)
This commit is contained in:
ed 2016-09-18 11:36:54 +00:00
parent 1d6d82b582
commit a9355d61c1
3 changed files with 696 additions and 0 deletions

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@ -0,0 +1,193 @@
/*-
* Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/
*
* 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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/imgact.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/sysent.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/frame.h>
#include <machine/pcb.h>
#include <machine/vmparam.h>
#include <compat/cloudabi/cloudabi_util.h>
#include <compat/cloudabi32/cloudabi32_syscall.h>
#include <compat/cloudabi32/cloudabi32_util.h>
extern const char *cloudabi32_syscallnames[];
extern struct sysent cloudabi32_sysent[];
static void
cloudabi32_proc_setregs(struct thread *td, struct image_params *imgp,
unsigned long stack)
{
struct trapframe *regs;
exec_setregs(td, imgp, stack);
/*
* The stack now contains a pointer to the TCB and the auxiliary
* vector. Let r0 point to the auxiliary vector, and set
* tpidrurw to the TCB.
*/
regs = td->td_frame;
regs->tf_r0 = td->td_retval[0] =
stack + roundup(sizeof(cloudabi32_tcb_t), sizeof(register_t));
(void)cpu_set_user_tls(td, (void *)stack);
}
static int
cloudabi32_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
{
struct trapframe *frame = td->td_frame;
int error;
/* Obtain system call number. */
sa->code = frame->tf_r12;
if (sa->code >= CLOUDABI32_SYS_MAXSYSCALL)
return (ENOSYS);
sa->callp = &cloudabi32_sysent[sa->code];
sa->narg = sa->callp->sy_narg;
/* Fetch system call arguments from registers and the stack. */
sa->args[0] = frame->tf_r0;
sa->args[1] = frame->tf_r1;
sa->args[2] = frame->tf_r2;
sa->args[3] = frame->tf_r3;
if (sa->narg > 4) {
error = copyin((void *)td->td_frame->tf_usr_sp, &sa->args[4],
(sa->narg - 4) * sizeof(register_t));
if (error != 0)
return (error);
}
/* Default system call return values. */
td->td_retval[0] = 0;
td->td_retval[1] = frame->tf_r1;
return (0);
}
static void
cloudabi32_set_syscall_retval(struct thread *td, int error)
{
struct trapframe *frame = td->td_frame;
switch (error) {
case 0:
/* System call succeeded. */
frame->tf_r0 = td->td_retval[0];
frame->tf_r1 = td->td_retval[1];
frame->tf_spsr &= ~PSR_C;
break;
case ERESTART:
/* Restart system call. */
frame->tf_pc -= 4;
break;
case EJUSTRETURN:
break;
default:
/* System call returned an error. */
frame->tf_r0 = cloudabi_convert_errno(error);
frame->tf_spsr |= PSR_C;
break;
}
}
static void
cloudabi32_schedtail(struct thread *td)
{
struct trapframe *frame = td->td_frame;
/*
* Initial register values for processes returning from fork.
* Make sure that we only set these values when forking, not
* when creating a new thread.
*/
if ((td->td_pflags & TDP_FORKING) != 0) {
frame->tf_r0 = CLOUDABI_PROCESS_CHILD;
frame->tf_r1 = td->td_tid;
}
}
int
cloudabi32_thread_setregs(struct thread *td,
const cloudabi32_threadattr_t *attr, uint32_t tcb)
{
struct trapframe *frame;
stack_t stack;
/* Perform standard register initialization. */
stack.ss_sp = TO_PTR(attr->stack);
stack.ss_size = attr->stack_size;
cpu_set_upcall(td, TO_PTR(attr->entry_point), NULL, &stack);
/*
* Pass in the thread ID of the new thread and the argument
* pointer provided by the parent thread in as arguments to the
* entry point.
*/
frame = td->td_frame;
frame->tf_r0 = td->td_tid;
frame->tf_r1 = attr->argument;
/* Set up TLS. */
return (cpu_set_user_tls(td, (void *)tcb));
}
static struct sysentvec cloudabi32_elf_sysvec = {
.sv_size = CLOUDABI32_SYS_MAXSYSCALL,
.sv_table = cloudabi32_sysent,
.sv_fixup = cloudabi32_fixup,
.sv_name = "CloudABI ELF32",
.sv_coredump = elf32_coredump,
.sv_pagesize = PAGE_SIZE,
.sv_minuser = VM_MIN_ADDRESS,
.sv_maxuser = VM_MAXUSER_ADDRESS,
.sv_stackprot = VM_PROT_READ | VM_PROT_WRITE,
.sv_copyout_strings = cloudabi32_copyout_strings,
.sv_setregs = cloudabi32_proc_setregs,
.sv_flags = SV_ABI_CLOUDABI | SV_CAPSICUM | SV_ILP32,
.sv_set_syscall_retval = cloudabi32_set_syscall_retval,
.sv_fetch_syscall_args = cloudabi32_fetch_syscall_args,
.sv_syscallnames = cloudabi32_syscallnames,
.sv_schedtail = cloudabi32_schedtail,
};
INIT_SYSENTVEC(elf_sysvec, &cloudabi32_elf_sysvec);
Elf32_Brandinfo cloudabi32_brand = {
.brand = ELFOSABI_CLOUDABI,
.machine = EM_ARM,
.sysvec = &cloudabi32_elf_sysvec,
.compat_3_brand = "CloudABI",
};

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@ -1,4 +1,16 @@
# $FreeBSD$
cloudabi32_vdso.o optional compat_cloudabi32 \
dependency "$S/contrib/cloudabi/cloudabi_vdso_armv6.S" \
compile-with "${CC} -x assembler-with-cpp -shared -nostdinc -nostdlib -Wl,-T$S/compat/cloudabi/cloudabi_vdso.lds $S/contrib/cloudabi/cloudabi_vdso_armv6.S -o ${.TARGET}" \
no-obj no-implicit-rule \
clean "cloudabi32_vdso.o"
#
cloudabi32_vdso_blob.o optional compat_cloudabi32 \
dependency "cloudabi32_vdso.o" \
compile-with "${OBJCOPY} --input-target binary --output-target elf32-littlearm --binary-architecture arm cloudabi32_vdso.o ${.TARGET}" \
no-implicit-rule \
clean "cloudabi32_vdso_blob.o"
#
arm/annapurna/alpine/alpine_ccu.c optional al_ccu fdt
arm/annapurna/alpine/alpine_nb_service.c optional al_nb_service fdt
arm/arm/autoconf.c standard
@ -85,6 +97,7 @@ arm/arm/undefined.c standard
arm/arm/unwind.c optional ddb | kdtrace_hooks
arm/arm/vm_machdep.c standard
arm/arm/vfp.c standard
arm/cloudabi32/cloudabi32_sysvec.c optional compat_cloudabi32
board_id.h standard \
dependency "$S/arm/conf/genboardid.awk $S/arm/conf/mach-types" \
compile-with "${AWK} -f $S/arm/conf/genboardid.awk $S/arm/conf/mach-types > board_id.h" \

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// Copyright (c) 2016 Nuxi (https://nuxi.nl/) and contributors.
//
// 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.
//
// This file is automatically generated. Do not edit.
//
// Source: https://github.com/NuxiNL/cloudabi
#define ENTRY(name) \
.text; \
.p2align 2; \
.global name; \
.type name, %function; \
name:
#define END(name) .size name, . - name
ENTRY(cloudabi_sys_clock_res_get)
str r1, [sp, #-4]
mov ip, #0
swi 0
ldr r2, [sp, #-4]
bcs 1f
str r0, [r2, 0]
str r1, [r2, 4]
mov r0, $0
1:
bx lr
END(cloudabi_sys_clock_res_get)
ENTRY(cloudabi_sys_clock_time_get)
str r3, [sp, #-4]
mov ip, #1
swi 0
ldr r2, [sp, #-4]
bcs 1f
str r0, [r2, 0]
str r1, [r2, 4]
mov r0, $0
1:
bx lr
END(cloudabi_sys_clock_time_get)
ENTRY(cloudabi_sys_condvar_signal)
mov ip, #2
swi 0
bx lr
END(cloudabi_sys_condvar_signal)
ENTRY(cloudabi_sys_fd_close)
mov ip, #3
swi 0
bx lr
END(cloudabi_sys_fd_close)
ENTRY(cloudabi_sys_fd_create1)
str r1, [sp, #-4]
mov ip, #4
swi 0
ldr r2, [sp, #-4]
bcs 1f
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_fd_create1)
ENTRY(cloudabi_sys_fd_create2)
str r1, [sp, #-4]
str r2, [sp, #-8]
mov ip, #5
swi 0
ldr r2, [sp, #-4]
ldr r3, [sp, #-8]
bcs 1f
str r0, [r2]
str r1, [r3]
mov r0, $0
1:
bx lr
END(cloudabi_sys_fd_create2)
ENTRY(cloudabi_sys_fd_datasync)
mov ip, #6
swi 0
bx lr
END(cloudabi_sys_fd_datasync)
ENTRY(cloudabi_sys_fd_dup)
str r1, [sp, #-4]
mov ip, #7
swi 0
ldr r2, [sp, #-4]
bcs 1f
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_fd_dup)
ENTRY(cloudabi_sys_fd_pread)
mov ip, #8
swi 0
bcs 1f
ldr r2, [sp, #8]
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_fd_pread)
ENTRY(cloudabi_sys_fd_pwrite)
mov ip, #9
swi 0
bcs 1f
ldr r2, [sp, #8]
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_fd_pwrite)
ENTRY(cloudabi_sys_fd_read)
str r3, [sp, #-4]
mov ip, #10
swi 0
ldr r2, [sp, #-4]
bcs 1f
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_fd_read)
ENTRY(cloudabi_sys_fd_replace)
mov ip, #11
swi 0
bx lr
END(cloudabi_sys_fd_replace)
ENTRY(cloudabi_sys_fd_seek)
mov ip, #12
swi 0
bcs 1f
ldr r2, [sp, #4]
str r0, [r2, 0]
str r1, [r2, 4]
mov r0, $0
1:
bx lr
END(cloudabi_sys_fd_seek)
ENTRY(cloudabi_sys_fd_stat_get)
mov ip, #13
swi 0
bx lr
END(cloudabi_sys_fd_stat_get)
ENTRY(cloudabi_sys_fd_stat_put)
mov ip, #14
swi 0
bx lr
END(cloudabi_sys_fd_stat_put)
ENTRY(cloudabi_sys_fd_sync)
mov ip, #15
swi 0
bx lr
END(cloudabi_sys_fd_sync)
ENTRY(cloudabi_sys_fd_write)
str r3, [sp, #-4]
mov ip, #16
swi 0
ldr r2, [sp, #-4]
bcs 1f
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_fd_write)
ENTRY(cloudabi_sys_file_advise)
mov ip, #17
swi 0
bx lr
END(cloudabi_sys_file_advise)
ENTRY(cloudabi_sys_file_allocate)
mov ip, #18
swi 0
bx lr
END(cloudabi_sys_file_allocate)
ENTRY(cloudabi_sys_file_create)
mov ip, #19
swi 0
bx lr
END(cloudabi_sys_file_create)
ENTRY(cloudabi_sys_file_link)
mov ip, #20
swi 0
bx lr
END(cloudabi_sys_file_link)
ENTRY(cloudabi_sys_file_open)
mov ip, #21
swi 0
bcs 1f
ldr r2, [sp, #12]
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_file_open)
ENTRY(cloudabi_sys_file_readdir)
mov ip, #22
swi 0
bcs 1f
ldr r2, [sp, #8]
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_file_readdir)
ENTRY(cloudabi_sys_file_readlink)
mov ip, #23
swi 0
bcs 1f
ldr r2, [sp, #8]
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_file_readlink)
ENTRY(cloudabi_sys_file_rename)
mov ip, #24
swi 0
bx lr
END(cloudabi_sys_file_rename)
ENTRY(cloudabi_sys_file_stat_fget)
mov ip, #25
swi 0
bx lr
END(cloudabi_sys_file_stat_fget)
ENTRY(cloudabi_sys_file_stat_fput)
mov ip, #26
swi 0
bx lr
END(cloudabi_sys_file_stat_fput)
ENTRY(cloudabi_sys_file_stat_get)
mov ip, #27
swi 0
bx lr
END(cloudabi_sys_file_stat_get)
ENTRY(cloudabi_sys_file_stat_put)
mov ip, #28
swi 0
bx lr
END(cloudabi_sys_file_stat_put)
ENTRY(cloudabi_sys_file_symlink)
mov ip, #29
swi 0
bx lr
END(cloudabi_sys_file_symlink)
ENTRY(cloudabi_sys_file_unlink)
mov ip, #30
swi 0
bx lr
END(cloudabi_sys_file_unlink)
ENTRY(cloudabi_sys_lock_unlock)
mov ip, #31
swi 0
bx lr
END(cloudabi_sys_lock_unlock)
ENTRY(cloudabi_sys_mem_advise)
mov ip, #32
swi 0
bx lr
END(cloudabi_sys_mem_advise)
ENTRY(cloudabi_sys_mem_lock)
mov ip, #33
swi 0
bx lr
END(cloudabi_sys_mem_lock)
ENTRY(cloudabi_sys_mem_map)
mov ip, #34
swi 0
bcs 1f
ldr r2, [sp, #16]
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_mem_map)
ENTRY(cloudabi_sys_mem_protect)
mov ip, #35
swi 0
bx lr
END(cloudabi_sys_mem_protect)
ENTRY(cloudabi_sys_mem_sync)
mov ip, #36
swi 0
bx lr
END(cloudabi_sys_mem_sync)
ENTRY(cloudabi_sys_mem_unlock)
mov ip, #37
swi 0
bx lr
END(cloudabi_sys_mem_unlock)
ENTRY(cloudabi_sys_mem_unmap)
mov ip, #38
swi 0
bx lr
END(cloudabi_sys_mem_unmap)
ENTRY(cloudabi_sys_poll)
str r3, [sp, #-4]
mov ip, #39
swi 0
ldr r2, [sp, #-4]
bcs 1f
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_poll)
ENTRY(cloudabi_sys_poll_fd)
mov ip, #40
swi 0
bcs 1f
ldr r2, [sp, #12]
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_poll_fd)
ENTRY(cloudabi_sys_proc_exec)
mov ip, #41
swi 0
bx lr
END(cloudabi_sys_proc_exec)
ENTRY(cloudabi_sys_proc_exit)
mov ip, #42
swi 0
END(cloudabi_sys_proc_exit)
ENTRY(cloudabi_sys_proc_fork)
str r0, [sp, #-4]
str r1, [sp, #-8]
mov ip, #43
swi 0
ldr r2, [sp, #-4]
ldr r3, [sp, #-8]
bcs 1f
str r0, [r2]
str r1, [r3]
mov r0, $0
1:
bx lr
END(cloudabi_sys_proc_fork)
ENTRY(cloudabi_sys_proc_raise)
mov ip, #44
swi 0
bx lr
END(cloudabi_sys_proc_raise)
ENTRY(cloudabi_sys_random_get)
mov ip, #45
swi 0
bx lr
END(cloudabi_sys_random_get)
ENTRY(cloudabi_sys_sock_accept)
str r2, [sp, #-4]
mov ip, #46
swi 0
ldr r2, [sp, #-4]
bcs 1f
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_sock_accept)
ENTRY(cloudabi_sys_sock_bind)
mov ip, #47
swi 0
bx lr
END(cloudabi_sys_sock_bind)
ENTRY(cloudabi_sys_sock_connect)
mov ip, #48
swi 0
bx lr
END(cloudabi_sys_sock_connect)
ENTRY(cloudabi_sys_sock_listen)
mov ip, #49
swi 0
bx lr
END(cloudabi_sys_sock_listen)
ENTRY(cloudabi_sys_sock_recv)
mov ip, #50
swi 0
bx lr
END(cloudabi_sys_sock_recv)
ENTRY(cloudabi_sys_sock_send)
mov ip, #51
swi 0
bx lr
END(cloudabi_sys_sock_send)
ENTRY(cloudabi_sys_sock_shutdown)
mov ip, #52
swi 0
bx lr
END(cloudabi_sys_sock_shutdown)
ENTRY(cloudabi_sys_sock_stat_get)
mov ip, #53
swi 0
bx lr
END(cloudabi_sys_sock_stat_get)
ENTRY(cloudabi_sys_thread_create)
str r1, [sp, #-4]
mov ip, #54
swi 0
ldr r2, [sp, #-4]
bcs 1f
str r0, [r2]
mov r0, $0
1:
bx lr
END(cloudabi_sys_thread_create)
ENTRY(cloudabi_sys_thread_exit)
mov ip, #55
swi 0
END(cloudabi_sys_thread_exit)
ENTRY(cloudabi_sys_thread_yield)
mov ip, #56
swi 0
bx lr
END(cloudabi_sys_thread_yield)