[linux] Use host glibc system call wrappers

When building as a Linux userspace application, iPXE currently
implements its own system calls to the host kernel rather than relying
on the host's C library.  The output binary is statically linked and
has no external dependencies.

This matches the general philosophy of other platforms on which iPXE
runs, since there are no external libraries available on either BIOS
or UEFI bare metal.  However, it would be useful for the Linux
userspace application to be able to link against host libraries such
as libslirp.

Modify the build process to perform a two-stage link: first picking
out the requested objects in the usual way from blib.a but with
relocations left present, then linking again with a helper object to
create a standard hosted application.  The helper object provides the
standard main() entry point and wrappers for the Linux system calls
required by the iPXE Linux drivers and interface code.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown
2021-02-28 13:45:58 +00:00
parent 040cdd0c65
commit f309d7a7b7
29 changed files with 553 additions and 601 deletions

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@@ -1,6 +1,14 @@
# -*- makefile -*- : Force emacs to use Makefile mode
# Linker script
#
LDSCRIPT = arch/i386/scripts/linux.lds
SRCDIRS += arch/i386/core/linux
# Compiler flags for building host API wrapper
#
LINUX_CFLAGS += -m32
# Include generic Linux Makefile
#
MAKEDEPS += arch/x86/Makefile.linux
include arch/x86/Makefile.linux

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@@ -1,45 +0,0 @@
.section ".data"
.globl linux_errno
linux_errno: .int 0
.section ".text"
.code32
.globl linux_syscall
.type linux_syscall, @function
linux_syscall:
/* Save registers */
pushl %ebx
pushl %esi
pushl %edi
pushl %ebp
movl 20(%esp), %eax // C arg1 -> syscall number
movl 24(%esp), %ebx // C arg2 -> syscall arg1
movl 28(%esp), %ecx // C arg3 -> syscall arg2
movl 32(%esp), %edx // C arg4 -> syscall arg3
movl 36(%esp), %esi // C arg5 -> syscall arg4
movl 40(%esp), %edi // C arg6 -> syscall arg5
movl 44(%esp), %ebp // C arg7 -> syscall arg6
int $0x80
/* Restore registers */
popl %ebp
popl %edi
popl %esi
popl %ebx
cmpl $-4095, %eax
jae 1f
ret
1:
negl %eax
movl %eax, linux_errno
movl $-1, %eax
ret
.size linux_syscall, . - linux_syscall

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@@ -1,28 +0,0 @@
#include <linux/unistd.h>
.section ".text"
.code32
.globl _linux_start
.type _linux_start, @function
_linux_start:
xorl %ebp, %ebp
popl %esi // save argc
movl %esp, %edi // save argv
andl $~15, %esp // 16-byte align the stack
pushl %edi // argv -> C arg2
pushl %esi // argc -> C arg1
call save_args
/* Our main doesn't use any arguments */
call main
movl %eax, %ebx // rc -> syscall arg1
movl $__NR_exit, %eax
int $0x80
.size _linux_start, . - _linux_start

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@@ -1,6 +0,0 @@
#ifndef _I386_LINUX_API_H
#define _I386_LINUX_API_H
#define __SYSCALL_mmap __NR_mmap2
#endif /* _I386_LINUX_API_H */

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@@ -1,15 +1,10 @@
MEDIA = linux
# enable valgrind
CFLAGS += -UNVALGRIND
SYMBOL_PREFIX = _ipxe__
# -*- makefile -*- : Force emacs to use Makefile mode
# Include x86 Linux headers
#
INCDIRS += arch/x86/include/linux
SRCDIRS += interface/linux
SRCDIRS += drivers/linux
SRCDIRS += arch/x86/core/linux
$(BIN)/%.linux : $(BIN)/%.linux.tmp
$(QM)$(ECHO) " [FINISH] $@"
$(Q)$(CP) $< $@
# Include generic Linux Makefile
#
MAKEDEPS += Makefile.linux
include Makefile.linux

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@@ -1,149 +0,0 @@
/*
* Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
/** @file
*
* Implementation of most of the linux API.
*/
#include <linux_api.h>
#include <stdarg.h>
#include <asm/unistd.h>
#include <string.h>
int linux_open ( const char *pathname, int flags ) {
return linux_syscall ( __NR_open, pathname, flags );
}
int linux_close ( int fd ) {
return linux_syscall ( __NR_close, fd );
}
off_t linux_lseek ( int fd, off_t offset, int whence ) {
return linux_syscall ( __NR_lseek, fd, offset, whence );
}
__kernel_ssize_t linux_read ( int fd, void *buf, __kernel_size_t count ) {
return linux_syscall ( __NR_read, fd, buf, count );
}
__kernel_ssize_t linux_write ( int fd, const void *buf,
__kernel_size_t count ) {
return linux_syscall ( __NR_write, fd, buf, count );
}
int linux_fcntl ( int fd, int cmd, ... ) {
long arg;
va_list list;
va_start ( list, cmd );
arg = va_arg ( list, long );
va_end ( list );
return linux_syscall ( __NR_fcntl, fd, cmd, arg );
}
int linux_ioctl ( int fd, int request, ... ) {
void *arg;
va_list list;
va_start ( list, request );
arg = va_arg ( list, void * );
va_end ( list );
return linux_syscall ( __NR_ioctl, fd, request, arg );
}
int linux_poll ( struct pollfd *fds, nfds_t nfds, int timeout ) {
return linux_syscall ( __NR_poll, fds, nfds, timeout );
}
int linux_nanosleep ( const struct timespec *req, struct timespec *rem ) {
return linux_syscall ( __NR_nanosleep, req, rem );
}
int linux_usleep ( useconds_t usec ) {
struct timespec ts = {
.tv_sec = ( ( long ) ( usec / 1000000 ) ),
.tv_nsec = ( ( long ) ( usec % 1000000 ) * 1000UL ),
};
return linux_nanosleep ( &ts, NULL );
}
int linux_gettimeofday ( struct timeval *tv, struct timezone *tz ) {
return linux_syscall ( __NR_gettimeofday, tv, tz );
}
void * linux_mmap ( void *addr, __kernel_size_t length, int prot, int flags,
int fd, __kernel_off_t offset ) {
return ( void * ) linux_syscall ( __SYSCALL_mmap, addr, length, prot,
flags, fd, offset );
}
void * linux_mremap ( void *old_address, __kernel_size_t old_size,
__kernel_size_t new_size, int flags ) {
return ( void * ) linux_syscall ( __NR_mremap, old_address, old_size,
new_size, flags );
}
int linux_munmap ( void *addr, __kernel_size_t length ) {
return linux_syscall ( __NR_munmap, addr, length );
}
int linux_socket ( int domain, int type_, int protocol ) {
#ifdef __NR_socket
return linux_syscall ( __NR_socket, domain, type_, protocol );
#else
#ifndef SOCKOP_socket
# define SOCKOP_socket 1
#endif
unsigned long sc_args[] = { domain, type_, protocol };
return linux_syscall ( __NR_socketcall, SOCKOP_socket, sc_args );
#endif
}
int linux_bind ( int fd, const struct sockaddr *addr, socklen_t addrlen ) {
#ifdef __NR_bind
return linux_syscall ( __NR_bind, fd, addr, addrlen );
#else
#ifndef SOCKOP_bind
# define SOCKOP_bind 2
#endif
unsigned long sc_args[] = { fd, (unsigned long)addr, addrlen };
return linux_syscall ( __NR_socketcall, SOCKOP_bind, sc_args );
#endif
}
ssize_t linux_sendto ( int fd, const void *buf, size_t len, int flags,
const struct sockaddr *daddr, socklen_t addrlen ) {
#ifdef __NR_sendto
return linux_syscall ( __NR_sendto, fd, buf, len, flags,
daddr, addrlen );
#else
#ifndef SOCKOP_sendto
# define SOCKOP_sendto 11
#endif
unsigned long sc_args[] = { fd, (unsigned long)buf, len,
flags, (unsigned long)daddr, addrlen };
return linux_syscall ( __NR_socketcall, SOCKOP_sendto, sc_args );
#endif
}

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@@ -1,169 +0,0 @@
/*
* Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
FILE_LICENCE(GPL2_OR_LATER);
/** @file
*
* linux_strerror implementation
*/
#include <linux_api.h>
#include <stdio.h>
/** Error names from glibc */
static const char *errors[] = {
"Success",
"Operation not permitted",
"No such file or directory",
"No such process",
"Interrupted system call",
"Input/output error",
"No such device or address",
"Argument list too long",
"Exec format error",
"Bad file descriptor",
"No child processes",
"Resource temporarily unavailable",
"Cannot allocate memory",
"Permission denied",
"Bad address",
"Block device required",
"Device or resource busy",
"File exists",
"Invalid cross-device link",
"No such device",
"Not a directory",
"Is a directory",
"Invalid argument",
"Too many open files in system",
"Too many open files",
"Inappropriate ioctl for device",
"Text file busy",
"File too large",
"No space left on device",
"Illegal seek",
"Read-only file system",
"Too many links",
"Broken pipe",
"Numerical argument out of domain",
"Numerical result out of range",
"Resource deadlock avoided",
"File name too long",
"No locks available",
"Function not implemented",
"Directory not empty",
"Too many levels of symbolic links",
"",
"No message of desired type",
"Identifier removed",
"Channel number out of range",
"Level 2 not synchronized",
"Level 3 halted",
"Level 3 reset",
"Link number out of range",
"Protocol driver not attached",
"No CSI structure available",
"Level 2 halted",
"Invalid exchange",
"Invalid request descriptor",
"Exchange full",
"No anode",
"Invalid request code",
"Invalid slot",
"",
"Bad font file format",
"Device not a stream",
"No data available",
"Timer expired",
"Out of streams resources",
"Machine is not on the network",
"Package not installed",
"Object is remote",
"Link has been severed",
"Advertise error",
"Srmount error",
"Communication error on send",
"Protocol error",
"Multihop attempted",
"RFS specific error",
"Bad message",
"Value too large for defined data type",
"Name not unique on network",
"File descriptor in bad state",
"Remote address changed",
"Can not access a needed shared library",
"Accessing a corrupted shared library",
".lib section in a.out corrupted",
"Attempting to link in too many shared libraries",
"Cannot exec a shared library directly",
"Invalid or incomplete multibyte or wide character",
"Interrupted system call should be restarted",
"Streams pipe error",
"Too many users",
"Socket operation on non-socket",
"Destination address required",
"Message too long",
"Protocol wrong type for socket",
"Protocol not available",
"Protocol not supported",
"Socket type not supported",
"Operation not supported",
"Protocol family not supported",
"Address family not supported by protocol",
"Address already in use",
"Cannot assign requested address",
"Network is down",
"Network is unreachable",
"Network dropped connection on reset",
"Software caused connection abort",
"Connection reset by peer",
"No buffer space available",
"Transport endpoint is already connected",
"Transport endpoint is not connected",
"Cannot send after transport endpoint shutdown",
"Too many references: cannot splice",
"Connection timed out",
"Connection refused",
"Host is down",
"No route to host",
"Operation already in progress",
"Operation now in progress",
"Stale NFS file handle",
"Structure needs cleaning",
"Not a XENIX named type file",
"No XENIX semaphores available",
"Is a named type file",
"Remote I/O error",
"Disk quota exceeded",
"No medium found",
"Wrong medium type",
};
const char *linux_strerror(int errnum)
{
static char errbuf[64];
static int errors_size = sizeof(errors) / sizeof(*errors);
if (errnum >= errors_size || errnum < 0) {
snprintf(errbuf, sizeof(errbuf), "Error %#08x", errnum);
return errbuf;
} else {
return errors[errnum];
}
}

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@@ -1,6 +0,0 @@
#ifndef _LINUX_API_PLATFORM_H
#define _LINUX_API_PLATFORM_H
extern int linux_errno;
#endif /* _LINUX_API_PLATFORM_H */

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@@ -1,6 +1,10 @@
# -*- makefile -*- : Force emacs to use Makefile mode
# Linker script
#
LDSCRIPT = arch/x86_64/scripts/linux.lds
SRCDIRS += arch/x86_64/core/linux
# Include generic Linux Makefile
#
MAKEDEPS += arch/x86/Makefile.linux
include arch/x86/Makefile.linux

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@@ -1,33 +0,0 @@
.section ".data"
.globl linux_errno
linux_errno: .int 0
.section ".text"
.code64
.globl linux_syscall
.type linux_syscall, @function
linux_syscall:
movq %rdi, %rax // C arg1 -> syscall number
movq %rsi, %rdi // C arg2 -> syscall arg1
movq %rdx, %rsi // C arg3 -> syscall arg2
movq %rcx, %rdx // C arg4 -> syscall arg3
movq %r8, %r10 // C arg5 -> syscall arg4
movq %r9, %r8 // C arg6 -> syscall arg5
movq 8(%rsp), %r9 // C arg7 -> syscall arg6
syscall
cmpq $-4095, %rax
jae 1f
ret
1:
negq %rax
movl %eax, linux_errno
movq $-1, %rax
ret
.size linux_syscall, . - linux_syscall

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@@ -1,25 +0,0 @@
#include <linux/unistd.h>
.section ".text"
.code64
.globl _linux_start
.type _linux_start, @function
_linux_start:
xorq %rbp, %rbp
popq %rdi // argc -> C arg1
movq %rsp, %rsi // argv -> C arg2
andq $~15, %rsp // 16-byte align the stack
call save_args
/* Our main doesn't use any arguments */
call main
movq %rax, %rdi // rc -> syscall arg1
movq $__NR_exit, %rax
syscall
.size _linux_start, . - _linux_start

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@@ -1,6 +0,0 @@
#ifndef _X86_64_LINUX_API_H
#define _X86_64_LINUX_API_H
#define __SYSCALL_mmap __NR_mmap
#endif /* _X86_64_LINUX_API_H */