/* $OpenBSD: ldasm.S,v 1.29 2019/02/03 02:20:36 guenther Exp $ */ /* * Copyright (c) 2013 Miodrag Vallat. * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* * Copyright (c) 2006 Dale Rahn * * 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 ``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 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 <machine/asm.h> #include <sys/syscall.h> #define AUX_base 7 #define AUX_entry 9 /* * ld.so entry point. * On entry: r31 points to the kernel argument struct (argv, argv, environ). * The environment pointers list is followed by an array of AuxInfo * structs filled by the kernel. */ ENTRY(_dl_start) /* * Two nop because execution may skip up to two instructions. * See setregs() in the kernel for details. * * Note that I have been hacking m88k for years and still fall * into this trap, every time. -- miod */ or %r0, %r0, %r0 or %r0, %r0, %r0 /* * Get some room for the contiguous AUX pointers array. */ or %r30, %r31, 0 subu %r31, %r31, (4 * (AUX_entry + 1)) /* * Align the stack to a 16 byte boundary. */ clr %r31, %r31, 4<0> /* * Invoke _dl_boot_bind */ or %r2, %r30, 0 | kernel args or %r3, %r31, 0 | array base bsr 1f | the following instruction is skipped bsr _DYNAMIC | but gives us the pc-relative offset 1: ld %r6, %r1, 0 | fetch branch instruction mak %r5, %r6, 26<2> | pick branch offset and shift left by 2 addu %r4, %r5, %r1 bsr _dl_boot_bind ld %r2, %r30, 0 | argc addu %r6, %r30, 4 + 4 lda %r3, %r6[%r2] | envp ld %r4, %r31, 4 * AUX_base| ldoff or %r5, %r31, 0 | array base bsr.n _dl_boot addu %r2, %r30, 4 | argv or %r31, %r30, 0 bsr 1f | the following instruction is skipped bcnd eq0, %r0, _dl_dtors | but gives us the pc-relative offset 1: ld.h %r5, %r1, 2 | fetch branch offset (low 16 bits) jmp.n %r2 lda %r5, %r1[%r5] | cleanup END(_dl_start) /* * PLT resolver entry point. * Invoked with the following stack frame: * r31(0x00) zero * r31(0x04) ELF object * r31(0x08) saved r11 * r31(0x0c) saved r1 * All registers but r1 and r11 must be preserved. The resolver must return * to the resolved address with r1 restored. */ #define OBJECT_OFFSET (4 * 1) #define R11_OFFSET (4 * 2) #define R1_OFFSET (4 * 3) #define PLT_FRAME_SIZE (4 * 4) #define REG_SIZE (4 * 12) ENTRY(_dl_bind_start) /* * Preserve caller-saved registers. */ subu %r31, %r31, REG_SIZE st.d %r2, %r31, 4 * 0 st.d %r4, %r31, 4 * 2 st.d %r6, %r31, 4 * 4 st.d %r8, %r31, 4 * 6 st %r10, %r31, 4 * 8 st.d %r12, %r31, 4 * 10 /* * Invoke resolver entry point. */ ld %r2, %r31, REG_SIZE + OBJECT_OFFSET bsr.n _dl_bind ld %r3, %r31, REG_SIZE + R11_OFFSET | reloff /* * Preserve return address. */ or %r11, %r2, %r0 /* * Restore caller-saved registers. */ ld.d %r12, %r31, 4 * 10 ld %r10, %r31, 4 * 8 ld.d %r8, %r31, 4 * 6 ld.d %r6, %r31, 4 * 4 ld.d %r4, %r31, 4 * 2 ld.d %r2, %r31, 4 * 0 ld %r1, %r31, REG_SIZE + R1_OFFSET jmp.n %r11 addu %r31, %r31, REG_SIZE + PLT_FRAME_SIZE END(_dl_bind_start) ENTRY(_dl_cacheflush) tb0 0, %r0, 451 or %r0, %r0, %r0 | never hit jmp %r1 END(_dl_cacheflush)
