/*- * Copyright (c) 2014 The FreeBSD Foundation * * This software was developed by Andrew Turner 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 <machine/asm.h> #include <sys/elf_common.h> ENTRY(.rtld_start) .cfi_undefined x30 mov x19, x0 /* Put ps_strings in a callee-saved register */ sub sp, sp, #16 /* Make room for obj_main & exit proc */ .cfi_adjust_cfa_offset 16 mov x1, sp /* exit_proc */ add x2, x1, #8 /* obj_main */ bl _rtld /* Call the loader */ mov x8, x0 /* Backup the entry point */ ldp x2, x1, [sp], #16 /* Load cleanup, obj_main */ .cfi_adjust_cfa_offset 0 mov x0, x19 /* Restore ps_strings */ br x8 /* Jump to the entry point */ END(.rtld_start) /* * sp + 0 = &GOT[x + 3] * sp + 8 = RA * x16 = &GOT[2] * x17 = &_rtld_bind_start */ ENTRY(_rtld_bind_start) mov x17, sp /* Save frame pointer and SP */ stp x29, x30, [sp, #-16]! mov x29, sp .cfi_def_cfa x29, 16 .cfi_offset x30, -8 .cfi_offset x29, -16 /* Save the arguments */ stp x0, x1, [sp, #-16]! stp x2, x3, [sp, #-16]! stp x4, x5, [sp, #-16]! stp x6, x7, [sp, #-16]! stp x8, xzr, [sp, #-16]! /* Save any floating-point arguments */ stp q0, q1, [sp, #-32]! stp q2, q3, [sp, #-32]! stp q4, q5, [sp, #-32]! stp q6, q7, [sp, #-32]! /* Calculate reloff */ ldr x2, [x17, #0] /* Get the address of the entry */ sub x1, x2, x16 /* Find its offset */ sub x1, x1, #8 /* Adjust for x16 not being at offset 0 */ /* Each rela item has 3 entriesso we need reloff = 3 * index */ lsl x3, x1, #1 /* x3 = 2 * offset */ add x1, x1, x3 /* x1 = x3 + offset = 3 * offset */ /* Load obj */ ldr x0, [x16, #-8] /* Call into rtld */ bl _rtld_bind /* Backup the address to branch to */ mov x16, x0 /* restore the arguments */ ldp q6, q7, [sp], #32 ldp q4, q5, [sp], #32 ldp q2, q3, [sp], #32 ldp q0, q1, [sp], #32 ldp x8, xzr, [sp], #16 ldp x6, x7, [sp], #16 ldp x4, x5, [sp], #16 ldp x2, x3, [sp], #16 ldp x0, x1, [sp], #16 /* Restore frame pointer */ ldp x29, xzr, [sp], #16 /* Restore link register saved by the plt code */ ldp xzr, x30, [sp], #16 /* Call into the correct function */ br x16 END(_rtld_bind_start) /* * struct rel_tlsdesc { * uint64_t resolver_fnc; * uint64_t resolver_arg; * * * uint64_t _rtld_tlsdesc_static(struct rel_tlsdesc *); * * Resolver function for TLS symbols resolved at load time */ ENTRY(_rtld_tlsdesc_static) ldr x0, [x0, #8] ret END(_rtld_tlsdesc_static) /* * uint64_t _rtld_tlsdesc_undef(void); * * Resolver function for weak and undefined TLS symbols */ ENTRY(_rtld_tlsdesc_undef) str x1, [sp, #-16]! .cfi_adjust_cfa_offset 16 mrs x1, tpidr_el0 ldr x0, [x0, #8] sub x0, x0, x1 ldr x1, [sp], #16 .cfi_adjust_cfa_offset -16 ret END(_rtld_tlsdesc_undef) /* * uint64_t _rtld_tlsdesc_dynamic(struct rel_tlsdesc *); * * Resolver function for TLS symbols from dlopen() */ ENTRY(_rtld_tlsdesc_dynamic) /* Save registers used in fast path */ stp x1, x2, [sp, #(-2 * 16)]! stp x3, x4, [sp, #(1 * 16)] .cfi_adjust_cfa_offset 2 * 16 .cfi_rel_offset x1, 0 .cfi_rel_offset x2, 8 .cfi_rel_offset x3, 16 .cfi_rel_offset x4, 24 /* Test fastpath - inlined version of tls_get_addr_common(). */ ldr x1, [x0, #8] /* tlsdesc ptr */ mrs x4, tpidr_el0 ldr x0, [x4] /* DTV pointer */ ldr x2, [x0] /* dtv[0] (generation count) */ ldr x3, [x1] /* tlsdec->dtv_gen */ cmp x2, x3 b.ne 1f /* dtv[0] != tlsdec->dtv_gen */ ldr w2, [x1, #8] /* tlsdec->tls_index */ add w2, w2, #1 ldr x3, [x0, w2, sxtw #3] /* dtv[tlsdesc->tls_index + 1] */ cbz x3, 1f /* Return (dtv[tlsdesc->tls_index + 1] + tlsdesc->tls_offs - tp) */ ldr x2, [x1, #16] /* tlsdec->tls_offs */ add x2, x2, x3 sub x0, x2, x4 /* Restore registers and return */ ldp x3, x4, [sp, #(1 * 16)] ldp x1, x2, [sp], #(2 * 16) .cfi_adjust_cfa_offset -2 * 16 ret /* * Slow path * return( * tls_get_addr_common(tcb, tlsdesc->tls_index, tlsdesc->tls_offs)); * */ 1: /* Save all integer registers */ stp x29, x30, [sp, #-(8 * 16)]! .cfi_adjust_cfa_offset 8 * 16 .cfi_rel_offset x29, 0 .cfi_rel_offset x30, 8 mov x29, sp stp x5, x6, [sp, #(1 * 16)] stp x7, x8, [sp, #(2 * 16)] stp x9, x10, [sp, #(3 * 16)] stp x11, x12, [sp, #(4 * 16)] stp x13, x14, [sp, #(5 * 16)] stp x15, x16, [sp, #(6 * 16)] stp x17, x18, [sp, #(7 * 16)] .cfi_rel_offset x5, 16 .cfi_rel_offset x6, 24 .cfi_rel_offset x7, 32 .cfi_rel_offset x8, 40 .cfi_rel_offset x9, 48 .cfi_rel_offset x10, 56 .cfi_rel_offset x11, 64 .cfi_rel_offset x12, 72 .cfi_rel_offset x13, 80 .cfi_rel_offset x14, 88 .cfi_rel_offset x15, 96 .cfi_rel_offset x16, 104 .cfi_rel_offset x17, 112 .cfi_rel_offset x18, 120 /* Find the tls offset */ mov x0, x4 /* tcb */ mov x3, x1 /* tlsdesc ptr */ ldr w1, [x3, #8] /* tlsdec->tls_index */ ldr x2, [x3, #16] /* tlsdec->tls_offs */ bl tls_get_addr_common mrs x1, tpidr_el0 sub x0, x0, x1 /* Restore slow patch registers */ ldp x17, x18, [sp, #(7 * 16)] ldp x15, x16, [sp, #(6 * 16)] ldp x13, x14, [sp, #(5 * 16)] ldp x11, x12, [sp, #(4 * 16)] ldp x9, x10, [sp, #(3 * 16)] ldp x7, x8, [sp, #(2 * 16)] ldp x5, x6, [sp, #(1 * 16)] ldp x29, x30, [sp], #(8 * 16) .cfi_adjust_cfa_offset -8 * 16 .cfi_restore x29 .cfi_restore x30 /* Restore fast path registers and return */ ldp x3, x4, [sp, #16] ldp x1, x2, [sp], #(2 * 16) .cfi_adjust_cfa_offset -2 * 16 ret END(_rtld_tlsdesc_dynamic) GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)
