| 1 | /* PLT trampolines. Nios II version. |
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| 2 | Copyright (C) 2005-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library. If not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <sysdep.h> |
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| 20 | #include <libc-symbols.h> |
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| 21 | |
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| 22 | .text |
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| 23 | .globl _dl_runtime_resolve |
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| 24 | cfi_startproc |
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| 25 | _dl_runtime_resolve: |
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| 26 | /* The runtime resolver receives the original function arguments in r4 |
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| 27 | through r7, the shared library identifier from GOT[1]? in r14, and the |
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| 28 | relocation index times four in r15. It updates the corresponding PLT GOT |
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| 29 | entry so that the PLT entry will transfer control directly to the target |
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| 30 | in the future, and then transfers control to the target. */ |
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| 31 | /* Save arguments and return address. */ |
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| 32 | subi sp, sp, 28 |
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| 33 | cfi_adjust_cfa_offset (28) |
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| 34 | stw r22, 24(sp) |
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| 35 | cfi_rel_offset (r22, 24) |
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| 36 | stw r8, 20(sp) /* save r8, because this might be a call to mcount */ |
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| 37 | cfi_rel_offset (r8, 20) |
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| 38 | stw r7, 16(sp) |
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| 39 | cfi_rel_offset (r7, 16) |
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| 40 | stw r6, 12(sp) |
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| 41 | cfi_rel_offset (r6, 12) |
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| 42 | stw r5, 8(sp) |
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| 43 | cfi_rel_offset (r5, 8) |
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| 44 | stw r4, 4(sp) |
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| 45 | cfi_rel_offset (r4, 4) |
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| 46 | stw ra, 0(sp) |
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| 47 | cfi_rel_offset (ra, 0) |
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| 48 | |
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| 49 | /* Get pointer to linker struct. */ |
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| 50 | mov r4, r14 |
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| 51 | |
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| 52 | /* Get the relocation offset. We're given a multiple of 4 and |
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| 53 | need a multiple of 12, so multiply by 3. */ |
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| 54 | slli r5, r15, 1 |
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| 55 | add r5, r5, r15 |
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| 56 | |
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| 57 | /* Call the fixup routine. */ |
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| 58 | nextpc r22 |
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| 59 | 1: movhi r2, %hiadj(_gp_got - 1b) |
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| 60 | addi r2, r2, %lo(_gp_got - 1b) |
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| 61 | add r22, r22, r2 |
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| 62 | ldw r2, %call(_dl_fixup)(r22) |
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| 63 | callr r2 |
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| 64 | |
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| 65 | /* Restore the arguments and return address. */ |
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| 66 | ldw ra, 0(sp) |
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| 67 | ldw r4, 4(sp) |
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| 68 | ldw r5, 8(sp) |
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| 69 | ldw r6, 12(sp) |
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| 70 | ldw r7, 16(sp) |
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| 71 | ldw r8, 20(sp) |
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| 72 | ldw r22, 24(sp) |
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| 73 | addi sp, sp, 28 |
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| 74 | cfi_adjust_cfa_offset (-28) |
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| 75 | |
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| 76 | /* Jump to the newly found address. */ |
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| 77 | jmp r2 |
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| 78 | |
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| 79 | cfi_endproc |
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| 80 | |
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