| 1 | //===-- Implementation of sigsetjmp ---------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "src/setjmp/sigsetjmp.h" |
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| 10 | #include "hdr/offsetof_macros.h" |
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| 11 | #include "src/__support/common.h" |
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| 12 | #include "src/__support/macros/config.h" |
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| 13 | #include "src/setjmp/setjmp_impl.h" |
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| 14 | #include "src/setjmp/sigsetjmp_epilogue.h" |
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| 15 | |
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| 16 | namespace LIBC_NAMESPACE_DECL { |
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| 17 | [[gnu::naked]] |
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| 18 | LLVM_LIBC_FUNCTION(int, sigsetjmp, (sigjmp_buf buf)) { |
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| 19 | #if defined(__thumb__) && __ARM_ARCH_ISA_THUMB == 1 |
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| 20 | // Thumb1 does not support the high registers > r7 in stmia, so move them |
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| 21 | // into lower GPRs first. |
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| 22 | asm(R"( |
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| 23 | tst r1, r1 |
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| 24 | bne .Ldosave |
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| 25 | b %c[setjmp] |
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| 26 | .Ldosave: |
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| 27 | str r4, [r0, #%c[extra]] |
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| 28 | mov r4, lr |
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| 29 | str r4, [r0, #%c[retaddr]] |
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| 30 | mov r4, r0 |
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| 31 | bl %c[setjmp] |
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| 32 | mov r1, r0 |
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| 33 | mov r0, r4 |
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| 34 | ldr r4, [r0, #%c[retaddr]] |
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| 35 | mov lr, r4 |
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| 36 | ldr r4, [r0, #%c[extra]] |
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| 37 | b %c[epilogue] |
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| 38 | )" ::[retaddr] "i" (offsetof(__jmp_buf, sig_retaddr)), |
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| 39 | [extra] "i" (offsetof(__jmp_buf, sig_extra)), [setjmp] "i" (setjmp), |
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| 40 | [epilogue] "i" (sigsetjmp_epilogue) |
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| 41 | : "r0" , "r1" , "r4" ); |
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| 42 | #else |
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| 43 | // Some thumb2 linkers do not support conditional branch to PLT. |
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| 44 | // We branch to local labels instead. |
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| 45 | asm(R"( |
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| 46 | tst r1, r1 |
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| 47 | bne .Ldosave |
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| 48 | b %c[setjmp] |
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| 49 | .Ldosave: |
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| 50 | str r4, [r0, #%c[extra]] |
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| 51 | str lr, [r0, #%c[retaddr]] |
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| 52 | mov r4, r0 |
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| 53 | bl %c[setjmp] |
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| 54 | mov r1, r0 |
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| 55 | mov r0, r4 |
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| 56 | ldr lr, [r0, #%c[retaddr]] |
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| 57 | ldr r4, [r0, #%c[extra]] |
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| 58 | b %c[epilogue] |
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| 59 | )" ::[retaddr] "i" (offsetof(__jmp_buf, sig_retaddr)), |
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| 60 | [extra] "i" (offsetof(__jmp_buf, sig_extra)), [setjmp] "X" (setjmp), |
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| 61 | [epilogue] "X" (sigsetjmp_epilogue) |
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| 62 | : "r0" , "r1" , "r4" ); |
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| 63 | #endif |
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| 64 | } |
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| 65 | } // namespace LIBC_NAMESPACE_DECL |
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| 66 | |
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