forked from OSchip/llvm-project
27 lines
725 B
C
27 lines
725 B
C
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// A shadow call stack runtime is not yet included with compiler-rt, provide a
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// minimal runtime to allocate a shadow call stack and assign %gs to point at
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// it.
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#pragma once
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#include <asm/prctl.h>
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#include <stdlib.h>
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#include <sys/mman.h>
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#include <sys/prctl.h>
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int arch_prctl(int code, void *addr);
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__attribute__((no_sanitize("shadow-call-stack")))
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static void __shadowcallstack_init() {
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void *stack = mmap(NULL, 8192, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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if (stack == MAP_FAILED)
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abort();
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if (arch_prctl(ARCH_SET_GS, stack))
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abort();
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}
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__attribute__((section(".preinit_array"), used))
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void (*__shadowcallstack_preinit)(void) = __shadowcallstack_init;
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