forked from OSchip/llvm-project
37 lines
982 B
C
37 lines
982 B
C
// 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 an
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// architecture-specific register to point at it.
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#pragma once
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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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#include "libc_support.h"
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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 defined(__aarch64__)
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__asm__ __volatile__("mov x18, %0" ::"r"(stack));
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#else
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#error Unsupported platform
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#endif
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}
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int scs_main(void);
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__attribute__((no_sanitize("shadow-call-stack"))) int main(void) {
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__shadowcallstack_init();
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// We can't simply return scs_main() because scs_main might have corrupted our
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// return address for testing purposes (see overflow.c), so we need to exit
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// ourselves.
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exit(scs_main());
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}
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