48 lines
1.2 KiB
C
48 lines
1.2 KiB
C
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include "bar.h"
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extern void foo(unsigned int *);
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void bar(char *ptr) {
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if (((uintptr_t)ptr >> 56) != 0x1f) {
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fprintf(stderr, "Top byte corrupted on Rust -> C FFI boundary!\n");
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exit(1);
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}
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}
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int main(void)
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{
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// Construct a pointer with an arbitrary tag in bits 56-59, simulating an MTE tag.
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// It's only necessary that the tag is preserved across FFI bounds for this test.
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unsigned int *ptr;
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ptr = alloc_page();
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if (ptr == MAP_FAILED)
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{
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perror("mmap() failed");
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return EXIT_FAILURE;
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}
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// Store an arbitrary tag in bits 56-59 of the pointer (where an MTE tag may be),
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// and a different value in the ignored top 4 bits.
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ptr = (unsigned int *)((uintptr_t)ptr | 0x1fl << 56);
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if (mte_enabled()) {
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set_tag(ptr);
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}
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ptr[0] = 61;
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ptr[1] = 62;
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foo(ptr); // should change the contents of the page to start with 0x63 0x64 and call `bar`
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if (ptr[0] != 0x63 || ptr[1] != 0x64) {
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fprintf(stderr, "invalid data in memory; expected '63 64', got '%d %d'\n", ptr[0], ptr[1]);
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return EXIT_FAILURE;
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}
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return 0;
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}
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