44 lines
1.3 KiB
C
44 lines
1.3 KiB
C
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#ifndef __BAR_H
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#define __BAR_H
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#include <sys/mman.h>
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#include <sys/auxv.h>
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#include <sys/prctl.h>
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#include <unistd.h>
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#include <stdio.h>
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// Set the allocation tag on the destination address using the STG instruction.
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#define set_tag(tagged_addr) do { \
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asm volatile("stg %0, [%0]" : : "r" (tagged_addr) : "memory"); \
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} while (0)
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int mte_enabled() {
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return (getauxval(AT_HWCAP2)) & HWCAP2_MTE;
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}
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void *alloc_page() {
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// Enable MTE with synchronous checking
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if (prctl(PR_SET_TAGGED_ADDR_CTRL,
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PR_TAGGED_ADDR_ENABLE | PR_MTE_TCF_SYNC | (0xfffe << PR_MTE_TAG_SHIFT),
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0, 0, 0))
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{
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perror("prctl() failed");
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}
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// Using `mmap` allows us to ensure that, on systems which support MTE, the allocated
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// memory is 16-byte aligned for MTE.
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// This also allows us to explicitly specify whether the region should be protected by
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// MTE or not.
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if (mte_enabled()) {
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void *ptr = mmap(NULL, sysconf(_SC_PAGESIZE),
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PROT_READ | PROT_WRITE | PROT_MTE, MAP_PRIVATE | MAP_ANONYMOUS,
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-1, 0);
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} else {
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void *ptr = mmap(NULL, sysconf(_SC_PAGESIZE),
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PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS,
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-1, 0);
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}
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}
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#endif // __BAR_H
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