rust/tests/run-make/mte-ffi/bar_float.c
Damian Heaton e8ce9fac85 Add tests to ensure MTE tags are preserved across FFI boundaries
Added run-make tests to verify that, between a Rust-C FFI boundary in both directions,
any MTE tags included in a pointer are preserved for the following pointer types, as
well as any information stored using TBI:
- int
- float
- string
- function
2024-07-30 10:12:51 +01:00

45 lines
991 B
C

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include "bar.h"
extern void foo(char*);
void bar(char *ptr) {
if (((uintptr_t)ptr >> 56) != 0x1f) {
fprintf(stderr, "Top byte corrupted on Rust -> C FFI boundary!\n");
exit(1);
}
}
int main(void)
{
float *ptr = alloc_page();
if (ptr == MAP_FAILED)
{
perror("mmap() failed");
return EXIT_FAILURE;
}
// Store an arbitrary tag in bits 56-59 of the pointer (where an MTE tag may be),
// and a different value in the ignored top 4 bits.
ptr = (float *)((uintptr_t)ptr | 0x1fl << 56);
if (mte_enabled()) {
set_tag(ptr);
}
ptr[0] = 2.0f;
ptr[1] = 1.5f;
foo(ptr); // should change the contents of the page and call `bar`
if (ptr[0] != 0.5f || ptr[1] != 0.2f) {
fprintf(stderr, "invalid data in memory; expected '0.5 0.2', got '%f %f'\n",
ptr[0], ptr[1]);
return EXIT_FAILURE;
}
return 0;
}