Add a test that locklessly changes and exercises page protection bits from various threads. This helps catch race conditions in the VMA handling. Acked-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Message-Id: <20221223120252.513319-1-iii@linux.ibm.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
		
			
				
	
	
		
			66 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			66 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Test that munmap() and thread creation do not race. */
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#include <assert.h>
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#include <pthread.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mman.h>
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#include <unistd.h>
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#include "nop_func.h"
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static void *thread_mmap_munmap(void *arg)
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{
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    volatile bool *run = arg;
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    char *p;
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    int ret;
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    while (*run) {
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        p = mmap(NULL, getpagesize(), PROT_READ | PROT_WRITE | PROT_EXEC,
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                 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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        assert(p != MAP_FAILED);
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        /* Create a small translation block.  */
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        memcpy(p, nop_func, sizeof(nop_func));
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        ((void(*)(void))p)();
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        ret = munmap(p, getpagesize());
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        assert(ret == 0);
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    }
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    return NULL;
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}
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static void *thread_dummy(void *arg)
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{
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    return NULL;
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}
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int main(void)
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{
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    pthread_t mmap_munmap, dummy;
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    volatile bool run = true;
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    int i, ret;
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    /* Without a template, nothing to test. */
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    if (sizeof(nop_func) == 0) {
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        return EXIT_SUCCESS;
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    }
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    ret = pthread_create(&mmap_munmap, NULL, thread_mmap_munmap, (void *)&run);
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    assert(ret == 0);
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    for (i = 0; i < 1000; i++) {
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        ret = pthread_create(&dummy, NULL, thread_dummy, NULL);
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        assert(ret == 0);
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        ret = pthread_join(dummy, NULL);
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        assert(ret == 0);
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    }
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    run = false;
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    ret = pthread_join(mmap_munmap, NULL);
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    assert(ret == 0);
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    return EXIT_SUCCESS;
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}
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