fe557319aa
Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* rodata_test.c: functional test for mark_rodata_ro function
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*
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* (C) Copyright 2008 Intel Corporation
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* Author: Arjan van de Ven <arjan@linux.intel.com>
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*/
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#define pr_fmt(fmt) "rodata_test: " fmt
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#include <linux/uaccess.h>
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#include <asm/sections.h>
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static const int rodata_test_data = 0xC3;
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void rodata_test(void)
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{
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unsigned long start, end;
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int zero = 0;
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/* test 1: read the value */
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/* If this test fails, some previous testrun has clobbered the state */
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if (!rodata_test_data) {
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pr_err("test 1 fails (start data)\n");
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return;
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}
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/* test 2: write to the variable; this should fault */
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if (!copy_to_kernel_nofault((void *)&rodata_test_data,
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(void *)&zero, sizeof(zero))) {
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pr_err("test data was not read only\n");
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return;
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}
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/* test 3: check the value hasn't changed */
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if (rodata_test_data == zero) {
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pr_err("test data was changed\n");
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return;
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}
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/* test 4: check if the rodata section is PAGE_SIZE aligned */
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start = (unsigned long)__start_rodata;
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end = (unsigned long)__end_rodata;
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if (start & (PAGE_SIZE - 1)) {
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pr_err("start of .rodata is not page size aligned\n");
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return;
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}
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if (end & (PAGE_SIZE - 1)) {
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pr_err("end of .rodata is not page size aligned\n");
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return;
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}
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pr_info("all tests were successful\n");
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}
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