From 2959a5f726f6510d6dd7c958f8877e08d0cf589c Mon Sep 17 00:00:00 2001 From: Jinbum Park Date: Mon, 27 Feb 2017 14:30:22 -0800 Subject: mm: add arch-independent testcases for RODATA This patch makes arch-independent testcases for RODATA. Both x86 and x86_64 already have testcases for RODATA, But they are arch-specific because using inline assembly directly. And cacheflush.h is not a suitable location for rodata-test related things. Since they were in cacheflush.h, If someone change the state of CONFIG_DEBUG_RODATA_TEST, It cause overhead of kernel build. To solve the above issues, write arch-independent testcases and move it to shared location. [jinb.park7@gmail.com: fix config dependency] Link: http://lkml.kernel.org/r/20170209131625.GA16954@pjb1027-Latitude-E5410 Link: http://lkml.kernel.org/r/20170129105436.GA9303@pjb1027-Latitude-E5410 Signed-off-by: Jinbum Park Acked-by: Kees Cook Cc: Ingo Molnar Cc: H. Peter Anvin Cc: Arjan van de Ven Cc: Laura Abbott Cc: Russell King Cc: Valentin Rothberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/rodata_test.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 mm/rodata_test.c (limited to 'mm/rodata_test.c') diff --git a/mm/rodata_test.c b/mm/rodata_test.c new file mode 100644 index 000000000000..0fd21670b513 --- /dev/null +++ b/mm/rodata_test.c @@ -0,0 +1,56 @@ +/* + * rodata_test.c: functional test for mark_rodata_ro function + * + * (C) Copyright 2008 Intel Corporation + * Author: Arjan van de Ven + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ +#include +#include + +const int rodata_test_data = 0xC3; +EXPORT_SYMBOL_GPL(rodata_test_data); + +void rodata_test(void) +{ + unsigned long start, end; + int zero = 0; + + /* test 1: read the value */ + /* If this test fails, some previous testrun has clobbered the state */ + if (!rodata_test_data) { + pr_err("rodata_test: test 1 fails (start data)\n"); + return; + } + + /* test 2: write to the variable; this should fault */ + if (!probe_kernel_write((void *)&rodata_test_data, + (void *)&zero, sizeof(zero))) { + pr_err("rodata_test: test data was not read only\n"); + return; + } + + /* test 3: check the value hasn't changed */ + if (rodata_test_data == zero) { + pr_err("rodata_test: test data was changed\n"); + return; + } + + /* test 4: check if the rodata section is PAGE_SIZE aligned */ + start = (unsigned long)__start_rodata; + end = (unsigned long)__end_rodata; + if (start & (PAGE_SIZE - 1)) { + pr_err("rodata_test: start of .rodata is not page size aligned\n"); + return; + } + if (end & (PAGE_SIZE - 1)) { + pr_err("rodata_test: end of .rodata is not page size aligned\n"); + return; + } + + pr_info("rodata_test: all tests were successful\n"); +} -- cgit v1.2.3-70-g09d2