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-rw-r--r--arch/x86/Kconfig.debug8
-rw-r--r--arch/x86/include/asm/cacheflush.h10
-rw-r--r--arch/x86/kernel/Makefile1
-rw-r--r--arch/x86/kernel/test_rodata.c75
-rw-r--r--arch/x86/mm/init_32.c4
-rw-r--r--arch/x86/mm/init_64.c5
-rw-r--r--include/linux/rodata_test.h23
-rw-r--r--init/main.c6
-rw-r--r--mm/Kconfig.debug6
-rw-r--r--mm/Makefile1
-rw-r--r--mm/rodata_test.c56
11 files changed, 90 insertions, 105 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index c4cba00dbdee..63c1d13aaf9f 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -74,14 +74,6 @@ config EFI_PGT_DUMP
issues with the mapping of the EFI runtime regions into that
table.
-config DEBUG_RODATA_TEST
- bool "Testcase for the marking rodata read-only"
- default y
- ---help---
- This option enables a testcase for the setting rodata read-only
- as well as for the change_page_attr() infrastructure.
- If in doubt, say "N"
-
config DEBUG_WX
bool "Warn on W+X mappings at boot"
select X86_PTDUMP_CORE
diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h
index 872877d930de..e7e1942edff7 100644
--- a/arch/x86/include/asm/cacheflush.h
+++ b/arch/x86/include/asm/cacheflush.h
@@ -90,18 +90,8 @@ void clflush_cache_range(void *addr, unsigned int size);
#define mmio_flush_range(addr, size) clflush_cache_range(addr, size)
-extern const int rodata_test_data;
extern int kernel_set_to_readonly;
void set_kernel_text_rw(void);
void set_kernel_text_ro(void);
-#ifdef CONFIG_DEBUG_RODATA_TEST
-int rodata_test(void);
-#else
-static inline int rodata_test(void)
-{
- return 0;
-}
-#endif
-
#endif /* _ASM_X86_CACHEFLUSH_H */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index bdcdb3b3a219..84c00592d359 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -100,7 +100,6 @@ obj-$(CONFIG_HPET_TIMER) += hpet.o
obj-$(CONFIG_APB_TIMER) += apb_timer.o
obj-$(CONFIG_AMD_NB) += amd_nb.o
-obj-$(CONFIG_DEBUG_RODATA_TEST) += test_rodata.o
obj-$(CONFIG_DEBUG_NMI_SELFTEST) += nmi_selftest.o
obj-$(CONFIG_KVM_GUEST) += kvm.o kvmclock.o
diff --git a/arch/x86/kernel/test_rodata.c b/arch/x86/kernel/test_rodata.c
deleted file mode 100644
index 222e84e2432e..000000000000
--- a/arch/x86/kernel/test_rodata.c
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * test_rodata.c: functional test for mark_rodata_ro function
- *
- * (C) Copyright 2008 Intel Corporation
- * Author: Arjan van de Ven <arjan@linux.intel.com>
- *
- * 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 <asm/cacheflush.h>
-#include <asm/sections.h>
-#include <asm/asm.h>
-
-int rodata_test(void)
-{
- unsigned long result;
- unsigned long start, end;
-
- /* test 1: read the value */
- /* If this test fails, some previous testrun has clobbered the state */
- if (!rodata_test_data) {
- printk(KERN_ERR "rodata_test: test 1 fails (start data)\n");
- return -ENODEV;
- }
-
- /* test 2: write to the variable; this should fault */
- /*
- * If this test fails, we managed to overwrite the data
- *
- * This is written in assembly to be able to catch the
- * exception that is supposed to happen in the correct
- * case
- */
-
- result = 1;
- asm volatile(
- "0: mov %[zero],(%[rodata_test])\n"
- " mov %[zero], %[rslt]\n"
- "1:\n"
- ".section .fixup,\"ax\"\n"
- "2: jmp 1b\n"
- ".previous\n"
- _ASM_EXTABLE(0b,2b)
- : [rslt] "=r" (result)
- : [rodata_test] "r" (&rodata_test_data), [zero] "r" (0UL)
- );
-
-
- if (!result) {
- printk(KERN_ERR "rodata_test: test data was not read only\n");
- return -ENODEV;
- }
-
- /* test 3: check the value hasn't changed */
- /* If this test fails, we managed to overwrite the data */
- if (!rodata_test_data) {
- printk(KERN_ERR "rodata_test: Test 3 fails (end data)\n");
- return -ENODEV;
- }
- /* test 4: check if the rodata section is 4Kb aligned */
- start = (unsigned long)__start_rodata;
- end = (unsigned long)__end_rodata;
- if (start & (PAGE_SIZE - 1)) {
- printk(KERN_ERR "rodata_test: .rodata is not 4k aligned\n");
- return -ENODEV;
- }
- if (end & (PAGE_SIZE - 1)) {
- printk(KERN_ERR "rodata_test: .rodata end is not 4k aligned\n");
- return -ENODEV;
- }
-
- return 0;
-}
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 928d657de829..2b4b53e6793f 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -864,9 +864,6 @@ static noinline int do_test_wp_bit(void)
return flag;
}
-const int rodata_test_data = 0xC3;
-EXPORT_SYMBOL_GPL(rodata_test_data);
-
int kernel_set_to_readonly __read_mostly;
void set_kernel_text_rw(void)
@@ -939,7 +936,6 @@ void mark_rodata_ro(void)
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
size >> 10);
- rodata_test();
#ifdef CONFIG_CPA_DEBUG
printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 97346f987ef2..15173d37f399 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1000,9 +1000,6 @@ void __init mem_init(void)
mem_init_print_info(NULL);
}
-const int rodata_test_data = 0xC3;
-EXPORT_SYMBOL_GPL(rodata_test_data);
-
int kernel_set_to_readonly;
void set_kernel_text_rw(void)
@@ -1071,8 +1068,6 @@ void mark_rodata_ro(void)
all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
- rodata_test();
-
#ifdef CONFIG_CPA_DEBUG
printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
set_memory_rw(start, (end-start) >> PAGE_SHIFT);
diff --git a/include/linux/rodata_test.h b/include/linux/rodata_test.h
new file mode 100644
index 000000000000..ea05f6c51413
--- /dev/null
+++ b/include/linux/rodata_test.h
@@ -0,0 +1,23 @@
+/*
+ * rodata_test.h: functional test for mark_rodata_ro function
+ *
+ * (C) Copyright 2008 Intel Corporation
+ * Author: Arjan van de Ven <arjan@linux.intel.com>
+ *
+ * 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.
+ */
+
+#ifndef _RODATA_TEST_H
+#define _RODATA_TEST_H
+
+#ifdef CONFIG_DEBUG_RODATA_TEST
+extern const int rodata_test_data;
+void rodata_test(void);
+#else
+static inline void rodata_test(void) {}
+#endif
+
+#endif /* _RODATA_TEST_H */
diff --git a/init/main.c b/init/main.c
index 6eb10ce472b9..47ea22d181ef 100644
--- a/init/main.c
+++ b/init/main.c
@@ -82,6 +82,7 @@
#include <linux/proc_ns.h>
#include <linux/io.h>
#include <linux/cache.h>
+#include <linux/rodata_test.h>
#include <asm/io.h>
#include <asm/bugs.h>
@@ -935,9 +936,10 @@ __setup("rodata=", set_debug_rodata);
#ifdef CONFIG_STRICT_KERNEL_RWX
static void mark_readonly(void)
{
- if (rodata_enabled)
+ if (rodata_enabled) {
mark_rodata_ro();
- else
+ rodata_test();
+ } else
pr_info("Kernel memory protection disabled.\n");
}
#else
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index afcc550877ff..79d0fd13b5b3 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -90,3 +90,9 @@ config DEBUG_PAGE_REF
careful when enabling this feature because it adds about 30 KB to the
kernel code. However the runtime performance overhead is virtually
nil until the tracepoints are actually enabled.
+
+config DEBUG_RODATA_TEST
+ bool "Testcase for the marking rodata read-only"
+ depends on STRICT_KERNEL_RWX
+ ---help---
+ This option enables a testcase for the setting rodata read-only.
diff --git a/mm/Makefile b/mm/Makefile
index aa0aa17cb413..026f6a828a50 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -85,6 +85,7 @@ obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o
obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
+obj-$(CONFIG_DEBUG_RODATA_TEST) += rodata_test.o
obj-$(CONFIG_PAGE_OWNER) += page_owner.o
obj-$(CONFIG_CLEANCACHE) += cleancache.o
obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
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 <arjan@linux.intel.com>
+ *
+ * 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 <linux/uaccess.h>
+#include <asm/sections.h>
+
+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");
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-24 16:45:40 +0000