| Message ID | 20170129105436.GA9303@pjb1027-Latitude-E5410 (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Jan 29, 2017 at 2:54 AM, Jinbum Park <jinb.park7@gmail.com> wrote: > 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 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 above issue, > write arch-independent testcases and move it to shared location. > > Signed-off-by: Jinbum Park <jinb.park7@gmail.com> This version looks good to me. Thanks! Acked-by: Kees Cook <keescook@chromium.org> -Kees > --- > v4: Move the rodata_test() call out into mark_readonly() > Delete some comment > > v3: Use probe_kernel_write() instead of put_user() > Move declaration of rodata_test_data to separate header (rodata_test.h) > Fix a kbuild-test-robot-error related to DEBUG_NX_TEST > > v2: Restore original credit of mm/rodata_test.c > > arch/x86/Kconfig.debug | 10 +----- > arch/x86/include/asm/cacheflush.h | 10 ------ > arch/x86/kernel/Makefile | 1 - > arch/x86/kernel/test_rodata.c | 75 --------------------------------------- > arch/x86/mm/init_32.c | 4 --- > arch/x86/mm/init_64.c | 5 --- > include/linux/rodata_test.h | 24 +++++++++++++ > init/main.c | 6 ++-- > mm/Kconfig.debug | 7 ++++ > mm/Makefile | 1 + > mm/rodata_test.c | 56 +++++++++++++++++++++++++++++ > 11 files changed, 93 insertions(+), 106 deletions(-) > delete mode 100644 arch/x86/kernel/test_rodata.c > create mode 100644 include/linux/rodata_test.h > create mode 100644 mm/rodata_test.c > > diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug > index 67eec55..3fa469c 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 > @@ -122,7 +114,7 @@ config DEBUG_SET_MODULE_RONX > > config DEBUG_NX_TEST > tristate "Testcase for the NX non-executable stack feature" > - depends on DEBUG_KERNEL && m > + depends on DEBUG_KERNEL && DEBUG_RODATA_TEST && m > ---help--- > This option enables a testcase for the CPU NX capability > and the software setup of this feature. > diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h > index 872877d..e7e1942e 100644 > --- a/arch/x86/include/asm/cacheflush.h > +++ b/arch/x86/include/asm/cacheflush.h > @@ -90,18 +90,8 @@ > > #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 581386c..f6caf82 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-$(CONFIG_DEBUG_NX_TEST) += test_nx.o > obj-$(CONFIG_DEBUG_NMI_SELFTEST) += nmi_selftest.o > > diff --git a/arch/x86/kernel/test_rodata.c b/arch/x86/kernel/test_rodata.c > deleted file mode 100644 > index 222e84e..0000000 > --- 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 928d657..2b4b53e 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 5fff913..a4880d8 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -1011,9 +1011,6 @@ 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) > @@ -1082,8 +1079,6 @@ 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 0000000..562537f > --- /dev/null > +++ b/include/linux/rodata_test.h > @@ -0,0 +1,24 @@ > +/* > + * 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 e47373d..1e417bb 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 @@ static int __init set_debug_rodata(char *str) > #ifdef CONFIG_DEBUG_RODATA > 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 afcc550..3e5eada 100644 > --- a/mm/Kconfig.debug > +++ b/mm/Kconfig.debug > @@ -90,3 +90,10 @@ 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 DEBUG_RODATA > + ---help--- > + This option enables a testcase for the setting rodata read-only. > + > diff --git a/mm/Makefile b/mm/Makefile > index 433eaf9..d6199d4 100644 > --- a/mm/Makefile > +++ b/mm/Makefile > @@ -83,6 +83,7 @@ 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 0000000..0fd2167 > --- /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"); > +} > -- > 1.9.1 >
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 67eec55..3fa469c 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 @@ -122,7 +114,7 @@ config DEBUG_SET_MODULE_RONX config DEBUG_NX_TEST tristate "Testcase for the NX non-executable stack feature" - depends on DEBUG_KERNEL && m + depends on DEBUG_KERNEL && DEBUG_RODATA_TEST && m ---help--- This option enables a testcase for the CPU NX capability and the software setup of this feature. diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h index 872877d..e7e1942e 100644 --- a/arch/x86/include/asm/cacheflush.h +++ b/arch/x86/include/asm/cacheflush.h @@ -90,18 +90,8 @@ #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 581386c..f6caf82 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-$(CONFIG_DEBUG_NX_TEST) += test_nx.o obj-$(CONFIG_DEBUG_NMI_SELFTEST) += nmi_selftest.o diff --git a/arch/x86/kernel/test_rodata.c b/arch/x86/kernel/test_rodata.c deleted file mode 100644 index 222e84e..0000000 --- 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 928d657..2b4b53e 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 5fff913..a4880d8 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1011,9 +1011,6 @@ 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) @@ -1082,8 +1079,6 @@ 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 0000000..562537f --- /dev/null +++ b/include/linux/rodata_test.h @@ -0,0 +1,24 @@ +/* + * 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 e47373d..1e417bb 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 @@ static int __init set_debug_rodata(char *str) #ifdef CONFIG_DEBUG_RODATA 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 afcc550..3e5eada 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -90,3 +90,10 @@ 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 DEBUG_RODATA + ---help--- + This option enables a testcase for the setting rodata read-only. + diff --git a/mm/Makefile b/mm/Makefile index 433eaf9..d6199d4 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -83,6 +83,7 @@ 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 0000000..0fd2167 --- /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"); +}
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 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 above issue, write arch-independent testcases and move it to shared location. Signed-off-by: Jinbum Park <jinb.park7@gmail.com> --- v4: Move the rodata_test() call out into mark_readonly() Delete some comment v3: Use probe_kernel_write() instead of put_user() Move declaration of rodata_test_data to separate header (rodata_test.h) Fix a kbuild-test-robot-error related to DEBUG_NX_TEST v2: Restore original credit of mm/rodata_test.c arch/x86/Kconfig.debug | 10 +----- arch/x86/include/asm/cacheflush.h | 10 ------ arch/x86/kernel/Makefile | 1 - arch/x86/kernel/test_rodata.c | 75 --------------------------------------- arch/x86/mm/init_32.c | 4 --- arch/x86/mm/init_64.c | 5 --- include/linux/rodata_test.h | 24 +++++++++++++ init/main.c | 6 ++-- mm/Kconfig.debug | 7 ++++ mm/Makefile | 1 + mm/rodata_test.c | 56 +++++++++++++++++++++++++++++ 11 files changed, 93 insertions(+), 106 deletions(-) delete mode 100644 arch/x86/kernel/test_rodata.c create mode 100644 include/linux/rodata_test.h create mode 100644 mm/rodata_test.c