Commit 2959a5f7 authored by Jinbum Park's avatar Jinbum Park Committed by Linus Torvalds
Browse files

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: default avatarJinbum Park <jinb.park7@gmail.com>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8d85063a

arch/x86/Kconfig.debug

+0 −8
Original line number Diff line number Diff line
@@ -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

arch/x86/include/asm/cacheflush.h

+0 −10
Original line number Diff line number Diff line
@@ -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 */

arch/x86/kernel/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -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

arch/x86/mm/init_32.c

+0 −4
Original line number Diff line number Diff line
@@ -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);

arch/x86/mm/init_64.c

+0 −5
Original line number Diff line number Diff line
@@ -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);

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