[PATCHv3 2/2] arch: Rename CONFIG_DEBUG_RODATA and CONFIG_DEBUG_MODULE_RONX

From: Laura Abbott
Date: Mon Feb 06 2017 - 19:32:31 EST


Both of these options are poorly named. The features they provide are
necessary for system security and should not be considered debug only.
Change the names to CONFIG_STRICT_KERNEL_RWX and
CONFIG_STRICT_MODULE_RWX to better describe what these options do.

Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
---
v3: Minor config text tweek per Kees. Corrected the change of config names in
the arm config files.
---
Documentation/DocBook/kgdb.tmpl | 8 ++++----
Documentation/security/self-protection.txt | 4 ++--
arch/Kconfig | 4 ++--
arch/arm/configs/aspeed_g4_defconfig | 4 ++--
arch/arm/configs/aspeed_g5_defconfig | 4 ++--
arch/arm/include/asm/cacheflush.h | 2 +-
arch/arm/kernel/patch.c | 4 ++--
arch/arm/kernel/vmlinux.lds.S | 8 ++++----
arch/arm/mm/Kconfig | 2 +-
arch/arm/mm/init.c | 4 ++--
arch/arm64/Kconfig.debug | 2 +-
arch/arm64/kernel/insn.c | 2 +-
arch/parisc/configs/712_defconfig | 1 -
arch/parisc/configs/c3000_defconfig | 1 -
arch/parisc/mm/init.c | 2 +-
include/linux/filter.h | 4 ++--
include/linux/init.h | 4 ++--
include/linux/module.h | 2 +-
init/main.c | 4 ++--
kernel/configs/android-recommended.config | 2 +-
kernel/module.c | 6 +++---
kernel/power/hibernate.c | 2 +-
kernel/power/power.h | 4 ++--
kernel/power/snapshot.c | 4 ++--
24 files changed, 41 insertions(+), 43 deletions(-)

diff --git a/Documentation/DocBook/kgdb.tmpl b/Documentation/DocBook/kgdb.tmpl
index f3abca7..856ac20 100644
--- a/Documentation/DocBook/kgdb.tmpl
+++ b/Documentation/DocBook/kgdb.tmpl
@@ -115,12 +115,12 @@
</para>
<para>
If the architecture that you are using supports the kernel option
- CONFIG_DEBUG_RODATA, you should consider turning it off. This
+ CONFIG_STRICT_KERNEL_RWX, you should consider turning it off. This
option will prevent the use of software breakpoints because it
marks certain regions of the kernel's memory space as read-only.
If kgdb supports it for the architecture you are using, you can
use hardware breakpoints if you desire to run with the
- CONFIG_DEBUG_RODATA option turned on, else you need to turn off
+ CONFIG_STRICT_KERNEL_RWX option turned on, else you need to turn off
this option.
</para>
<para>
@@ -135,7 +135,7 @@
<para>Here is an example set of .config symbols to enable or
disable for kgdb:
<itemizedlist>
- <listitem><para># CONFIG_DEBUG_RODATA is not set</para></listitem>
+ <listitem><para># CONFIG_STRICT_KERNEL_RWX is not set</para></listitem>
<listitem><para>CONFIG_FRAME_POINTER=y</para></listitem>
<listitem><para>CONFIG_KGDB=y</para></listitem>
<listitem><para>CONFIG_KGDB_SERIAL_CONSOLE=y</para></listitem>
@@ -166,7 +166,7 @@
</para>
<para>Here is an example set of .config symbols to enable/disable kdb:
<itemizedlist>
- <listitem><para># CONFIG_DEBUG_RODATA is not set</para></listitem>
+ <listitem><para># CONFIG_STRICT_KERNEL_RWX is not set</para></listitem>
<listitem><para>CONFIG_FRAME_POINTER=y</para></listitem>
<listitem><para>CONFIG_KGDB=y</para></listitem>
<listitem><para>CONFIG_KGDB_SERIAL_CONSOLE=y</para></listitem>
diff --git a/Documentation/security/self-protection.txt b/Documentation/security/self-protection.txt
index f41dd00..141acfe 100644
--- a/Documentation/security/self-protection.txt
+++ b/Documentation/security/self-protection.txt
@@ -51,8 +51,8 @@ kernel, they are implemented in a way where the memory is temporarily
made writable during the update, and then returned to the original
permissions.)

-In support of this are (the poorly named) CONFIG_DEBUG_RODATA and
-CONFIG_DEBUG_SET_MODULE_RONX, which seek to make sure that code is not
+In support of this are CONFIG_STRICT_KERNEL_RWX and
+CONFIG_STRICT_MODULE_RWX, which seek to make sure that code is not
writable, data is not executable, and read-only data is neither writable
nor executable.

diff --git a/arch/Kconfig b/arch/Kconfig
index 3f8b8be..33f5a55 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -790,7 +790,7 @@ config ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
config ARCH_HAS_STRICT_KERNEL_RWX
def_bool n

-config DEBUG_RODATA
+config STRICT_KERNEL_RWX
bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX
depends on ARCH_HAS_STRICT_KERNEL_RWX
default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
@@ -806,7 +806,7 @@ config DEBUG_RODATA
config ARCH_HAS_STRICT_MODULE_RWX
def_bool n

-config DEBUG_SET_MODULE_RONX
+config STRICT_MODULE_RWX
bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX
depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES
default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
diff --git a/arch/arm/configs/aspeed_g4_defconfig b/arch/arm/configs/aspeed_g4_defconfig
index ca39c04..05b99bc 100644
--- a/arch/arm/configs/aspeed_g4_defconfig
+++ b/arch/arm/configs/aspeed_g4_defconfig
@@ -25,7 +25,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_ARCH_MULTI_V7 is not set
CONFIG_ARCH_ASPEED=y
CONFIG_MACH_ASPEED_G4=y
-CONFIG_DEBUG_RODATA=y
CONFIG_AEABI=y
CONFIG_UACCESS_WITH_MEMCPY=y
CONFIG_SECCOMP=y
@@ -79,7 +78,8 @@ CONFIG_DEBUG_LL_UART_8250=y
CONFIG_DEBUG_UART_PHYS=0x1e784000
CONFIG_DEBUG_UART_VIRT=0xe8784000
CONFIG_EARLY_PRINTK=y
-CONFIG_DEBUG_SET_MODULE_RONX=y
+CONFIG_STRICT_MODULE_RWX=y
+CONFIG_STRICT_KERNEL_RWX=y
# CONFIG_XZ_DEC_X86 is not set
# CONFIG_XZ_DEC_POWERPC is not set
# CONFIG_XZ_DEC_IA64 is not set
diff --git a/arch/arm/configs/aspeed_g5_defconfig b/arch/arm/configs/aspeed_g5_defconfig
index 4f366b0..05a16d5 100644
--- a/arch/arm/configs/aspeed_g5_defconfig
+++ b/arch/arm/configs/aspeed_g5_defconfig
@@ -26,7 +26,6 @@ CONFIG_ARCH_MULTI_V6=y
# CONFIG_ARCH_MULTI_V7 is not set
CONFIG_ARCH_ASPEED=y
CONFIG_MACH_ASPEED_G5=y
-CONFIG_DEBUG_RODATA=y
CONFIG_AEABI=y
CONFIG_UACCESS_WITH_MEMCPY=y
CONFIG_SECCOMP=y
@@ -81,7 +80,8 @@ CONFIG_DEBUG_LL_UART_8250=y
CONFIG_DEBUG_UART_PHYS=0x1e784000
CONFIG_DEBUG_UART_VIRT=0xe8784000
CONFIG_EARLY_PRINTK=y
-CONFIG_DEBUG_SET_MODULE_RONX=y
+CONFIG_STRICT_MODULE_RWX=y
+CONFIG_STRICT_KERNEL_RWX=y
# CONFIG_XZ_DEC_X86 is not set
# CONFIG_XZ_DEC_POWERPC is not set
# CONFIG_XZ_DEC_IA64 is not set
diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index bdd283b..02454fa 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -490,7 +490,7 @@ static inline int set_memory_x(unsigned long addr, int numpages) { return 0; }
static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }
#endif

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
void set_kernel_text_rw(void);
void set_kernel_text_ro(void);
#else
diff --git a/arch/arm/kernel/patch.c b/arch/arm/kernel/patch.c
index 69bda1a..020560b 100644
--- a/arch/arm/kernel/patch.c
+++ b/arch/arm/kernel/patch.c
@@ -24,9 +24,9 @@ static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
bool module = !core_kernel_text(uintaddr);
struct page *page;

- if (module && IS_ENABLED(CONFIG_DEBUG_SET_MODULE_RONX))
+ if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
page = vmalloc_to_page(addr);
- else if (!module && IS_ENABLED(CONFIG_DEBUG_RODATA))
+ else if (!module && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
page = virt_to_page(addr);
else
return addr;
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index f7f55df..ce18007 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -97,7 +97,7 @@ SECTIONS
HEAD_TEXT
}

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
. = ALIGN(1<<SECTION_SHIFT);
#endif

@@ -158,7 +158,7 @@ SECTIONS

NOTES

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
. = ALIGN(1<<SECTION_SHIFT);
#else
. = ALIGN(PAGE_SIZE);
@@ -230,7 +230,7 @@ SECTIONS
PERCPU_SECTION(L1_CACHE_BYTES)
#endif

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
. = ALIGN(1<<SECTION_SHIFT);
#else
. = ALIGN(THREAD_SIZE);
@@ -325,7 +325,7 @@ SECTIONS
STABS_DEBUG
}

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
/*
* Without CONFIG_DEBUG_ALIGN_RODATA, __start_rodata_section_aligned will
* be the first section-aligned location after __start_rodata. Otherwise,
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 419a035..35e3a56 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -1053,7 +1053,7 @@ config ARCH_SUPPORTS_BIG_ENDIAN

config DEBUG_ALIGN_RODATA
bool "Make rodata strictly non-executable"
- depends on DEBUG_RODATA
+ depends on STRICT_KERNEL_RWX
default y
help
If this is set, rodata will be made explicitly non-executable. This
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 370581a..4be0bee 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -572,7 +572,7 @@ void __init mem_init(void)
}
}

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
struct section_perm {
const char *name;
unsigned long start;
@@ -741,7 +741,7 @@ void set_kernel_text_ro(void)

#else
static inline void fix_kernmem_perms(void) { }
-#endif /* CONFIG_DEBUG_RODATA */
+#endif /* CONFIG_STRICT_KERNEL_RWX */

void free_tcmmem(void)
{
diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
index 939815e..560a8d8 100644
--- a/arch/arm64/Kconfig.debug
+++ b/arch/arm64/Kconfig.debug
@@ -72,7 +72,7 @@ config DEBUG_WX
If in doubt, say "Y".

config DEBUG_ALIGN_RODATA
- depends on DEBUG_RODATA
+ depends on STRICT_KERNEL_RWX
bool "Align linker sections up to SECTION_SIZE"
help
If this option is enabled, sections that may potentially be marked as
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index 94b62c1..67f9cb9 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -93,7 +93,7 @@ static void __kprobes *patch_map(void *addr, int fixmap)
bool module = !core_kernel_text(uintaddr);
struct page *page;

- if (module && IS_ENABLED(CONFIG_DEBUG_SET_MODULE_RONX))
+ if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
page = vmalloc_to_page(addr);
else if (!module)
page = pfn_to_page(PHYS_PFN(__pa(addr)));
diff --git a/arch/parisc/configs/712_defconfig b/arch/parisc/configs/712_defconfig
index db8f56b..143d026 100644
--- a/arch/parisc/configs/712_defconfig
+++ b/arch/parisc/configs/712_defconfig
@@ -182,7 +182,6 @@ CONFIG_DEBUG_FS=y
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_MUTEXES=y
# CONFIG_RCU_CPU_STALL_DETECTOR is not set
-CONFIG_DEBUG_RODATA=y
CONFIG_CRYPTO_NULL=m
CONFIG_CRYPTO_TEST=m
CONFIG_CRYPTO_HMAC=y
diff --git a/arch/parisc/configs/c3000_defconfig b/arch/parisc/configs/c3000_defconfig
index fb92b89..8e8f0e3 100644
--- a/arch/parisc/configs/c3000_defconfig
+++ b/arch/parisc/configs/c3000_defconfig
@@ -166,7 +166,6 @@ CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_MUTEXES=y
# CONFIG_DEBUG_BUGVERBOSE is not set
# CONFIG_RCU_CPU_STALL_DETECTOR is not set
-CONFIG_DEBUG_RODATA=y
CONFIG_CRYPTO_NULL=m
CONFIG_CRYPTO_TEST=m
CONFIG_CRYPTO_MD5=m
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index e02ada3..a055e5b 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -545,7 +545,7 @@ void free_initmem(void)
}


-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void)
{
/* rodata memory was already mapped with KERNEL_RO access rights by
diff --git a/include/linux/filter.h b/include/linux/filter.h
index e4eb254..c2d2827 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -545,7 +545,7 @@ static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)

#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))

-#ifdef CONFIG_DEBUG_SET_MODULE_RONX
+#ifdef CONFIG_STRICT_MODULE_RWX
static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
{
set_memory_ro((unsigned long)fp, fp->pages);
@@ -563,7 +563,7 @@ static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
{
}
-#endif /* CONFIG_DEBUG_SET_MODULE_RONX */
+#endif /* CONFIG_STRICT_MODULE_RWX */

int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
diff --git a/include/linux/init.h b/include/linux/init.h
index 885c3e6..79af096 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -126,10 +126,10 @@ void prepare_namespace(void);
void __init load_default_modules(void);
int __init init_rootfs(void);

-#if defined(CONFIG_DEBUG_RODATA) || defined(CONFIG_DEBUG_SET_MODULE_RONX)
+#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
extern bool rodata_enabled;
#endif
-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void);
#endif

diff --git a/include/linux/module.h b/include/linux/module.h
index cc7cba2..e270da2 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -764,7 +764,7 @@ extern int module_sysfs_initialized;

#define __MODULE_STRING(x) __stringify(x)

-#ifdef CONFIG_DEBUG_SET_MODULE_RONX
+#ifdef CONFIG_STRICT_MODULE_RWX
extern void set_all_modules_text_rw(void);
extern void set_all_modules_text_ro(void);
extern void module_enable_ro(const struct module *mod, bool after_init);
diff --git a/init/main.c b/init/main.c
index b0c9d6f..0b7bae2 100644
--- a/init/main.c
+++ b/init/main.c
@@ -925,7 +925,7 @@ static int try_to_run_init_process(const char *init_filename)

static noinline void __init kernel_init_freeable(void);

-#if defined(CONFIG_DEBUG_RODATA) || defined(CONFIG_DEBUG_SET_MODULE_RONX)
+#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
bool rodata_enabled __ro_after_init = true;
static int __init set_debug_rodata(char *str)
{
@@ -934,7 +934,7 @@ static int __init set_debug_rodata(char *str)
__setup("rodata=", set_debug_rodata);
#endif

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
static void mark_readonly(void)
{
if (rodata_enabled)
diff --git a/kernel/configs/android-recommended.config b/kernel/configs/android-recommended.config
index 297756b..99127ed 100644
--- a/kernel/configs/android-recommended.config
+++ b/kernel/configs/android-recommended.config
@@ -11,7 +11,7 @@ CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_SIZE=8192
CONFIG_COMPACTION=y
-CONFIG_DEBUG_RODATA=y
+CONFIG_STRICT_KERNEL_RWX=y
CONFIG_DM_CRYPT=y
CONFIG_DM_UEVENT=y
CONFIG_DM_VERITY=y
diff --git a/kernel/module.c b/kernel/module.c
index 3d8f126..58856a4 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -74,9 +74,9 @@
/*
* Modules' sections will be aligned on page boundaries
* to ensure complete separation of code and data, but
- * only when CONFIG_DEBUG_SET_MODULE_RONX=y
+ * only when CONFIG_STRICT_MODULE_RWX=y
*/
-#ifdef CONFIG_DEBUG_SET_MODULE_RONX
+#ifdef CONFIG_STRICT_MODULE_RWX
# define debug_align(X) ALIGN(X, PAGE_SIZE)
#else
# define debug_align(X) (X)
@@ -1844,7 +1844,7 @@ static void mod_sysfs_teardown(struct module *mod)
mod_sysfs_fini(mod);
}

-#ifdef CONFIG_DEBUG_SET_MODULE_RONX
+#ifdef CONFIG_STRICT_MODULE_RWX
/*
* LKM RO/NX protection: protect module's text/ro-data
* from modification and any data from execution.
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index b26dbc4..86385af 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -1156,7 +1156,7 @@ static int __init hibernate_setup(char *str)
} else if (!strncmp(str, "no", 2)) {
noresume = 1;
nohibernate = 1;
- } else if (IS_ENABLED(CONFIG_DEBUG_RODATA)
+ } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
&& !strncmp(str, "protect_image", 13)) {
enable_restore_image_protection();
}
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 1dfa0da..7fdc40d 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -61,12 +61,12 @@ extern int hibernation_snapshot(int platform_mode);
extern int hibernation_restore(int platform_mode);
extern int hibernation_platform_enter(void);

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
/* kernel/power/snapshot.c */
extern void enable_restore_image_protection(void);
#else
static inline void enable_restore_image_protection(void) {}
-#endif /* CONFIG_DEBUG_RODATA */
+#endif /* CONFIG_STRICT_KERNEL_RWX */

#else /* !CONFIG_HIBERNATION */

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 2d8e2b2..905d5bb 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -38,7 +38,7 @@

#include "power.h"

-#ifdef CONFIG_DEBUG_RODATA
+#ifdef CONFIG_STRICT_KERNEL_RWX
static bool hibernate_restore_protection;
static bool hibernate_restore_protection_active;

@@ -73,7 +73,7 @@ static inline void hibernate_restore_protection_begin(void) {}
static inline void hibernate_restore_protection_end(void) {}
static inline void hibernate_restore_protect_page(void *page_address) {}
static inline void hibernate_restore_unprotect_page(void *page_address) {}
-#endif /* CONFIG_DEBUG_RODATA */
+#endif /* CONFIG_STRICT_KERNEL_RWX */

static int swsusp_page_is_free(struct page *);
static void swsusp_set_page_forbidden(struct page *);
--
2.7.4