Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables
The changes to automatically test for working stack protector compiler
support in the Kconfig files removed the special STACKPROTECTOR_AUTO
option that picked the strongest stack protector that the compiler
supported.
That was all a nice cleanup - it makes no sense to have the AUTO case
now that the Kconfig phase can just determine the compiler support
directly.
HOWEVER.
It also meant that doing "make oldconfig" would now _disable_ the strong
stackprotector if you had AUTO enabled, because in a legacy config file,
the sane stack protector configuration would look like
CONFIG_HAVE_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR_NONE is not set
# CONFIG_CC_STACKPROTECTOR_REGULAR is not set
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_CC_STACKPROTECTOR_AUTO=y
and when you ran this through "make oldconfig" with the Kbuild changes,
it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
used to be disabled (because it was really enabled by AUTO), and would
disable it in the new config, resulting in:
CONFIG_HAVE_CC_STACKPROTECTOR=y
CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
CONFIG_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
That's dangerously subtle - people could suddenly find themselves with
the weaker stack protector setup without even realizing.
The solution here is to just rename not just the old RECULAR stack
protector option, but also the strong one. This does that by just
removing the CC_ prefix entirely for the user choices, because it really
is not about the compiler support (the compiler support now instead
automatially impacts _visibility_ of the options to users).
This results in "make oldconfig" actually asking the user for their
choice, so that we don't have any silent subtle security model changes.
The end result would generally look like this:
CONFIG_HAVE_CC_STACKPROTECTOR=y
CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
CONFIG_STACKPROTECTOR=y
CONFIG_STACKPROTECTOR_STRONG=y
CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
where the "CC_" versions really are about internal compiler
infrastructure, not the user selections.
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt
index a4eb018..3534a84 100644
--- a/Documentation/kbuild/kconfig-language.txt
+++ b/Documentation/kbuild/kconfig-language.txt
@@ -480,7 +480,7 @@
to describe the dependency on the compiler feature is to use "depends on"
followed by a test macro.
-config CC_STACKPROTECTOR
+config STACKPROTECTOR
bool "Stack Protector buffer overflow detection"
depends on $(cc-option,-fstack-protector)
...
diff --git a/Documentation/security/self-protection.rst b/Documentation/security/self-protection.rst
index 0f53826..e1ca698 100644
--- a/Documentation/security/self-protection.rst
+++ b/Documentation/security/self-protection.rst
@@ -156,7 +156,7 @@
of a variable stored on the stack, ultimately writing a controlled value
to the stack frame's stored return address. The most widely used defense
is the presence of a stack canary between the stack variables and the
-return address (``CONFIG_CC_STACKPROTECTOR``), which is verified just before
+return address (``CONFIG_STACKPROTECTOR``), which is verified just before
the function returns. Other defenses include things like shadow stacks.
Stack depth overflow
diff --git a/Makefile b/Makefile
index 73f0bb2..8a26b59 100644
--- a/Makefile
+++ b/Makefile
@@ -687,8 +687,8 @@
endif
stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
-stackp-flags-$(CONFIG_CC_STACKPROTECTOR) := -fstack-protector
-stackp-flags-$(CONFIG_CC_STACKPROTECTOR_STRONG) := -fstack-protector-strong
+stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
+stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
KBUILD_CFLAGS += $(stackp-flags-y)
diff --git a/arch/Kconfig b/arch/Kconfig
index ebbb450..c302b3d 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -558,7 +558,7 @@
config CC_HAS_STACKPROTECTOR_NONE
def_bool $(cc-option,-fno-stack-protector)
-config CC_STACKPROTECTOR
+config STACKPROTECTOR
bool "Stack Protector buffer overflow detection"
depends on HAVE_CC_STACKPROTECTOR
depends on $(cc-option,-fstack-protector)
@@ -582,9 +582,9 @@
about 3% of all kernel functions, which increases kernel code size
by about 0.3%.
-config CC_STACKPROTECTOR_STRONG
+config STACKPROTECTOR_STRONG
bool "Strong Stack Protector"
- depends on CC_STACKPROTECTOR
+ depends on STACKPROTECTOR
depends on $(cc-option,-fstack-protector-strong)
default y
help
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index 27c5381..974d8d7 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -61,7 +61,7 @@
int main(void)
{
DEFINE(TSK_ACTIVE_MM, offsetof(struct task_struct, active_mm));
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
DEFINE(TSK_STACK_CANARY, offsetof(struct task_struct, stack_canary));
#endif
BLANK();
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 1752033..179a9f6 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -791,7 +791,7 @@
ldr r6, [r2, #TI_CPU_DOMAIN]
#endif
switch_tls r1, r4, r5, r3, r7
-#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
ldr r7, [r2, #TI_TASK]
ldr r8, =__stack_chk_guard
.if (TSK_STACK_CANARY > IMM12_MASK)
@@ -807,7 +807,7 @@
ldr r0, =thread_notify_head
mov r1, #THREAD_NOTIFY_SWITCH
bl atomic_notifier_call_chain
-#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
str r7, [r8]
#endif
THUMB( mov ip, r4 )
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 1523cb1..225d1c5 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -39,7 +39,7 @@
#include <asm/tls.h>
#include <asm/vdso.h>
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index f08a2ed..e10bc363 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -59,7 +59,7 @@
#include <asm/processor.h>
#include <asm/stacktrace.h>
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c
index c1cd414..cbe4742 100644
--- a/arch/mips/kernel/asm-offsets.c
+++ b/arch/mips/kernel/asm-offsets.c
@@ -83,7 +83,7 @@
OFFSET(TASK_FLAGS, task_struct, flags);
OFFSET(TASK_MM, task_struct, mm);
OFFSET(TASK_PID, task_struct, pid);
-#if defined(CONFIG_CC_STACKPROTECTOR)
+#if defined(CONFIG_STACKPROTECTOR)
OFFSET(TASK_STACK_CANARY, task_struct, stack_canary);
#endif
DEFINE(TASK_STRUCT_SIZE, sizeof(struct task_struct));
diff --git a/arch/mips/kernel/octeon_switch.S b/arch/mips/kernel/octeon_switch.S
index e42113f..896080b 100644
--- a/arch/mips/kernel/octeon_switch.S
+++ b/arch/mips/kernel/octeon_switch.S
@@ -61,7 +61,7 @@
#endif
3:
-#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
PTR_LA t8, __stack_chk_guard
LONG_L t9, TASK_STACK_CANARY(a1)
LONG_S t9, 0(t8)
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 3775a8d..8d85046 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -180,7 +180,7 @@
return 0;
}
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
diff --git a/arch/mips/kernel/r2300_switch.S b/arch/mips/kernel/r2300_switch.S
index 6658971..71b1aaf 100644
--- a/arch/mips/kernel/r2300_switch.S
+++ b/arch/mips/kernel/r2300_switch.S
@@ -36,7 +36,7 @@
cpu_save_nonscratch a0
sw ra, THREAD_REG31(a0)
-#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
PTR_LA t8, __stack_chk_guard
LONG_L t9, TASK_STACK_CANARY(a1)
LONG_S t9, 0(t8)
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S
index 17cf934..58232ae 100644
--- a/arch/mips/kernel/r4k_switch.S
+++ b/arch/mips/kernel/r4k_switch.S
@@ -31,7 +31,7 @@
cpu_save_nonscratch a0
LONG_S ra, THREAD_REG31(a0)
-#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
PTR_LA t8, __stack_chk_guard
LONG_L t9, TASK_STACK_CANARY(a1)
LONG_S t9, 0(t8)
diff --git a/arch/sh/kernel/process.c b/arch/sh/kernel/process.c
index 68b1a67..4d1bfc8 100644
--- a/arch/sh/kernel/process.c
+++ b/arch/sh/kernel/process.c
@@ -12,7 +12,7 @@
struct kmem_cache *task_xstate_cachep = NULL;
unsigned int xstate_size;
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 9352206..27fddb5 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -177,7 +177,7 @@
{
struct thread_struct *next_t = &next->thread;
-#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
__stack_chk_guard = next->stack_canary;
#endif
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index bef8e2b..2582881 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -239,7 +239,7 @@
movl %esp, TASK_threadsp(%eax)
movl TASK_threadsp(%edx), %esp
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
movl TASK_stack_canary(%edx), %ebx
movl %ebx, PER_CPU_VAR(stack_canary)+stack_canary_offset
#endif
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 3166b96..73a522d 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -357,7 +357,7 @@
movq %rsp, TASK_threadsp(%rdi)
movq TASK_threadsp(%rsi), %rsp
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
movq TASK_stack_canary(%rsi), %rbx
movq %rbx, PER_CPU_VAR(irq_stack_union)+stack_canary_offset
#endif
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index e28add6..cfd29ee 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -412,7 +412,7 @@
void save_fsgs_for_kvm(void);
#endif
#else /* X86_64 */
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
/*
* Make sure stack canary segment base is cached-aligned:
* "For Intel Atom processors, avoid non zero segment base address
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 8f09012b..e293c12 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -146,7 +146,7 @@
# define __KERNEL_PERCPU 0
#endif
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
# define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8)
#else
# define __KERNEL_STACK_CANARY 0
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
index 371b3a4..8ec97a6 100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@ -34,7 +34,7 @@
#ifndef _ASM_STACKPROTECTOR_H
#define _ASM_STACKPROTECTOR_H 1
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
#include <asm/tsc.h>
#include <asm/processor.h>
@@ -105,7 +105,7 @@
#endif
}
-#else /* CC_STACKPROTECTOR */
+#else /* STACKPROTECTOR */
#define GDT_STACK_CANARY_INIT
@@ -121,5 +121,5 @@
#endif
}
-#endif /* CC_STACKPROTECTOR */
+#endif /* STACKPROTECTOR */
#endif /* _ASM_STACKPROTECTOR_H */
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 76417a9..dcb008c 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -32,7 +32,7 @@
void common(void) {
BLANK();
OFFSET(TASK_threadsp, task_struct, thread.sp);
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
OFFSET(TASK_stack_canary, task_struct, stack_canary);
#endif
diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c
index f91ba53..a4a3be3 100644
--- a/arch/x86/kernel/asm-offsets_32.c
+++ b/arch/x86/kernel/asm-offsets_32.c
@@ -50,7 +50,7 @@
DEFINE(TSS_sysenter_sp0, offsetof(struct cpu_entry_area, tss.x86_tss.sp0) -
offsetofend(struct cpu_entry_area, entry_stack_page.stack));
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
BLANK();
OFFSET(stack_canary_offset, stack_canary, canary);
#endif
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index bf51e51..b2dcd16 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -69,7 +69,7 @@
OFFSET(TSS_sp1, tss_struct, x86_tss.sp1);
BLANK();
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
DEFINE(stack_canary_offset, offsetof(union irq_stack_union, stack_canary));
BLANK();
#endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 910b47e..0df7151 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1599,7 +1599,7 @@
(unsigned long)&init_thread_union + THREAD_SIZE;
EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack);
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
#endif
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index b59e4fb..abe6df1 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -375,7 +375,7 @@
*/
__INIT
setup_once:
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
/*
* Configure the stack canary. The linker can't handle this by
* relocation. Manually set base address in stack canary
diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c
index 022cf91..67904f5 100644
--- a/arch/xtensa/kernel/asm-offsets.c
+++ b/arch/xtensa/kernel/asm-offsets.c
@@ -76,7 +76,7 @@
DEFINE(TASK_PID, offsetof (struct task_struct, pid));
DEFINE(TASK_THREAD, offsetof (struct task_struct, thread));
DEFINE(TASK_THREAD_INFO, offsetof (struct task_struct, stack));
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
DEFINE(TASK_STACK_CANARY, offsetof(struct task_struct, stack_canary));
#endif
DEFINE(TASK_STRUCT_SIZE, sizeof (struct task_struct));
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 5caff07..9cbc380 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1971,7 +1971,7 @@
s32i a1, a2, THREAD_SP # save stack pointer
#endif
-#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
movi a6, __stack_chk_guard
l32i a8, a3, TASK_STACK_CANARY
s32i a8, a6, 0
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 8dd0593..483dcfb 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -58,7 +58,7 @@
EXPORT_SYMBOL(pm_power_off);
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 16e4d98..cfb7da8 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -742,7 +742,7 @@
pid_t pid;
pid_t tgid;
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
/* Canary value for the -fstack-protector GCC feature: */
unsigned long stack_canary;
#endif
diff --git a/include/linux/stackprotector.h b/include/linux/stackprotector.h
index 03696c7..6b792d0 100644
--- a/include/linux/stackprotector.h
+++ b/include/linux/stackprotector.h
@@ -6,7 +6,7 @@
#include <linux/sched.h>
#include <linux/random.h>
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
# include <asm/stackprotector.h>
#else
static inline void boot_init_stack_canary(void)
diff --git a/kernel/configs/android-recommended.config b/kernel/configs/android-recommended.config
index 946fb92..81e9af7 100644
--- a/kernel/configs/android-recommended.config
+++ b/kernel/configs/android-recommended.config
@@ -12,7 +12,7 @@
CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_RAM=y
CONFIG_BLK_DEV_RAM_SIZE=8192
-CONFIG_CC_STACKPROTECTOR_STRONG=y
+CONFIG_STACKPROTECTOR_STRONG=y
CONFIG_COMPACTION=y
CONFIG_CPU_SW_DOMAIN_PAN=y
CONFIG_DM_CRYPT=y
diff --git a/kernel/fork.c b/kernel/fork.c
index 08c6e5e..92870be 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -811,7 +811,7 @@
clear_tsk_need_resched(tsk);
set_task_stack_end_magic(tsk);
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
tsk->stack_canary = get_random_canary();
#endif
diff --git a/kernel/panic.c b/kernel/panic.c
index 42e4874..8b2e002 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -623,7 +623,7 @@
device_initcall(register_warn_debugfs);
#endif
-#ifdef CONFIG_CC_STACKPROTECTOR
+#ifdef CONFIG_STACKPROTECTOR
/*
* Called when gcc's -fstack-protector feature is used, and