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/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 @@ void output_task_defines(void)
 	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 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
 	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 @@ __switch_to(struct task_struct *prev, struct task_struct *next)
 {
 	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 @@ extern asmlinkage void ignore_sysret(void);
 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 @@ static inline void load_stack_canary_segment(void)
 #endif
 }
 
-#else	/* CC_STACKPROTECTOR */
+#else	/* STACKPROTECTOR */
 
 #define GDT_STACK_CANARY_INIT
 
@@ -121,5 +121,5 @@ static inline void load_stack_canary_segment(void)
 #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 @@ void foo(void)
 	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 @@ int main(void)
 	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 @@ DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) =
 	(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 @@ int main(void)
 	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 @@ void (*pm_power_off)(void) = NULL;
 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);