powerpc: Unconditionally enabled irq stacks

Irq stacks provide an essential protection from stack overflows through
external interrupts, at the cost of two additionals stacks per CPU.

Enable them unconditionally to simplify the kernel build and prevent
people from accidentally disabling them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

6 files changed, 0 insertions, 29 deletions

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 30817d9b20cb..3333bbdd23ef 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -317,7 +317,6 @@ void fixup_irqs(const struct cpumask *map)
 }
 #endif
 
-#ifdef CONFIG_IRQSTACKS
 static inline void handle_one_irq(unsigned int irq)
 {
         struct thread_info *curtp, *irqtp;
@@ -358,12 +357,6 @@ static inline void handle_one_irq(unsigned int irq)
         if (irqtp->flags)
                 set_bits(irqtp->flags, &curtp->flags);
 }
-#else
-static inline void handle_one_irq(unsigned int irq)
-{
-        generic_handle_irq(irq);
-}
-#endif
 
 static inline void check_stack_overflow(void)
 {
@@ -455,7 +448,6 @@ void exc_lvl_ctx_init(void)
 }
 #endif
 
-#ifdef CONFIG_IRQSTACKS
 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 
@@ -492,10 +484,6 @@ static inline void do_softirq_onstack(void)
         irqtp->task = NULL;
 }
 
-#else
-#define do_softirq_onstack()    __do_softirq()
-#endif /* CONFIG_IRQSTACKS */
-
 void do_softirq(void)
 {
         unsigned long flags;
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index dc66d52dcff5..6bbd7a604d24 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -33,7 +33,6 @@
 
         .text
 
-#ifdef CONFIG_IRQSTACKS
 _GLOBAL(call_do_softirq)
         mflr    r0
         stw     r0,4(r1)
@@ -56,7 +55,6 @@ _GLOBAL(call_handle_irq)
         lwz     r0,4(r1)
         mtlr    r0
         blr
-#endif /* CONFIG_IRQSTACKS */
 
 /*
  * This returns the high 64 bits of the product of two 64-bit numbers.
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index a2b18dffa03e..e5144906a56d 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -28,7 +28,6 @@
 
         .text
 
-#ifdef CONFIG_IRQSTACKS
 _GLOBAL(call_do_softirq)
         mflr    r0
         std     r0,16(r1)
@@ -52,7 +51,6 @@ _GLOBAL(call_handle_irq)
         ld      r0,16(r1)
         mtlr    r0
         blr
-#endif /* CONFIG_IRQSTACKS */
 
         .section        ".toc","aw"
 PPC64_CACHES:
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9d255b4f0a0e..773424df828a 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1005,7 +1005,6 @@ out:
         return error;
 }
 
-#ifdef CONFIG_IRQSTACKS
 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
                                   unsigned long nbytes)
 {
@@ -1030,10 +1029,6 @@ static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
         return 0;
 }
 
-#else
-#define valid_irq_stack(sp, p, nb)      0
-#endif /* CONFIG_IRQSTACKS */
-
 int validate_sp(unsigned long sp, struct task_struct *p,
                        unsigned long nbytes)
 {
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 8f58986c2ad9..7d84b210f168 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -241,7 +241,6 @@ int __init ppc_init(void)
 
 arch_initcall(ppc_init);
 
-#ifdef CONFIG_IRQSTACKS
 static void __init irqstack_early_init(void)
 {
         unsigned int i;
@@ -255,9 +254,6 @@ static void __init irqstack_early_init(void)
                         __va(lmb_alloc(THREAD_SIZE, THREAD_SIZE));
         }
 }
-#else
-#define irqstack_early_init()
-#endif
 
 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 static void __init exc_lvl_early_init(void)
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index f3fb5a79de52..643dcac40fcb 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -432,7 +432,6 @@ static u64 slb0_limit(void)
         return 1UL << SID_SHIFT;
 }
 
-#ifdef CONFIG_IRQSTACKS
 static void __init irqstack_early_init(void)
 {
         u64 limit = slb0_limit();
@@ -451,9 +450,6 @@ static void __init irqstack_early_init(void)
                                             THREAD_SIZE, limit));
         }
 }
-#else
-#define irqstack_early_init()
-#endif
 
 #ifdef CONFIG_PPC_BOOK3E
 static void __init exc_lvl_early_init(void)