5 files changed, 29 insertions, 9 deletions

diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index ad36e8e34fa1..a402f7f94896 100644
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -49,6 +49,14 @@ static inline unsigned long klp_get_ftrace_location(unsigned long faddr)
 	 */
 	return ftrace_location_range(faddr, faddr + 16);
 }
+
+static inline void klp_init_thread_info(struct thread_info *ti)
+{
+	/* + 1 to account for STACK_END_MAGIC */
+	ti->livepatch_sp = (unsigned long *)(ti + 1) + 1;
+}
+#else
+static void klp_init_thread_info(struct thread_info *ti) { }
 #endif /* CONFIG_LIVEPATCH */
 
 #endif /* _ASM_POWERPC_LIVEPATCH_H */
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 7efee4a3240b..8febc3f66d53 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -43,7 +43,9 @@ struct thread_info {
 	int		preempt_count;		/* 0 => preemptable,
 						   <0 => BUG */
 	unsigned long	local_flags;		/* private flags for thread */
-
+#ifdef CONFIG_LIVEPATCH
+	unsigned long *livepatch_sp;
+#endif
 	/* low level flags - has atomic operations done on it */
 	unsigned long	flags ____cacheline_aligned_in_smp;
 };
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 290559df1e8b..3cb46a3b1de7 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -66,6 +66,7 @@
 #include <asm/udbg.h>
 #include <asm/smp.h>
 #include <asm/debug.h>
+#include <asm/livepatch.h>
 
 #ifdef CONFIG_PPC64
 #include <asm/paca.h>
@@ -607,10 +608,12 @@ void irq_ctx_init(void)
 		memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 		tp = softirq_ctx[i];
 		tp->cpu = i;
+		klp_init_thread_info(tp);
 
 		memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 		tp = hardirq_ctx[i];
 		tp->cpu = i;
+		klp_init_thread_info(tp);
 	}
 }
 
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index dccc87e8fee5..a38ce49648cb 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -55,6 +55,8 @@
 #include <asm/firmware.h>
 #endif
 #include <asm/code-patching.h>
+#include <asm/livepatch.h>
+
 #include <linux/kprobes.h>
 #include <linux/kdebug.h>
 
@@ -1267,13 +1269,15 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	extern void ret_from_kernel_thread(void);
 	void (*f)(void);
 	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+	struct thread_info *ti = task_thread_info(p);
+
+	klp_init_thread_info(ti);
 
 	/* Copy registers */
 	sp -= sizeof(struct pt_regs);
 	childregs = (struct pt_regs *) sp;
 	if (unlikely(p->flags & PF_KTHREAD)) {
 		/* kernel thread */
-		struct thread_info *ti = (void *)task_stack_page(p);
 		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->gpr[1] = sp + sizeof(struct pt_regs);
 		/* function */
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 5c03a6a9b054..e37b92ebb315 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -69,6 +69,7 @@
 #include <asm/kvm_ppc.h>
 #include <asm/hugetlb.h>
 #include <asm/epapr_hcalls.h>
+#include <asm/livepatch.h>
 
 #ifdef DEBUG
 #define DBG(fmt...) udbg_printf(fmt)
@@ -670,16 +671,16 @@ static void __init emergency_stack_init(void)
 	limit = min(safe_stack_limit(), ppc64_rma_size);
 
 	for_each_possible_cpu(i) {
-		unsigned long sp;
-		sp  = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
-		sp += THREAD_SIZE;
-		paca[i].emergency_sp = __va(sp);
+		struct thread_info *ti;
+		ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit));
+		klp_init_thread_info(ti);
+		paca[i].emergency_sp = (void *)ti + THREAD_SIZE;
 
 #ifdef CONFIG_PPC_BOOK3S_64
 		/* emergency stack for machine check exception handling. */
-		sp  = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
-		sp += THREAD_SIZE;
-		paca[i].mc_emergency_sp = __va(sp);
+		ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit));
+		klp_init_thread_info(ti);
+		paca[i].mc_emergency_sp = (void *)ti + THREAD_SIZE;
 #endif
 	}
 }
@@ -703,6 +704,8 @@ void __init setup_arch(char **cmdline_p)
 	if (ppc_md.panic)
 		setup_panic();
 
+	klp_init_thread_info(&init_thread_info);
+
 	init_mm.start_code = (unsigned long)_stext;
 	init_mm.end_code = (unsigned long) _etext;
 	init_mm.end_data = (unsigned long) _edata;