Merge tag 'powerpc-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Enable THREAD_INFO_IN_TASK to move thread_info off the stack.

   - A big series from Christoph reworking our DMA code to use more of
     the generic infrastructure, as he said:
       "This series switches the powerpc port to use the generic swiotlb
        and noncoherent dma ops, and to use more generic code for the
        coherent direct mapping, as well as removing a lot of dead
        code."

   - Increase our vmalloc space to 512T with the Hash MMU on modern
     CPUs, allowing us to support machines with larger amounts of total
     RAM or distance between nodes.

   - Two series from Christophe, one to optimise TLB miss handlers on
     6xx, and another to optimise the way STRICT_KERNEL_RWX is
     implemented on some 32-bit CPUs.

   - Support for KCOV coverage instrumentation which means we can run
     syzkaller and discover even more bugs in our code.

  And as always many clean-ups, reworks and minor fixes etc.

  Thanks to: Alan Modra, Alexey Kardashevskiy, Alistair Popple, Andrea
  Arcangeli, Andrew Donnellan, Aneesh Kumar K.V, Aravinda Prasad, Balbir
  Singh, Brajeswar Ghosh, Breno Leitao, Christian Lamparter, Christian
  Zigotzky, Christophe Leroy, Christoph Hellwig, Corentin Labbe, Daniel
  Axtens, David Gibson, Diana Craciun, Firoz Khan, Gustavo A. R. Silva,
  Igor Stoppa, Joe Lawrence, Joel Stanley, Jonathan Neuschäfer, Jordan
  Niethe, Laurent Dufour, Madhavan Srinivasan, Mahesh Salgaonkar, Mark
  Cave-Ayland, Masahiro Yamada, Mathieu Malaterre, Matteo Croce, Meelis
  Roos, Michael W. Bringmann, Nathan Chancellor, Nathan Fontenot,
  Nicholas Piggin, Nick Desaulniers, Nicolai Stange, Oliver O'Halloran,
  Paul Mackerras, Peter Xu, PrasannaKumar Muralidharan, Qian Cai,
  Rashmica Gupta, Reza Arbab, Robert P. J. Day, Russell Currey,
  Sabyasachi Gupta, Sam Bobroff, Sandipan Das, Sergey Senozhatsky,
  Souptick Joarder, Stewart Smith, Tyrel Datwyler, Vaibhav Jain,
  YueHaibing"

* tag 'powerpc-5.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (200 commits)
  powerpc/32: Clear on-stack exception marker upon exception return
  powerpc: Remove export of save_stack_trace_tsk_reliable()
  powerpc/mm: fix "section_base" set but not used
  powerpc/mm: Fix "sz" set but not used warning
  powerpc/mm: Check secondary hash page table
  powerpc: remove nargs from __SYSCALL
  powerpc/64s: Fix unrelocated interrupt trampoline address test
  powerpc/powernv/ioda: Fix locked_vm counting for memory used by IOMMU tables
  powerpc/fsl: Fix the flush of branch predictor.
  powerpc/powernv: Make opal log only readable by root
  powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc
  powerpc/powernv: move OPAL call wrapper tracing and interrupt handling to C
  powerpc/64s: Fix data interrupts vs d-side MCE reentrancy
  powerpc/64s: Prepare to handle data interrupts vs d-side MCE reentrancy
  powerpc/64s: system reset interrupt preserve HSRRs
  powerpc/64s: Fix HV NMI vs HV interrupt recoverability test
  powerpc/mm/hash: Handle mmap_min_addr correctly in get_unmapped_area topdown search
  powerpc/hugetlb: Handle mmap_min_addr correctly in get_unmapped_area callback
  selftests/powerpc: Remove duplicate header
  powerpc sstep: Add support for modsd, modud instructions
  ...

1 files changed, 41 insertions, 27 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ce393df243aa..dd9e0d5386ee 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -176,7 +176,7 @@ static void __giveup_fpu(struct task_struct *tsk)
 
 	save_fpu(tsk);
 	msr = tsk->thread.regs->msr;
-	msr &= ~MSR_FP;
+	msr &= ~(MSR_FP|MSR_FE0|MSR_FE1);
 #ifdef CONFIG_VSX
 	if (cpu_has_feature(CPU_FTR_VSX))
 		msr &= ~MSR_VSX;
@@ -1231,8 +1231,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
 		batch->active = 1;
 	}
 
-	if (current_thread_info()->task->thread.regs) {
-		restore_math(current_thread_info()->task->thread.regs);
+	if (current->thread.regs) {
+		restore_math(current->thread.regs);
 
 		/*
 		 * The copy-paste buffer can only store into foreign real
@@ -1242,7 +1242,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
 		 * mappings, we must issue a cp_abort to clear any state and
 		 * prevent snooping, corruption or a covert channel.
 		 */
-		if (current_thread_info()->task->thread.used_vas)
+		if (current->thread.used_vas)
 			asm volatile(PPC_CP_ABORT);
 	}
 #endif /* CONFIG_PPC_BOOK3S_64 */
@@ -1634,7 +1634,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 	struct thread_info *ti = task_thread_info(p);
 
-	klp_init_thread_info(ti);
+	klp_init_thread_info(p);
 
 	/* Copy registers */
 	sp -= sizeof(struct pt_regs);
@@ -1691,8 +1691,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	sp -= STACK_FRAME_OVERHEAD;
 	p->thread.ksp = sp;
 #ifdef CONFIG_PPC32
-	p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
-				_ALIGN_UP(sizeof(struct thread_info), 16);
+	p->thread.ksp_limit = (unsigned long)end_of_stack(p);
 #endif
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	p->thread.ptrace_bps[0] = NULL;
@@ -1995,21 +1994,14 @@ static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
 	unsigned long stack_page;
 	unsigned long cpu = task_cpu(p);
 
-	/*
-	 * Avoid crashing if the stack has overflowed and corrupted
-	 * task_cpu(p), which is in the thread_info struct.
-	 */
-	if (cpu < NR_CPUS && cpu_possible(cpu)) {
-		stack_page = (unsigned long) hardirq_ctx[cpu];
-		if (sp >= stack_page + sizeof(struct thread_struct)
-		    && sp <= stack_page + THREAD_SIZE - nbytes)
-			return 1;
-
-		stack_page = (unsigned long) softirq_ctx[cpu];
-		if (sp >= stack_page + sizeof(struct thread_struct)
-		    && sp <= stack_page + THREAD_SIZE - nbytes)
-			return 1;
-	}
+	stack_page = (unsigned long)hardirq_ctx[cpu];
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+	stack_page = (unsigned long)softirq_ctx[cpu];
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
 	return 0;
 }
 
@@ -2018,8 +2010,10 @@ int validate_sp(unsigned long sp, struct task_struct *p,
 {
 	unsigned long stack_page = (unsigned long)task_stack_page(p);
 
-	if (sp >= stack_page + sizeof(struct thread_struct)
-	    && sp <= stack_page + THREAD_SIZE - nbytes)
+	if (sp < THREAD_SIZE)
+		return 0;
+
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
 		return 1;
 
 	return valid_irq_stack(sp, p, nbytes);
@@ -2027,7 +2021,7 @@ int validate_sp(unsigned long sp, struct task_struct *p,
 
 EXPORT_SYMBOL(validate_sp);
 
-unsigned long get_wchan(struct task_struct *p)
+static unsigned long __get_wchan(struct task_struct *p)
 {
 	unsigned long ip, sp;
 	int count = 0;
@@ -2053,6 +2047,20 @@ unsigned long get_wchan(struct task_struct *p)
 	return 0;
 }
 
+unsigned long get_wchan(struct task_struct *p)
+{
+	unsigned long ret;
+
+	if (!try_get_task_stack(p))
+		return 0;
+
+	ret = __get_wchan(p);
+
+	put_task_stack(p);
+
+	return ret;
+}
+
 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
 
 void show_stack(struct task_struct *tsk, unsigned long *stack)
@@ -2067,9 +2075,13 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
 	int curr_frame = 0;
 #endif
 
-	sp = (unsigned long) stack;
 	if (tsk == NULL)
 		tsk = current;
+
+	if (!try_get_task_stack(tsk))
+		return;
+
+	sp = (unsigned long) stack;
 	if (sp == 0) {
 		if (tsk == current)
 			sp = current_stack_pointer();
@@ -2081,7 +2093,7 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
 	printk("Call Trace:\n");
 	do {
 		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
-			return;
+			break;
 
 		stack = (unsigned long *) sp;
 		newsp = stack[0];
@@ -2121,6 +2133,8 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
 
 		sp = newsp;
 	} while (count++ < kstack_depth_to_print);
+
+	put_task_stack(tsk);
 }
 
 #ifdef CONFIG_PPC64