Merge tag 'powerpc-4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Support for split PMD page table lock on 64-bit Book3S (Power8/9).

   - Add support for HAVE_RELIABLE_STACKTRACE, so we properly support
     live patching again.

   - Add support for patching barrier_nospec in copy_from_user() and
     syscall entry.

   - A couple of fixes for our data breakpoints on Book3S.

   - A series from Nick optimising TLB/mm handling with the Radix MMU.

   - Numerous small cleanups to squash sparse/gcc warnings from Mathieu
     Malaterre.

   - Several series optimising various parts of the 32-bit code from
     Christophe Leroy.

   - Removal of support for two old machines, "SBC834xE" and "C2K"
     ("GEFanuc,C2K"), which is why the diffstat has so many deletions.

  And many other small improvements & fixes.

  There's a few out-of-area changes. Some minor ftrace changes OK'ed by
  Steve, and a fix to our powernv cpuidle driver. Then there's a series
  touching mm, x86 and fs/proc/task_mmu.c, which cleans up some details
  around pkey support. It was ack'ed/reviewed by Ingo & Dave and has
  been in next for several weeks.

  Thanks to: Akshay Adiga, Alastair D'Silva, Alexey Kardashevskiy, Al
  Viro, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Arnd
  Bergmann, Balbir Singh, Cédric Le Goater, Christophe Leroy, Christophe
  Lombard, Colin Ian King, Dave Hansen, Fabio Estevam, Finn Thain,
  Frederic Barrat, Gautham R. Shenoy, Haren Myneni, Hari Bathini, Ingo
  Molnar, Jonathan Neuschäfer, Josh Poimboeuf, Kamalesh Babulal,
  Madhavan Srinivasan, Mahesh Salgaonkar, Mark Greer, Mathieu Malaterre,
  Matthew Wilcox, Michael Neuling, Michal Suchanek, Naveen N. Rao,
  Nicholas Piggin, Nicolai Stange, Olof Johansson, Paul Gortmaker, Paul
  Mackerras, Peter Rosin, Pridhiviraj Paidipeddi, Ram Pai, Rashmica
  Gupta, Ravi Bangoria, Russell Currey, Sam Bobroff, Samuel
  Mendoza-Jonas, Segher Boessenkool, Shilpasri G Bhat, Simon Guo,
  Souptick Joarder, Stewart Smith, Thiago Jung Bauermann, Torsten Duwe,
  Vaibhav Jain, Wei Yongjun, Wolfram Sang, Yisheng Xie, YueHaibing"

* tag 'powerpc-4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (251 commits)
  powerpc/64s/radix: Fix missing ptesync in flush_cache_vmap
  cpuidle: powernv: Fix promotion from snooze if next state disabled
  powerpc: fix build failure by disabling attribute-alias warning in pci_32
  ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()
  powerpc-opal: fix spelling mistake "Uniterrupted" -> "Uninterrupted"
  powerpc: fix spelling mistake: "Usupported" -> "Unsupported"
  powerpc/pkeys: Detach execute_only key on !PROT_EXEC
  powerpc/powernv: copy/paste - Mask SO bit in CR
  powerpc: Remove core support for Marvell mv64x60 hostbridges
  powerpc/boot: Remove core support for Marvell mv64x60 hostbridges
  powerpc/boot: Remove support for Marvell mv64x60 i2c controller
  powerpc/boot: Remove support for Marvell MPSC serial controller
  powerpc/embedded6xx: Remove C2K board support
  powerpc/lib: optimise PPC32 memcmp
  powerpc/lib: optimise 32 bits __clear_user()
  powerpc/time: inline arch_vtime_task_switch()
  powerpc/Makefile: set -mcpu=860 flag for the 8xx
  powerpc: Implement csum_ipv6_magic in assembly
  powerpc/32: Optimise __csum_partial()
  powerpc/lib: Adjust .balign inside string functions for PPC32
  ...

1 files changed, 174 insertions, 7 deletions

diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index d534ed901538..07e97f289c52 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -1,21 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+
 /*
- * Stack trace utility
+ * Stack trace utility functions etc.
  *
  * Copyright 2008 Christoph Hellwig, IBM Corp.
- *
- *
- *      This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
+ * Copyright 2018 SUSE Linux GmbH
+ * Copyright 2018 Nick Piggin, Michael Ellerman, IBM Corp.
  */
 
 #include <linux/export.h>
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+#include <linux/nmi.h>
 #include <linux/sched.h>
 #include <linux/sched/debug.h>
+#include <linux/sched/task_stack.h>
 #include <linux/stacktrace.h>
 #include <asm/ptrace.h>
 #include <asm/processor.h>
+#include <linux/ftrace.h>
+#include <asm/kprobes.h>
+
+#include <asm/paca.h>
 
 /*
  * Save stack-backtrace addresses into a stack_trace buffer.
@@ -76,3 +82,164 @@ save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
 	save_context_stack(trace, regs->gpr[1], current, 0);
 }
 EXPORT_SYMBOL_GPL(save_stack_trace_regs);
+
+#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
+int
+save_stack_trace_tsk_reliable(struct task_struct *tsk,
+				struct stack_trace *trace)
+{
+	unsigned long sp;
+	unsigned long stack_page = (unsigned long)task_stack_page(tsk);
+	unsigned long stack_end;
+	int graph_idx = 0;
+
+	/*
+	 * The last frame (unwinding first) may not yet have saved
+	 * its LR onto the stack.
+	 */
+	int firstframe = 1;
+
+	if (tsk == current)
+		sp = current_stack_pointer();
+	else
+		sp = tsk->thread.ksp;
+
+	stack_end = stack_page + THREAD_SIZE;
+	if (!is_idle_task(tsk)) {
+		/*
+		 * For user tasks, this is the SP value loaded on
+		 * kernel entry, see "PACAKSAVE(r13)" in _switch() and
+		 * system_call_common()/EXCEPTION_PROLOG_COMMON().
+		 *
+		 * Likewise for non-swapper kernel threads,
+		 * this also happens to be the top of the stack
+		 * as setup by copy_thread().
+		 *
+		 * Note that stack backlinks are not properly setup by
+		 * copy_thread() and thus, a forked task() will have
+		 * an unreliable stack trace until it's been
+		 * _switch()'ed to for the first time.
+		 */
+		stack_end -= STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+	} else {
+		/*
+		 * idle tasks have a custom stack layout,
+		 * c.f. cpu_idle_thread_init().
+		 */
+		stack_end -= STACK_FRAME_OVERHEAD;
+	}
+
+	if (sp < stack_page + sizeof(struct thread_struct) ||
+	    sp > stack_end - STACK_FRAME_MIN_SIZE) {
+		return 1;
+	}
+
+	for (;;) {
+		unsigned long *stack = (unsigned long *) sp;
+		unsigned long newsp, ip;
+
+		/* sanity check: ABI requires SP to be aligned 16 bytes. */
+		if (sp & 0xF)
+			return 1;
+
+		/* Mark stacktraces with exception frames as unreliable. */
+		if (sp <= stack_end - STACK_INT_FRAME_SIZE &&
+		    stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
+			return 1;
+		}
+
+		newsp = stack[0];
+		/* Stack grows downwards; unwinder may only go up. */
+		if (newsp <= sp)
+			return 1;
+
+		if (newsp != stack_end &&
+		    newsp > stack_end - STACK_FRAME_MIN_SIZE) {
+			return 1; /* invalid backlink, too far up. */
+		}
+
+		/* Examine the saved LR: it must point into kernel code. */
+		ip = stack[STACK_FRAME_LR_SAVE];
+		if (!firstframe && !__kernel_text_address(ip))
+			return 1;
+		firstframe = 0;
+
+		/*
+		 * FIXME: IMHO these tests do not belong in
+		 * arch-dependent code, they are generic.
+		 */
+		ip = ftrace_graph_ret_addr(tsk, &graph_idx, ip, NULL);
+#ifdef CONFIG_KPROBES
+		/*
+		 * Mark stacktraces with kretprobed functions on them
+		 * as unreliable.
+		 */
+		if (ip == (unsigned long)kretprobe_trampoline)
+			return 1;
+#endif
+
+		if (!trace->skip)
+			trace->entries[trace->nr_entries++] = ip;
+		else
+			trace->skip--;
+
+		if (newsp == stack_end)
+			break;
+
+		if (trace->nr_entries >= trace->max_entries)
+			return -E2BIG;
+
+		sp = newsp;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk_reliable);
+#endif /* CONFIG_HAVE_RELIABLE_STACKTRACE */
+
+#ifdef CONFIG_PPC_BOOK3S_64
+static void handle_backtrace_ipi(struct pt_regs *regs)
+{
+	nmi_cpu_backtrace(regs);
+}
+
+static void raise_backtrace_ipi(cpumask_t *mask)
+{
+	unsigned int cpu;
+
+	for_each_cpu(cpu, mask) {
+		if (cpu == smp_processor_id())
+			handle_backtrace_ipi(NULL);
+		else
+			smp_send_safe_nmi_ipi(cpu, handle_backtrace_ipi, 5 * USEC_PER_SEC);
+	}
+
+	for_each_cpu(cpu, mask) {
+		struct paca_struct *p = paca_ptrs[cpu];
+
+		cpumask_clear_cpu(cpu, mask);
+
+		pr_warn("CPU %d didn't respond to backtrace IPI, inspecting paca.\n", cpu);
+		if (!virt_addr_valid(p)) {
+			pr_warn("paca pointer appears corrupt? (%px)\n", p);
+			continue;
+		}
+
+		pr_warn("irq_soft_mask: 0x%02x in_mce: %d in_nmi: %d",
+			p->irq_soft_mask, p->in_mce, p->in_nmi);
+
+		if (virt_addr_valid(p->__current))
+			pr_cont(" current: %d (%s)\n", p->__current->pid,
+				p->__current->comm);
+		else
+			pr_cont(" current pointer corrupt? (%px)\n", p->__current);
+
+		pr_warn("Back trace of paca->saved_r1 (0x%016llx) (possibly stale):\n", p->saved_r1);
+		show_stack(p->__current, (unsigned long *)p->saved_r1);
+	}
+}
+
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
+{
+	nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi);
+}
+#endif /* CONFIG_PPC64 */