Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

Pull powerpc updates from Benjamin Herrenschmidt:
 "Some highlights in addition to the usual batch of fixes:

   - 64TB address space support for 64-bit processes by Aneesh Kumar

   - Gavin Shan did a major cleanup & re-organization of our EEH support
     code (IBM fancy PCI error handling & recovery infrastructure) which
     paves the way for supporting different platform backends, along
     with some rework of the PCIe code for the PowerNV platform in order
     to remove home made resource allocations and instead use the
     generic code (which is possible after some small improvements to it
     done by Gavin).

   - Uprobes support by Ananth N Mavinakayanahalli

   - A pile of embedded updates from Freescale folks, including new SoC
     and board supports, more KVM stuff including preparing for 64-bit
     BookE KVM support, ePAPR 1.1 updates, etc..."

Fixup trivial conflicts in drivers/scsi/ipr.c

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (146 commits)
  powerpc/iommu: Fix multiple issues with IOMMU pools code
  powerpc: Fix VMX fix for memcpy case
  driver/mtd:IFC NAND:Initialise internal SRAM before any write
  powerpc/fsl-pci: use 'Header Type' to identify PCIE mode
  powerpc/eeh: Don't release eeh_mutex in eeh_phb_pe_get
  powerpc: Remove tlb batching hack for nighthawk
  powerpc: Set paca->data_offset = 0 for boot cpu
  powerpc/perf: Sample only if SIAR-Valid bit is set in P7+
  powerpc/fsl-pci: fix warning when CONFIG_SWIOTLB is disabled
  powerpc/mpc85xx: Update interrupt handling for IFC controller
  powerpc/85xx: Enable USB support in p1023rds_defconfig
  powerpc/smp: Do not disable IPI interrupts during suspend
  powerpc/eeh: Fix crash on converting OF node to edev
  powerpc/eeh: Lock module while handling EEH event
  powerpc/kprobe: Don't emulate store when kprobe stwu r1
  powerpc/kprobe: Complete kprobe and migrate exception frame
  powerpc/kprobe: Introduce a new thread flag
  powerpc: Remove unused __get_user64() and __put_user64()
  powerpc/eeh: Global mutex to protect PE tree
  powerpc/eeh: Remove EEH PE for normal PCI hotplug
  ...

1 files changed, 34 insertions, 2 deletions

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 9a52349874e..e15c521846c 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -566,7 +566,7 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
 	unsigned long int ea;
 	unsigned int cr, mb, me, sh;
 	int err;
-	unsigned long old_ra;
+	unsigned long old_ra, val3;
 	long ival;
 
 	opcode = instr >> 26;
@@ -1486,11 +1486,43 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
 		goto ldst_done;
 
 	case 36:	/* stw */
-	case 37:	/* stwu */
 		val = regs->gpr[rd];
 		err = write_mem(val, dform_ea(instr, regs), 4, regs);
 		goto ldst_done;
 
+	case 37:	/* stwu */
+		val = regs->gpr[rd];
+		val3 = dform_ea(instr, regs);
+		/*
+		 * For PPC32 we always use stwu to change stack point with r1. So
+		 * this emulated store may corrupt the exception frame, now we
+		 * have to provide the exception frame trampoline, which is pushed
+		 * below the kprobed function stack. So we only update gpr[1] but
+		 * don't emulate the real store operation. We will do real store
+		 * operation safely in exception return code by checking this flag.
+		 */
+		if ((ra == 1) && !(regs->msr & MSR_PR) \
+			&& (val3 >= (regs->gpr[1] - STACK_INT_FRAME_SIZE))) {
+			/*
+			 * Check if we will touch kernel sack overflow
+			 */
+			if (val3 - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) {
+				printk(KERN_CRIT "Can't kprobe this since Kernel stack overflow.\n");
+				err = -EINVAL;
+				break;
+			}
+
+			/*
+			 * Check if we already set since that means we'll
+			 * lose the previous value.
+			 */
+			WARN_ON(test_thread_flag(TIF_EMULATE_STACK_STORE));
+			set_thread_flag(TIF_EMULATE_STACK_STORE);
+			err = 0;
+		} else
+			err = write_mem(val, val3, 4, regs);
+		goto ldst_done;
+
 	case 38:	/* stb */
 	case 39:	/* stbu */
 		val = regs->gpr[rd];