Merge tag 'powerpc-4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - support "hybrid" iommu/direct DMA ops for coherent_mask < dma_mask
   from Benjamin Herrenschmidt

 - EEH fixes for SRIOV from Gavin

 - introduce rtas_get_sensor_fast() for IRQ handlers from Thomas Huth

 - use hardware RNG for arch_get_random_seed_* not arch_get_random_*
   from Paul Mackerras

 - seccomp filter support from Michael Ellerman

 - opal_cec_reboot2() handling for HMIs & machine checks from Mahesh
   Salgaonkar

 - add powerpc timebase as a trace clock source from Naveen N.  Rao

 - misc cleanups in the xmon, signal & SLB code from Anshuman Khandual

 - add an inline function to update POWER8 HID0 from Gautham R.  Shenoy

 - fix pte_pagesize_index() crash on 4K w/64K hash from Michael Ellerman

 - drop support for 64K local store on 4K kernels from Michael Ellerman

 - move dma_get_required_mask() from pnv_phb to pci_controller_ops from
   Andrew Donnellan

 - initialize distance lookup table from drconf path from Nikunj A
   Dadhania

 - enable RTC class support from Vaibhav Jain

 - disable automatically blocked PCI config from Gavin Shan

 - add LEDs driver for PowerNV platform from Vasant Hegde

 - fix endianness issues in the HVSI driver from Laurent Dufour

 - kexec endian fixes from Samuel Mendoza-Jonas

 - fix corrupted pdn list from Gavin Shan

 - fix fenced PHB caused by eeh_slot_error_detail() from Gavin Shan

 - Freescale updates from Scott: Highlights include 32-bit memcpy/memset
   optimizations, checksum optimizations, 85xx config fragments and
   updates, device tree updates, e6500 fixes for non-SMP, and misc
   cleanup and minor fixes.

 - a ton of cxl updates & fixes:
    - add explicit precision specifiers from Rasmus Villemoes
    - use more common format specifier from Rasmus Villemoes
    - destroy cxl_adapter_idr on module_exit from Johannes Thumshirn
    - destroy afu->contexts_idr on release of an afu from Johannes
      Thumshirn
    - compile with -Werror from Daniel Axtens
    - EEH support from Daniel Axtens
    - plug irq_bitmap getting leaked in cxl_context from Vaibhav Jain
    - add alternate MMIO error handling from Ian Munsie
    - allow release of contexts which have been OPENED but not STARTED
      from Andrew Donnellan
    - remove use of macro DEFINE_PCI_DEVICE_TABLE from Vaishali Thakkar
    - release irqs if memory allocation fails from Vaibhav Jain
    - remove racy attempt to force EEH invocation in reset from Daniel
      Axtens
    - fix + cleanup error paths in cxl_dev_context_init from Ian Munsie
    - fix force unmapping mmaps of contexts allocated through the kernel
      api from Ian Munsie
    - set up and enable PSL Timebase from Philippe Bergheaud

* tag 'powerpc-4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (140 commits)
  cxl: Set up and enable PSL Timebase
  cxl: Fix force unmapping mmaps of contexts allocated through the kernel api
  cxl: Fix + cleanup error paths in cxl_dev_context_init
  powerpc/eeh: Fix fenced PHB caused by eeh_slot_error_detail()
  powerpc/pseries: Cleanup on pci_dn_reconfig_notifier()
  powerpc/pseries: Fix corrupted pdn list
  powerpc/powernv: Enable LEDS support
  powerpc/iommu: Set default DMA offset in dma_dev_setup
  cxl: Remove racy attempt to force EEH invocation in reset
  cxl: Release irqs if memory allocation fails
  cxl: Remove use of macro DEFINE_PCI_DEVICE_TABLE
  powerpc/powernv: Fix mis-merge of OPAL support for LEDS driver
  powerpc/powernv: Reset HILE before kexec_sequence()
  powerpc/kexec: Reset secondary cpu endianness before kexec
  powerpc/hvsi: Fix endianness issues in the HVSI driver
  leds/powernv: Add driver for PowerNV platform
  powerpc/powernv: Create LED platform device
  powerpc/powernv: Add OPAL interfaces for accessing and modifying system LED states
  powerpc/powernv: Fix the log message when disabling VF
  cxl: Allow release of contexts which have been OPENED but not STARTED
  ...

1 files changed, 33 insertions, 21 deletions

diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index ff21b7a2f0cc..ab9f3f0a8637 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -22,10 +22,15 @@
 extern const unsigned long sys_call_table[];
 #endif /* CONFIG_FTRACE_SYSCALLS */
 
-static inline long syscall_get_nr(struct task_struct *task,
-				  struct pt_regs *regs)
+static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
 {
-	return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L;
+	/*
+	 * Note that we are returning an int here. That means 0xffffffff, ie.
+	 * 32-bit negative 1, will be interpreted as -1 on a 64-bit kernel.
+	 * This is important for seccomp so that compat tasks can set r0 = -1
+	 * to reject the syscall.
+	 */
+	return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1;
 }
 
 static inline void syscall_rollback(struct task_struct *task,
@@ -34,12 +39,6 @@ static inline void syscall_rollback(struct task_struct *task,
 	regs->gpr[3] = regs->orig_gpr3;
 }
 
-static inline long syscall_get_error(struct task_struct *task,
-				     struct pt_regs *regs)
-{
-	return (regs->ccr & 0x10000000) ? -regs->gpr[3] : 0;
-}
-
 static inline long syscall_get_return_value(struct task_struct *task,
 					    struct pt_regs *regs)
 {
@@ -50,9 +49,15 @@ static inline void syscall_set_return_value(struct task_struct *task,
 					    struct pt_regs *regs,
 					    int error, long val)
 {
+	/*
+	 * In the general case it's not obvious that we must deal with CCR
+	 * here, as the syscall exit path will also do that for us. However
+	 * there are some places, eg. the signal code, which check ccr to
+	 * decide if the value in r3 is actually an error.
+	 */
 	if (error) {
 		regs->ccr |= 0x10000000L;
-		regs->gpr[3] = -error;
+		regs->gpr[3] = error;
 	} else {
 		regs->ccr &= ~0x10000000L;
 		regs->gpr[3] = val;
@@ -64,19 +69,22 @@ static inline void syscall_get_arguments(struct task_struct *task,
 					 unsigned int i, unsigned int n,
 					 unsigned long *args)
 {
+	unsigned long val, mask = -1UL;
+
 	BUG_ON(i + n > 6);
-#ifdef CONFIG_PPC64
-	if (test_tsk_thread_flag(task, TIF_32BIT)) {
-		/*
-		 * Zero-extend 32-bit argument values.  The high bits are
-		 * garbage ignored by the actual syscall dispatch.
-		 */
-		while (n-- > 0)
-			args[n] = (u32) regs->gpr[3 + i + n];
-		return;
-	}
+
+#ifdef CONFIG_COMPAT
+	if (test_tsk_thread_flag(task, TIF_32BIT))
+		mask = 0xffffffff;
 #endif
-	memcpy(args, &regs->gpr[3 + i], n * sizeof(args[0]));
+	while (n--) {
+		if (n == 0 && i == 0)
+			val = regs->orig_gpr3;
+		else
+			val = regs->gpr[3 + i + n];
+
+		args[n] = val & mask;
+	}
 }
 
 static inline void syscall_set_arguments(struct task_struct *task,
@@ -86,6 +94,10 @@ static inline void syscall_set_arguments(struct task_struct *task,
 {
 	BUG_ON(i + n > 6);
 	memcpy(&regs->gpr[3 + i], args, n * sizeof(args[0]));
+
+	/* Also copy the first argument into orig_gpr3 */
+	if (i == 0 && n > 0)
+		regs->orig_gpr3 = args[0];
 }
 
 static inline int syscall_get_arch(void)