Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile

Pull Tile arch updates from Chris Metcalf:
 "These changes bring in a bunch of new functionality that has been
  maintained internally at Tilera over the last year, plus other stray
  bits of work that I've taken into the tile tree from other folks.

  The changes include some PCI root complex work, interrupt-driven
  console support, support for performing fast-path unaligned data
  fixups by kernel-based JIT code generation, CONFIG_PREEMPT support,
  vDSO support for gettimeofday(), a serial driver for the tilegx
  on-chip UART, KGDB support, more optimized string routines, support
  for ftrace and kprobes, improved ASLR, and many bug fixes.

  We also remove support for the old TILE64 chip, which is no longer
  buildable"

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (85 commits)
  tile: refresh tile defconfig files
  tile: rework <asm/cmpxchg.h>
  tile PCI RC: make default consistent DMA mask 32-bit
  tile: add null check for kzalloc in tile/kernel/setup.c
  tile: make __write_once a synonym for __read_mostly
  tile: remove support for TILE64
  tile: use asm-generic/bitops/builtin-*.h
  tile: eliminate no-op "noatomichash" boot argument
  tile: use standard tile_bundle_bits type in traps.c
  tile: simplify code referencing hypervisor API addresses
  tile: change <asm/system.h> to <asm/switch_to.h> in comments
  tile: mark pcibios_init() as __init
  tile: check for correct compiler earlier in asm-offsets.c
  tile: use standard 'generic-y' model for <asm/hw_irq.h>
  tile: use asm-generic version of <asm/local64.h>
  tile PCI RC: add comment about "PCI hole" problem
  tile: remove DEBUG_EXTRA_FLAGS kernel config option
  tile: add virt_to_kpte() API and clean up and document behavior
  tile: support FRAME_POINTER
  tile: support reporting Tilera hypervisor statistics
  ...

1 files changed, 17 insertions, 2 deletions

diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c
index 0f83ed4602b2..de98c6ddf136 100644
--- a/arch/tile/kernel/ptrace.c
+++ b/arch/tile/kernel/ptrace.c
@@ -265,6 +265,21 @@ int do_syscall_trace_enter(struct pt_regs *regs)
 
 void do_syscall_trace_exit(struct pt_regs *regs)
 {
+	long errno;
+
+	/*
+	 * The standard tile calling convention returns the value (or negative
+	 * errno) in r0, and zero (or positive errno) in r1.
+	 * It saves a couple of cycles on the hot path to do this work in
+	 * registers only as we return, rather than updating the in-memory
+	 * struct ptregs.
+	 */
+	errno = (long) regs->regs[0];
+	if (errno < 0 && errno > -4096)
+		regs->regs[1] = -errno;
+	else
+		regs->regs[1] = 0;
+
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall_exit(regs, 0);
 
@@ -272,7 +287,7 @@ void do_syscall_trace_exit(struct pt_regs *regs)
 		trace_sys_exit(regs, regs->regs[0]);
 }
 
-void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
+void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs)
 {
 	struct siginfo info;
 
@@ -288,5 +303,5 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
 /* Handle synthetic interrupt delivered only by the simulator. */
 void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num)
 {
-	send_sigtrap(current, regs, fault_num);
+	send_sigtrap(current, regs);
 }