Merge tag 'v3.2-rc7' into staging/for_v3.3

Linux 3.2-rc7

* tag 'v3.2-rc7': (1304 commits)
  Linux 3.2-rc7
  netfilter: xt_connbytes: handle negation correctly
  Btrfs: call d_instantiate after all ops are setup
  Btrfs: fix worker lock misuse in find_worker
  net: relax rcvbuf limits
  rps: fix insufficient bounds checking in store_rps_dev_flow_table_cnt()
  net: introduce DST_NOPEER dst flag
  mqprio: Avoid panic if no options are provided
  bridge: provide a mtu() method for fake_dst_ops
  md/bitmap: It is OK to clear bits during recovery.
  md: don't give up looking for spares on first failure-to-add
  md/raid5: ensure correct assessment of drives during degraded reshape.
  md/linear: fix hot-add of devices to linear arrays.
  sparc64: Fix MSIQ HV call ordering in pci_sun4v_msiq_build_irq().
  pata_of_platform: Add missing CONFIG_OF_IRQ dependency.
  ipv4: using prefetch requires including prefetch.h
  VFS: Fix race between CPU hotplug and lglocks
  vfs: __read_cache_page should use gfp argument rather than GFP_KERNEL
  USB: Fix usb/isp1760 build on sparc
  net: Add a flow_cache_flush_deferred function
  ...

Conflicts:
	drivers/media/common/tuners/tda18218.c
	drivers/media/video/omap3isp/ispccdc.c
	drivers/staging/media/as102/as102_drv.h

1 files changed, 28 insertions, 14 deletions

diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c
index a2b81598d90..f0836cd0e2f 100644
--- a/arch/sparc/kernel/signal_64.c
+++ b/arch/sparc/kernel/signal_64.c
@@ -529,11 +529,27 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 	siginfo_t info;
 	int signr;
 	
+	/* It's a lot of work and synchronization to add a new ptrace
+	 * register for GDB to save and restore in order to get
+	 * orig_i0 correct for syscall restarts when debugging.
+	 *
+	 * Although it should be the case that most of the global
+	 * registers are volatile across a system call, glibc already
+	 * depends upon that fact that we preserve them.  So we can't
+	 * just use any global register to save away the orig_i0 value.
+	 *
+	 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
+	 * preserved across a system call trap by various pieces of
+	 * code in glibc.
+	 *
+	 * %g7 is used as the "thread register".   %g6 is not used in
+	 * any fixed manner.  %g6 is used as a scratch register and
+	 * a compiler temporary, but it's value is never used across
+	 * a system call.  Therefore %g6 is usable for orig_i0 storage.
+	 */
 	if (pt_regs_is_syscall(regs) &&
-	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
-		restart_syscall = 1;
-	} else
-		restart_syscall = 0;
+	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
+		regs->u_regs[UREG_G6] = orig_i0;
 
 	if (current_thread_info()->status & TS_RESTORE_SIGMASK)
 		oldset = &current->saved_sigmask;
@@ -542,22 +558,20 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 
 #ifdef CONFIG_COMPAT
 	if (test_thread_flag(TIF_32BIT)) {
-		extern void do_signal32(sigset_t *, struct pt_regs *,
-					int restart_syscall,
-					unsigned long orig_i0);
-		do_signal32(oldset, regs, restart_syscall, orig_i0);
+		extern void do_signal32(sigset_t *, struct pt_regs *);
+		do_signal32(oldset, regs);
 		return;
 	}
 #endif	
 
 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 
-	/* If the debugger messes with the program counter, it clears
-	 * the software "in syscall" bit, directing us to not perform
-	 * a syscall restart.
-	 */
-	if (restart_syscall && !pt_regs_is_syscall(regs))
-		restart_syscall = 0;
+	restart_syscall = 0;
+	if (pt_regs_is_syscall(regs) &&
+	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
+		restart_syscall = 1;
+		orig_i0 = regs->u_regs[UREG_G6];
+	}
 
 	if (signr > 0) {
 		if (restart_syscall)