Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm

Pull ARM updates from Russell King:
 "Here's the updates for ARM for this merge window, which cover quite a
  variety of areas.

  There's a bunch of patch series from Will tackling various bugs like
  the PROT_NONE handling, ASID allocation, cluster boot protocol and
  ASID TLB tagging updates.

  We move to a build-time sorted exception table rather than doing the
  sorting at run-time, add support for the secure computing filter, and
  some updates to the perf code.  We also have sorted out the placement
  of some headers, fixed some build warnings, fixed some hotplug
  problems with the per-cpu TWD code."

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (73 commits)
  ARM: 7594/1: Add .smp entry for REALVIEW_EB
  ARM: 7599/1: head: Remove boot-time HYP mode check for v5 and below
  ARM: 7598/1: net: bpf_jit_32: fix sp-relative load/stores offsets.
  ARM: 7595/1: syscall: rework ordering in syscall_trace_exit
  ARM: 7596/1: mmci: replace readsl/writesl with ioread32_rep/iowrite32_rep
  ARM: 7597/1: net: bpf_jit_32: fix kzalloc gfp/size mismatch.
  ARM: 7593/1: nommu: do not enable DCACHE_WORD_ACCESS when !CONFIG_MMU
  ARM: 7592/1: nommu: prevent generation of kernel unaligned memory accesses
  ARM: 7591/1: nommu: Enable the strict alignment (CR_A) bit only if ARCH < v6
  ARM: 7590/1: /proc/interrupts: limit the display of IPIs to online CPUs only
  ARM: 7587/1: implement optimized percpu variable access
  ARM: 7589/1: integrator: pass the lm resource to amba
  ARM: 7588/1: amba: create a resource parent registrator
  ARM: 7582/2: rename kvm_seq to vmalloc_seq so to avoid confusion with KVM
  ARM: 7585/1: kernel: fix nr_cpu_ids check in DT logical map init
  ARM: 7584/1: perf: fix link error when CONFIG_HW_PERF_EVENTS is not selected
  ARM: gic: use a private mapping for CPU target interfaces
  ARM: kernel: add logical mappings look-up
  ARM: kernel: add cpu logical map DT init in setup_arch
  ARM: kernel: add device tree init map function
  ...

1 files changed, 30 insertions, 13 deletions

diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 739db3a1b2d2..03deeffd9f6d 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -916,16 +916,11 @@ enum ptrace_syscall_dir {
 	PTRACE_SYSCALL_EXIT,
 };
 
-static int ptrace_syscall_trace(struct pt_regs *regs, int scno,
-				enum ptrace_syscall_dir dir)
+static int tracehook_report_syscall(struct pt_regs *regs,
+				    enum ptrace_syscall_dir dir)
 {
 	unsigned long ip;
 
-	current_thread_info()->syscall = scno;
-
-	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		return scno;
-
 	/*
 	 * IP is used to denote syscall entry/exit:
 	 * IP = 0 -> entry, =1 -> exit
@@ -944,19 +939,41 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno,
 
 asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)
 {
-	scno = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER);
+	current_thread_info()->syscall = scno;
+
+	/* Do the secure computing check first; failures should be fast. */
+	if (secure_computing(scno) == -1)
+		return -1;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		scno = tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
+
 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 		trace_sys_enter(regs, scno);
+
 	audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0, regs->ARM_r1,
 			    regs->ARM_r2, regs->ARM_r3);
+
 	return scno;
 }
 
-asmlinkage int syscall_trace_exit(struct pt_regs *regs, int scno)
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 {
-	scno = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_EXIT);
-	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
-		trace_sys_exit(regs, scno);
+	/*
+	 * Audit the syscall before anything else, as a debugger may
+	 * come in and change the current registers.
+	 */
 	audit_syscall_exit(regs);
-	return scno;
+
+	/*
+	 * Note that we haven't updated the ->syscall field for the
+	 * current thread. This isn't a problem because it will have
+	 * been set on syscall entry and there hasn't been an opportunity
+	 * for a PTRACE_SET_SYSCALL since then.
+	 */
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_exit(regs, regs_return_value(regs));
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
 }