Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck

* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck: (39 commits)
  signal: fix __send_signal() false positive kmemcheck warning
  fs: fix do_mount_root() false positive kmemcheck warning
  fs: introduce __getname_gfp()
  trace: annotate bitfields in struct ring_buffer_event
  net: annotate struct sock bitfield
  c2port: annotate bitfield for kmemcheck
  net: annotate inet_timewait_sock bitfields
  ieee1394/csr1212: fix false positive kmemcheck report
  ieee1394: annotate bitfield
  net: annotate bitfields in struct inet_sock
  net: use kmemcheck bitfields API for skbuff
  kmemcheck: introduce bitfield API
  kmemcheck: add opcode self-testing at boot
  x86: unify pte_hidden
  x86: make _PAGE_HIDDEN conditional
  kmemcheck: make kconfig accessible for other architectures
  kmemcheck: enable in the x86 Kconfig
  kmemcheck: add hooks for the page allocator
  kmemcheck: add hooks for page- and sg-dma-mappings
  kmemcheck: don't track page tables
  ...

arch/x86/kernel/cpu/intel.c

@@ -86,6 +86,29 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
 	 */
 	if (c->x86 == 6 && c->x86_model < 15)
 		clear_cpu_cap(c, X86_FEATURE_PAT);
+
+#ifdef CONFIG_KMEMCHECK
+	/*
+	 * P4s have a "fast strings" feature which causes single-
+	 * stepping REP instructions to only generate a #DB on
+	 * cache-line boundaries.
+	 *
+	 * Ingo Molnar reported a Pentium D (model 6) and a Xeon
+	 * (model 2) with the same problem.
+	 */
+	if (c->x86 == 15) {
+		u64 misc_enable;
+
+		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+
+		if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) {
+			printk(KERN_INFO "kmemcheck: Disabling fast string operations\n");
+
+			misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING;
+			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+		}
+	}
+#endif
 }
 
 #ifdef CONFIG_X86_32

arch/x86/kernel/process.c

@@ -63,7 +63,7 @@ void arch_task_cache_init(void)
         task_xstate_cachep =
         	kmem_cache_create("task_xstate", xstate_size,
 				  __alignof__(union thread_xstate),
-				  SLAB_PANIC, NULL);
+				  SLAB_PANIC | SLAB_NOTRACK, NULL);
 }
 
 /*

arch/x86/kernel/stacktrace.c

@@ -77,6 +77,13 @@ void save_stack_trace(struct stack_trace *trace)
 }
 EXPORT_SYMBOL_GPL(save_stack_trace);
 
+void save_stack_trace_bp(struct stack_trace *trace, unsigned long bp)
+{
+	dump_trace(current, NULL, NULL, bp, &save_stack_ops, trace);
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 {
 	dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);

arch/x86/kernel/traps.c

@@ -45,6 +45,7 @@
 #include <linux/edac.h>
 #endif
 
+#include <asm/kmemcheck.h>
 #include <asm/stacktrace.h>
 #include <asm/processor.h>
 #include <asm/debugreg.h>
@@ -534,6 +535,10 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
 
 	get_debugreg(condition, 6);
 
+	/* Catch kmemcheck conditions first of all! */
+	if (condition & DR_STEP && kmemcheck_trap(regs))
+		return;
+
 	/*
 	 * The processor cleared BTF, so don't mark that we need it set.
 	 */