Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (92 commits)
  powerpc: Remove unused 'protect4gb' boot parameter
  powerpc: Build-in e1000e for pseries & ppc64_defconfig
  powerpc/pseries: Make request_ras_irqs() available to other pseries code
  powerpc/numa: Use ibm,architecture-vec-5 to detect form 1 affinity
  powerpc/numa: Set a smaller value for RECLAIM_DISTANCE to enable zone reclaim
  powerpc: Use smt_snooze_delay=-1 to always busy loop
  powerpc: Remove check of ibm,smt-snooze-delay OF property
  powerpc/kdump: Fix race in kdump shutdown
  powerpc/kexec: Fix race in kexec shutdown
  powerpc/kexec: Speedup kexec hash PTE tear down
  powerpc/pseries: Add hcall to read 4 ptes at a time in real mode
  powerpc: Use more accurate limit for first segment memory allocations
  powerpc/kdump: Use chip->shutdown to disable IRQs
  powerpc/kdump: CPUs assume the context of the oopsing CPU
  powerpc/crashdump: Do not fail on NULL pointer dereferencing
  powerpc/eeh: Fix oops when probing in early boot
  powerpc/pci: Check devices status property when scanning OF tree
  powerpc/vio: Switch VIO Bus PM to use generic helpers
  powerpc: Avoid bad relocations in iSeries code
  powerpc: Use common cpu_die (fixes SMP+SUSPEND build)
  ...

1 files changed, 64 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 9e2d84c06b7..5d8be041622 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -89,6 +89,7 @@ struct pt_regs {
 
 #define instruction_pointer(regs) ((regs)->nip)
 #define user_stack_pointer(regs) ((regs)->gpr[1])
+#define kernel_stack_pointer(regs) ((regs)->gpr[1])
 #define regs_return_value(regs) ((regs)->gpr[3])
 
 #ifdef CONFIG_SMP
@@ -141,6 +142,69 @@ do {									      \
 #define arch_has_block_step()	(!cpu_has_feature(CPU_FTR_601))
 #define ARCH_HAS_USER_SINGLE_STEP_INFO
 
+/*
+ * kprobe-based event tracer support
+ */
+
+#include <linux/stddef.h>
+#include <linux/thread_info.h>
+extern int regs_query_register_offset(const char *name);
+extern const char *regs_query_register_name(unsigned int offset);
+#define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
+
+/**
+ * regs_get_register() - get register value from its offset
+ * @regs:	   pt_regs from which register value is gotten
+ * @offset:    offset number of the register.
+ *
+ * regs_get_register returns the value of a register whose offset from @regs.
+ * The @offset is the offset of the register in struct pt_regs.
+ * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
+ */
+static inline unsigned long regs_get_register(struct pt_regs *regs,
+						unsigned int offset)
+{
+	if (unlikely(offset > MAX_REG_OFFSET))
+		return 0;
+	return *(unsigned long *)((unsigned long)regs + offset);
+}
+
+/**
+ * regs_within_kernel_stack() - check the address in the stack
+ * @regs:      pt_regs which contains kernel stack pointer.
+ * @addr:      address which is checked.
+ *
+ * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
+ * If @addr is within the kernel stack, it returns true. If not, returns false.
+ */
+
+static inline bool regs_within_kernel_stack(struct pt_regs *regs,
+						unsigned long addr)
+{
+	return ((addr & ~(THREAD_SIZE - 1))  ==
+		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
+}
+
+/**
+ * regs_get_kernel_stack_nth() - get Nth entry of the stack
+ * @regs:	pt_regs which contains kernel stack pointer.
+ * @n:		stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
+ * is specified by @regs. If the @n th entry is NOT in the kernel stack,
+ * this returns 0.
+ */
+static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
+						      unsigned int n)
+{
+	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+	addr += n;
+	if (regs_within_kernel_stack(regs, (unsigned long)addr))
+		return *addr;
+	else
+		return 0;
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */