x86, perf, bts, mm: Delete the never used BTS-ptrace code

Support for the PMU's BTS features has been upstreamed in
v2.6.32, but we still have the old and disabled ptrace-BTS,
as Linus noticed it not so long ago.

It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without
regard for other uses (perf) and doesn't provide the flexibility
needed for perf either.

Its users are ptrace-block-step and ptrace-bts, since ptrace-bts
was never used and ptrace-block-step can be implemented using a
much simpler approach.

So axe all 3000 lines of it. That includes the *locked_memory*()
APIs in mm/mlock.c as well.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Markus Metzger <markus.t.metzger@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <20100325135413.938004390@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

34 files changed, 9 insertions, 3269 deletions

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index a19829374e6a..918fbb1855cc 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -502,23 +502,3 @@ config CPU_SUP_UMC_32
           CPU might render the kernel unbootable.
 
           If unsure, say N.
-
-config X86_DS
-        def_bool X86_PTRACE_BTS
-        depends on X86_DEBUGCTLMSR
-        select HAVE_HW_BRANCH_TRACER
-
-config X86_PTRACE_BTS
-        bool "Branch Trace Store"
-        default y
-        depends on X86_DEBUGCTLMSR
-        depends on BROKEN
-        ---help---
-          This adds a ptrace interface to the hardware's branch trace store.
-
-          Debuggers may use it to collect an execution trace of the debugged
-          application in order to answer the question 'how did I get here?'.
-          Debuggers may trace user mode as well as kernel mode.
-
-          Say Y unless there is no application development on this machine
-          and you want to save a small amount of code size.
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index bc01e3ebfeb2..bd58c8abbfbd 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -174,15 +174,6 @@ config IOMMU_LEAK
           Add a simple leak tracer to the IOMMU code. This is useful when you
           are debugging a buggy device driver that leaks IOMMU mappings.
 
-config X86_DS_SELFTEST
-    bool "DS selftest"
-    default y
-    depends on DEBUG_KERNEL
-    depends on X86_DS
-        ---help---
-          Perform Debug Store selftests at boot time.
-          If in doubt, say "N".
-
 config HAVE_MMIOTRACE_SUPPORT
         def_bool y
 
diff --git a/arch/x86/include/asm/ds.h b/arch/x86/include/asm/ds.h
deleted file mode 100644
index 70dac199b093..000000000000
--- a/arch/x86/include/asm/ds.h
+++ /dev/null
@@ -1,302 +0,0 @@
-/*
- * Debug Store (DS) support
- *
- * This provides a low-level interface to the hardware's Debug Store
- * feature that is used for branch trace store (BTS) and
- * precise-event based sampling (PEBS).
- *
- * It manages:
- * - DS and BTS hardware configuration
- * - buffer overflow handling (to be done)
- * - buffer access
- *
- * It does not do:
- * - security checking (is the caller allowed to trace the task)
- * - buffer allocation (memory accounting)
- *
- *
- * Copyright (C) 2007-2009 Intel Corporation.
- * Markus Metzger <markus.t.metzger@intel.com>, 2007-2009
- */
-
-#ifndef _ASM_X86_DS_H
-#define _ASM_X86_DS_H
-
-
-#include <linux/types.h>
-#include <linux/init.h>
-#include <linux/err.h>
-
-
-#ifdef CONFIG_X86_DS
-
-struct task_struct;
-struct ds_context;
-struct ds_tracer;
-struct bts_tracer;
-struct pebs_tracer;
-
-typedef void (*bts_ovfl_callback_t)(struct bts_tracer *);
-typedef void (*pebs_ovfl_callback_t)(struct pebs_tracer *);
-
-
-/*
- * A list of features plus corresponding macros to talk about them in
- * the ds_request function's flags parameter.
- *
- * We use the enum to index an array of corresponding control bits;
- * we use the macro to index a flags bit-vector.
- */
-enum ds_feature {
-        dsf_bts = 0,
-        dsf_bts_kernel,
-#define BTS_KERNEL (1 << dsf_bts_kernel)
-        /* trace kernel-mode branches */
-
-        dsf_bts_user,
-#define BTS_USER (1 << dsf_bts_user)
-        /* trace user-mode branches */
-
-        dsf_bts_overflow,
-        dsf_bts_max,
-        dsf_pebs = dsf_bts_max,
-
-        dsf_pebs_max,
-        dsf_ctl_max = dsf_pebs_max,
-        dsf_bts_timestamps = dsf_ctl_max,
-#define BTS_TIMESTAMPS (1 << dsf_bts_timestamps)
-        /* add timestamps into BTS trace */
-
-#define BTS_USER_FLAGS (BTS_KERNEL | BTS_USER | BTS_TIMESTAMPS)
-};
-
-
-/*
- * Request BTS or PEBS
- *
- * Due to alignement constraints, the actual buffer may be slightly
- * smaller than the requested or provided buffer.
- *
- * Returns a pointer to a tracer structure on success, or
- * ERR_PTR(errcode) on failure.
- *
- * The interrupt threshold is independent from the overflow callback
- * to allow users to use their own overflow interrupt handling mechanism.
- *
- * The function might sleep.
- *
- * task: the task to request recording for
- * cpu:  the cpu to request recording for
- * base: the base pointer for the (non-pageable) buffer;
- * size: the size of the provided buffer in bytes
- * ovfl: pointer to a function to be called on buffer overflow;
- *       NULL if cyclic buffer requested
- * th: the interrupt threshold in records from the end of the buffer;
- *     -1 if no interrupt threshold is requested.
- * flags: a bit-mask of the above flags
- */
-extern struct bts_tracer *ds_request_bts_task(struct task_struct *task,