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[PATCH 1/3] perf, x86: clean up debugctlmsr bit definitions

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[view original message]
From: Peter Zijlstra
Subject: [PATCH 0/3] Fix ptrace debugctlmsr stomping and kill ptrace-bts
Date: Thursday, March 25, 2010 - 6:51 am

ptrace was stomping all over debugctlmsr and since ptrace-bts was never used
kill that and reimplement ptrace block-step to not trample on the msr.

--


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[view original message]
From: Peter Zijlstra
Subject: [PATCH 1/3] perf, x86: clean up debugctlmsr bit definitions
Date: Thursday, March 25, 2010 - 6:51 am

Move all debugctlmsr thingies into msr-index.h

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 arch/x86/include/asm/msr-index.h           |   13 ++++++++-----
 arch/x86/kernel/cpu/perf_event_intel_ds.c  |   23 +++++++----------------
 arch/x86/kernel/cpu/perf_event_intel_lbr.c |    7 ++-----
 3 files changed, 17 insertions(+), 26 deletions(-)

Index: linux-2.6/arch/x86/include/asm/msr-index.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/msr-index.h
+++ linux-2.6/arch/x86/include/asm/msr-index.h
@@ -71,11 +71,14 @@
 #define MSR_IA32_LASTINTTOIP		0x000001de
 
 /* DEBUGCTLMSR bits (others vary by model): */
-#define _DEBUGCTLMSR_LBR	0 /* last branch recording */
-#define _DEBUGCTLMSR_BTF	1 /* single-step on branches */
-
-#define DEBUGCTLMSR_LBR		(1UL << _DEBUGCTLMSR_LBR)
-#define DEBUGCTLMSR_BTF		(1UL << _DEBUGCTLMSR_BTF)
+#define DEBUGCTLMSR_LBR			(1UL <<  0) /* last branch recording */
+#define DEBUGCTLMSR_BTF			(1UL <<  1) /* single-step on branches */
+#define DEBUGCTLMSR_TR			(1UL <<  6)
+#define DEBUGCTLMSR_BTS			(1UL <<  7)
+#define DEBUGCTLMSR_BTINT		(1UL <<  8)
+#define DEBUGCTLMSR_BTS_OFF_OS		(1UL <<  9)
+#define DEBUGCTLMSR_BTS_OFF_USR		(1UL << 10)
+#define DEBUGCTLMSR_FREEZE_LBRS_ON_PMI	(1UL << 11)
 
 #define MSR_IA32_MC0_CTL		0x00000400
 #define MSR_IA32_MC0_STATUS		0x00000401
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -38,15 +38,6 @@ struct pebs_record_nhm {
 };
 
 /*
- * Bits in the debugctlmsr controlling branch tracing.
- */
-#define X86_DEBUGCTL_TR			(1 << 6)
-#define X86_DEBUGCTL_BTS		(1 << 7)
-#define X86_DEBUGCTL_BTINT		(1 << 8)
-#define X86_DEBUGCTL_BTS_OFF_OS		(1 << 9)
-#define X86_DEBUGCTL_BTS_OFF_USR	(1 << 10)
-
-/*
  * A debug store configuration.
  *
  * We ...
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From: tip-bot for Peter Zijlstra
Subject: [tip:perf/core] perf, x86: Clean up debugctlmsr bit definitions
Date: Friday, March 26, 2010 - 5:58 am

Commit-ID:  7c5ecaf7666617889f337296c610815b519abfa9
Gitweb:     http://git.kernel.org/tip/7c5ecaf7666617889f337296c610815b519abfa9
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 25 Mar 2010 14:51:49 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 26 Mar 2010 09:41:03 +0100

perf, x86: Clean up debugctlmsr bit definitions

Move all debugctlmsr thingies into msr-index.h

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100325135413.861425293@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/include/asm/msr-index.h           |   13 ++++++++-----
 arch/x86/kernel/cpu/perf_event_intel_ds.c  |   23 +++++++----------------
 arch/x86/kernel/cpu/perf_event_intel_lbr.c |    7 ++-----
 3 files changed, 17 insertions(+), 26 deletions(-)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index aef562c..06e4cf0 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -71,11 +71,14 @@
 #define MSR_IA32_LASTINTTOIP		0x000001de
 
 /* DEBUGCTLMSR bits (others vary by model): */
-#define _DEBUGCTLMSR_LBR	0 /* last branch recording */
-#define _DEBUGCTLMSR_BTF	1 /* single-step on branches */
-
-#define DEBUGCTLMSR_LBR		(1UL << _DEBUGCTLMSR_LBR)
-#define DEBUGCTLMSR_BTF		(1UL << _DEBUGCTLMSR_BTF)
+#define DEBUGCTLMSR_LBR			(1UL <<  0) /* last branch recording */
+#define DEBUGCTLMSR_BTF			(1UL <<  1) /* single-step on branches */
+#define DEBUGCTLMSR_TR			(1UL <<  6)
+#define DEBUGCTLMSR_BTS			(1UL <<  7)
+#define DEBUGCTLMSR_BTINT		(1UL <<  8)
+#define DEBUGCTLMSR_BTS_OFF_OS		(1UL <<  9)
+#define DEBUGCTLMSR_BTS_OFF_USR		(1UL << 10)
+#define DEBUGCTLMSR_FREEZE_LBRS_ON_PMI	(1UL << 11)
 
 #define MSR_IA32_MC0_CTL		0x00000400
 #define MSR_IA32_MC0_STATUS		0x00000401
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index c59678a..2fea362 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ ...
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[view original message]
From: Peter Zijlstra
Subject: [PATCH 3/3] x86, ptrace: Fix block-step
Date: Thursday, March 25, 2010 - 6:51 am

Implement ptrace-block-step using TIF_BLOCKSTEP which will set
DEBUGCTLMSR_BTF when set for a task while preserving any other
DEBUGCTLMSR bits.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 arch/x86/include/asm/processor.h   |    4 ++--
 arch/x86/include/asm/thread_info.h |    4 +++-
 arch/x86/kernel/kprobes.c          |   14 ++++++++++++--
 arch/x86/kernel/process.c          |   11 +++++++++++
 arch/x86/kernel/step.c             |   24 ++++++++++++++++++++----
 arch/x86/kernel/traps.c            |    5 +++++
 6 files changed, 53 insertions(+), 9 deletions(-)

Index: linux-2.6/arch/x86/include/asm/processor.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/processor.h
+++ linux-2.6/arch/x86/include/asm/processor.h
@@ -798,7 +798,7 @@ extern void cpu_init(void);
 
 static inline unsigned long get_debugctlmsr(void)
 {
-    unsigned long debugctlmsr = 0;
+	unsigned long debugctlmsr = 0;
 
 #ifndef CONFIG_X86_DEBUGCTLMSR
 	if (boot_cpu_data.x86 < 6)
@@ -806,7 +806,7 @@ static inline unsigned long get_debugctl
 #endif
 	rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
 
-    return debugctlmsr;
+	return debugctlmsr;
 }
 
 static inline void update_debugctlmsr(unsigned long debugctlmsr)
Index: linux-2.6/arch/x86/include/asm/thread_info.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/thread_info.h
+++ linux-2.6/arch/x86/include/asm/thread_info.h
@@ -92,6 +92,7 @@ struct thread_info {
 #define TIF_IO_BITMAP		22	/* uses I/O bitmap */
 #define TIF_FREEZE		23	/* is freezing for suspend */
 #define TIF_FORCED_TF		24	/* true if TF in eflags artificially */
+#define TIF_BLOCKSTEP		25	/* set when we want DEBUGCTLMSR_BTF */
 #define TIF_LAZY_MMU_UPDATES	27	/* task is updating the mmu lazily */
 #define TIF_SYSCALL_TRACEPOINT	28	/* syscall tracepoint instrumentation */
 
@@ -113,6 +114,7 @@ struct thread_info {
 #define _TIF_IO_BITMAP		(1 << ...
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From: tip-bot for Peter Zijlstra
Subject: [tip:perf/core] x86, ptrace: Fix block-step
Date: Friday, March 26, 2010 - 5:58 am

Commit-ID:  ea8e61b7bbc4a2faef77db34eb2db2a2c2372ff6
Gitweb:     http://git.kernel.org/tip/ea8e61b7bbc4a2faef77db34eb2db2a2c2372ff6
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 25 Mar 2010 14:51:51 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 26 Mar 2010 11:33:57 +0100

x86, ptrace: Fix block-step

Implement ptrace-block-step using TIF_BLOCKSTEP which will set
DEBUGCTLMSR_BTF when set for a task while preserving any other
DEBUGCTLMSR bits.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100325135414.017536066@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/include/asm/processor.h   |    4 ++--
 arch/x86/include/asm/thread_info.h |    4 +++-
 arch/x86/kernel/kprobes.c          |   14 ++++++++++++--
 arch/x86/kernel/process.c          |   11 +++++++++++
 arch/x86/kernel/step.c             |   24 ++++++++++++++++++++----
 arch/x86/kernel/traps.c            |    5 +++++
 6 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 5bec21a..32428b4 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -799,7 +799,7 @@ extern void cpu_init(void);
 
 static inline unsigned long get_debugctlmsr(void)
 {
-    unsigned long debugctlmsr = 0;
+	unsigned long debugctlmsr = 0;
 
 #ifndef CONFIG_X86_DEBUGCTLMSR
 	if (boot_cpu_data.x86 < 6)
@@ -807,7 +807,7 @@ static inline unsigned long get_debugctlmsr(void)
 #endif
 	rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
 
-    return debugctlmsr;
+	return debugctlmsr;
 }
 
 static inline void update_debugctlmsr(unsigned long debugctlmsr)
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index dc85e12..d017ed5 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -92,6 +92,7 @@ struct thread_info {
 #define TIF_IO_BITMAP		22	/* uses I/O bitmap */
 #define ...
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[view original message]
From: Peter Zijlstra
Subject: [PATCH 2/3] x86, ptrace, bts: Delete the never used ptrace-bts code
Date: Thursday, March 25, 2010 - 6:51 am

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

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 axe all of it.

Cc: Markus Metzger <markus.t.metzger@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 arch/x86/Kconfig.cpu               |   20 
 arch/x86/Kconfig.debug             |    9 
 arch/x86/include/asm/ds.h          |  302 -------
 arch/x86/include/asm/processor.h   |   32 
 arch/x86/include/asm/ptrace-abi.h  |   59 -
 arch/x86/include/asm/ptrace.h      |   10 
 arch/x86/include/asm/thread_info.h |    6 
 arch/x86/kernel/Makefile           |    2 
 arch/x86/kernel/cpu/intel.c        |    2 
 arch/x86/kernel/ds.c               | 1437 -------------------------------------
 arch/x86/kernel/ds_selftest.c      |  408 ----------
 arch/x86/kernel/ds_selftest.h      |   15 
 arch/x86/kernel/dumpstack.c        |    5 
 arch/x86/kernel/kprobes.c          |    6 
 arch/x86/kernel/process.c          |    9 
 arch/x86/kernel/process_32.c       |    8 
 arch/x86/kernel/process_64.c       |    8 
 arch/x86/kernel/ptrace.c           |  382 ---------
 arch/x86/kernel/step.c             |   36 
 arch/x86/kernel/traps.c            |    5 
 include/linux/ftrace.h             |   12 
 include/linux/mm.h                 |    4 
 include/linux/ptrace.h             |   12 
 include/linux/sched.h              |    9 
 kernel/fork.c                      |    3 
 kernel/ptrace.c                    |    1 
 kernel/sched.c                     |   43 -
 kernel/trace/Kconfig               |   11 
 kernel/trace/Makefile              |    1 
 kernel/trace/trace.h               |    4 
 kernel/trace/trace_entries.h       |   12 
 kernel/trace/trace_hw_branches.c   |  312 --------
 kernel/trace/trace_selftest.c      |   57 -
 mm/mlock.c           ...
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From: tip-bot for Peter Zijlstra
Subject: [tip:perf/core] x86, perf, bts, mm: Delete the never used BTS-ptrace code
Date: Friday, March 26, 2010 - 5:58 am

Commit-ID:  faa4602e47690fb11221e00f9b9697c8dc0d4b19
Gitweb:     http://git.kernel.org/tip/faa4602e47690fb11221e00f9b9697c8dc0d4b19
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 25 Mar 2010 14:51:50 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 26 Mar 2010 11:33:55 +0100

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>
---
 arch/x86/Kconfig.cpu               |   20 -
 arch/x86/Kconfig.debug             |    9 -
 arch/x86/include/asm/ds.h          |  302 --------
 arch/x86/include/asm/processor.h   |   33 +-
 arch/x86/include/asm/ptrace-abi.h  |   57 +--
 arch/x86/include/asm/ptrace.h      |    6 -
 arch/x86/include/asm/thread_info.h |    6 +-
 arch/x86/kernel/Makefile           |    2 -
 arch/x86/kernel/cpu/intel.c        |    2 -
 arch/x86/kernel/ds.c               | 1437 ------------------------------------
 arch/x86/kernel/ds_selftest.c      |  408 ----------
 arch/x86/kernel/ds_selftest.h      |   15 -
 arch/x86/kernel/dumpstack.c        |    5 -
 ...
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Previous thread: Re: [PATCH] trace-cmd: Add BUILDING and INSTALL instructions to README by Steven Rostedt on Thursday, March 25, 2010 - 6:31 am. (1 message)

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