2014-10-01 21:37:11

by Frederic Weisbecker

[permalink] [raw]
Subject: [GIT PULL] hw_breakpoints: Support AMD range breakpoints

Ingo,

Please pull the perf/core-v2 branch that can be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
perf/core-v2

HEAD: 33252c1bb36dd7405f412a9ef8fc05dec995064a

It has been acked by Jiri and Oleg.
---
Summary:

* Extend breakpoint tools and core to support address range through perf
event with initial backend support for AMD extended breakpoints.
Syntax is:

perf record -e mem:addr/len:type

For example set write breakpoint from 0x1000 to 0x1200 (0x1000 + 512)

perf record -e mem:0x1000/512:w

* Clean up a bit breakpoint code validation
---

Thanks,
Frederic
---

Jacob Shin (4):
perf/x86/amd: AMD support for bp_len > HW_BREAKPOINT_LEN_8
perf tools: allow user to specify hardware breakpoint bp_len
perf tools: add hardware breakpoint bp_len test cases
perf/x86: Remove get_hbp_len and replace with bp_len


arch/x86/include/asm/cpufeature.h | 2 ++
arch/x86/include/asm/debugreg.h | 5 +++
arch/x86/include/asm/hw_breakpoint.h | 1 +
arch/x86/include/uapi/asm/msr-index.h | 4 +++
arch/x86/kernel/cpu/amd.c | 19 +++++++++++
arch/x86/kernel/hw_breakpoint.c | 45 ++++++++++---------------
tools/perf/Documentation/perf-record.txt | 7 ++--
tools/perf/tests/parse-events.c | 58 ++++++++++++++++++++++++++++++++
tools/perf/util/parse-events.c | 21 ++++++------
tools/perf/util/parse-events.h | 2 +-
tools/perf/util/parse-events.l | 1 +
tools/perf/util/parse-events.y | 26 ++++++++++++--
12 files changed, 148 insertions(+), 43 deletions(-)


2014-10-01 21:37:14

by Frederic Weisbecker

[permalink] [raw]
Subject: [PATCH 1/4] perf/x86/amd: AMD support for bp_len > HW_BREAKPOINT_LEN_8

From: Jacob Shin <[email protected]>

Implement hardware breakpoint address mask for AMD Family 16h and
above processors. CPUID feature bit indicates hardware support for
DRn_ADDR_MASK MSRs. These masks further qualify DRn/DR7 hardware
breakpoint addresses to allow matching of larger addresses ranges.

Valuable advice and pseudo code from Oleg Nesterov <[email protected]>

Signed-off-by: Jacob Shin <[email protected]>
Signed-off-by: Suravee Suthikulpanit <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Reviewed-by: Oleg Nesterov <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: xiakaixu <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
---
arch/x86/include/asm/cpufeature.h | 2 ++
arch/x86/include/asm/debugreg.h | 5 +++++
arch/x86/include/asm/hw_breakpoint.h | 1 +
arch/x86/include/uapi/asm/msr-index.h | 4 ++++
arch/x86/kernel/cpu/amd.c | 19 +++++++++++++++++++
arch/x86/kernel/hw_breakpoint.c | 20 ++++++++++++++++----
6 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index bb9b258..73dffed 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -170,6 +170,7 @@
#define X86_FEATURE_TOPOEXT ( 6*32+22) /* topology extensions CPUID leafs */
#define X86_FEATURE_PERFCTR_CORE ( 6*32+23) /* core performance counter extensions */
#define X86_FEATURE_PERFCTR_NB ( 6*32+24) /* NB performance counter extensions */
+#define X86_FEATURE_BPEXT (6*32+26) /* data breakpoint extension */
#define X86_FEATURE_PERFCTR_L2 ( 6*32+28) /* L2 performance counter extensions */

/*
@@ -352,6 +353,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
#define cpu_has_cx16 boot_cpu_has(X86_FEATURE_CX16)
#define cpu_has_eager_fpu boot_cpu_has(X86_FEATURE_EAGER_FPU)
#define cpu_has_topoext boot_cpu_has(X86_FEATURE_TOPOEXT)
+#define cpu_has_bpext boot_cpu_has(X86_FEATURE_BPEXT)

#ifdef CONFIG_X86_64

diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h
index 4b528a9..145b009 100644
--- a/arch/x86/include/asm/debugreg.h
+++ b/arch/x86/include/asm/debugreg.h
@@ -114,5 +114,10 @@ static inline void debug_stack_usage_inc(void) { }
static inline void debug_stack_usage_dec(void) { }
#endif /* X86_64 */

+#ifdef CONFIG_CPU_SUP_AMD
+extern void set_dr_addr_mask(unsigned long mask, int dr);
+#else
+static inline void set_dr_addr_mask(unsigned long mask, int dr) { }
+#endif

#endif /* _ASM_X86_DEBUGREG_H */
diff --git a/arch/x86/include/asm/hw_breakpoint.h b/arch/x86/include/asm/hw_breakpoint.h
index ef1c4d2..6c98be8 100644
--- a/arch/x86/include/asm/hw_breakpoint.h
+++ b/arch/x86/include/asm/hw_breakpoint.h
@@ -12,6 +12,7 @@
*/
struct arch_hw_breakpoint {
unsigned long address;
+ unsigned long mask;
u8 len;
u8 type;
};
diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h
index e21331c..60046b9 100644
--- a/arch/x86/include/uapi/asm/msr-index.h
+++ b/arch/x86/include/uapi/asm/msr-index.h
@@ -211,6 +211,10 @@
/* Fam 16h MSRs */
#define MSR_F16H_L2I_PERF_CTL 0xc0010230
#define MSR_F16H_L2I_PERF_CTR 0xc0010231
+#define MSR_F16H_DR1_ADDR_MASK 0xc0011019
+#define MSR_F16H_DR2_ADDR_MASK 0xc001101a
+#define MSR_F16H_DR3_ADDR_MASK 0xc001101b
+#define MSR_F16H_DR0_ADDR_MASK 0xc0011027

/* Fam 15h MSRs */
#define MSR_F15H_PERF_CTL 0xc0010200
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 60e5497..0d9dbc3 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -863,3 +863,22 @@ static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum)

return false;
}
+
+void set_dr_addr_mask(unsigned long mask, int dr)
+{
+ if (!cpu_has_bpext)
+ return;
+
+ switch (dr) {
+ case 0:
+ wrmsr(MSR_F16H_DR0_ADDR_MASK, mask, 0);
+ break;
+ case 1:
+ case 2:
+ case 3:
+ wrmsr(MSR_F16H_DR1_ADDR_MASK - 1 + dr, mask, 0);
+ break;
+ default:
+ break;
+ }
+}
diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index 5f9cf20..91ce081 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -126,6 +126,8 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
*dr7 |= encode_dr7(i, info->len, info->type);

set_debugreg(*dr7, 7);
+ if (info->mask)
+ set_dr_addr_mask(info->mask, i);

return 0;
}
@@ -161,6 +163,8 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
*dr7 &= ~__encode_dr7(i, info->len, info->type);

set_debugreg(*dr7, 7);
+ if (info->mask)
+ set_dr_addr_mask(0, i);
}

static int get_hbp_len(u8 hbp_len)
@@ -277,6 +281,8 @@ static int arch_build_bp_info(struct perf_event *bp)
}

/* Len */
+ info->mask = 0;
+
switch (bp->attr.bp_len) {
case HW_BREAKPOINT_LEN_1:
info->len = X86_BREAKPOINT_LEN_1;
@@ -293,11 +299,17 @@ static int arch_build_bp_info(struct perf_event *bp)
break;
#endif
default:
- return -EINVAL;
+ if (!is_power_of_2(bp->attr.bp_len))
+ return -EINVAL;
+ if (!cpu_has_bpext)
+ return -EOPNOTSUPP;
+ info->mask = bp->attr.bp_len - 1;
+ info->len = X86_BREAKPOINT_LEN_1;
}

return 0;
}
+
/*
* Validate the arch-specific HW Breakpoint register settings
*/
@@ -312,11 +324,11 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
if (ret)
return ret;

- ret = -EINVAL;
-
switch (info->len) {
case X86_BREAKPOINT_LEN_1:
align = 0;
+ if (info->mask)
+ align = info->mask;
break;
case X86_BREAKPOINT_LEN_2:
align = 1;
@@ -330,7 +342,7 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
break;
#endif
default:
- return ret;
+ WARN_ON_ONCE(1);
}

/*
--
2.1.0

2014-10-01 21:37:19

by Frederic Weisbecker

[permalink] [raw]
Subject: [PATCH 3/4] perf tools: add hardware breakpoint bp_len test cases

From: Jacob Shin <[email protected]>

Signed-off-by: Jacob Shin <[email protected]>
Signed-off-by: Suravee Suthikulpanit <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Reviewed-by: Oleg Nesterov <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: xiakaixu <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
---
tools/perf/tests/parse-events.c | 58 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)

diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 5941927..d32b5c1 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -1115,6 +1115,49 @@ static int test__pinned_group(struct perf_evlist *evlist)
return 0;
}

+static int test__checkevent_breakpoint_len(struct perf_evlist *evlist)
+{
+ struct perf_evsel *evsel = perf_evlist__first(evlist);
+
+ TEST_ASSERT_VAL("wrong number of entries", 1 == evlist->nr_entries);
+ TEST_ASSERT_VAL("wrong type", PERF_TYPE_BREAKPOINT == evsel->attr.type);
+ TEST_ASSERT_VAL("wrong config", 0 == evsel->attr.config);
+ TEST_ASSERT_VAL("wrong bp_type", (HW_BREAKPOINT_R | HW_BREAKPOINT_W) ==
+ evsel->attr.bp_type);
+ TEST_ASSERT_VAL("wrong bp_len", HW_BREAKPOINT_LEN_1 ==
+ evsel->attr.bp_len);
+
+ return 0;
+}
+
+static int test__checkevent_breakpoint_len_w(struct perf_evlist *evlist)
+{
+ struct perf_evsel *evsel = perf_evlist__first(evlist);
+
+ TEST_ASSERT_VAL("wrong number of entries", 1 == evlist->nr_entries);
+ TEST_ASSERT_VAL("wrong type", PERF_TYPE_BREAKPOINT == evsel->attr.type);
+ TEST_ASSERT_VAL("wrong config", 0 == evsel->attr.config);
+ TEST_ASSERT_VAL("wrong bp_type", HW_BREAKPOINT_W ==
+ evsel->attr.bp_type);
+ TEST_ASSERT_VAL("wrong bp_len", HW_BREAKPOINT_LEN_2 ==
+ evsel->attr.bp_len);
+
+ return 0;
+}
+
+static int
+test__checkevent_breakpoint_len_rw_modifier(struct perf_evlist *evlist)
+{
+ struct perf_evsel *evsel = perf_evlist__first(evlist);
+
+ TEST_ASSERT_VAL("wrong exclude_user", !evsel->attr.exclude_user);
+ TEST_ASSERT_VAL("wrong exclude_kernel", evsel->attr.exclude_kernel);
+ TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
+ TEST_ASSERT_VAL("wrong precise_ip", !evsel->attr.precise_ip);
+
+ return test__checkevent_breakpoint_rw(evlist);
+}
+
static int count_tracepoints(void)
{
char events_path[PATH_MAX];
@@ -1390,6 +1433,21 @@ static struct evlist_test test__events[] = {
.check = test__pinned_group,
.id = 41,
},
+ {
+ .name = "mem:0/1",
+ .check = test__checkevent_breakpoint_len,
+ .id = 42,
+ },
+ {
+ .name = "mem:0/2:w",
+ .check = test__checkevent_breakpoint_len_w,
+ .id = 43,
+ },
+ {
+ .name = "mem:0/4:rw:u",
+ .check = test__checkevent_breakpoint_len_rw_modifier,
+ .id = 44
+ },
#if defined(__s390x__)
{
.name = "kvm-s390:kvm_s390_create_vm",
--
2.1.0

2014-10-01 21:37:40

by Frederic Weisbecker

[permalink] [raw]
Subject: [PATCH 4/4] perf/x86: Remove get_hbp_len and replace with bp_len

From: Jacob Shin <[email protected]>

Clean up the logic for determining the breakpoint length

Signed-off-by: Jacob Shin <[email protected]>
Signed-off-by: Suravee Suthikulpanit <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Reviewed-by: Oleg Nesterov <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: xiakaixu <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
---
arch/x86/kernel/hw_breakpoint.c | 25 +------------------------
1 file changed, 1 insertion(+), 24 deletions(-)

diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index 91ce081..edb70e9 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -167,29 +167,6 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
set_dr_addr_mask(0, i);
}

-static int get_hbp_len(u8 hbp_len)
-{
- unsigned int len_in_bytes = 0;
-
- switch (hbp_len) {
- case X86_BREAKPOINT_LEN_1:
- len_in_bytes = 1;
- break;
- case X86_BREAKPOINT_LEN_2:
- len_in_bytes = 2;
- break;
- case X86_BREAKPOINT_LEN_4:
- len_in_bytes = 4;
- break;
-#ifdef CONFIG_X86_64
- case X86_BREAKPOINT_LEN_8:
- len_in_bytes = 8;
- break;
-#endif
- }
- return len_in_bytes;
-}
-
/*
* Check for virtual address in kernel space.
*/
@@ -200,7 +177,7 @@ int arch_check_bp_in_kernelspace(struct perf_event *bp)
struct arch_hw_breakpoint *info = counter_arch_bp(bp);

va = info->address;
- len = get_hbp_len(info->len);
+ len = bp->attr.bp_len;

return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
}
--
2.1.0

2014-10-01 21:38:28

by Frederic Weisbecker

[permalink] [raw]
Subject: [PATCH 2/4] perf tools: allow user to specify hardware breakpoint bp_len

From: Jacob Shin <[email protected]>

Currently bp_len is given a default value of 4. Allow user to override it:

$ perf stat -e mem:0x1000/8
^
bp_len

If no value is given, it will default to 4 as it did before.

Signed-off-by: Jacob Shin <[email protected]>
Signed-off-by: Suravee Suthikulpanit <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Reviewed-by: Oleg Nesterov <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: xiakaixu <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
---
tools/perf/Documentation/perf-record.txt | 7 +++++--
tools/perf/util/parse-events.c | 21 +++++++++++----------
tools/perf/util/parse-events.h | 2 +-
tools/perf/util/parse-events.l | 1 +
tools/perf/util/parse-events.y | 26 ++++++++++++++++++++++++--
5 files changed, 42 insertions(+), 15 deletions(-)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index d460049..a625bf8 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -33,12 +33,15 @@ OPTIONS
- a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a
hexadecimal event descriptor.

- - a hardware breakpoint event in the form of '\mem:addr[:access]'
+ - a hardware breakpoint event in the form of '\mem:addr[/len][:access]'
where addr is the address in memory you want to break in.
Access is the memory access type (read, write, execute) it can
- be passed as follows: '\mem:addr[:[r][w][x]]'.
+ be passed as follows: '\mem:addr[:[r][w][x]]'. len is the range,
+ number of bytes from specified addr, which the breakpoint will cover.
If you want to profile read-write accesses in 0x1000, just set
'mem:0x1000:rw'.
+ If you want to profile write accesses in [0x1000~1008), just set
+ 'mem:0x1000/8:w'.

--filter=<filter>::
Event filter.
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 61be3e6..3edb9e1 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -517,7 +517,7 @@ do { \
}

int parse_events_add_breakpoint(struct list_head *list, int *idx,
- void *ptr, char *type)
+ void *ptr, char *type, u64 len)
{
struct perf_event_attr attr;

@@ -527,14 +527,15 @@ int parse_events_add_breakpoint(struct list_head *list, int *idx,
if (parse_breakpoint_type(type, &attr))
return -EINVAL;

- /*
- * We should find a nice way to override the access length
- * Provide some defaults for now
- */
- if (attr.bp_type == HW_BREAKPOINT_X)
- attr.bp_len = sizeof(long);
- else
- attr.bp_len = HW_BREAKPOINT_LEN_4;
+ /* Provide some defaults if len is not specified */
+ if (!len) {
+ if (attr.bp_type == HW_BREAKPOINT_X)
+ len = sizeof(long);
+ else
+ len = HW_BREAKPOINT_LEN_4;
+ }
+
+ attr.bp_len = len;

attr.type = PERF_TYPE_BREAKPOINT;
attr.sample_period = 1;
@@ -1276,7 +1277,7 @@ void print_events(const char *event_glob, bool name_only)
printf("\n");

printf(" %-50s [%s]\n",
- "mem:<addr>[:access]",
+ "mem:<addr>[/len][:access]",
event_type_descriptors[PERF_TYPE_BREAKPOINT]);
printf("\n");
}
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index df094b4..00a5eb4 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -92,7 +92,7 @@ int parse_events_add_numeric(struct list_head *list, int *idx,
int parse_events_add_cache(struct list_head *list, int *idx,
char *type, char *op_result1, char *op_result2);
int parse_events_add_breakpoint(struct list_head *list, int *idx,
- void *ptr, char *type);
+ void *ptr, char *type, u64 len);
int parse_events_add_pmu(struct list_head *list, int *idx,
char *pmu , struct list_head *head_config);
void parse_events__set_leader(char *name, struct list_head *list);
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 3432995..199e18a 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -141,6 +141,7 @@ branch_type { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE
<mem>{
{modifier_bp} { return str(yyscanner, PE_MODIFIER_BP); }
: { return ':'; }
+"/" { return '/'; }
{num_dec} { return value(yyscanner, 10); }
{num_hex} { return value(yyscanner, 16); }
/*
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index 55fab6a..525ace069 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -286,6 +286,28 @@ PE_NAME_CACHE_TYPE
}

event_legacy_mem:
+PE_PREFIX_MEM PE_VALUE '/' PE_VALUE ':' PE_MODIFIER_BP sep_dc
+{
+ struct parse_events_evlist *data = _data;
+ struct list_head *list;
+
+ ALLOC_LIST(list);
+ ABORT_ON(parse_events_add_breakpoint(list, &data->idx,
+ (void *) $2, $6, $4));
+ $$ = list;
+}
+|
+PE_PREFIX_MEM PE_VALUE '/' PE_VALUE sep_dc
+{
+ struct parse_events_evlist *data = _data;
+ struct list_head *list;
+
+ ALLOC_LIST(list);
+ ABORT_ON(parse_events_add_breakpoint(list, &data->idx,
+ (void *) $2, NULL, $4));
+ $$ = list;
+}
+|
PE_PREFIX_MEM PE_VALUE ':' PE_MODIFIER_BP sep_dc
{
struct parse_events_evlist *data = _data;
@@ -293,7 +315,7 @@ PE_PREFIX_MEM PE_VALUE ':' PE_MODIFIER_BP sep_dc

ALLOC_LIST(list);
ABORT_ON(parse_events_add_breakpoint(list, &data->idx,
- (void *) $2, $4));
+ (void *) $2, $4, 0));
$$ = list;
}
|
@@ -304,7 +326,7 @@ PE_PREFIX_MEM PE_VALUE sep_dc

ALLOC_LIST(list);
ABORT_ON(parse_events_add_breakpoint(list, &data->idx,
- (void *) $2, NULL));
+ (void *) $2, NULL, 0));
$$ = list;
}

--
2.1.0