[PATCH V7 7/8] perf/tools: Add branch privilege information request flag

From: Anshuman Khandual
Date: Wed Aug 24 2022 - 00:49:52 EST


This updates the perf tools with branch privilege information request flag
i.e PERF_SAMPLE_BRANCH_PRIV_SAVE that has been added earlier in the kernel.
This also updates 'perf record' documentation, branch_modes[], and generic
branch privilege level enumeration as added earlier in the kernel.

Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-perf-users@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
tools/include/uapi/linux/perf_event.h | 14 +++++++++++++-
tools/perf/Documentation/perf-record.txt | 1 +
tools/perf/util/branch.h | 3 ++-
tools/perf/util/parse-branch-options.c | 1 +
tools/perf/util/perf_event_attr_fprintf.c | 2 +-
5 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index 0f7c7ce29899..51168e22f4d8 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -204,6 +204,8 @@ enum perf_branch_sample_type_shift {

PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT = 17, /* save low level index of raw branch records */

+ PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT = 18, /* save privilege mode */
+
PERF_SAMPLE_BRANCH_MAX_SHIFT /* non-ABI */
};

@@ -233,6 +235,8 @@ enum perf_branch_sample_type {

PERF_SAMPLE_BRANCH_HW_INDEX = 1U << PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT,

+ PERF_SAMPLE_BRANCH_PRIV_SAVE = 1U << PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT,
+
PERF_SAMPLE_BRANCH_MAX = 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT,
};

@@ -271,6 +275,13 @@ enum {
PERF_BR_NEW_MAX,
};

+enum {
+ PERF_BR_PRIV_UNKNOWN = 0,
+ PERF_BR_PRIV_USER = 1,
+ PERF_BR_PRIV_KERNEL = 2,
+ PERF_BR_PRIV_HV = 3,
+};
+
#define PERF_SAMPLE_BRANCH_PLM_ALL \
(PERF_SAMPLE_BRANCH_USER|\
PERF_SAMPLE_BRANCH_KERNEL|\
@@ -1389,7 +1400,8 @@ struct perf_branch_entry {
cycles:16, /* cycle count to last branch */
type:4, /* branch type */
new_type:4, /* additional branch type */
- reserved:36;
+ priv:3, /* privilege level */
+ reserved:33;
};

union perf_sample_weight {
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 099817ef5150..4d4a9f6e5147 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -397,6 +397,7 @@ following filters are defined:
- abort_tx: only when the target is a hardware transaction abort
- cond: conditional branches
- save_type: save branch type during sampling in case binary is not available later
+ - priv: save privilege state during sampling in case binary is not available later

+
The option requires at least one branch type among any, any_call, any_ret, ind_call, cond.
diff --git a/tools/perf/util/branch.h b/tools/perf/util/branch.h
index 8d251b35428a..f838b23db180 100644
--- a/tools/perf/util/branch.h
+++ b/tools/perf/util/branch.h
@@ -25,7 +25,8 @@ struct branch_flags {
u64 cycles:16;
u64 type:4;
u64 new_type:4;
- u64 reserved:36;
+ u64 priv:3;
+ u64 reserved:33;
};
};
};
diff --git a/tools/perf/util/parse-branch-options.c b/tools/perf/util/parse-branch-options.c
index bb4aa88c50a8..00588b9db474 100644
--- a/tools/perf/util/parse-branch-options.c
+++ b/tools/perf/util/parse-branch-options.c
@@ -32,6 +32,7 @@ static const struct branch_mode branch_modes[] = {
BRANCH_OPT("call", PERF_SAMPLE_BRANCH_CALL),
BRANCH_OPT("save_type", PERF_SAMPLE_BRANCH_TYPE_SAVE),
BRANCH_OPT("stack", PERF_SAMPLE_BRANCH_CALL_STACK),
+ BRANCH_OPT("priv", PERF_SAMPLE_BRANCH_PRIV_SAVE),
BRANCH_END
};

diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c
index 98af3fa4ea35..4b0db27b7199 100644
--- a/tools/perf/util/perf_event_attr_fprintf.c
+++ b/tools/perf/util/perf_event_attr_fprintf.c
@@ -52,7 +52,7 @@ static void __p_branch_sample_type(char *buf, size_t size, u64 value)
bit_name(ABORT_TX), bit_name(IN_TX), bit_name(NO_TX),
bit_name(COND), bit_name(CALL_STACK), bit_name(IND_JUMP),
bit_name(CALL), bit_name(NO_FLAGS), bit_name(NO_CYCLES),
- bit_name(TYPE_SAVE), bit_name(HW_INDEX),
+ bit_name(TYPE_SAVE), bit_name(HW_INDEX), bit_name(PRIV_SAVE),
{ .name = NULL, }
};
#undef bit_name
--
2.25.1