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perf: Add PERF_SAMPLE_PHYS_ADDR

PATCH Superseded [email protected] 2 participants 3 messages Aug 9, 2017 – Aug 17, 2017

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x86 perf events

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PATCH v3 1/1 perf: Add PERF_SAMPLE_PHYS_ADDR

From: Kan Liang <[email protected]>

For understanding how the workload maps to memory channels and hardware behavior, it's very important to collect address maps with physical addresses. For example, 3D XPoint access can only be found by filtering the physical address.
However, perf doesn't collect physical address information in sampling.

The load latency/DLA information in PEBS can be used to calculate the physical address.
For kernel direct mapping addresses, virt_to_phys is used to convert the virtual addresses from DLA to physical address.
For user virtual addresses, __get_user_pages_fast is used to walk the pages tables for user physical address.
This does not work for vmalloc addresses. Right now these are not resolved, but code to do that could be added.
For security, the physical address can only be exposed to root or privileged user.
A new sample type PERF_SAMPLE_PHYS_ADDR is introduced to expose the physical addresses.

Signed-off-by Kan Liang <[email protected]>

---

The V2 version can be found here.
https://patchwork.kernel.org/patch/7979771/

Changes since V2
- Only the kernel patch
- Add example in changelog
- Include a perf_paranoid_kernel() test (PeterZ)
- Fix minor complier warning

 arch/x86/events/intel/ds.c      | 24 ++++++++++++++++++++++++
 arch/x86/events/perf_event.h    |  2 +-
 include/linux/perf_event.h      |  3 +++
 include/uapi/linux/perf_event.h |  4 +++-
 kernel/events/core.c            | 12 ++++++++++++
 5 files changed, 43 insertions(+), 2 deletions(-)
arch/x86/events/intel/ds.c +24 -0
index a322fed..712c86b 100644
@@ -1083,6 +1083,7 @@ static void setup_pebs_sample_data(struct perf_event *event,
 	u64 sample_type;
 	int fll, fst, dsrc;
 	int fl = event->hw.flags;
+	struct page *p = NULL;
 
 	if (pebs == NULL)
 		return;

@@ -1179,6 +1180,29 @@ static void setup_pebs_sample_data(struct perf_event *event,
 	    x86_pmu.intel_cap.pebs_format >= 1)
 		data->addr = pebs->dla;
 
+	if ((sample_type & PERF_SAMPLE_PHYS_ADDR) && (data->addr != 0)) {
+		if (data->addr >= TASK_SIZE) {
+			/* If it's vmalloc()d memory, leave phys_addr as 0 */
+			if (virt_addr_valid(data->addr) &&
+			    !(data->addr >= VMALLOC_START && data->addr < VMALLOC_END))
+				data->phys_addr = (u64)virt_to_phys((void *)(uintptr_t)data->addr);
+		} else {
+			/*
+			 * Walking the pages tables for user address.
+			 * Interrupts are disabled, so it prevents any tear down
+			 * of the page tables.
+			 * Try IRQ-safe __get_user_pages_fast first.
+			 * If failed, leave phys_addr as 0.
+			 */
+			if ((current->mm != NULL) &&
+			    (__get_user_pages_fast(data->addr, 1, 0, &p) == 1))
+				data->phys_addr = page_to_phys(p) + data->addr % PAGE_SIZE;
+
+			if (p)
+				put_page(p);
+		}
+	}
+
 	if (x86_pmu.intel_cap.pebs_format >= 2) {
 		/* Only set the TSX weight when no memory weight. */
 		if ((sample_type & PERF_SAMPLE_WEIGHT) && !fll)
arch/x86/events/perf_event.h +1 -1
index 476aec3..65bb91e 100644
@@ -91,7 +91,7 @@ struct amd_nb {
 	(PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_ADDR | \
 	PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_STREAM_ID | \
 	PERF_SAMPLE_DATA_SRC | PERF_SAMPLE_IDENTIFIER | \
-	PERF_SAMPLE_TRANSACTION)
+	PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR)
 
 /*
  * A debug store configuration.
include/linux/perf_event.h +3 -0
index a3b873f..6783c69 100644
@@ -944,6 +944,8 @@ struct perf_sample_data {
 
 	struct perf_regs		regs_intr;
 	u64				stack_user_size;
+
+	u64				phys_addr;
 } ____cacheline_aligned;
 
 /* default value for data source */

@@ -964,6 +966,7 @@ static inline void perf_sample_data_init(struct perf_sample_data *data,
 	data->weight = 0;
 	data->data_src.val = PERF_MEM_NA;
 	data->txn = 0;
+	data->phys_addr = 0;
 }
 
 extern void perf_output_sample(struct perf_output_handle *handle,
include/uapi/linux/perf_event.h +3 -1
index 642db5f..cbea02f 100644
@@ -139,8 +139,9 @@ enum perf_event_sample_format {
 	PERF_SAMPLE_IDENTIFIER			= 1U << 16,
 	PERF_SAMPLE_TRANSACTION			= 1U << 17,
 	PERF_SAMPLE_REGS_INTR			= 1U << 18,
+	PERF_SAMPLE_PHYS_ADDR			= 1U << 19,
 
-	PERF_SAMPLE_MAX = 1U << 19,		/* non-ABI */
+	PERF_SAMPLE_MAX = 1U << 20,		/* non-ABI */
 };
 
 /*

@@ -814,6 +815,7 @@ enum perf_event_type {
 	 *	{ u64			transaction; } && PERF_SAMPLE_TRANSACTION
 	 *	{ u64			abi; # enum perf_sample_regs_abi
 	 *	  u64			regs[weight(mask)]; } && PERF_SAMPLE_REGS_INTR
+	 *	{ u64			phys_addr;} && PERF_SAMPLE_PHYS_ADDR
 	 * };
 	 */
 	PERF_RECORD_SAMPLE			= 9,
kernel/events/core.c +12 -0
index 426c2ff..07d4a74 100644
@@ -1570,6 +1570,9 @@ static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
 	if (sample_type & PERF_SAMPLE_TRANSACTION)
 		size += sizeof(data->txn);
 
+	if (sample_type & PERF_SAMPLE_PHYS_ADDR)
+		size += sizeof(data->phys_addr);
+
 	event->header_size = size;
 }
 

@@ -5952,6 +5955,9 @@ void perf_output_sample(struct perf_output_handle *handle,
 	if (sample_type & PERF_SAMPLE_DATA_SRC)
 		perf_output_put(handle, data->data_src.val);
 
+	if (sample_type & PERF_SAMPLE_PHYS_ADDR)
+		perf_output_put(handle, data->phys_addr);
+
 	if (sample_type & PERF_SAMPLE_TRANSACTION)
 		perf_output_put(handle, data->txn);
 

@@ -9852,6 +9858,12 @@ SYSCALL_DEFINE5(perf_event_open,
 			return -EINVAL;
 	}
 
+	/* Only privileged users can get kernel addresses */
+	if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) &&
+	    perf_paranoid_kernel() &&
+	    !capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
 	if (!attr.sample_max_stack)
 		attr.sample_max_stack = sysctl_perf_event_max_stack;
Signature · 1 line
2.4.3
#1 lore raw
Quoted 21 lines · On Wed, Aug 9, 2017 at 1:42 PM, <[email protected]> wrote:

From: Kan Liang <[email protected]>

For understanding how the workload maps to memory channels and hardware behavior, it's very important to collect address maps with physical addresses. For example, 3D XPoint access can only be found by filtering the physical address.
However, perf doesn't collect physical address information in sampling.

The load latency/DLA information in PEBS can be used to calculate the physical address.
For kernel direct mapping addresses, virt_to_phys is used to convert the virtual addresses from DLA to physical address.
For user virtual addresses, __get_user_pages_fast is used to walk the pages tables for user physical address.
This does not work for vmalloc addresses. Right now these are not resolved, but code to do that could be added.
For security, the physical address can only be exposed to root or privileged user.
A new sample type PERF_SAMPLE_PHYS_ADDR is introduced to expose the physical addresses.

Quoted 1 line
Signed-off-by Kan Liang <[email protected]>

This is a useful feature that I would like to use for some of the analysis we would like to do.
Please apply.
I am assuming you have the support in perf record/report?

Quoted 47 lines

---

The V2 version can be found here.
https://patchwork.kernel.org/patch/7979771/

Changes since V2
- Only the kernel patch
- Add example in changelog
- Include a perf_paranoid_kernel() test (PeterZ)
- Fix minor complier warning

 arch/x86/events/intel/ds.c      | 24 ++++++++++++++++++++++++
 arch/x86/events/perf_event.h    |  2 +-
 include/linux/perf_event.h      |  3 +++
 include/uapi/linux/perf_event.h |  4 +++-
 kernel/events/core.c            | 12 ++++++++++++
 5 files changed, 43 insertions(+), 2 deletions(-)
arch/x86/events/intel/ds.c +14 -0
index a322fed..712c86b 100644
@@ -1083,6 +1083,7 @@ static void setup_pebs_sample_data(struct perf_event *event,
        u64 sample_type;
        int fll, fst, dsrc;
        int fl = event->hw.flags;
+       struct page *p = NULL;
 
        if (pebs == NULL)
                return;

@@ -1179,6 +1180,29 @@ static void setup_pebs_sample_data(struct perf_event *event,
            x86_pmu.intel_cap.pebs_format >= 1)
                data->addr = pebs->dla;
 
+       if ((sample_type & PERF_SAMPLE_PHYS_ADDR) && (data->addr != 0)) {
+               if (data->addr >= TASK_SIZE) {
+                       /* If it's vmalloc()d memory, leave phys_addr as 0 */
+                       if (virt_addr_valid(data->addr) &&
+                           !(data->addr >= VMALLOC_START && data->addr < VMALLOC_END))
+                               data->phys_addr = (u64)virt_to_phys((void *)(uintptr_t)data->addr);
+               } else {
+                       /*
+                        * Walking the pages tables for user address.
+                        * Interrupts are disabled, so it prevents any tear down
+                        * of the page tables.
+                        * Try IRQ-safe __get_user_pages_fast first.
+                        * If failed, leave phys_addr as 0.

arch/x86/events/intel/ds.c static void setup_pebs_sample_data(struct perf_event *event, · line 1205

Quoted 10 lines
arch/x86/events/intel/ds.c +10 -0
+                        */
+                       if ((current->mm != NULL) &&
+                           (__get_user_pages_fast(data->addr, 1, 0, &p) == 1))
+                               data->phys_addr = page_to_phys(p) + data->addr % PAGE_SIZE;
+
+                       if (p)
+                               put_page(p);
+               }
+       }
+

This would be cleaner in a separate function in my opinion.

Quoted 75 lines
arch/x86/events/intel/ds.c +0 -0
        if (x86_pmu.intel_cap.pebs_format >= 2) {
                /* Only set the TSX weight when no memory weight. */
                if ((sample_type & PERF_SAMPLE_WEIGHT) && !fll)
arch/x86/events/perf_event.h +1 -1
index 476aec3..65bb91e 100644
@@ -91,7 +91,7 @@ struct amd_nb {
        (PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_ADDR | \
        PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_STREAM_ID | \
        PERF_SAMPLE_DATA_SRC | PERF_SAMPLE_IDENTIFIER | \
-       PERF_SAMPLE_TRANSACTION)
+       PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR)
 
 /*
  * A debug store configuration.
include/linux/perf_event.h +3 -0
index a3b873f..6783c69 100644
@@ -944,6 +944,8 @@ struct perf_sample_data {
 
        struct perf_regs                regs_intr;
        u64                             stack_user_size;
+
+       u64                             phys_addr;
 } ____cacheline_aligned;
 
 /* default value for data source */

@@ -964,6 +966,7 @@ static inline void perf_sample_data_init(struct perf_sample_data *data,
        data->weight = 0;
        data->data_src.val = PERF_MEM_NA;
        data->txn = 0;
+       data->phys_addr = 0;
 }
 
 extern void perf_output_sample(struct perf_output_handle *handle,
include/uapi/linux/perf_event.h +3 -1
index 642db5f..cbea02f 100644
@@ -139,8 +139,9 @@ enum perf_event_sample_format {
        PERF_SAMPLE_IDENTIFIER                  = 1U << 16,
        PERF_SAMPLE_TRANSACTION                 = 1U << 17,
        PERF_SAMPLE_REGS_INTR                   = 1U << 18,
+       PERF_SAMPLE_PHYS_ADDR                   = 1U << 19,
 
-       PERF_SAMPLE_MAX = 1U << 19,             /* non-ABI */
+       PERF_SAMPLE_MAX = 1U << 20,             /* non-ABI */
 };
 
 /*

@@ -814,6 +815,7 @@ enum perf_event_type {
         *      { u64                   transaction; } && PERF_SAMPLE_TRANSACTION
         *      { u64                   abi; # enum perf_sample_regs_abi
         *        u64                   regs[weight(mask)]; } && PERF_SAMPLE_REGS_INTR
+        *      { u64                   phys_addr;} && PERF_SAMPLE_PHYS_ADDR
         * };
         */
        PERF_RECORD_SAMPLE                      = 9,
kernel/events/core.c +3 -0
index 426c2ff..07d4a74 100644
@@ -1570,6 +1570,9 @@ static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
        if (sample_type & PERF_SAMPLE_TRANSACTION)
                size += sizeof(data->txn);
 
+       if (sample_type & PERF_SAMPLE_PHYS_ADDR)
+               size += sizeof(data->phys_addr);
+
        event->header_size = size;
 }

kernel/events/core.c void perf_output_sample(struct perf_output_handle *handle, · line 5960

Quoted 6 lines
kernel/events/core.c +3 -0
@@ -5952,6 +5955,9 @@ void perf_output_sample(struct perf_output_handle *handle,
        if (sample_type & PERF_SAMPLE_DATA_SRC)
                perf_output_put(handle, data->data_src.val);
 
+       if (sample_type & PERF_SAMPLE_PHYS_ADDR)
+               perf_output_put(handle, data->phys_addr);
+

I think this is misplaced. You need to output in the order in which you describe the record in the header file.
You have: DATA_SRC, SAMPLE_TRANSACTION, REGS_INTR, PHYS_ADDR. That means you need to
output in that order. Otherwise your PHYS_ADDR may be interpreted as a SAMPLE_TRANSACTION in case it is active.
At least this is my understanding of the ABI here.

Quoted 19 lines
kernel/events/core.c +6 -1
        if (sample_type & PERF_SAMPLE_TRANSACTION)
                perf_output_put(handle, data->txn);
 

@@ -9852,6 +9858,12 @@ SYSCALL_DEFINE5(perf_event_open,
                        return -EINVAL;
        }
 
+       /* Only privileged users can get kernel addresses */
+       if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) &&
+           perf_paranoid_kernel() &&
+           !capable(CAP_SYS_ADMIN))
+               return -EACCES;
+
        if (!attr.sample_max_stack)
                attr.sample_max_stack = sysctl_perf_event_max_stack;
 
--

2.4.3

author
#2 lore raw
Quoted 25 lines · On Wed, Aug 9, 2017 at 1:42 PM, <[email protected]> wrote:
Quoted 3 lines

From: Kan Liang <[email protected]>

For understanding how the workload maps to memory channels and

hardware

Quoted 18 lines

behavior, it's very important to collect address maps with physical addresses. For example, 3D XPoint access can only be found by filtering the physical address.
However, perf doesn't collect physical address information in sampling.

The load latency/DLA information in PEBS can be used to calculate the physical address.
For kernel direct mapping addresses, virt_to_phys is used to convert the virtual addresses from DLA to physical address.
For user virtual addresses, __get_user_pages_fast is used to walk the pages tables for user physical address.
This does not work for vmalloc addresses. Right now these are not resolved, but code to do that could be added.
For security, the physical address can only be exposed to root or privileged user.
A new sample type PERF_SAMPLE_PHYS_ADDR is introduced to expose the physical addresses.

Quoted 7 lines
Quoted 1 line
Signed-off-by Kan Liang <[email protected]>

This is a useful feature that I would like to use for some of the analysis we would like to do.
Please apply.
I am assuming you have the support in perf record/report?

Yes, the previous version includes both kernel and user space code.
https://lkml.org/lkml/2016/1/7/608
V3 only includes the kernel version.
Once it is accepted, I will send out the rest of patches for review.

Quoted 55 lines

arch/x86/events/intel/ds.c static void setup_pebs_sample_data(struct

Quoted 23 lines

---

The V2 version can be found here.
https://patchwork.kernel.org/patch/7979771/

Changes since V2
- Only the kernel patch
- Add example in changelog
- Include a perf_paranoid_kernel() test (PeterZ)
- Fix minor complier warning

 arch/x86/events/intel/ds.c      | 24 ++++++++++++++++++++++++
 arch/x86/events/perf_event.h    |  2 +-
 include/linux/perf_event.h      |  3 +++
 include/uapi/linux/perf_event.h |  4 +++-
 kernel/events/core.c            | 12 ++++++++++++
 5 files changed, 43 insertions(+), 2 deletions(-)
arch/x86/events/intel/ds.c +0 -0
index a322fed..712c86b 100644
@@ -1083,6 +1083,7 @@ static void setup_pebs_sample_data(struct

perf_event *event,

arch/x86/events/intel/ds.c static void setup_pebs_sample_data(struct

Quoted 8 lines
arch/x86/events/intel/ds.c +1 -0
        u64 sample_type;
        int fll, fst, dsrc;
        int fl = event->hw.flags;
+       struct page *p = NULL;
 
        if (pebs == NULL)
                return;

@@ -1179,6 +1180,29 @@ static void setup_pebs_sample_data(struct

perf_event *event,

arch/x86/events/intel/ds.c static void setup_pebs_sample_data(struct perf_event *event,

Quoted 8 lines
arch/x86/events/intel/ds.c +5 -0
            x86_pmu.intel_cap.pebs_format >= 1)
                data->addr = pebs->dla;
 
+       if ((sample_type & PERF_SAMPLE_PHYS_ADDR) && (data->addr != 0)) {
+               if (data->addr >= TASK_SIZE) {
+                       /* If it's vmalloc()d memory, leave phys_addr as 0 */
+                       if (virt_addr_valid(data->addr) &&
+                           !(data->addr >= VMALLOC_START && data->addr <

VMALLOC_END))

arch/x86/events/intel/ds.c static void setup_pebs_sample_data(struct · line 1188

Quoted 1 line
arch/x86/events/intel/ds.c +1 -0
+                               data->phys_addr = (u64)virt_to_phys((void

*)(uintptr_t)data->addr);

arch/x86/events/intel/ds.c static void setup_pebs_sample_data(struct perf_event *event,

Quoted 11 lines
arch/x86/events/intel/ds.c +11 -0
+               } else {
+                       /*
+                        * Walking the pages tables for user address.
+                        * Interrupts are disabled, so it prevents any tear down
+                        * of the page tables.
+                        * Try IRQ-safe __get_user_pages_fast first.
+                        * If failed, leave phys_addr as 0.
+                        */
+                       if ((current->mm != NULL) &&
+                           (__get_user_pages_fast(data->addr, 1, 0, &p) == 1))
+                               data->phys_addr = page_to_phys(p) + data->addr %
Quoted 8 lines

PAGE_SIZE;

arch/x86/events/intel/ds.c static void setup_pebs_sample_data(struct perf_event *event, · line 1205

Quoted 6 lines
arch/x86/events/intel/ds.c +6 -0
+
+                       if (p)
+                               put_page(p);
+               }
+       }
+

This would be cleaner in a separate function in my opinion.

Will change it in next version.

Quoted 89 lines

arch/x86/events/perf_event.h struct amd_nb { · line 92

Quoted 11 lines
arch/x86/events/intel/ds.c +0 -0
        if (x86_pmu.intel_cap.pebs_format >= 2) {
                /* Only set the TSX weight when no memory weight. */
                if ((sample_type & PERF_SAMPLE_WEIGHT) && !fll)
arch/x86/events/perf_event.h +0 -0
index 476aec3..65bb91e 100644
@@ -91,7 +91,7 @@ struct amd_nb {
        (PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_ADDR | \
        PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_STREAM_ID |

\

include/linux/perf_event.h static inline void perf_sample_data_init(struct

Quoted 20 lines
arch/x86/events/perf_event.h +1 -1
        PERF_SAMPLE_DATA_SRC | PERF_SAMPLE_IDENTIFIER | \
-       PERF_SAMPLE_TRANSACTION)
+       PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR)
 
 /*
  * A debug store configuration.
include/linux/perf_event.h +2 -0
index a3b873f..6783c69 100644
@@ -944,6 +944,8 @@ struct perf_sample_data {
 
        struct perf_regs                regs_intr;
        u64                             stack_user_size;
+
+       u64                             phys_addr;
 } ____cacheline_aligned;
 
 /* default value for data source */

@@ -964,6 +966,7 @@ static inline void perf_sample_data_init(struct

perf_sample_data *data,

Review

Quoted 8 lines
include/linux/perf_event.h +1 -0
        data->weight = 0;
        data->data_src.val = PERF_MEM_NA;
        data->txn = 0;
+       data->phys_addr = 0;
 }
 
 extern void perf_output_sample(struct perf_output_handle *handle,
(quoted diff) +0 -0

b/include/uapi/linux/perf_event.h

Quoted 15 lines

index 642db5f..cbea02f 100644

include/uapi/linux/perf_event.h +2 -1
@@ -139,8 +139,9 @@ enum perf_event_sample_format {
        PERF_SAMPLE_IDENTIFIER                  = 1U << 16,
        PERF_SAMPLE_TRANSACTION                 = 1U << 17,
        PERF_SAMPLE_REGS_INTR                   = 1U << 18,
+       PERF_SAMPLE_PHYS_ADDR                   = 1U << 19,
 
-       PERF_SAMPLE_MAX = 1U << 19,             /* non-ABI */
+       PERF_SAMPLE_MAX = 1U << 20,             /* non-ABI */
 };
 
 /*

include/uapi/linux/perf_event.h enum perf_event_type { · line 817

Quoted 3 lines
include/uapi/linux/perf_event.h +0 -0
@@ -814,6 +815,7 @@ enum perf_event_type {
         *      { u64                   transaction; } && PERF_SAMPLE_TRANSACTION
         *      { u64                   abi; # enum perf_sample_regs_abi
         *        u64                   regs[weight(mask)]; } &&

PERF_SAMPLE_REGS_INTR

kernel/events/core.c static void __perf_event_header_size(struct

Quoted 9 lines
include/uapi/linux/perf_event.h +1 -0
+        *      { u64                   phys_addr;} && PERF_SAMPLE_PHYS_ADDR
         * };
         */
        PERF_RECORD_SAMPLE                      = 9,
kernel/events/core.c +0 -0
index 426c2ff..07d4a74 100644
@@ -1570,6 +1570,9 @@ static void __perf_event_header_size(struct

perf_event *event, u64 sample_type)

kernel/events/core.c void perf_output_sample(struct

Quoted 10 lines
kernel/events/core.c +3 -0
        if (sample_type & PERF_SAMPLE_TRANSACTION)
                size += sizeof(data->txn);
 
+       if (sample_type & PERF_SAMPLE_PHYS_ADDR)
+               size += sizeof(data->phys_addr);
+
        event->header_size = size;
 }
 

@@ -5952,6 +5955,9 @@ void perf_output_sample(struct

perf_output_handle *handle,

kernel/events/core.c void perf_output_sample(struct perf_output_handle *handle, · line 5960

Quoted 6 lines
kernel/events/core.c +3 -0
        if (sample_type & PERF_SAMPLE_DATA_SRC)
                perf_output_put(handle, data->data_src.val);
 
+       if (sample_type & PERF_SAMPLE_PHYS_ADDR)
+               perf_output_put(handle, data->phys_addr);
+
Quoted 8 lines

I think this is misplaced. You need to output in the order in which you describe the record in the header file.
You have: DATA_SRC, SAMPLE_TRANSACTION, REGS_INTR, PHYS_ADDR. That means you need to
output in that order. Otherwise your PHYS_ADDR may be interpreted as a SAMPLE_TRANSACTION in case it is active.
At least this is my understanding of the ABI here.

Will change it in next version.

Thanks,
Kan

Quoted 20 lines
Quoted 20 lines
kernel/events/core.c +6 -1
        if (sample_type & PERF_SAMPLE_TRANSACTION)
                perf_output_put(handle, data->txn);
 

@@ -9852,6 +9858,12 @@ SYSCALL_DEFINE5(perf_event_open,
                        return -EINVAL;
        }
 
+       /* Only privileged users can get kernel addresses */
+       if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) &&
+           perf_paranoid_kernel() &&
+           !capable(CAP_SYS_ADMIN))
+               return -EACCES;
+
        if (!attr.sample_max_stack)
                attr.sample_max_stack = sysctl_perf_event_max_stack;
 
--

2.4.3