[PATCH V2 5/5] Adjust objdump start/end range per map pgoff parameter

[PATCH V2 5/5] Adjust objdump start/end range per map pgoff parameter

[Steve Clevenger]

Changes in V2:
  - Updated mailing list distribution

Extract map_pgoff parameter from the dictionary, and adjust start/end
range passed to objdump based on the value.

The start_addr/stop_addr address checks are changed to print a warning
only if verbose == True. This script repeatedly sees a zero value passed
in for
      start_addr = cpu_data[str(cpu) + 'addr']

These zero values are not a new problem. The start_addr/stop_addr warning
clutters the instruction trace output, hence this change.

Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
---
 .../perf/scripts/python/arm-cs-trace-disasm.py  | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/tools/perf/scripts/python/arm-cs-trace-disasm.py b/tools/perf/scripts/python/arm-cs-trace-disasm.py
index d973c2baed1c..6bf806078f9a 100755
--- a/tools/perf/scripts/python/arm-cs-trace-disasm.py
+++ b/tools/perf/scripts/python/arm-cs-trace-disasm.py
@@ -187,6 +187,7 @@ def process_event(param_dict):
 	dso_start = get_optional(param_dict, "dso_map_start")
 	dso_end = get_optional(param_dict, "dso_map_end")
 	symbol = get_optional(param_dict, "symbol")
+	map_pgoff = get_optional(param_dict, "map_pgoff")
 
 	cpu = sample["cpu"]
 	ip = sample["ip"]
@@ -250,13 +251,25 @@ def process_event(param_dict):
 		return
 
 	if (start_addr < int(dso_start) or start_addr > int(dso_end)):
-		print("Start address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (start_addr, int(dso_start), int(dso_end), dso))
+		if (options.verbose == True):
+			print("Start address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (start_addr, int(dso_start), int(dso_end), dso))
 		return
 
 	if (stop_addr < int(dso_start) or stop_addr > int(dso_end)):
-		print("Stop address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (stop_addr, int(dso_start), int(dso_end), dso))
+		if (options.verbose == True):
+			print("Stop address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (stop_addr, int(dso_start), int(dso_end), dso))
 		return
 
+	if map_pgoff != None and map_pgoff != '[unknown]':
+		if (dso == "[kernel.kallsyms]"):
+			dso_vm_start = 0
+			map_pgoff = '[unknown]'
+		else:
+			dso_vm_start = int(dso_start)
+			start_addr += map_pgoff
+			stop_addr += map_pgoff
+			map_pgoff = '[unknown]'
+
 	if (options.objdump_name != None):
 		# It doesn't need to decrease virtual memory offset for disassembly
 		# for kernel dso and executable file dso, so in this case we set
-- 
2.25.1

[PATCH V2 4/5] Add map pgoff to python dictionary based on MAPPING_TYPE

[Steve Clevenger]

Changes in V2:
  - Updated mailing list distribution

Add map_pgoff parameter to python dictionary so it can be seen by the
python script, arm-cs-trace-disasm.py. map_pgoff is forced to zero in
the dictionary if file type is MAPPING_TYPE__IDENTITY. Otherwise, the
map_pgoff value is directly added to the dictionary.

Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
---
 .../util/scripting-engines/trace-event-python.c     | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index fb00f3ad6815..8a056c3574ec 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -798,7 +798,8 @@ static int set_regs_in_dict(PyObject *dict,
 static void set_sym_in_dict(PyObject *dict, struct addr_location *al,
 			    const char *dso_field, const char *dso_bid_field,
 			    const char *dso_map_start, const char *dso_map_end,
-			    const char *sym_field, const char *symoff_field)
+			    const char *sym_field, const char *symoff_field,
+			    const char *map_pgoff)
 {
 	char sbuild_id[SBUILD_ID_SIZE];
 
@@ -814,6 +815,12 @@ static void set_sym_in_dict(PyObject *dict, struct addr_location *al,
 			PyLong_FromUnsignedLong(map__start(al->map)));
 		pydict_set_item_string_decref(dict, dso_map_end,
 			PyLong_FromUnsignedLong(map__end(al->map)));
+		if (al->map->mapping_type == MAPPING_TYPE__DSO)
+			pydict_set_item_string_decref(dict, map_pgoff,
+				PyLong_FromUnsignedLongLong(al->map->pgoff));
+		else
+			pydict_set_item_string_decref(dict, map_pgoff,
+				PyLong_FromUnsignedLongLong(0));
 	}
 	if (al->sym) {
 		pydict_set_item_string_decref(dict, sym_field,
@@ -898,7 +905,7 @@ static PyObject *get_perf_sample_dict(struct perf_sample *sample,
 	pydict_set_item_string_decref(dict, "comm",
 			_PyUnicode_FromString(thread__comm_str(al->thread)));
 	set_sym_in_dict(dict, al, "dso", "dso_bid", "dso_map_start", "dso_map_end",
-			"symbol", "symoff");
+			"symbol", "symoff", "map_pgoff")
 
 	pydict_set_item_string_decref(dict, "callchain", callchain);
 
@@ -923,7 +930,7 @@ static PyObject *get_perf_sample_dict(struct perf_sample *sample,
 			PyBool_FromLong(1));
 		set_sym_in_dict(dict_sample, addr_al, "addr_dso", "addr_dso_bid",
 				"addr_dso_map_start", "addr_dso_map_end",
-				"addr_symbol", "addr_symoff");
+				"addr_symbol", "addr_symoff", "map_pgoff");
 	}
 
 	if (sample->flags)
-- 
2.25.1

[PATCH V2 3/5] Force MAPPING_TYPE__IDENTIY for PIE

[Steve Clevenger]

Changes in V2:
  - Updated mailing list distribution

Use dso__is_pie() to check whether the DSO file is a Position
Independent Executable (PIE). If PIE, change the MAPPING_TYPE to
MAPPING_TYPE__IDENTITY so a zero map pgoff (text offset) is passed
into the script.


Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
---
 tools/perf/util/map.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index e1d14936a60d..df7c06fc373e 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -171,8 +171,11 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
 		assert(!dso__kernel(dso));
 		map__init(result, start, start + len, pgoff, dso);
 
+		if (map->pgoff && !no_dso)
+			no_dso = dso__is_pie(dso);	// PIE check
+
 		if (anon || no_dso) {
-			map->mapping_type = MAPPING_TYPE__IDENTITY;
+			map__set_mapping_type(map, MAPPING_TYPE__IDENTITY);
 
 			/*
 			 * Set memory without DSO as loaded. All map__find_*
-- 
2.25.1

[PATCH V2 2/5] Add dso__is_pie prototype

[Steve Clevenger]

Changes in V2:
  - Updated mailing list distribution

Add prototype to dso__is_pie() global.

Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
---
 tools/perf/util/symbol.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 3fb5d146d9b1..33ea2596ce31 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -127,6 +127,7 @@ void dso__insert_symbol(struct dso *dso,
 			struct symbol *sym);
 void dso__delete_symbol(struct dso *dso,
 			struct symbol *sym);
+bool dso__is_pie(struct dso *dso);
 
 struct symbol *dso__find_symbol(struct dso *dso, u64 addr);
 struct symbol *dso__find_symbol_nocache(struct dso *dso, u64 addr);
-- 
2.25.1

[PATCH V2 1/5] Add dso__is_pie call to identify ELF PIE

[Steve Clevenger]

Changes in V2:
  - Updated mailing list distribution
  - Decrease indentation, add null pointer checks per Leo Yan review

Add dso__is_pie global to read the .dynamic section DT_FLAGS_1 entry for
the DF_1_PIE flag. This identifies position executable code.

Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
---
 tools/perf/util/symbol-elf.c | 60 ++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index e398abfd13a0..0e49c1345a67 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -662,6 +662,66 @@ static int dso__synthesize_plt_got_symbols(struct dso *dso, Elf *elf,
 	return err;
 }
 
+/*
+ * Check dynamic section DT_FLAGS_1 for a Position Independent
+ * Executable (PIE).
+ */
+bool dso__is_pie(struct dso *dso)
+{
+	Elf *elf = NULL;
+	Elf_Scn *scn = NULL;
+	GElf_Ehdr ehdr;
+	GElf_Shdr shdr;
+	bool is_pie = false;
+	char dso_path[PATH_MAX];
+	int fd = -1;
+
+	if (!dso || (elf_version(EV_CURRENT) == EV_NONE))
+		goto exit;	// false
+
+	dso__build_id_filename(dso, dso_path, sizeof(dso_path), false);
+
+	fd = open(dso_path, O_RDONLY);
+
+	if (fd < 0) {
+		pr_debug("%s: cannot read cached %s.\n", __func__, dso_path);
+		goto exit;	// false
+	}
+
+	elf = elf_begin(fd, ELF_C_READ, NULL);
+	gelf_getehdr(elf, &ehdr);
+
+	if (ehdr.e_type == ET_DYN) {
+		Elf_Data *data;
+		GElf_Dyn *entry;
+		int n_entries = shdr.sh_size / sizeof(GElf_Dyn);
+
+		scn = elf_section_by_name(elf, &ehdr, &shdr, ".dynamic", NULL);
+		if (!scn)
+			goto exit;	// false
+
+		data = (Elf_Data *) elf_getdata(scn, NULL);
+		if (!data || !data->d_buf)
+			goto exit;	// false
+
+		// check DT_FLAGS_1
+		for (int i = 0; i < n_entries; i++) {
+			entry = ((GElf_Dyn *) data->d_buf) + i;
+			if (entry->d_tag == DT_FLAGS_1) {
+				if ((entry->d_un.d_val & DF_1_PIE) != 0) {
+					is_pie = true;
+					break;
+				}
+			}
+		} // end for
+	}
+
+	elf_end(elf);
+	close(fd);
+exit:
+	return is_pie;
+}
+
 /*
  * We need to check if we have a .dynsym, so that we can handle the
  * .plt, synthesizing its symbols, that aren't on the symtabs (be it
-- 
2.25.1

[PATCH V2 0/5] arm-cs-trace-disasm.py/perf must accommodate non-zero DSO text offset

[Steve Clevenger]

Changes in V2:
  - Updated mailing list distribution

Fedora 37 distributed shared binary and executable mapped files show a
zero text section offset. Starting with the Fedora 38 distribution, the
shared binary and executable mapped files show a non-zero text section
offset for some binaries. The text offset parameter is never passed into
the arm-cs-trace-disasm.py script to allow the script to adjust the
start/end address range passed to objdump. This adjustment is required
to correctly offset into the dso text section. Not doing so results in
an incorrect user instruction trace display for Fedora 38 (and later)
user trace output.

Steve Clevenger (5):
  Add dso__is_pie call to identify ELF PIE
  Add dso__is_pie prototype
  Force MAPPING_TYPE__IDENTIY for PIE
  Add map pgoff to python dictionary based on MAPPING_TYPE
  Adjust objdump start/end range per map pgoff parameter

 .../scripts/python/arm-cs-trace-disasm.py     | 17 +++++-
 tools/perf/util/map.c                         |  5 +-
 .../scripting-engines/trace-event-python.c    | 13 +++-
 tools/perf/util/symbol-elf.c                  | 60 +++++++++++++++++++
 tools/perf/util/symbol.h                      |  1 +
 5 files changed, 90 insertions(+), 6 deletions(-)

-- 
2.25.1

Re: [PATCH V2 2/5] Add dso__is_pie prototype

[Leo Yan]

On 8/26/2024 10:35 PM, Steve Clevenger wrote:
> 
> Changes in V2:
>   - Updated mailing list distribution

Usually, we record the change history into the cover letter, or put it under
the line starting with `---` in the commit. This can avoid the change history
to be merged into the mainline.

> Add prototype to dso__is_pie() global.

Please squash the patch 02 into 01. Otherwise, the patch 01 will introduce
building regression:

util/symbol-elf.c:669:6: error: no previous prototype for ‘dso__is_pie’
[-Werror=missing-prototypes]
  669 | bool dso__is_pie(struct dso *dso)
      |      ^~~~~~~~~~~

Thanks,
Leo

> Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
> ---
>  tools/perf/util/symbol.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> index 3fb5d146d9b1..33ea2596ce31 100644
> --- a/tools/perf/util/symbol.h
> +++ b/tools/perf/util/symbol.h
> @@ -127,6 +127,7 @@ void dso__insert_symbol(struct dso *dso,
>                         struct symbol *sym);
>  void dso__delete_symbol(struct dso *dso,
>                         struct symbol *sym);
> +bool dso__is_pie(struct dso *dso);
> 
>  struct symbol *dso__find_symbol(struct dso *dso, u64 addr);
>  struct symbol *dso__find_symbol_nocache(struct dso *dso, u64 addr);
> --
> 2.25.1
> 

Re: [PATCH V2 3/5] Force MAPPING_TYPE__IDENTIY for PIE

[Leo Yan]

On 8/26/2024 10:35 PM, Steve Clevenger wrote:
> 
> Changes in V2:
>   - Updated mailing list distribution
> 
> Use dso__is_pie() to check whether the DSO file is a Position
> Independent Executable (PIE). If PIE, change the MAPPING_TYPE to
> MAPPING_TYPE__IDENTITY so a zero map pgoff (text offset) is passed
> into the script.
> 
> 
> Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
> ---
>  tools/perf/util/map.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index e1d14936a60d..df7c06fc373e 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -171,8 +171,11 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
>                 assert(!dso__kernel(dso));
>                 map__init(result, start, start + len, pgoff, dso);
> 
> +               if (map->pgoff && !no_dso)
> +                       no_dso = dso__is_pie(dso);      // PIE check

Here the logic is whatever the `pgoff` is (zero or non-zero), we need to
always set the mapping type as MAPPING_TYPE__IDENTITY. It is no need to check
pgoff and is no matter with 'no_dso'. So we can simply check dso__is_pie() and
set IDENTITY flag for the true case.

    if (dso__is_pie(dso)) {
            map__set_mapping_type(map, MAPPING_TYPE__IDENTITY);
    } else if (anon || no_dso) {
            ...
    }

BTW, please rebase the series on the top of the perf-tools-next branch [1], I
saw this patch has merging conflict on it.

Thanks,
Leo

[1] https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git
    branch: perf-tools-next
> +
>                 if (anon || no_dso) {
> -                       map->mapping_type = MAPPING_TYPE__IDENTITY;
> +                       map__set_mapping_type(map, MAPPING_TYPE__IDENTITY);
> 
>                         /*
>                          * Set memory without DSO as loaded. All map__find_*
> --
> 2.25.1
> 

Re: [PATCH V2 5/5] Adjust objdump start/end range per map pgoff parameter

[Leo Yan]

On 8/26/2024 10:35 PM, Steve Clevenger wrote:
> 
> Changes in V2:
>   - Updated mailing list distribution
> 
> Extract map_pgoff parameter from the dictionary, and adjust start/end
> range passed to objdump based on the value.
> 
> The start_addr/stop_addr address checks are changed to print a warning
> only if verbose == True. This script repeatedly sees a zero value passed
> in for
>       start_addr = cpu_data[str(cpu) + 'addr']
> 
> These zero values are not a new problem. The start_addr/stop_addr warning
> clutters the instruction trace output, hence this change.
> 
> Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
> ---
>  .../perf/scripts/python/arm-cs-trace-disasm.py  | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/scripts/python/arm-cs-trace-disasm.py b/tools/perf/scripts/python/arm-cs-trace-disasm.py
> index d973c2baed1c..6bf806078f9a 100755
> --- a/tools/perf/scripts/python/arm-cs-trace-disasm.py
> +++ b/tools/perf/scripts/python/arm-cs-trace-disasm.py
> @@ -187,6 +187,7 @@ def process_event(param_dict):
>         dso_start = get_optional(param_dict, "dso_map_start")
>         dso_end = get_optional(param_dict, "dso_map_end")
>         symbol = get_optional(param_dict, "symbol")
> +       map_pgoff = get_optional(param_dict, "map_pgoff")
> 
>         cpu = sample["cpu"]
>         ip = sample["ip"]
> @@ -250,13 +251,25 @@ def process_event(param_dict):
>                 return
> 
>         if (start_addr < int(dso_start) or start_addr > int(dso_end)):
> -               print("Start address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (start_addr, int(dso_start), int(dso_end), dso))
> +               if (options.verbose == True):
> +                       print("Start address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (start_addr, int(dso_start), int(dso_end), dso))
>                 return
> 
>         if (stop_addr < int(dso_start) or stop_addr > int(dso_end)):
> -               print("Stop address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (stop_addr, int(dso_start), int(dso_end), dso))
> +               if (options.verbose == True):
> +                       print("Stop address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (stop_addr, int(dso_start), int(dso_end), dso))
>                 return
> 
> +       if map_pgoff != None and map_pgoff != '[unknown]':
> +               if (dso == "[kernel.kallsyms]"):
> +                       dso_vm_start = 0
> +                       map_pgoff = '[unknown]'
> +               else:
> +                       dso_vm_start = int(dso_start)
> +                       start_addr += map_pgoff
> +                       stop_addr += map_pgoff
> +                       map_pgoff = '[unknown]'

Every sample has its own field `map_pgoff`. So I am confused why we need the
sentence: map_pgoff = '[unknown]'. And you can see with above change, we will
set dso_vm_start delicately with below code section.

How about a simple change like below?

@@ -267,7 +268,7 @@ def process_event(param_dict):

  dso_fname = get_dso_file_path(dso, dso_bid)
  if path.exists(dso_fname):
-     print_disam(dso_fname, dso_vm_start, start_addr, stop_addr)
+     print_disam(dso_fname, dso_vm_start, start_addr + map_pgoff, stop_addr +
map_pgoff)

If this change does not work, I am curious if anything we missed to handle in
the perf's C code (frontend).

Thanks,
Leo

>         if (options.objdump_name != None):
>                 # It doesn't need to decrease virtual memory offset for disassembly
>                 # for kernel dso and executable file dso, so in this case we set
> --
> 2.25.1
> 

Re: [PATCH V2 3/5] Force MAPPING_TYPE__IDENTIY for PIE

[Steve Clevenger]

On 8/27/2024 12:55 PM, Leo Yan wrote:
> On 8/26/2024 10:35 PM, Steve Clevenger wrote:
>>
>> Changes in V2:
>>   - Updated mailing list distribution
>>
>> Use dso__is_pie() to check whether the DSO file is a Position
>> Independent Executable (PIE). If PIE, change the MAPPING_TYPE to
>> MAPPING_TYPE__IDENTITY so a zero map pgoff (text offset) is passed
>> into the script.
>>
>>
>> Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
>> ---
>>  tools/perf/util/map.c | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>> index e1d14936a60d..df7c06fc373e 100644
>> --- a/tools/perf/util/map.c
>> +++ b/tools/perf/util/map.c
>> @@ -171,8 +171,11 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
>>                 assert(!dso__kernel(dso));
>>                 map__init(result, start, start + len, pgoff, dso);
>>
>> +               if (map->pgoff && !no_dso)
>> +                       no_dso = dso__is_pie(dso);      // PIE check
> 
> Here the logic is whatever the `pgoff` is (zero or non-zero), we need to
> always set the mapping type as MAPPING_TYPE__IDENTITY. It is no need to check
> pgoff and is no matter with 'no_dso'. So we can simply check dso__is_pie() and
> set IDENTITY flag for the true case.
> 
>     if (dso__is_pie(dso)) {
>             map__set_mapping_type(map, MAPPING_TYPE__IDENTITY);
>     } else if (anon || no_dso) {
>             ...
>     }
> 
> BTW, please rebase the series on the top of the perf-tools-next branch [1], I
> saw this patch has merging conflict on it.
> 
> Thanks,
> Leo

Hi Leo,

I combined the dso__is_pie() call onto the end of the existing 'if'
statement you now show as an 'else if'. Please see V3 of the patch series.

Steve

> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git
>     branch: perf-tools-next
>> +
>>                 if (anon || no_dso) {
>> -                       map->mapping_type = MAPPING_TYPE__IDENTITY;
>> +                       map__set_mapping_type(map, MAPPING_TYPE__IDENTITY);
>>
>>                         /*
>>                          * Set memory without DSO as loaded. All map__find_*
>> --
>> 2.25.1
>>

Re: [PATCH V2 5/5] Adjust objdump start/end range per map pgoff parameter

[Steve Clevenger]

On 8/27/2024 1:23 PM, Leo Yan wrote:
> On 8/26/2024 10:35 PM, Steve Clevenger wrote:
>>
>> Changes in V2:
>>   - Updated mailing list distribution
>>
>> Extract map_pgoff parameter from the dictionary, and adjust start/end
>> range passed to objdump based on the value.
>>
>> The start_addr/stop_addr address checks are changed to print a warning
>> only if verbose == True. This script repeatedly sees a zero value passed
>> in for
>>       start_addr = cpu_data[str(cpu) + 'addr']
>>
>> These zero values are not a new problem. The start_addr/stop_addr warning
>> clutters the instruction trace output, hence this change.
>>
>> Signed-off-by: Steve Clevenger <scclevenger@os.amperecomputing.com>
>> ---
>>  .../perf/scripts/python/arm-cs-trace-disasm.py  | 17 +++++++++++++++--
>>  1 file changed, 15 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/perf/scripts/python/arm-cs-trace-disasm.py b/tools/perf/scripts/python/arm-cs-trace-disasm.py
>> index d973c2baed1c..6bf806078f9a 100755
>> --- a/tools/perf/scripts/python/arm-cs-trace-disasm.py
>> +++ b/tools/perf/scripts/python/arm-cs-trace-disasm.py
>> @@ -187,6 +187,7 @@ def process_event(param_dict):
>>         dso_start = get_optional(param_dict, "dso_map_start")
>>         dso_end = get_optional(param_dict, "dso_map_end")
>>         symbol = get_optional(param_dict, "symbol")
>> +       map_pgoff = get_optional(param_dict, "map_pgoff")
>>
>>         cpu = sample["cpu"]
>>         ip = sample["ip"]
>> @@ -250,13 +251,25 @@ def process_event(param_dict):
>>                 return
>>
>>         if (start_addr < int(dso_start) or start_addr > int(dso_end)):
>> -               print("Start address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (start_addr, int(dso_start), int(dso_end), dso))
>> +               if (options.verbose == True):
>> +                       print("Start address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (start_addr, int(dso_start), int(dso_end), dso))
>>                 return
>>
>>         if (stop_addr < int(dso_start) or stop_addr > int(dso_end)):
>> -               print("Stop address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (stop_addr, int(dso_start), int(dso_end), dso))
>> +               if (options.verbose == True):
>> +                       print("Stop address 0x%x is out of range [ 0x%x .. 0x%x ] for dso %s" % (stop_addr, int(dso_start), int(dso_end), dso))
>>                 return
>>
>> +       if map_pgoff != None and map_pgoff != '[unknown]':
>> +               if (dso == "[kernel.kallsyms]"):
>> +                       dso_vm_start = 0
>> +                       map_pgoff = '[unknown]'
>> +               else:
>> +                       dso_vm_start = int(dso_start)
>> +                       start_addr += map_pgoff
>> +                       stop_addr += map_pgoff
>> +                       map_pgoff = '[unknown]'
> 
> Every sample has its own field `map_pgoff`. So I am confused why we need the
> sentence: map_pgoff = '[unknown]'. And you can see with above change, we will
> set dso_vm_start delicately with below code section.
> 
> How about a simple change like below?
> 
> @@ -267,7 +268,7 @@ def process_event(param_dict):
> 
>   dso_fname = get_dso_file_path(dso, dso_bid)
>   if path.exists(dso_fname):
> -     print_disam(dso_fname, dso_vm_start, start_addr, stop_addr)
> +     print_disam(dso_fname, dso_vm_start, start_addr + map_pgoff, stop_addr +
> map_pgoff)
> 
> If this change does not work, I am curious if anything we missed to handle in
> the perf's C code (frontend).
> 
> Thanks,
> Leo

Leo,

Sorry, the map_pgoff = '[unknown]' instances are actually leftover debug
artifacts used for print type debug. I resorted to print debug after I
didn't see success attempting mixed-mode debug with Visual Studio Code
on AARCH64. If you have a known working launch configuration, please
share it. See V3 of the patch series. I've rebased to the
perf-tools-next branch.

Steve
> 
>>         if (options.objdump_name != None):
>>                 # It doesn't need to decrease virtual memory offset for disassembly
>>                 # for kernel dso and executable file dso, so in this case we set
>> --
>> 2.25.1
>>