Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-10 Thread Masami Hiramatsu 
On Mon, 10 Apr 2017 09:53:48 -0500
Paul Clarke  wrote:
> >> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> >> index 5245d2f..bde2100 100644
> >> --- a/tools/perf/util/symbol.h
> >> +++ b/tools/perf/util/symbol.h
> >> @@ -348,8 +348,17 @@ void arch__sym_update(struct symbol *s, GElf_Sym 
> >> *sym);
> >>   #define SYMBOL_A 0
> >>   #define SYMBOL_B 1
> >>
> >> +int arch__compare_symbol_names(const char *namea, const char *nameb);
> >> +int arch__compare_symbol_names_n(const char *namea, const char *nameb,
> >> +   unsigned int n);
> >>   int arch__choose_best_symbol(struct symbol *syma, struct symbol *symb);
> >>
> >> +#define SYMBOLS__TAG_INCLUDE_NONE 0
> >> +#define SYMBOLS__TAG_INCLUDE_DEFAULT_ONLY 1
> >
> > Hmm, even if you like to pass an obvious flag, these should be
> > defined by enum, and please choose simpler and clear flag name.
> >
> > E.g.
> > enum {
> > SYMBOLS__COMP_WITH_TAG,
> > SYMBOLS__COMP_WITHOUT_TAG,
> > };
> 
> Earlier in this thread, we discussed supporting non-default tagged symbols 
> (those tagged with "@version").  To allow for that, I was thinking of these 
> three cases:
> - SYMBOLS__TAG_INCLUDE_NONE: ignore all tagged symbols (the current behavior)
> - SYMBOLS__TAG_INCLUDE_DEFAULT_ONLY:  match tagged symbols when tagged as 
> default ("@@"; added with this patch)
> - SYMBOLS__TAG_INCLUDE_ALL:  match all tagged symbols ("@" and "@@"; future)

Ah, I see now.

> For the names of the enums, I chose "SYMBOLS__TAG..." to put it first in the 
> SYMBOLS namespace, and second in a "TAG" sub-namespace.

For the namespace, we should use same namespase as enum's name.

> I'm happy to fix the discrepancy with signed/unsigned by changing to enum.
> 
> Let me know what enum names are preferred, given the above discussion, and 
> I'll post a new patch.

OK, then what about enum symbol_tag and use "SYMBOL_TAG__" for namespace?

Thank you,



-- 
Masami Hiramatsu

Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-10 Thread Masami Hiramatsu 
On Mon, 10 Apr 2017 09:53:48 -0500
Paul Clarke  wrote:
> >> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> >> index 5245d2f..bde2100 100644
> >> --- a/tools/perf/util/symbol.h
> >> +++ b/tools/perf/util/symbol.h
> >> @@ -348,8 +348,17 @@ void arch__sym_update(struct symbol *s, GElf_Sym 
> >> *sym);
> >>   #define SYMBOL_A 0
> >>   #define SYMBOL_B 1
> >>
> >> +int arch__compare_symbol_names(const char *namea, const char *nameb);
> >> +int arch__compare_symbol_names_n(const char *namea, const char *nameb,
> >> +   unsigned int n);
> >>   int arch__choose_best_symbol(struct symbol *syma, struct symbol *symb);
> >>
> >> +#define SYMBOLS__TAG_INCLUDE_NONE 0
> >> +#define SYMBOLS__TAG_INCLUDE_DEFAULT_ONLY 1
> >
> > Hmm, even if you like to pass an obvious flag, these should be
> > defined by enum, and please choose simpler and clear flag name.
> >
> > E.g.
> > enum {
> > SYMBOLS__COMP_WITH_TAG,
> > SYMBOLS__COMP_WITHOUT_TAG,
> > };
> 
> Earlier in this thread, we discussed supporting non-default tagged symbols 
> (those tagged with "@version").  To allow for that, I was thinking of these 
> three cases:
> - SYMBOLS__TAG_INCLUDE_NONE: ignore all tagged symbols (the current behavior)
> - SYMBOLS__TAG_INCLUDE_DEFAULT_ONLY:  match tagged symbols when tagged as 
> default ("@@"; added with this patch)
> - SYMBOLS__TAG_INCLUDE_ALL:  match all tagged symbols ("@" and "@@"; future)

Ah, I see now.

> For the names of the enums, I chose "SYMBOLS__TAG..." to put it first in the 
> SYMBOLS namespace, and second in a "TAG" sub-namespace.

For the namespace, we should use same namespase as enum's name.

> I'm happy to fix the discrepancy with signed/unsigned by changing to enum.
> 
> Let me know what enum names are preferred, given the above discussion, and 
> I'll post a new patch.

OK, then what about enum symbol_tag and use "SYMBOL_TAG__" for namespace?

Thank you,



-- 
Masami Hiramatsu

Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-10 Thread Paul Clarke 

On 04/10/2017 08:11 AM, Masami Hiramatsu wrote:

On Wed, 5 Apr 2017 22:30:03 -0500
Paul Clarke  wrote:

Symbol versioning, as in glibc, results in symbols being defined as:
@[@]
(Note that "@@" identifies a default symbol, if the symbol name
is repeated.)

perf is currently unable to deal with this, and is unable to create
user probes at such symbols:
--
$ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
8d30 t __pthread_create_2_1
8d30 T pthread_create@@GLIBC_2.17
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
probe-definition(0): pthread_create
symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
Try to find probe point from debuginfo.
Probe point 'pthread_create' not found.
Error: Failed to add events. Reason: No such file or directory (Code: -2)
--

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:
--
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create@@GLIBC_2.17
probe-definition(0): pthread_create@@GLIBC_2.17
Semantic error :SRC@SRC is not allowed.
0 arguments
Error: Command Parse Error. Reason: Invalid argument (Code: -22)
--

This patch ignores the versioning tag for default symbols, thus
allowing probes to be created for these symbols:
--
$ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
Added new event:
probe_libpthread:pthread_create (on pthread_create in 
/lib/powerpc64le-linux-gnu/libpthread-2.19.so)

You can now use it in all perf tools, such as:

  perf record -e probe_libpthread:pthread_create -aR sleep 1

$ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
$ /usr/bin/sudo ./perf script
  test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
(3fff99248d38)
  test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
(3fff99248d38)
$ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
Removed event: probe_libpthread:pthread_create
--

Signed-off-by: Paul A. Clarke 
---
v4:
- rebased to acme/perf/core
- moved changes from "map" namespace to "symbol" namespace,
- rewrote symbol__compare (now *match) to avoid need for strdup
- new symbol__match_symbol_name to support versioned symbols, ignoring default
   tags
- new arch__compare_symbol_names_n to map to strncmp
- dso__find_symbol_by_name: now tries exact match (as before), then tries
also adding symbols tagged as default (@@)
- symbols__find_by_name: new parameter to support finding with or without 
default
   tags
- does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)

v3:
- code style fixes per David Ahern

v2:
- move logic from arch__compare_symbol_names to new map__compare_symbol_names
- call through from map__compare_symbol_names to arch__compare_symbol_names
- redirect uses of arch__compare_symbol_names
- send patch to LKML
  tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
  tools/perf/util/map.c   |  5 ---
  tools/perf/util/map.h   |  5 ++-
  tools/perf/util/symbol.c| 62 +++--
  tools/perf/util/symbol.h|  9 +
  5 files changed, 73 insertions(+), 20 deletions(-)

diff --git a/tools/perf/arch/powerpc/util/sym-handling.c 
b/tools/perf/arch/powerpc/util/sym-handling.c
index 39dbe51..0d40e17 100644
--- a/tools/perf/arch/powerpc/util/sym-handling.c
+++ b/tools/perf/arch/powerpc/util/sym-handling.c
@@ -52,6 +52,18 @@ int arch__compare_symbol_names(const char *namea, const char 
*nameb)

return strcmp(namea, nameb);
  }
+
+int arch__compare_symbol_names_n(const char *namea, const char *nameb,
+   unsigned int n)
+{
+   /* Skip over initial dot */
+   if (*namea == '.')
+   namea++;
+   if (*nameb == '.')
+   nameb++;
+
+   return strncmp(namea, nameb, n);
+}
  #endif

  #if defined(_CALL_ELF) && _CALL_ELF == 2
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index c1870ac..f4d8272 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -325,11 +325,6 @@ int map__load(struct map *map)
return 0;
  }

-int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
-{
-   return strcmp(namea, nameb);
-}
-
  struct symbol *map__find_symbol(struct map *map, u64 addr)
  {
if (map__load(map) < 0)
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index c8a5a64..325bbc8 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -130,13 +130,14 @@ struct thread;
   */
  #define

Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-10 Thread Paul Clarke 

On 04/10/2017 08:11 AM, Masami Hiramatsu wrote:

On Wed, 5 Apr 2017 22:30:03 -0500
Paul Clarke  wrote:

Symbol versioning, as in glibc, results in symbols being defined as:
@[@]
(Note that "@@" identifies a default symbol, if the symbol name
is repeated.)

perf is currently unable to deal with this, and is unable to create
user probes at such symbols:
--
$ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
8d30 t __pthread_create_2_1
8d30 T pthread_create@@GLIBC_2.17
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
probe-definition(0): pthread_create
symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
Try to find probe point from debuginfo.
Probe point 'pthread_create' not found.
Error: Failed to add events. Reason: No such file or directory (Code: -2)
--

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:
--
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create@@GLIBC_2.17
probe-definition(0): pthread_create@@GLIBC_2.17
Semantic error :SRC@SRC is not allowed.
0 arguments
Error: Command Parse Error. Reason: Invalid argument (Code: -22)
--

This patch ignores the versioning tag for default symbols, thus
allowing probes to be created for these symbols:
--
$ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
Added new event:
probe_libpthread:pthread_create (on pthread_create in 
/lib/powerpc64le-linux-gnu/libpthread-2.19.so)

You can now use it in all perf tools, such as:

  perf record -e probe_libpthread:pthread_create -aR sleep 1

$ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
$ /usr/bin/sudo ./perf script
  test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
(3fff99248d38)
  test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
(3fff99248d38)
$ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
Removed event: probe_libpthread:pthread_create
--

Signed-off-by: Paul A. Clarke 
---
v4:
- rebased to acme/perf/core
- moved changes from "map" namespace to "symbol" namespace,
- rewrote symbol__compare (now *match) to avoid need for strdup
- new symbol__match_symbol_name to support versioned symbols, ignoring default
   tags
- new arch__compare_symbol_names_n to map to strncmp
- dso__find_symbol_by_name: now tries exact match (as before), then tries
also adding symbols tagged as default (@@)
- symbols__find_by_name: new parameter to support finding with or without 
default
   tags
- does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)

v3:
- code style fixes per David Ahern

v2:
- move logic from arch__compare_symbol_names to new map__compare_symbol_names
- call through from map__compare_symbol_names to arch__compare_symbol_names
- redirect uses of arch__compare_symbol_names
- send patch to LKML
  tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
  tools/perf/util/map.c   |  5 ---
  tools/perf/util/map.h   |  5 ++-
  tools/perf/util/symbol.c| 62 +++--
  tools/perf/util/symbol.h|  9 +
  5 files changed, 73 insertions(+), 20 deletions(-)

diff --git a/tools/perf/arch/powerpc/util/sym-handling.c 
b/tools/perf/arch/powerpc/util/sym-handling.c
index 39dbe51..0d40e17 100644
--- a/tools/perf/arch/powerpc/util/sym-handling.c
+++ b/tools/perf/arch/powerpc/util/sym-handling.c
@@ -52,6 +52,18 @@ int arch__compare_symbol_names(const char *namea, const char 
*nameb)

return strcmp(namea, nameb);
  }
+
+int arch__compare_symbol_names_n(const char *namea, const char *nameb,
+   unsigned int n)
+{
+   /* Skip over initial dot */
+   if (*namea == '.')
+   namea++;
+   if (*nameb == '.')
+   nameb++;
+
+   return strncmp(namea, nameb, n);
+}
  #endif

  #if defined(_CALL_ELF) && _CALL_ELF == 2
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index c1870ac..f4d8272 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -325,11 +325,6 @@ int map__load(struct map *map)
return 0;
  }

-int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
-{
-   return strcmp(namea, nameb);
-}
-
  struct symbol *map__find_symbol(struct map *map, u64 addr)
  {
if (map__load(map) < 0)
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index c8a5a64..325bbc8 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -130,13 +130,14 @@ struct thread;
   */
  #define __map__for_each_symbol_by_name(map, sym_name, pos)\

Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-10 Thread Masami Hiramatsu 
On Wed, 5 Apr 2017 22:30:03 -0500
Paul Clarke  wrote:

> Symbol versioning, as in glibc, results in symbols being defined as:
> @[@]
> (Note that "@@" identifies a default symbol, if the symbol name
> is repeated.)
> 
> perf is currently unable to deal with this, and is unable to create
> user probes at such symbols:
> --
> $ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
> 8d30 t __pthread_create_2_1
> 8d30 T pthread_create@@GLIBC_2.17
> $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create
> probe-definition(0): pthread_create
> symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
> 0 arguments
> Open Debuginfo file: 
> /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
> Try to find probe point from debuginfo.
> Probe point 'pthread_create' not found.
> Error: Failed to add events. Reason: No such file or directory (Code: -2)
> --
> 
> One is not able to specify the fully versioned symbol, either, due to
> syntactic conflicts with other uses of "@" by perf:
> --
> $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create@@GLIBC_2.17
> probe-definition(0): pthread_create@@GLIBC_2.17
> Semantic error :SRC@SRC is not allowed.
> 0 arguments
> Error: Command Parse Error. Reason: Invalid argument (Code: -22)
> --
> 
> This patch ignores the versioning tag for default symbols, thus
> allowing probes to be created for these symbols:
> --
> $ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create
> Added new event:
> probe_libpthread:pthread_create (on pthread_create in 
> /lib/powerpc64le-linux-gnu/libpthread-2.19.so)
> 
> You can now use it in all perf tools, such as:
> 
>   perf record -e probe_libpthread:pthread_create -aR sleep 1
> 
> $ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
> $ /usr/bin/sudo ./perf script
>   test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
> (3fff99248d38)
>   test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
> (3fff99248d38)
> $ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
> Removed event: probe_libpthread:pthread_create
> --
> 
> Signed-off-by: Paul A. Clarke 
> ---
> v4:
> - rebased to acme/perf/core
> - moved changes from "map" namespace to "symbol" namespace,
> - rewrote symbol__compare (now *match) to avoid need for strdup
> - new symbol__match_symbol_name to support versioned symbols, ignoring default
>tags
> - new arch__compare_symbol_names_n to map to strncmp
> - dso__find_symbol_by_name: now tries exact match (as before), then tries
> also adding symbols tagged as default (@@)
> - symbols__find_by_name: new parameter to support finding with or without 
> default
>tags
> - does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)
> 
> v3:
> - code style fixes per David Ahern
> 
> v2:
> - move logic from arch__compare_symbol_names to new map__compare_symbol_names
> - call through from map__compare_symbol_names to arch__compare_symbol_names
> - redirect uses of arch__compare_symbol_names
> - send patch to LKML
>   tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
>   tools/perf/util/map.c   |  5 ---
>   tools/perf/util/map.h   |  5 ++-
>   tools/perf/util/symbol.c| 62 
> +++--
>   tools/perf/util/symbol.h|  9 +
>   5 files changed, 73 insertions(+), 20 deletions(-)
> 
> diff --git a/tools/perf/arch/powerpc/util/sym-handling.c 
> b/tools/perf/arch/powerpc/util/sym-handling.c
> index 39dbe51..0d40e17 100644
> --- a/tools/perf/arch/powerpc/util/sym-handling.c
> +++ b/tools/perf/arch/powerpc/util/sym-handling.c
> @@ -52,6 +52,18 @@ int arch__compare_symbol_names(const char *namea, const 
> char *nameb)
>   
>   return strcmp(namea, nameb);
>   }
> +
> +int arch__compare_symbol_names_n(const char *namea, const char *nameb,
> + unsigned int n)
> +{
> + /* Skip over initial dot */
> + if (*namea == '.')
> + namea++;
> + if (*nameb == '.')
> + nameb++;
> +
> + return strncmp(namea, nameb, n);
> +}
>   #endif
>   
>   #if defined(_CALL_ELF) && _CALL_ELF == 2
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index c1870ac..f4d8272 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -325,11 +325,6 @@ int map__load(struct map *map)
>   return 0;
>   }
>   
> -int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
> -{
> - return strcmp(namea, nameb);
> -}
> -
>   struct symbol *map__find_symbol(struct map *map, u64 addr)
>   {
>   if (map__load(map) < 0)
> diff --git

Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-10 Thread Masami Hiramatsu 
On Wed, 5 Apr 2017 22:30:03 -0500
Paul Clarke  wrote:

> Symbol versioning, as in glibc, results in symbols being defined as:
> @[@]
> (Note that "@@" identifies a default symbol, if the symbol name
> is repeated.)
> 
> perf is currently unable to deal with this, and is unable to create
> user probes at such symbols:
> --
> $ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
> 8d30 t __pthread_create_2_1
> 8d30 T pthread_create@@GLIBC_2.17
> $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create
> probe-definition(0): pthread_create
> symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
> 0 arguments
> Open Debuginfo file: 
> /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
> Try to find probe point from debuginfo.
> Probe point 'pthread_create' not found.
> Error: Failed to add events. Reason: No such file or directory (Code: -2)
> --
> 
> One is not able to specify the fully versioned symbol, either, due to
> syntactic conflicts with other uses of "@" by perf:
> --
> $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create@@GLIBC_2.17
> probe-definition(0): pthread_create@@GLIBC_2.17
> Semantic error :SRC@SRC is not allowed.
> 0 arguments
> Error: Command Parse Error. Reason: Invalid argument (Code: -22)
> --
> 
> This patch ignores the versioning tag for default symbols, thus
> allowing probes to be created for these symbols:
> --
> $ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create
> Added new event:
> probe_libpthread:pthread_create (on pthread_create in 
> /lib/powerpc64le-linux-gnu/libpthread-2.19.so)
> 
> You can now use it in all perf tools, such as:
> 
>   perf record -e probe_libpthread:pthread_create -aR sleep 1
> 
> $ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
> $ /usr/bin/sudo ./perf script
>   test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
> (3fff99248d38)
>   test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
> (3fff99248d38)
> $ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
> Removed event: probe_libpthread:pthread_create
> --
> 
> Signed-off-by: Paul A. Clarke 
> ---
> v4:
> - rebased to acme/perf/core
> - moved changes from "map" namespace to "symbol" namespace,
> - rewrote symbol__compare (now *match) to avoid need for strdup
> - new symbol__match_symbol_name to support versioned symbols, ignoring default
>tags
> - new arch__compare_symbol_names_n to map to strncmp
> - dso__find_symbol_by_name: now tries exact match (as before), then tries
> also adding symbols tagged as default (@@)
> - symbols__find_by_name: new parameter to support finding with or without 
> default
>tags
> - does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)
> 
> v3:
> - code style fixes per David Ahern
> 
> v2:
> - move logic from arch__compare_symbol_names to new map__compare_symbol_names
> - call through from map__compare_symbol_names to arch__compare_symbol_names
> - redirect uses of arch__compare_symbol_names
> - send patch to LKML
>   tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
>   tools/perf/util/map.c   |  5 ---
>   tools/perf/util/map.h   |  5 ++-
>   tools/perf/util/symbol.c| 62 
> +++--
>   tools/perf/util/symbol.h|  9 +
>   5 files changed, 73 insertions(+), 20 deletions(-)
> 
> diff --git a/tools/perf/arch/powerpc/util/sym-handling.c 
> b/tools/perf/arch/powerpc/util/sym-handling.c
> index 39dbe51..0d40e17 100644
> --- a/tools/perf/arch/powerpc/util/sym-handling.c
> +++ b/tools/perf/arch/powerpc/util/sym-handling.c
> @@ -52,6 +52,18 @@ int arch__compare_symbol_names(const char *namea, const 
> char *nameb)
>   
>   return strcmp(namea, nameb);
>   }
> +
> +int arch__compare_symbol_names_n(const char *namea, const char *nameb,
> + unsigned int n)
> +{
> + /* Skip over initial dot */
> + if (*namea == '.')
> + namea++;
> + if (*nameb == '.')
> + nameb++;
> +
> + return strncmp(namea, nameb, n);
> +}
>   #endif
>   
>   #if defined(_CALL_ELF) && _CALL_ELF == 2
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index c1870ac..f4d8272 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -325,11 +325,6 @@ int map__load(struct map *map)
>   return 0;
>   }
>   
> -int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
> -{
> - return strcmp(namea, nameb);
> -}
> -
>   struct symbol *map__find_symbol(struct map *map, u64 addr)
>   {
>   if (map__load(map) < 0)
> diff --git a/tools/perf/util/map.h

Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-06 Thread Paul Clarke 

On 04/06/2017 09:36 AM, Arnaldo Carvalho de Melo wrote:

Em Wed, Apr 05, 2017 at 10:30:03PM -0500, Paul Clarke escreveu:

Symbol versioning, as in glibc, results in symbols being defined as:
@[@]
(Note that "@@" identifies a default symbol, if the symbol name
is repeated.)

perf is currently unable to deal with this, and is unable to create
user probes at such symbols:
--
$ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
8d30 t __pthread_create_2_1
8d30 T pthread_create@@GLIBC_2.17
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
probe-definition(0): pthread_create
symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
Try to find probe point from debuginfo.
Probe point 'pthread_create' not found.
   Error: Failed to add events. Reason: No such file or directory (Code: -2)
--

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:
--
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create@@GLIBC_2.17
probe-definition(0): pthread_create@@GLIBC_2.17
Semantic error :SRC@SRC is not allowed.
0 arguments
   Error: Command Parse Error. Reason: Invalid argument (Code: -22)
--

This patch ignores the versioning tag for default symbols, thus
allowing probes to be created for these symbols:
--
$ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
Added new event:
   probe_libpthread:pthread_create (on pthread_create in 
/lib/powerpc64le-linux-gnu/libpthread-2.19.so)

You can now use it in all perf tools, such as:

 perf record -e probe_libpthread:pthread_create -aR sleep 1

$ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
$ /usr/bin/sudo ./perf script
 test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
(3fff99248d38)
 test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
(3fff99248d38)
$ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
Removed event: probe_libpthread:pthread_create
--

Signed-off-by: Paul A. Clarke 
---
v4:
- rebased to acme/perf/core
- moved changes from "map" namespace to "symbol" namespace,
- rewrote symbol__compare (now *match) to avoid need for strdup
- new symbol__match_symbol_name to support versioned symbols, ignoring default
  tags
- new arch__compare_symbol_names_n to map to strncmp
- dso__find_symbol_by_name: now tries exact match (as before), then tries
   also adding symbols tagged as default (@@)
- symbols__find_by_name: new parameter to support finding with or without 
default
  tags
- does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)

v3:
- code style fixes per David Ahern

v2:
- move logic from arch__compare_symbol_names to new map__compare_symbol_names
- call through from map__compare_symbol_names to arch__compare_symbol_names
- redirect uses of arch__compare_symbol_names
- send patch to LKML
 tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
 tools/perf/util/map.c   |  5 ---
 tools/perf/util/map.h   |  5 ++-
 tools/perf/util/symbol.c| 62 +++--
 tools/perf/util/symbol.h|  9 +
 5 files changed, 73 insertions(+), 20 deletions(-)

[...]

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 9b4d8ba..c29440d 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -87,6 +87,17 @@ static int prefix_underscores_count(const char *str)
return tail - str;
 }
+int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
+{
+   return strcmp(namea, nameb);
+}
+
+int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
+   unsigned int n)
+{
+   return strncmp(namea, nameb, n);
+}
+
 int __weak arch__choose_best_symbol(struct symbol *syma,
struct symbol *symb __maybe_unused)
 {
@@ -396,8 +407,26 @@ static void symbols__sort_by_name(struct rb_root *symbols,
}
 }
+int symbol__match_symbol_name(const char *name, const char *str,
+   int including_tags)
+{
+   const char *versioning;
+
+   if (including_tags == SYMBOLS__TAG_INCLUDE_DEFAULT_ONLY &&
+   (versioning = strstr(name,"@@"))) {
+
+   unsigned int len = strlen(str);
+   if (len < versioning - name)
+   len = versioning - name;
+
+   return arch__compare_symbol_names_n(name, str, len);
+   } else
+   return arch__compare_symbol_names(name, str);
+}
+
 static struct symbol

Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-06 Thread Paul Clarke 

On 04/06/2017 09:36 AM, Arnaldo Carvalho de Melo wrote:

Em Wed, Apr 05, 2017 at 10:30:03PM -0500, Paul Clarke escreveu:

Symbol versioning, as in glibc, results in symbols being defined as:
@[@]
(Note that "@@" identifies a default symbol, if the symbol name
is repeated.)

perf is currently unable to deal with this, and is unable to create
user probes at such symbols:
--
$ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
8d30 t __pthread_create_2_1
8d30 T pthread_create@@GLIBC_2.17
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
probe-definition(0): pthread_create
symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
Try to find probe point from debuginfo.
Probe point 'pthread_create' not found.
   Error: Failed to add events. Reason: No such file or directory (Code: -2)
--

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:
--
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create@@GLIBC_2.17
probe-definition(0): pthread_create@@GLIBC_2.17
Semantic error :SRC@SRC is not allowed.
0 arguments
   Error: Command Parse Error. Reason: Invalid argument (Code: -22)
--

This patch ignores the versioning tag for default symbols, thus
allowing probes to be created for these symbols:
--
$ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
Added new event:
   probe_libpthread:pthread_create (on pthread_create in 
/lib/powerpc64le-linux-gnu/libpthread-2.19.so)

You can now use it in all perf tools, such as:

 perf record -e probe_libpthread:pthread_create -aR sleep 1

$ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
$ /usr/bin/sudo ./perf script
 test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
(3fff99248d38)
 test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
(3fff99248d38)
$ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
Removed event: probe_libpthread:pthread_create
--

Signed-off-by: Paul A. Clarke 
---
v4:
- rebased to acme/perf/core
- moved changes from "map" namespace to "symbol" namespace,
- rewrote symbol__compare (now *match) to avoid need for strdup
- new symbol__match_symbol_name to support versioned symbols, ignoring default
  tags
- new arch__compare_symbol_names_n to map to strncmp
- dso__find_symbol_by_name: now tries exact match (as before), then tries
   also adding symbols tagged as default (@@)
- symbols__find_by_name: new parameter to support finding with or without 
default
  tags
- does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)

v3:
- code style fixes per David Ahern

v2:
- move logic from arch__compare_symbol_names to new map__compare_symbol_names
- call through from map__compare_symbol_names to arch__compare_symbol_names
- redirect uses of arch__compare_symbol_names
- send patch to LKML
 tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
 tools/perf/util/map.c   |  5 ---
 tools/perf/util/map.h   |  5 ++-
 tools/perf/util/symbol.c| 62 +++--
 tools/perf/util/symbol.h|  9 +
 5 files changed, 73 insertions(+), 20 deletions(-)

[...]

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 9b4d8ba..c29440d 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -87,6 +87,17 @@ static int prefix_underscores_count(const char *str)
return tail - str;
 }
+int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
+{
+   return strcmp(namea, nameb);
+}
+
+int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
+   unsigned int n)
+{
+   return strncmp(namea, nameb, n);
+}
+
 int __weak arch__choose_best_symbol(struct symbol *syma,
struct symbol *symb __maybe_unused)
 {
@@ -396,8 +407,26 @@ static void symbols__sort_by_name(struct rb_root *symbols,
}
 }
+int symbol__match_symbol_name(const char *name, const char *str,
+   int including_tags)
+{
+   const char *versioning;
+
+   if (including_tags == SYMBOLS__TAG_INCLUDE_DEFAULT_ONLY &&
+   (versioning = strstr(name,"@@"))) {
+
+   unsigned int len = strlen(str);
+   if (len < versioning - name)
+   len = versioning - name;
+
+   return arch__compare_symbol_names_n(name, str, len);
+   } else
+   return arch__compare_symbol_names(name, str);
+}
+
 static struct symbol *symbols__find_by_name(struct rb_root

Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-06 Thread Arnaldo Carvalho de Melo 
Em Wed, Apr 05, 2017 at 10:30:03PM -0500, Paul Clarke escreveu:
> Symbol versioning, as in glibc, results in symbols being defined as:
> @[@]
> (Note that "@@" identifies a default symbol, if the symbol name
> is repeated.)
> 
> perf is currently unable to deal with this, and is unable to create
> user probes at such symbols:
> --
> $ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
> 8d30 t __pthread_create_2_1
> 8d30 T pthread_create@@GLIBC_2.17
> $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create
> probe-definition(0): pthread_create
> symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
> 0 arguments
> Open Debuginfo file: 
> /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
> Try to find probe point from debuginfo.
> Probe point 'pthread_create' not found.
>Error: Failed to add events. Reason: No such file or directory (Code: -2)
> --
> 
> One is not able to specify the fully versioned symbol, either, due to
> syntactic conflicts with other uses of "@" by perf:
> --
> $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create@@GLIBC_2.17
> probe-definition(0): pthread_create@@GLIBC_2.17
> Semantic error :SRC@SRC is not allowed.
> 0 arguments
>Error: Command Parse Error. Reason: Invalid argument (Code: -22)
> --
> 
> This patch ignores the versioning tag for default symbols, thus
> allowing probes to be created for these symbols:
> --
> $ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create
> Added new event:
>probe_libpthread:pthread_create (on pthread_create in 
> /lib/powerpc64le-linux-gnu/libpthread-2.19.so)
> 
> You can now use it in all perf tools, such as:
> 
>  perf record -e probe_libpthread:pthread_create -aR sleep 1
> 
> $ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
> $ /usr/bin/sudo ./perf script
>  test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
> (3fff99248d38)
>  test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
> (3fff99248d38)
> $ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
> Removed event: probe_libpthread:pthread_create
> --
> 
> Signed-off-by: Paul A. Clarke 
> ---
> v4:
> - rebased to acme/perf/core
> - moved changes from "map" namespace to "symbol" namespace,
> - rewrote symbol__compare (now *match) to avoid need for strdup
> - new symbol__match_symbol_name to support versioned symbols, ignoring default
>   tags
> - new arch__compare_symbol_names_n to map to strncmp
> - dso__find_symbol_by_name: now tries exact match (as before), then tries
>also adding symbols tagged as default (@@)
> - symbols__find_by_name: new parameter to support finding with or without 
> default
>   tags
> - does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)
> 
> v3:
> - code style fixes per David Ahern
> 
> v2:
> - move logic from arch__compare_symbol_names to new map__compare_symbol_names
> - call through from map__compare_symbol_names to arch__compare_symbol_names
> - redirect uses of arch__compare_symbol_names
> - send patch to LKML
>  tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
>  tools/perf/util/map.c   |  5 ---
>  tools/perf/util/map.h   |  5 ++-
>  tools/perf/util/symbol.c| 62 
> +++--
>  tools/perf/util/symbol.h|  9 +
>  5 files changed, 73 insertions(+), 20 deletions(-)
> 
> diff --git a/tools/perf/arch/powerpc/util/sym-handling.c 
> b/tools/perf/arch/powerpc/util/sym-handling.c
> index 39dbe51..0d40e17 100644
> --- a/tools/perf/arch/powerpc/util/sym-handling.c
> +++ b/tools/perf/arch/powerpc/util/sym-handling.c
> @@ -52,6 +52,18 @@ int arch__compare_symbol_names(const char *namea, const 
> char *nameb)
>   return strcmp(namea, nameb);
>  }
> +
> +int arch__compare_symbol_names_n(const char *namea, const char *nameb,
> + unsigned int n)
> +{
> + /* Skip over initial dot */
> + if (*namea == '.')
> + namea++;
> + if (*nameb == '.')
> + nameb++;
> +
> + return strncmp(namea, nameb, n);
> +}
>  #endif
>  #if defined(_CALL_ELF) && _CALL_ELF == 2
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index c1870ac..f4d8272 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -325,11 +325,6 @@ int map__load(struct map *map)
>   return 0;
>  }
> -int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
> -{
> - return strcmp(namea, nameb);
> -}
> -
>  struct symbol *map__find_symbol(struct map *map, u64 addr)
>  {
>   if (map__load(map) < 0)
> diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
> index

Re: [PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-06 Thread Arnaldo Carvalho de Melo 
Em Wed, Apr 05, 2017 at 10:30:03PM -0500, Paul Clarke escreveu:
> Symbol versioning, as in glibc, results in symbols being defined as:
> @[@]
> (Note that "@@" identifies a default symbol, if the symbol name
> is repeated.)
> 
> perf is currently unable to deal with this, and is unable to create
> user probes at such symbols:
> --
> $ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
> 8d30 t __pthread_create_2_1
> 8d30 T pthread_create@@GLIBC_2.17
> $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create
> probe-definition(0): pthread_create
> symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
> 0 arguments
> Open Debuginfo file: 
> /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
> Try to find probe point from debuginfo.
> Probe point 'pthread_create' not found.
>Error: Failed to add events. Reason: No such file or directory (Code: -2)
> --
> 
> One is not able to specify the fully versioned symbol, either, due to
> syntactic conflicts with other uses of "@" by perf:
> --
> $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create@@GLIBC_2.17
> probe-definition(0): pthread_create@@GLIBC_2.17
> Semantic error :SRC@SRC is not allowed.
> 0 arguments
>Error: Command Parse Error. Reason: Invalid argument (Code: -22)
> --
> 
> This patch ignores the versioning tag for default symbols, thus
> allowing probes to be created for these symbols:
> --
> $ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
> pthread_create
> Added new event:
>probe_libpthread:pthread_create (on pthread_create in 
> /lib/powerpc64le-linux-gnu/libpthread-2.19.so)
> 
> You can now use it in all perf tools, such as:
> 
>  perf record -e probe_libpthread:pthread_create -aR sleep 1
> 
> $ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
> $ /usr/bin/sudo ./perf script
>  test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
> (3fff99248d38)
>  test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
> (3fff99248d38)
> $ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
> Removed event: probe_libpthread:pthread_create
> --
> 
> Signed-off-by: Paul A. Clarke 
> ---
> v4:
> - rebased to acme/perf/core
> - moved changes from "map" namespace to "symbol" namespace,
> - rewrote symbol__compare (now *match) to avoid need for strdup
> - new symbol__match_symbol_name to support versioned symbols, ignoring default
>   tags
> - new arch__compare_symbol_names_n to map to strncmp
> - dso__find_symbol_by_name: now tries exact match (as before), then tries
>also adding symbols tagged as default (@@)
> - symbols__find_by_name: new parameter to support finding with or without 
> default
>   tags
> - does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)
> 
> v3:
> - code style fixes per David Ahern
> 
> v2:
> - move logic from arch__compare_symbol_names to new map__compare_symbol_names
> - call through from map__compare_symbol_names to arch__compare_symbol_names
> - redirect uses of arch__compare_symbol_names
> - send patch to LKML
>  tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
>  tools/perf/util/map.c   |  5 ---
>  tools/perf/util/map.h   |  5 ++-
>  tools/perf/util/symbol.c| 62 
> +++--
>  tools/perf/util/symbol.h|  9 +
>  5 files changed, 73 insertions(+), 20 deletions(-)
> 
> diff --git a/tools/perf/arch/powerpc/util/sym-handling.c 
> b/tools/perf/arch/powerpc/util/sym-handling.c
> index 39dbe51..0d40e17 100644
> --- a/tools/perf/arch/powerpc/util/sym-handling.c
> +++ b/tools/perf/arch/powerpc/util/sym-handling.c
> @@ -52,6 +52,18 @@ int arch__compare_symbol_names(const char *namea, const 
> char *nameb)
>   return strcmp(namea, nameb);
>  }
> +
> +int arch__compare_symbol_names_n(const char *namea, const char *nameb,
> + unsigned int n)
> +{
> + /* Skip over initial dot */
> + if (*namea == '.')
> + namea++;
> + if (*nameb == '.')
> + nameb++;
> +
> + return strncmp(namea, nameb, n);
> +}
>  #endif
>  #if defined(_CALL_ELF) && _CALL_ELF == 2
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index c1870ac..f4d8272 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -325,11 +325,6 @@ int map__load(struct map *map)
>   return 0;
>  }
> -int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
> -{
> - return strcmp(namea, nameb);
> -}
> -
>  struct symbol *map__find_symbol(struct map *map, u64 addr)
>  {
>   if (map__load(map) < 0)
> diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
> index c8a5a64..325bbc8

[PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-05 Thread Paul Clarke 

Symbol versioning, as in glibc, results in symbols being defined as:
@[@]
(Note that "@@" identifies a default symbol, if the symbol name
is repeated.)

perf is currently unable to deal with this, and is unable to create
user probes at such symbols:
--
$ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
8d30 t __pthread_create_2_1
8d30 T pthread_create@@GLIBC_2.17
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
probe-definition(0): pthread_create
symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
Try to find probe point from debuginfo.
Probe point 'pthread_create' not found.
   Error: Failed to add events. Reason: No such file or directory (Code: -2)
--

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:
--
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create@@GLIBC_2.17
probe-definition(0): pthread_create@@GLIBC_2.17
Semantic error :SRC@SRC is not allowed.
0 arguments
   Error: Command Parse Error. Reason: Invalid argument (Code: -22)
--

This patch ignores the versioning tag for default symbols, thus
allowing probes to be created for these symbols:
--
$ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
Added new event:
   probe_libpthread:pthread_create (on pthread_create in 
/lib/powerpc64le-linux-gnu/libpthread-2.19.so)

You can now use it in all perf tools, such as:

 perf record -e probe_libpthread:pthread_create -aR sleep 1

$ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
$ /usr/bin/sudo ./perf script
 test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
(3fff99248d38)
 test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
(3fff99248d38)
$ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
Removed event: probe_libpthread:pthread_create
--

Signed-off-by: Paul A. Clarke 
---
v4:
- rebased to acme/perf/core
- moved changes from "map" namespace to "symbol" namespace,
- rewrote symbol__compare (now *match) to avoid need for strdup
- new symbol__match_symbol_name to support versioned symbols, ignoring default
  tags
- new arch__compare_symbol_names_n to map to strncmp
- dso__find_symbol_by_name: now tries exact match (as before), then tries
   also adding symbols tagged as default (@@)
- symbols__find_by_name: new parameter to support finding with or without 
default
  tags
- does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)

v3:
- code style fixes per David Ahern

v2:
- move logic from arch__compare_symbol_names to new map__compare_symbol_names
- call through from map__compare_symbol_names to arch__compare_symbol_names
- redirect uses of arch__compare_symbol_names
- send patch to LKML
 tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
 tools/perf/util/map.c   |  5 ---
 tools/perf/util/map.h   |  5 ++-
 tools/perf/util/symbol.c| 62 +++--
 tools/perf/util/symbol.h|  9 +
 5 files changed, 73 insertions(+), 20 deletions(-)

diff --git a/tools/perf/arch/powerpc/util/sym-handling.c 
b/tools/perf/arch/powerpc/util/sym-handling.c
index 39dbe51..0d40e17 100644
--- a/tools/perf/arch/powerpc/util/sym-handling.c
+++ b/tools/perf/arch/powerpc/util/sym-handling.c
@@ -52,6 +52,18 @@ int arch__compare_symbol_names(const char *namea, const char 
*nameb)
 
 	return strcmp(namea, nameb);

 }
+
+int arch__compare_symbol_names_n(const char *namea, const char *nameb,
+   unsigned int n)
+{
+   /* Skip over initial dot */
+   if (*namea == '.')
+   namea++;
+   if (*nameb == '.')
+   nameb++;
+
+   return strncmp(namea, nameb, n);
+}
 #endif
 
 #if defined(_CALL_ELF) && _CALL_ELF == 2

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index c1870ac..f4d8272 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -325,11 +325,6 @@ int map__load(struct map *map)
return 0;
 }
 
-int __weak arch__compare_symbol_names(const char *namea, const char *nameb)

-{
-   return strcmp(namea, nameb);
-}
-
 struct symbol *map__find_symbol(struct map *map, u64 addr)
 {
if (map__load(map) < 0)
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index c8a5a64..325bbc8 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -130,13 +130,14 @@ struct thread;
  */
 #define __map__for_each_symbol_by_name(map, sym_name, pos) \
for (pos = map__find_symbol_by_name(map, sym_name); \
-pos &&

[PATCH v4] tools/perf: Allow user probes on versioned symbols

2017-04-05 Thread Paul Clarke 

Symbol versioning, as in glibc, results in symbols being defined as:
@[@]
(Note that "@@" identifies a default symbol, if the symbol name
is repeated.)

perf is currently unable to deal with this, and is unable to create
user probes at such symbols:
--
$ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
8d30 t __pthread_create_2_1
8d30 T pthread_create@@GLIBC_2.17
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
probe-definition(0): pthread_create
symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
Try to find probe point from debuginfo.
Probe point 'pthread_create' not found.
   Error: Failed to add events. Reason: No such file or directory (Code: -2)
--

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:
--
$ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create@@GLIBC_2.17
probe-definition(0): pthread_create@@GLIBC_2.17
Semantic error :SRC@SRC is not allowed.
0 arguments
   Error: Command Parse Error. Reason: Invalid argument (Code: -22)
--

This patch ignores the versioning tag for default symbols, thus
allowing probes to be created for these symbols:
--
$ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 
pthread_create
Added new event:
   probe_libpthread:pthread_create (on pthread_create in 
/lib/powerpc64le-linux-gnu/libpthread-2.19.so)

You can now use it in all perf tools, such as:

 perf record -e probe_libpthread:pthread_create -aR sleep 1

$ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
$ /usr/bin/sudo ./perf script
 test  2915 [000] 19124.260729: probe_libpthread:pthread_create: 
(3fff99248d38)
 test  2916 [000] 19124.260962: probe_libpthread:pthread_create: 
(3fff99248d38)
$ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
Removed event: probe_libpthread:pthread_create
--

Signed-off-by: Paul A. Clarke 
---
v4:
- rebased to acme/perf/core
- moved changes from "map" namespace to "symbol" namespace,
- rewrote symbol__compare (now *match) to avoid need for strdup
- new symbol__match_symbol_name to support versioned symbols, ignoring default
  tags
- new arch__compare_symbol_names_n to map to strncmp
- dso__find_symbol_by_name: now tries exact match (as before), then tries
   also adding symbols tagged as default (@@)
- symbols__find_by_name: new parameter to support finding with or without 
default
  tags
- does NOT handle setting probes using the tagged symbol name (symbol@[@]tag)

v3:
- code style fixes per David Ahern

v2:
- move logic from arch__compare_symbol_names to new map__compare_symbol_names
- call through from map__compare_symbol_names to arch__compare_symbol_names
- redirect uses of arch__compare_symbol_names
- send patch to LKML
 tools/perf/arch/powerpc/util/sym-handling.c | 12 ++
 tools/perf/util/map.c   |  5 ---
 tools/perf/util/map.h   |  5 ++-
 tools/perf/util/symbol.c| 62 +++--
 tools/perf/util/symbol.h|  9 +
 5 files changed, 73 insertions(+), 20 deletions(-)

diff --git a/tools/perf/arch/powerpc/util/sym-handling.c 
b/tools/perf/arch/powerpc/util/sym-handling.c
index 39dbe51..0d40e17 100644
--- a/tools/perf/arch/powerpc/util/sym-handling.c
+++ b/tools/perf/arch/powerpc/util/sym-handling.c
@@ -52,6 +52,18 @@ int arch__compare_symbol_names(const char *namea, const char 
*nameb)
 
 	return strcmp(namea, nameb);

 }
+
+int arch__compare_symbol_names_n(const char *namea, const char *nameb,
+   unsigned int n)
+{
+   /* Skip over initial dot */
+   if (*namea == '.')
+   namea++;
+   if (*nameb == '.')
+   nameb++;
+
+   return strncmp(namea, nameb, n);
+}
 #endif
 
 #if defined(_CALL_ELF) && _CALL_ELF == 2

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index c1870ac..f4d8272 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -325,11 +325,6 @@ int map__load(struct map *map)
return 0;
 }
 
-int __weak arch__compare_symbol_names(const char *namea, const char *nameb)

-{
-   return strcmp(namea, nameb);
-}
-
 struct symbol *map__find_symbol(struct map *map, u64 addr)
 {
if (map__load(map) < 0)
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index c8a5a64..325bbc8 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -130,13 +130,14 @@ struct thread;
  */
 #define __map__for_each_symbol_by_name(map, sym_name, pos) \
for (pos = map__find_symbol_by_name(map, sym_name); \
-pos && arch__compare_symbol_names(pos->name,