Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old

Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old

[Arnaldo Carvalho de Melo]

Em Mon, May 10, 2010 at 01:12:07PM -0400, Masami Hiramatsu escreveu:
> Check elfutils version, and if it is old don't compile
> CFI analysis code. This allows to compile perf with
> old elfutils.

_ELFUTILS_PREREQ was introduced in:

commit fbc7245df72ce0142f0a21fa0f4f88c97278bf60
Author: Roland McGrath <roland@redhat.com>
Date:   Tue Dec 16 17:03:03 2008 -0800

Which was released in elfutils 0.138, guess this is coverage enough?
Richard, which version is in your machine?

- Arnaldo
 
> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
> Reported-by: Robert Richter <robert.richter@amd.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> ---
> 
>  tools/perf/util/probe-finder.c |    4 ++++
>  tools/perf/util/probe-finder.h |    3 +++
>  2 files changed, 7 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> index 562b144..93583eb 100644
> --- a/tools/perf/util/probe-finder.c
> +++ b/tools/perf/util/probe-finder.c
> @@ -668,6 +668,7 @@ static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
>  	ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
>  	if (ret <= 0 || nops == 0) {
>  		pf->fb_ops = NULL;
> +#if _ELFUTILS_PREREQ(0, 142)
>  	} else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
>  		   pf->cfi != NULL) {
>  		Dwarf_Frame *frame;
> @@ -677,6 +678,7 @@ static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
>  				   (uintmax_t)pf->addr);
>  			return -ENOENT;
>  		}
> +#endif
>  	}
>  
>  	/* Find each argument */
> @@ -956,8 +958,10 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
>  		return -EBADF;
>  	}
>  
> +#if _ELFUTILS_PREREQ(0, 142)
>  	/* Get the call frame information from this dwarf */
>  	pf.cfi = dwarf_getcfi(dbg);
> +#endif
>  
>  	off = 0;
>  	line_list__init(&pf.lcache);
> diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
> index 66f1980..e1f61dc 100644
> --- a/tools/perf/util/probe-finder.h
> +++ b/tools/perf/util/probe-finder.h
> @@ -29,6 +29,7 @@ extern int find_line_range(int fd, struct line_range *lr);
>  
>  #include <dwarf.h>
>  #include <libdw.h>
> +#include <version.h>
>  
>  struct probe_finder {
>  	struct perf_probe_event	*pev;		/* Target probe event */
> @@ -44,7 +45,9 @@ struct probe_finder {
>  	struct list_head	lcache;		/* Line cache for lazy match */
>  
>  	/* For variable searching */
> +#if _ELFUTILS_PREREQ(0, 142)
>  	Dwarf_CFI		*cfi;		/* Call Frame Information */
> +#endif
>  	Dwarf_Op		*fb_ops;	/* Frame base attribute */
>  	struct perf_probe_arg	*pvar;		/* Current target variable */
>  	struct kprobe_trace_arg	*tvar;		/* Current result variable */
> 
> 
> -- 
> Masami Hiramatsu
> e-mail: mhiramat@redhat.com

[PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old

[Masami Hiramatsu]

Check elfutils version, and if it is old don't compile
CFI analysis code. This allows to compile perf with
old elfutils.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Reported-by: Robert Richter <robert.richter@amd.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
---

 tools/perf/util/probe-finder.c |    4 ++++
 tools/perf/util/probe-finder.h |    3 +++
 2 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 562b144..93583eb 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -668,6 +668,7 @@ static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
 	ret = dwarf_getlocation_addr(&fb_attr, pf->addr, &pf->fb_ops, &nops, 1);
 	if (ret <= 0 || nops == 0) {
 		pf->fb_ops = NULL;
+#if _ELFUTILS_PREREQ(0, 142)
 	} else if (nops == 1 && pf->fb_ops[0].atom == DW_OP_call_frame_cfa &&
 		   pf->cfi != NULL) {
 		Dwarf_Frame *frame;
@@ -677,6 +678,7 @@ static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf)
 				   (uintmax_t)pf->addr);
 			return -ENOENT;
 		}
+#endif
 	}
 
 	/* Find each argument */
@@ -956,8 +958,10 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
 		return -EBADF;
 	}
 
+#if _ELFUTILS_PREREQ(0, 142)
 	/* Get the call frame information from this dwarf */
 	pf.cfi = dwarf_getcfi(dbg);
+#endif
 
 	off = 0;
 	line_list__init(&pf.lcache);
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index 66f1980..e1f61dc 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -29,6 +29,7 @@ extern int find_line_range(int fd, struct line_range *lr);
 
 #include <dwarf.h>
 #include <libdw.h>
+#include <version.h>
 
 struct probe_finder {
 	struct perf_probe_event	*pev;		/* Target probe event */
@@ -44,7 +45,9 @@ struct probe_finder {
 	struct list_head	lcache;		/* Line cache for lazy match */
 
 	/* For variable searching */
+#if _ELFUTILS_PREREQ(0, 142)
 	Dwarf_CFI		*cfi;		/* Call Frame Information */
+#endif
 	Dwarf_Op		*fb_ops;	/* Frame base attribute */
 	struct perf_probe_arg	*pvar;		/* Current target variable */
 	struct kprobe_trace_arg	*tvar;		/* Current result variable */


-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old

[Robert Richter]

On 10.05.10 13:28:54, Arnaldo Carvalho de Melo wrote:
> Em Mon, May 10, 2010 at 01:12:07PM -0400, Masami Hiramatsu escreveu:
> > Check elfutils version, and if it is old don't compile
> > CFI analysis code. This allows to compile perf with
> > old elfutils.
> 
> _ELFUTILS_PREREQ was introduced in:
> 
> commit fbc7245df72ce0142f0a21fa0f4f88c97278bf60
> Author: Roland McGrath <roland@redhat.com>
> Date:   Tue Dec 16 17:03:03 2008 -0800
> 
> Which was released in elfutils 0.138, guess this is coverage enough?
> Richard, which version is in your machine?

Right, this does not work, I am using 0.131. As expected,
"_ELFUTILS_PREREQ" is not defined:

gcc -o builtin-probe.o -c -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Wformat-y2k -Wshadow -Winit-self -Wpacked -Wredundant-decls -Wstack-protector -Wstrict-aliasing=3 -Wswitch-default -Wswitch-enum -Wno-system-headers -Wundef -Wvolatile-register-var -Wwrite-strings -Wbad-function-cast -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wstrict-prototypes -Wdeclaration-after-statement  -fstack-protector-all -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Iutil/include -Iarch/x86/include -I/usr/include/elfutils -DDWARF_SUPPORT -DNO_NEWT_SUPPORT -DNO_LIBPERL -DSHA1_HEADER='<openssl/sha.h>'  builtin-probe.c
In file included from builtin-probe.c:43:
util/probe-finder.h:47:5: error: "_ELFUTILS_PREREQ" is not defined
util/probe-finder.h:47:21: error: missing binary operator before token "("
make: *** [builtin-probe.o] Error 1

Why not create a compile test as for NO_DWARF in tools/perf/Makefile?

-Robert

-- 
Advanced Micro Devices, Inc.
Operating System Research Center
email: robert.richter@amd.com

Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old

[Masami Hiramatsu]

Robert Richter wrote:
> On 10.05.10 13:28:54, Arnaldo Carvalho de Melo wrote:
>> Em Mon, May 10, 2010 at 01:12:07PM -0400, Masami Hiramatsu escreveu:
>>> Check elfutils version, and if it is old don't compile
>>> CFI analysis code. This allows to compile perf with
>>> old elfutils.
>>
>> _ELFUTILS_PREREQ was introduced in:
>>
>> commit fbc7245df72ce0142f0a21fa0f4f88c97278bf60
>> Author: Roland McGrath <roland@redhat.com>
>> Date:   Tue Dec 16 17:03:03 2008 -0800
>>
>> Which was released in elfutils 0.138, guess this is coverage enough?
>> Richard, which version is in your machine?
> 
> Right, this does not work, I am using 0.131. As expected,
> "_ELFUTILS_PREREQ" is not defined:
> 
> gcc -o builtin-probe.o -c -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Wformat-y2k -Wshadow -Winit-self -Wpacked -Wredundant-decls -Wstack-protector -Wstrict-aliasing=3 -Wswitch-default -Wswitch-enum -Wno-system-headers -Wundef -Wvolatile-register-var -Wwrite-strings -Wbad-function-cast -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wstrict-prototypes -Wdeclaration-after-statement  -fstack-protector-all -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Iutil/include -Iarch/x86/include -I/usr/include/elfutils -DDWARF_SUPPORT -DNO_NEWT_SUPPORT -DNO_LIBPERL -DSHA1_HEADER='<openssl/sha.h>'  builtin-probe.c
> In file included from builtin-probe.c:43:
> util/probe-finder.h:47:5: error: "_ELFUTILS_PREREQ" is not defined
> util/probe-finder.h:47:21: error: missing binary operator before token "("
> make: *** [builtin-probe.o] Error 1
> 
> Why not create a compile test as for NO_DWARF in tools/perf/Makefile?

Hmm, ok, version.h is also introduced at the same time.

# git log ./config/version.h.in
commit fbc7245df72ce0142f0a21fa0f4f88c97278bf60
Author: Roland McGrath <roland@redhat.com>
Date:   Tue Dec 16 17:03:03 2008 -0800

    Install elfutils/version.h header for library compatibility checking.

So, I think we'd better set NO_DWARF if the elfutils
is older than 0.138, since we can't check API compatibility
easily.

Thank you,

-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old

[Arnaldo Carvalho de Melo]

Em Mon, May 10, 2010 at 08:36:54PM +0200, Robert Richter escreveu:
> On 10.05.10 13:28:54, Arnaldo Carvalho de Melo wrote:
> > Em Mon, May 10, 2010 at 01:12:07PM -0400, Masami Hiramatsu escreveu:
> > > Check elfutils version, and if it is old don't compile CFI
> > > analysis code. This allows to compile perf with old elfutils.

> > _ELFUTILS_PREREQ was introduced in:

> > commit fbc7245df72ce0142f0a21fa0f4f88c97278bf60
> > Author: Roland McGrath <roland@redhat.com>
> > Date:   Tue Dec 16 17:03:03 2008 -0800

> > Which was released in elfutils 0.138, guess this is coverage enough?
> > Richard, which version is in your machine?

> Right, this does not work, I am using 0.131. As expected,
> "_ELFUTILS_PREREQ" is not defined:

> util/probe-finder.h:47:5: error: "_ELFUTILS_PREREQ" is not defined
> util/probe-finder.h:47:21: error: missing binary operator before token "("
> make: *** [builtin-probe.o] Error 1

> Why not create a compile test as for NO_DWARF in tools/perf/Makefile?

Right, that would be better.

- Arnaldo

Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old

[Arnaldo Carvalho de Melo]

Em Mon, May 10, 2010 at 02:57:34PM -0400, Masami Hiramatsu escreveu:
> Hmm, ok, version.h is also introduced at the same time.
> 
> # git log ./config/version.h.in
> commit fbc7245df72ce0142f0a21fa0f4f88c97278bf60
> Author: Roland McGrath <roland@redhat.com>
> Date:   Tue Dec 16 17:03:03 2008 -0800
> 
>     Install elfutils/version.h header for library compatibility checking.
> 
> So, I think we'd better set NO_DWARF if the elfutils
> is older than 0.138, since we can't check API compatibility
> easily.

Well, for that you can just add some of the code you ifdefed in this
patch into the tools/perf/Makefile test, or better, duplicate the test,
including just the CPI stuff in the new test, and then set NO_DWARF_CFI
and use it as the ifdef condition :-)

- Arnaldo

Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old

[Masami Hiramatsu]

Arnaldo Carvalho de Melo wrote:
> Em Mon, May 10, 2010 at 02:57:34PM -0400, Masami Hiramatsu escreveu:
>> Hmm, ok, version.h is also introduced at the same time.
>>
>> # git log ./config/version.h.in
>> commit fbc7245df72ce0142f0a21fa0f4f88c97278bf60
>> Author: Roland McGrath <roland@redhat.com>
>> Date:   Tue Dec 16 17:03:03 2008 -0800
>>
>>     Install elfutils/version.h header for library compatibility checking.
>>
>> So, I think we'd better set NO_DWARF if the elfutils
>> is older than 0.138, since we can't check API compatibility
>> easily.
> 
> Well, for that you can just add some of the code you ifdefed in this
> patch into the tools/perf/Makefile test, or better, duplicate the test,
> including just the CPI stuff in the new test, and then set NO_DWARF_CFI
> and use it as the ifdef condition :-)

Hm, I'd like to add just '#ifndef _ELFUTILS_PREREQ;#error;#endif' to
NO_DWARF checking in Makefile, because it's easier to expand to another
API dependency.

Thank you,

-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

[PATCH -tip] perf probe: Check older elfutils and set NO_DWARF

[Masami Hiramatsu]

Check whether elfutils is older than 0.138 (from which version checking
routine has been introduced). And if so, set NO_DWARF because it is hard
to check the API dependency without version checking.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Reported-by: Robert Richter <robert.richter@amd.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
---

 tools/perf/Makefile |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 0ef5cfe..b28bb73 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -506,8 +506,8 @@ PERFLIBS = $(LIB_FILE)
 -include config.mak
 
 ifndef NO_DWARF
-ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
-	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/libdw-dev);
+ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo '\#include <version.h>'; echo '\#ifndef _ELFUTILS_PREREQ'; echo '\#error'; echo '\#endif'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
+	msg := $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev);
 	NO_DWARF := 1
 endif # Dwarf support
 endif # NO_DWARF


-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old

[Mark Wielaard]

On Mon, 2010-05-10 at 15:19 -0400, Masami Hiramatsu wrote:
> Hm, I'd like to add just '#ifndef _ELFUTILS_PREREQ;#error;#endif' to
> NO_DWARF checking in Makefile, because it's easier to expand to another
> API dependency.

You might want to check systemtap/dwarf-wrappers.h which handles missing
_ELFUTILS_PREREQ, so you can use it as if it is always defined. That
said, 0.138 is pretty old (latest is 0.147), so just requiring something
fresh might not be a bad thing.

Cheers,

Mark

Re: [PATCH -tip] perf probe: Check older elfutils and set NO_DWARF

[Robert Richter]

On 11.05.10 00:59:53, Masami Hiramatsu wrote:
> Check whether elfutils is older than 0.138 (from which version checking
> routine has been introduced). And if so, set NO_DWARF because it is hard
> to check the API dependency without version checking.

This works for me, now the DWARF_SUPPORT macro is undefined and a
warning is generated:

Makefile:510: No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev

Thanks,

-Robert

-- 
Advanced Micro Devices, Inc.
Operating System Research Center
email: robert.richter@amd.com