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Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old
- From: Arnaldo Carvalho de Melo <acme at infradead dot org>
- To: Masami Hiramatsu <mhiramat at redhat dot com>
- Cc: Ingo Molnar <mingo at elte dot hu>, lkml <linux-kernel at vger dot kernel dot org>, Robert Richter <robert dot richter at amd dot com>, systemtap <systemtap at sources dot redhat dot com>, Roland McGrath <roland at redhat dot com>, DLE <dle-develop at lists dot sourceforge dot net>
- Date: Mon, 10 May 2010 14:28:54 -0300
- Subject: Re: [PATCH -tip] perf probe: Don't compile CFI related code if elfutils is old
- References: <20100510171207.26029.97604.stgit@localhost6.localdomain6>
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