Em Mon, Oct 07, 2013 at 12:53:40PM +0900, Masami Hiramatsu escreveu: > Ping? :)
I'll send a perf/urgent pull req later today, this patch is there. - Arnaldo > (2013/09/30 18:21), Masami Hiramatsu wrote: > > Fix to find the correct (as much as possible) line information > > for listing probes. Without this fix, perf probe --list action > > will show incorrect line information as below; > > > > # perf probe getname_flags > > # perf probe -l > > probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c) > > probe:getname_flags_1 (on getname:-89@x86/include/asm/current.h) > > probe:getname_flags_2 (on > > user_path_at_empty:-2054@x86/include/asm/current.h) > > > > The minus line number is obviously wrong, and current.h is not > > related to the probe point. Deeper investigation discovered > > that there were 2 issues related to this bug, and minor typos too. > > > > 1st issue is the rack of considering about nested inlined > > functions, which causes the wrong (relative) line number. > > 2nd issue is that the dwarf line info is not correct at > > those points. It points 14th line of current.h. > > > > Since it seems that the line info includes somewhat unreliable > > information, this fixes perf to try to find correct line information > > from both of debuginfo and line info as below. > > > > 1) Probe address is the entry of a function instance > > In this case, the line is set as the function declared line. > > > > 2) Probe address is the entry of an expanded inline function block > > In this case, the line is set as the function call-site line. > > This means that the line number is relative from the entry line > > of caller function (which can be an inlined function if nested) > > > > 3) Probe address is inside a function instance or an expanded > > inline function block > > In this case, perf probe queries the line number from lineinfo > > and verify the function declared file is same as the file name > > queried from lineinfo. > > If the file name is different, it is a failure case. The probe > > address is shown as symbol+offset. > > > > 4) Probe address is not in the any function instance > > This is a failure case, the probe address is shown as > > symbol+offset. > > > > With this fix, perf probe -l shows correct probe lines as below; > > > > # perf probe -l > > probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c) > > probe:getname_flags_1 (on getname:2@ksrc/linux-3/fs/namei.c) > > probe:getname_flags_2 (on user_path_at_empty:4@ksrc/linux-3/fs/namei.c) > > > > Changes at v2: > > - Fix typos in the function comments. (Thanks to Namhyung Kim) > > - Use die_find_top_inlinefunc instead of die_find_inlinefunc_next. > > > > Signed-off-by: Masami Hiramatsu <[email protected]> > > Cc: Peter Zijlstra <[email protected]> > > Cc: Paul Mackerras <[email protected]> > > Cc: Ingo Molnar <[email protected]> > > Cc: Arnaldo Carvalho de Melo <[email protected]> > > Cc: Namhyung Kim <[email protected]> > > --- > > tools/perf/util/dwarf-aux.c | 25 +++++++++++++++++--- > > tools/perf/util/dwarf-aux.h | 6 ++++- > > tools/perf/util/probe-finder.c | 49 > > +++++++++++++++++++++++++++------------- > > 3 files changed, 59 insertions(+), 21 deletions(-) > > > > diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c > > index e23bde1..7defd77 100644 > > --- a/tools/perf/util/dwarf-aux.c > > +++ b/tools/perf/util/dwarf-aux.c > > @@ -426,7 +426,7 @@ static int __die_search_func_cb(Dwarf_Die *fn_die, void > > *data) > > * @die_mem: a buffer for result DIE > > * > > * Search a non-inlined function DIE which includes @addr. Stores the > > - * DIE to @die_mem and returns it if found. Returns NULl if failed. > > + * DIE to @die_mem and returns it if found. Returns NULL if failed. > > */ > > Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, > > Dwarf_Die *die_mem) > > @@ -454,15 +454,32 @@ static int __die_find_inline_cb(Dwarf_Die *die_mem, > > void *data) > > } > > > > /** > > + * die_find_top_inlinefunc - Search the top inlined function at given > > address > > + * @sp_die: a subprogram DIE which including @addr > > + * @addr: target address > > + * @die_mem: a buffer for result DIE > > + * > > + * Search an inlined function DIE which includes @addr. Stores the > > + * DIE to @die_mem and returns it if found. Returns NULL if failed. > > + * Even if several inlined functions are expanded recursively, this > > + * doesn't trace it down, and returns the topmost one. > > + */ > > +Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, > > + Dwarf_Die *die_mem) > > +{ > > + return die_find_child(sp_die, __die_find_inline_cb, &addr, die_mem); > > +} > > + > > +/** > > * die_find_inlinefunc - Search an inlined function at given address > > - * @cu_die: a CU DIE which including @addr > > + * @sp_die: a subprogram DIE which including @addr > > * @addr: target address > > * @die_mem: a buffer for result DIE > > * > > * Search an inlined function DIE which includes @addr. Stores the > > - * DIE to @die_mem and returns it if found. Returns NULl if failed. > > + * DIE to @die_mem and returns it if found. Returns NULL if failed. > > * If several inlined functions are expanded recursively, this trace > > - * it and returns deepest one. > > + * it down and returns deepest one. > > */ > > Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, > > Dwarf_Die *die_mem) > > diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h > > index 8658d41..b4fe90c 100644 > > --- a/tools/perf/util/dwarf-aux.h > > +++ b/tools/perf/util/dwarf-aux.h > > @@ -79,7 +79,11 @@ extern Dwarf_Die *die_find_child(Dwarf_Die *rt_die, > > extern Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr, > > Dwarf_Die *die_mem); > > > > -/* Search an inlined function including given address */ > > +/* Search the top inlined function including given address */ > > +extern Dwarf_Die *die_find_top_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr > > addr, > > + Dwarf_Die *die_mem); > > + > > +/* Search the deepest inlined function including given address */ > > extern Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr, > > Dwarf_Die *die_mem); > > > > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c > > index 371476c..c09e0a9 100644 > > --- a/tools/perf/util/probe-finder.c > > +++ b/tools/perf/util/probe-finder.c > > @@ -1327,8 +1327,8 @@ int debuginfo__find_probe_point(struct debuginfo > > *self, unsigned long addr, > > struct perf_probe_point *ppt) > > { > > Dwarf_Die cudie, spdie, indie; > > - Dwarf_Addr _addr, baseaddr; > > - const char *fname = NULL, *func = NULL, *tmp; > > + Dwarf_Addr _addr = 0, baseaddr = 0; > > + const char *fname = NULL, *func = NULL, *basefunc = NULL, *tmp; > > int baseline = 0, lineno = 0, ret = 0; > > > > /* Adjust address with bias */ > > @@ -1349,27 +1349,36 @@ int debuginfo__find_probe_point(struct debuginfo > > *self, unsigned long addr, > > /* Find a corresponding function (name, baseline and baseaddr) */ > > if (die_find_realfunc(&cudie, (Dwarf_Addr)addr, &spdie)) { > > /* Get function entry information */ > > - tmp = dwarf_diename(&spdie); > > - if (!tmp || > > + func = basefunc = dwarf_diename(&spdie); > > + if (!func || > > dwarf_entrypc(&spdie, &baseaddr) != 0 || > > - dwarf_decl_line(&spdie, &baseline) != 0) > > + dwarf_decl_line(&spdie, &baseline) != 0) { > > + lineno = 0; > > goto post; > > - func = tmp; > > + } > > > > - if (addr == (unsigned long)baseaddr) > > + if (addr == (unsigned long)baseaddr) { > > /* Function entry - Relative line number is 0 */ > > lineno = baseline; > > - else if (die_find_inlinefunc(&spdie, (Dwarf_Addr)addr, > > - &indie)) { > > + fname = dwarf_decl_file(&spdie); > > + goto post; > > + } > > + > > + /* Track down the inline functions step by step */ > > + while (die_find_top_inlinefunc(&spdie, (Dwarf_Addr)addr, > > + &indie)) { > > + /* There is an inline function */ > > if (dwarf_entrypc(&indie, &_addr) == 0 && > > - _addr == addr) > > + _addr == addr) { > > /* > > * addr is at an inline function entry. > > * In this case, lineno should be the call-site > > - * line number. > > + * line number. (overwrite lineinfo) > > */ > > lineno = die_get_call_lineno(&indie); > > - else { > > + fname = die_get_call_file(&indie); > > + break; > > + } else { > > /* > > * addr is in an inline function body. > > * Since lineno points one of the lines > > @@ -1377,19 +1386,27 @@ int debuginfo__find_probe_point(struct debuginfo > > *self, unsigned long addr, > > * be the entry line of the inline function. > > */ > > tmp = dwarf_diename(&indie); > > - if (tmp && > > - dwarf_decl_line(&spdie, &baseline) == 0) > > - func = tmp; > > + if (!tmp || > > + dwarf_decl_line(&indie, &baseline) != 0) > > + break; > > + func = tmp; > > + spdie = indie; > > } > > } > > + /* Verify the lineno and baseline are in a same file */ > > + tmp = dwarf_decl_file(&spdie); > > + if (!tmp || strcmp(tmp, fname) != 0) > > + lineno = 0; > > } > > > > post: > > /* Make a relative line number or an offset */ > > if (lineno) > > ppt->line = lineno - baseline; > > - else if (func) > > + else if (basefunc) { > > ppt->offset = addr - (unsigned long)baseaddr; > > + func = basefunc; > > + } > > > > /* Duplicate strings */ > > if (func) { > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to [email protected] > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > > > > -- > Masami HIRAMATSU > IT Management Research Dept. Linux Technology Center > Hitachi, Ltd., Yokohama Research Laboratory > E-mail: [email protected] > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
