Messages in this thread | | | Date | Wed, 24 Nov 2010 12:11:29 -0200 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 2/2] perf:tools: figure out start address of kernel map from /proc/kallsyms |
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Em Wed, Nov 24, 2010 at 07:35:33PM +0800, tom.leiming@gmail.com escreveu: > From: Ming Lei <tom.leiming@gmail.com> > > On ARM, module symbol start address is ahead of kernel symbol start > address, so we can't suppose that the start address of kenerl map > always is zero, otherwise may cause incorrect .start and .end of kernel map > (caused by fixup) when there are modules loaded, then map_groups__find > may return incorrect map for symbol query. > > This patch always figures out the start address of kernel map from > /proc/kallsyms if the file is available, so fix the issues on ARM for > module loaded case. > > This patch fixes the following issues on ARM when modules are loaded: > > - vmlinux symbol can't be found by kallsyms maps doing 'perf test' > - module symbols are parsed mistakenlly when doing 'perf top'/'perf report' > > Cc: Ian Munsie <imunsie@au1.ibm.com> > Cc: Ingo Molnar <mingo@elte.hu> > Cc: Paul Mackerras <paulus@samba.org> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Tom Zanussi <tzanussi@gmail.com> > Signed-off-by: Ming Lei <tom.leiming@gmail.com> > --- > tools/perf/util/symbol.c | 60 +++++++++++++++++++++++++++++++++++++++++++++- > 1 files changed, 59 insertions(+), 1 deletions(-) > > diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c > index c5b4ccb..1a8895c 100644 > --- a/tools/perf/util/symbol.c > +++ b/tools/perf/util/symbol.c > @@ -2183,14 +2183,72 @@ static struct dso *machine__create_kernel(struct machine *self) > return kernel; > } > > +/*figure out the start address of kernel map from /proc/kallsyms*/ > +static u64 __machine_get_kernel_start_addr(struct machine *self) > +{ > + char *line = NULL; > + size_t n; > + u64 start_addr = 0; > + FILE *file; > + const char *filename; > + char path[PATH_MAX]; > + > + if (machine__is_default_guest(self)) { > + filename = symbol_conf.default_guest_kallsyms; > + if (!filename) > + goto out_failure; > + } else { > + sprintf(path, "%s/proc/kallsyms", self->root_dir); > + filename = path; > + } > + > + file = fopen(filename, "r");
Can you please use kallsyms__parse()? Please take a look at event__synthesize_kernel_mmap as it also uses it.
> + if (file == NULL) > + goto out_failure; > + > + while (!feof(file)) { > + u64 start = 0; > + int line_len, len; > + > + line_len = getline(&line, &n, file); > + if (line_len < 0 || !line) > + break; > + > + line[--line_len] = '\0'; /* \n */ > + > + /*if the line is for module symbol, skip it*/ > + if (strchr(line, '[')) > + continue; > + > + len = hex2u64(line, &start); > + > + len++; > + if (len + 2 >= line_len) > + continue; > + > + start_addr = start; > + break; > + } > + > + free(line); > + fclose(file);
Out failure could be here, avoiding one return case.
> + return start_addr; > + > +out_failure: > + return start_addr; > +} > + > int __machine__create_kernel_maps(struct machine *self, struct dso *kernel) > { > enum map_type type; > + u64 start; > > + start = __machine_get_kernel_start_addr(self); > for (type = 0; type < MAP__NR_TYPES; ++type) { > struct kmap *kmap; > > - self->vmlinux_maps[type] = map__new2(0, kernel, type); > + self->vmlinux_maps[type] = map__new2(start, kernel, type); > if (self->vmlinux_maps[type] == NULL) > return -1; > > -- > 1.7.3
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