Messages in this thread | | | Date | Wed, 31 Jul 2013 00:12:15 +0300 | From | Adrian Hunter <> | Subject | Re: [PATCH 7/9] perf tools: add support for reading from /proc/kcore |
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On 30/07/2013 7:37 a.m., Namhyung Kim wrote: > Hi, > > On Thu, 25 Jul 2013 17:01:28 +0300, Adrian Hunter wrote: >> In the absence of vmlinux, perf tools uses kallsyms >> for symbols. If the user has access, now also map to >> /proc/kcore. >> >> The dso data_type is now set to either >> DSO_BINARY_TYPE__KCORE or DSO_BINARY_TYPE__GUEST_KCORE >> as approprite. > > [SNIP] >> + >> +static bool is_host_buildid_str(const char *str) >> +{ >> + u8 host_build_id[BUILD_ID_SIZE]; >> + char host_build_id_str[BUILD_ID_SIZE * 2 + 1]; >> + >> + if (sysfs__read_build_id("/sys/kernel/notes", host_build_id, >> + sizeof(host_build_id))) >> + return false; >> + >> + build_id__sprintf(host_build_id, sizeof(host_build_id), >> + host_build_id_str); >> + >> + return !strcmp(str, host_build_id_str); >> +} >> + >> +/* >> + * If kallsyms is referenced by name then we look for kcore in the same >> + * directory. Otherwise we use /proc/kcore but only if the buildid matches the >> + * host. >> + */ >> +static bool kcore_filename_from_kallsyms_filename(char *kcore_filename, >> + const char *kallsyms_filename) >> +{ >> + char *name; >> + >> + strcpy(kcore_filename, kallsyms_filename); >> + name = strrchr(kcore_filename, '/'); >> + if (!name) >> + return false; >> + >> + if (!strcmp(name, "/kallsyms")) { >> + strcpy(name, "/kcore"); >> + return true; >> + } >> + >> + if (is_host_buildid_str(name)) { > > IIUC the name should start with '/' but build-id is not. So doesn't it > always fail?
In fact I realized the whole thing is not necessary. Fixed in V2.
> > Thanks, > Namhyung > > >> + strcpy(kcore_filename, "/proc/kcore"); >> + return true; >> + } >> + >> + return false; >> +}
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