On Thu, 11 Jan 2018 12:06:31 -0300 Arnaldo Carvalho de Melo <[email protected]> wrote:
> Em Thu, Jan 11, 2018 at 11:59:32AM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Thu, Jan 11, 2018 at 09:31:19PM +0900, Masami Hiramatsu escreveu: > > > On Thu, 4 Jan 2018 13:17:28 -0300 > > > Arnaldo Carvalho de Melo <[email protected]> wrote: > > > > Em Mon, Dec 18, 2017 at 04:29:03PM +0900, Masami Hiramatsu escreveu: > > > > > Ensure that the build-id of debuginfo is correctly matched to > > > > > target build-id, if not, it warns user to check the system > > > > > debuginfo package is correctly installed. > > > > > So we look at a variety of files looking for one that has a matching > > > > build-id, I think the warning message should state that the file with > > > > the unmatched build-id is simply being skipped, no? > > > > Actually, this patch series came from your request that you faced > > > buildid mismatch between running binary and debuginfo binary, and > > > you asked me to show the message to tell user what he needs to > > > check. > > > > > And why do this at 'perf probe -l' time? I.e. at that point whatever > > > > probes that are in place already have all the needed debug info? > > > > As I pointed, this is not only for perf-probe -l but also perf-probe -a > > > > yeah, I recently noticed this while doind a gdb session, where it warned > > about buildid mismatches. > > > I'll apply your patch, thanks for working on it! > > Trying to test it, got no warning for the vmlinux case, need to > investigate, but have not time right now, so, just for documenting it > here and letting you know: Thank you for reporting! hmm, I just tested glibc. So I need to recheck with vmlinux case. Tomorrow I'll investigate it. Thanks! > > [root@jouet ~]# perf probe $verbose "vfs_getname=getname_flags:72 > pathname=result->name:string" > Added new event: > probe:vfs_getname (on getname_flags:72 with pathname=result->name:string) > > You can now use it in all perf tools, such as: > > perf record -e probe:vfs_getname -aR sleep 1 > > [root@jouet ~]# perf probe -l > probe:vfs_getname (on getname_flags:72@acme/git/linux/fs/namei.c with > pathname) > [root@jouet ~]# > [root@jouet ~]# uname -a > Linux jouet 4.15.0-rc7+ #6 SMP Thu Jan 11 11:39:11 -03 2018 x86_64 x86_64 > x86_64 GNU/Linux > [root@jouet ~]# mv /lib/modules/4.15.0-rc7+/build/vmlinux > /lib/modules/4.15.0-rc7+/build/vmlinux.OFF > [root@jouet ~]# cp /lib/modules/4.14.0+/build/vmlinux > /lib/modules/4.15.0-rc7+/build/vmlinux > [root@jouet ~]# perf probe -l > probe:vfs_getname (on getname_flags+147 with pathname) > [root@jouet ~]# perf probe -v -l > Opening /sys/kernel/debug/tracing//kprobe_events write=0 > Opening /sys/kernel/debug/tracing//uprobe_events write=0 > Parsing probe_events: p:probe/vfs_getname _text+2601267 > pathname=+0(+0(%bx)):string > Group:probe Event:vfs_getname probe:p > Looking at the vmlinux_path (8 entries long) > symsrc__init: build id mismatch for /lib/modules/4.15.0-rc7+/build/vmlinux. > symsrc__init: cannot get elf header. > Using /proc/kcore for kernel object code > Using /proc/kallsyms for symbols > try to find information at 27b133 in kernel > Looking at the vmlinux_path (8 entries long) > symsrc__init: build id mismatch for /lib/modules/4.15.0-rc7+/build/vmlinux. > Failed to find the path for kernel: No such file or directory > Failed to find corresponding probes from debuginfo. > probe:vfs_getname (on getname_flags+147 with pathname) > [root@jouet ~]# > > - Arnaldo -- Masami Hiramatsu <[email protected]>
