Re: [PATCH v1 1/3] lib subcmd: Fix memory leak in uniq

From: Ian Rogers
Date: Sat Jan 06 2024 - 00:45:27 EST


On Fri, Jan 5, 2024 at 6:54 AM Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
>
> Em Thu, Jan 04, 2024 at 03:29:34PM -0800, Ian Rogers escreveu:
> > On Thu, Jan 4, 2024 at 1:03 PM Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
> > > Em Tue, Jan 02, 2024 at 11:30:39AM -0800, Ian Rogers escreveu:
> > > > On Thu, Dec 7, 2023 at 4:05 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
> > > > > uniq will write one command name over another causing the overwritten
> > > > > string to be leaked. Fix by doing a pass that removes duplicates and a
> > > > > second that removes the holes.
>
> > > I applied the first one, the fix for uniq(), but somehow the second
> > > didn't work for me as in your examples, nor the third, the output is the
> > > same as before.
>
> > I tried to repro the failure with a rebase but couldn't. I suspected
> > libsubcmd wasn't being rebuilt or something like that. I suspect now
> > that you have ~/.perfconfig with help.autocorrect set, which means the
> > output will vary as it will automatically try to run the autocorrected
> > command. Could you check for me?
>
> [acme@quaco perf-tools-next]$ perf reccord
> Failed to run command 'reccord': No such file or directory
> [acme@quaco perf-tools-next]$ perf -v
> perf version 6.7.rc6.gcd1e3ef8bfe8
> [acme@quaco perf-tools-next]$ git log --oneline -5
> cd1e3ef8bfe8f827 (HEAD -> perf-tools-next) perf help: Lower levenshtein penality for deleting character
> c5c7365af812728e perf: Suggest inbuilt commands for unknown command
> b6d8b858dbbbd832 (perf-tools-next.korg/tmp.perf-tools-next, perf-tools-next.korg/perf-tools-next, number/perf-tools-next, five/perf-tools-next, acme.korg/tmp.perf-tools-next, acme.korg/perf-tools-next) perf test: test case 'Setup struct perf_event_attr' fails on s390 on z/vm
> 1e24ce402c97dc3c (perf-tools-next/tmp.perf-tools-next, acme/tmp.perf-tools-next) perf db-export: Fix missing reference count get in call_path_from_sample()
> bb177a85e82b37d3 perf tests: Add perf script test
> [acme@quaco perf-tools-next]$ perf reccord
> Failed to run command 'reccord': No such file or directory
> [acme@quaco perf-tools-next]$ cat ~/.perfconfig
> [acme@quaco perf-tools-next]$ sudo cat /etc/perfconfig
> [sudo] password for acme:
> cat: /etc/perfconfig: No such file or directory
> [acme@quaco perf-tools-next]$
> [acme@quaco perf-tools-next]$
> [acme@quaco perf-tools-next]$ sudo su -
> [root@quaco ~]# perf -v
> perf version 6.7.rc6.gcd1e3ef8bfe8
> [root@quaco ~]# perf reccord
> Failed to run command 'reccord': No such file or directory
> [root@quaco ~]# cat ~/.perfconfig
> [root@quaco ~]# perf trace -e open*,access* perf reccord
> 0.000 ( 0.006 ms): perf/10791 access(filename: "/etc/ld.so.preload", mode: R) = -1 ENOENT (No such file or directory)
> 0.012 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/etc/ld.so.cache", flags: RDONLY|CLOEXEC) = 3
> 0.035 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libunwind-x86_64.so.8", flags: RDONLY|CLOEXEC) = 3
> 0.084 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libunwind.so.8", flags: RDONLY|CLOEXEC) = 3
> 0.128 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/liblzma.so.5", flags: RDONLY|CLOEXEC) = 3
> 0.170 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libm.so.6", flags: RDONLY|CLOEXEC) = 3
> 0.221 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libopencsd_c_api.so.1", flags: RDONLY|CLOEXEC) = 3
> 0.264 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libz.so.1", flags: RDONLY|CLOEXEC) = 3
> 0.305 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libelf.so.1", flags: RDONLY|CLOEXEC) = 3
> 0.348 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libdebuginfod.so.1", flags: RDONLY|CLOEXEC) = 3
> 0.386 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libdw.so.1", flags: RDONLY|CLOEXEC) = 3
> 0.428 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libcrypto.so.3", flags: RDONLY|CLOEXEC) = 3
> 0.480 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libslang.so.2", flags: RDONLY|CLOEXEC) = 3
> 0.526 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libperl.so.5.36", flags: RDONLY|CLOEXEC) = 3
> 0.575 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libc.so.6", flags: RDONLY|CLOEXEC) = 3
> 0.628 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libpython3.11.so.1.0", flags: RDONLY|CLOEXEC) = 3
> 0.675 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libstdc++.so.6", flags: RDONLY|CLOEXEC) = 3
> 0.729 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libzstd.so.1", flags: RDONLY|CLOEXEC) = 3
> 0.772 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libcap.so.2", flags: RDONLY|CLOEXEC) = 3
> 0.811 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libnuma.so.1", flags: RDONLY|CLOEXEC) = 3
> 0.849 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libbabeltrace-ctf.so.1", flags: RDONLY|CLOEXEC) = 3
> 0.895 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libpfm.so.4", flags: RDONLY|CLOEXEC) = 3
> 0.940 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libtraceevent.so.1", flags: RDONLY|CLOEXEC) = 3
> 0.976 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libgcc_s.so.1", flags: RDONLY|CLOEXEC) = 3
> 1.023 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libopencsd.so.1", flags: RDONLY|CLOEXEC) = 3
> 1.071 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libcurl.so.4", flags: RDONLY|CLOEXEC) = 3
> 1.116 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libbz2.so.1", flags: RDONLY|CLOEXEC) = 3
> 1.157 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libcrypt.so.2", flags: RDONLY|CLOEXEC) = 3
> 1.216 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libbabeltrace.so.1", flags: RDONLY|CLOEXEC) = 3
> 1.260 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libpopt.so.0", flags: RDONLY|CLOEXEC) = 3
> 1.299 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libuuid.so.1", flags: RDONLY|CLOEXEC) = 3
> 1.341 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libgmodule-2.0.so.0", flags: RDONLY|CLOEXEC) = 3
> 1.382 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libglib-2.0.so.0", flags: RDONLY|CLOEXEC) = 3
> 1.438 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libnghttp2.so.14", flags: RDONLY|CLOEXEC) = 3
> 1.478 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libidn2.so.0", flags: RDONLY|CLOEXEC) = 3
> 1.525 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libssh.so.4", flags: RDONLY|CLOEXEC) = 3
> 1.576 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libpsl.so.5", flags: RDONLY|CLOEXEC) = 3
> 1.621 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libssl.so.3", flags: RDONLY|CLOEXEC) = 3
> 1.663 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libgssapi_krb5.so.2", flags: RDONLY|CLOEXEC) = 3
> 1.707 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libldap.so.2", flags: RDONLY|CLOEXEC) = 3
> 1.755 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/liblber.so.2", flags: RDONLY|CLOEXEC) = 3
> 1.795 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libbrotlidec.so.1", flags: RDONLY|CLOEXEC) = 3
> 1.852 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libpcre2-8.so.0", flags: RDONLY|CLOEXEC) = 3
> 1.899 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libunistring.so.2", flags: RDONLY|CLOEXEC) = 3
> 1.948 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libkrb5.so.3", flags: RDONLY|CLOEXEC) = 3
> 1.997 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libk5crypto.so.3", flags: RDONLY|CLOEXEC) = 3
> 2.040 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libcom_err.so.2", flags: RDONLY|CLOEXEC) = 3
> 2.089 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libkrb5support.so.0", flags: RDONLY|CLOEXEC) = 3
> 2.132 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libkeyutils.so.1", flags: RDONLY|CLOEXEC) = 3
> 2.175 ( 0.004 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libresolv.so.2", flags: RDONLY|CLOEXEC) = 3
> 2.237 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libevent-2.1.so.7", flags: RDONLY|CLOEXEC) = 3
> 2.288 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libsasl2.so.3", flags: RDONLY|CLOEXEC) = 3
> 2.337 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libbrotlicommon.so.1", flags: RDONLY|CLOEXEC) = 3
> 2.399 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/lib64/libselinux.so.1", flags: RDONLY|CLOEXEC) = 3
> 9.457 ( 0.006 ms): perf/10791 access(filename: "/etc/selinux/config") = 0
> 9.719 ( 0.014 ms): perf/10791 openat(dfd: CWD, filename: "/proc/self/status") = 3
> 9.759 ( 0.007 ms): perf/10791 openat(dfd: CWD, filename: "/sys/devices/system/node", flags: RDONLY|CLOEXEC|DIRECTORY|NONBLOCK) = 3
> 9.786 ( 0.006 ms): perf/10791 openat(dfd: CWD, filename: "/sys/devices/system/node/node0/meminfo") = 4
> 9.825 ( 0.006 ms): perf/10791 openat(dfd: CWD, filename: "/sys/devices/system/cpu/possible", flags: RDONLY|CLOEXEC) = 3
> 9.837 ( 0.005 ms): perf/10791 openat(dfd: CWD, filename: "/proc/self/status") = 3
> 9.962 ( 0.005 ms): perf/10791 access(filename: "/home/acme/etc/perfconfig", mode: R) = -1 ENOENT (No such file or directory)
> Failed to run command 'reccord': No such file or directory
> [root@quaco ~]#
> [root@quaco ~]# perf -vv
> perf version 6.7.rc6.gcd1e3ef8bfe8
> dwarf: [ on ] # HAVE_DWARF_SUPPORT
> dwarf_getlocations: [ on ] # HAVE_DWARF_GETLOCATIONS_SUPPORT
> syscall_table: [ on ] # HAVE_SYSCALL_TABLE_SUPPORT
> libbfd: [ OFF ] # HAVE_LIBBFD_SUPPORT
> debuginfod: [ on ] # HAVE_DEBUGINFOD_SUPPORT
> libelf: [ on ] # HAVE_LIBELF_SUPPORT
> libnuma: [ on ] # HAVE_LIBNUMA_SUPPORT
> numa_num_possible_cpus: [ on ] # HAVE_LIBNUMA_SUPPORT
> libperl: [ on ] # HAVE_LIBPERL_SUPPORT
> libpython: [ on ] # HAVE_LIBPYTHON_SUPPORT
> libslang: [ on ] # HAVE_SLANG_SUPPORT
> libcrypto: [ on ] # HAVE_LIBCRYPTO_SUPPORT
> libunwind: [ on ] # HAVE_LIBUNWIND_SUPPORT
> libdw-dwarf-unwind: [ on ] # HAVE_DWARF_SUPPORT
> zlib: [ on ] # HAVE_ZLIB_SUPPORT
> lzma: [ on ] # HAVE_LZMA_SUPPORT
> get_cpuid: [ on ] # HAVE_AUXTRACE_SUPPORT
> bpf: [ on ] # HAVE_LIBBPF_SUPPORT
> aio: [ on ] # HAVE_AIO_SUPPORT
> zstd: [ on ] # HAVE_ZSTD_SUPPORT
> libpfm4: [ on ] # HAVE_LIBPFM
> libtraceevent: [ on ] # HAVE_LIBTRACEEVENT
> bpf_skeletons: [ on ] # HAVE_BPF_SKEL
> [root@quaco ~]#

Thanks Arnaldo,

I tried b4 am-ing the patches and repro-ing in a clean tree. I'm still
not able to do it. Knowing what is going on in help_unknown_cmd in
tools/perf/util/help-unknown-cmd.c would shed some light on the
matter. I'll see if I can get other ideas.

Thanks,
Ian