Re: [PATCH] perf test: Fix perf probe testsuite

[Namhyung Kim <namhyung@kernel.org>]

Hello James,

On Thu, Nov 05, 2026 at 03:56:03PM +0000, James Clark wrote:
> 
> 
> On 05/11/2026 15:08, James Clark wrote:
> > 
> > 
> > On 05/11/2026 07:17, Namhyung Kim wrote:
> > > The perf probe test suite fails on my machine.  It seems it's because
> > > the kernel debug info is not available.  Actually NO_DEBUGINFO is to
> > > check the condition and skip affected tests.
> > > 
> > > But it didn't work well as the skip_if_no_debuginfo function misses a
> > > new error string for v7.0+ kernels.  Internally it uses the
> > > add_probe_vfs_getname() to check if perf probe handles debuginfo and
> > > check the error string.  But it didn't add the new error string.
> > > 
> > >    "Could not find probeable line"
> > > 
> > > With that added, it now passes like below:
> > > 
> > >    $ sudo perf test -vv 189
> > >    Not taking turns using the perf mlock budget: nothing can exhaust it
> > >    189: perftool-testsuite_probe:
> > >    ---- start ----
> > >    test child forked, pid 26135
> > >    Probing warn_thunk_thunk
> > >    -- [ PASS ] -- perf_probe :: test_adding_blacklisted :: adding
> > > blacklisted function warn_thunk_thunk
> > >    -- [ PASS ] -- perf_probe :: test_adding_blacklisted :: listing
> > > blacklisted probe (should NOT be listed)
> > >    ## [ PASS ] ## perf_probe :: test_adding_blacklisted SUMMARY
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: adding probe
> > > inode_permission ::
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: adding probe
> > > inode_permission :: -a
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: adding probe
> > > inode_permission :: --add
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: listing added
> > > probe :: perf list
> > >    -- [ SKIP ] -- perf_probe :: test_adding_kernel :: 1 1 Skipped
> > > due to missing debuginfo :: testcase skipped
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: using added probe
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: deleting added
> > > probe
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: listing
> > > removed probe (should NOT be listed)
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: dry run ::
> > > adding probe
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: force-adding
> > > probes :: first probe adding
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: force-adding
> > > probes :: second probe adding (without force)
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: force-adding
> > > probes :: second probe adding (with force)
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: using doubled probe
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: removing
> > > multiple probes
> > >    Regexp not found: "probe:vfs_mknod"
> > >    Regexp not found: "probe:vfs_create"
> > >    Regexp not found: "probe:vfs_rmdir"
> > >    Regexp not found: "probe:vfs_link"
> > >    Regexp not found: "probe:vfs_write"
> > >    -- [ SKIP ] -- perf_probe :: test_adding_kernel :: 1 1 Skipped
> > > due to missing debuginfo :: testcase skipped
> > >    Regexp not found:
> > > "somenonexistingrandomstuffwhichisalsoprettylongorevenlongertoexceed64"
> > >    Regexp not found: "in this function|at this address"
> > >    -- [ SKIP ] -- perf_probe :: test_adding_kernel :: 1 1 Skipped
> > > due to missing debuginfo :: testcase skipped
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: function with
> > > retval :: add
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: function with
> > > retval :: record
> > >    -- [ PASS ] -- perf_probe :: test_adding_kernel :: function
> > > argument probing :: script
> > >    ## [ PASS ] ## perf_probe :: test_adding_kernel SUMMARY
> > >    -- [ SKIP ] -- perf_probe :: test_basic :: help message ::
> > > testcase skipped
> > >    -- [ PASS ] -- perf_probe :: test_basic :: usage message
> > >    -- [ PASS ] -- perf_probe :: test_basic :: quiet switch
> > >    ## [ PASS ] ## perf_probe :: test_basic SUMMARY
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: missing
> > > argument for -a
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: missing
> > > argument for -d
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: missing
> > > argument for -L
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: missing
> > > argument for -V
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: unnecessary
> > > argument for -F
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: unnecessary
> > > argument for -l
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -a xxx -d xxx
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -a xxx -L foo
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -a xxx -V foo
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -a xxx -l
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -a xxx -F
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -d xxx -L foo
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -d xxx -V foo
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -d xxx -l
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -d xxx -F
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -L foo -V bar
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -L foo -l
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -L foo -F
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -V foo -l
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -V foo -F
> > >    -- [ PASS ] -- perf_probe :: test_invalid_options :: mutually
> > > exclusive options :: -l -F
> > >    ## [ PASS ] ## perf_probe :: test_invalid_options SUMMARY
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: acceptable
> > > descriptions :: func
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: acceptable
> > > descriptions :: func:10
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: acceptable
> > > descriptions :: func:0-10
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: acceptable
> > > descriptions :: func:2+10
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: acceptable
> > > descriptions :: func@source.c
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: acceptable
> > > descriptions :: func@source.c:1
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: acceptable
> > > descriptions :: source.c:1
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: acceptable
> > > descriptions :: source.c:1+1
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: acceptable
> > > descriptions :: source.c:1-10
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: unacceptable
> > > descriptions :: func:foo
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: unacceptable
> > > descriptions :: func:1-foo
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: unacceptable
> > > descriptions :: func:1+foo
> > >    -- [ PASS ] -- perf_probe :: test_line_semantics :: unacceptable
> > > descriptions :: func;lazy\*pattern
> > >    ## [ PASS ] ## perf_probe :: test_line_semantics SUMMARY
> > >    ---- end(0) ----
> > >    189: perftool-
> > > testsuite_probe                                                         
> > > : Ok
> > > 
> > > Fixes: 92b664dcefab ("perf test probe_vfs_getname: Skip if no
> > > suitable line detected")
> > > Cc: Jakub Brnak <jbrnak@redhat.com>
> > > Cc: Michael Petlan <mpetlan@redhat.com>
> > > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > > ---
> > >   tools/perf/tests/shell/lib/probe_vfs_getname.sh | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/tools/perf/tests/shell/lib/probe_vfs_getname.sh
> > > b/tools/ perf/tests/shell/lib/probe_vfs_getname.sh
> > > index 57a59ae7d4ae3d71..c091cd208beec056 100644
> > > --- a/tools/perf/tests/shell/lib/probe_vfs_getname.sh
> > > +++ b/tools/perf/tests/shell/lib/probe_vfs_getname.sh
> > > @@ -64,7 +64,7 @@ add_probe_vfs_getname() {
> > >   }
> > >   skip_if_no_debuginfo() {
> > > -    add_probe_vfs_getname -v 2>&1 | grep -E -q "^(Failed to find
> > > the path for the kernel|Debuginfo-analysis is not supported)|(file
> > > has no debug information)" && return 2
> > > +    add_probe_vfs_getname -v 2>&1 | grep -E -q "^(Failed to find
> > > the path for the kernel|Debuginfo-analysis is not supported)|(file
> > > has no debug information|Could not find probeable line)" && return 2
> > >       return 1
> > >   }
> > 
> > I was just about to send a fix for the same thing, but I had something
> > slightly different. I think adding "Could not find probeable line"
> > allows for false skips in the future even when debug symbols are
> > present, like when that function was re-worked other times. And that
> > seems to be what Sashiko mentions as well.
> > 
> > If you just try to do a dry run probe of getname_flags() which has
> > always existed, then its a pretty stable equivalent for whether debug
> > info exists or not:
> > 
> >    perf probe -n -v 'getname_flags $params' 2>&1 | grep -E -q "^(Failed
> > to find the path for the kernel|Debuginfo-analysis is not supported)|
> > (file has no debug information)" && return 2
> > 
> 
> I included it here: https://lore.kernel.org/linux-perf-users/20261105-james-perf-test-fixes-v1-0-0b279bee5830@linaro.org/T/#t

Thanks, looks good.
Namhyung