[PATCH] tools/perf: Handle perftool-testsuite_probe testcases fail when kernel debuginfo is not present
James Clark
james.clark at arm.com
Tue Jun 18 20:44:16 AEST 2024
On 17/06/2024 17:47, Athira Rajeev wrote:
>
>
>> On 17 Jun 2024, at 8:30 PM, James Clark <james.clark at arm.com> wrote:
>>
>>
>>
>> On 17/06/2024 13:21, Athira Rajeev wrote:
>>> Running "perftool-testsuite_probe" fails as below:
>>>
>>> ./perf test -v "perftool-testsuite_probe"
>>> 83: perftool-testsuite_probe : FAILED
>>>
>>> There are three fails:
>>>
>>> 1. Regexp not found: "\s*probe:inode_permission(?:_\d+)?\s+\(on inode_permission(?:[:\+][0-9A-Fa-f]+)?@.+\)"
>>> -- [ FAIL ] -- perf_probe :: test_adding_kernel :: listing added probe :: perf probe -l (output regexp parsing)
>>>
>>
>> On a machine where NO_DEBUGINFO gets set, this one skips for me. But on
>> a machine where there _is_ debug info this test still fails.
>>
>> But in both cases the probe looks like it was added successfully. So I'm
>> wondering if this one does need to be skipped, or it's just always
>> failing? Do you have this test passing anywhere where there is debug info?
>>
>> The list command looks like it successfully lists the probe for me in
>> both cases, it just doesn't have an address on the end:
>>
>> perf list 'probe:*'
>>
>> probe:inode_permission (on inode_permission)
>>
>> Does the missing address mean anything or is it just not handled
>> properly by the test?
>>
>> Ironically the machine that _does_ pass the debug info test also prints
>> this, but it looks like it still adds and lists the probe correctly:
>>
>> perf probe -l probe:*
>>
>> Failed to find debug information for address 0xffff80008047ac30
>> probe:inode_permission (on inode_permission)
>
> Hi James,
>
> Thanks for checking this patch.
>
> In environment where kernel is compiled with debuginfo:
>
> 1) Add probe point
>
> # ./perf probe --add inode_permission
> Added new event:
> probe:inode_permission (on inode_permission)
>
> You can now use it in all perf tools, such as:
>
> perf record -e probe:inode_permission -aR sleep 1
>
>
> 2) Check using perf probe -l
>
> # ./perf probe -l
> probe:inode_permission (on inode_permission:2 at fs/namei.c)
>
> With debuginfo, the result has additional info.
> The test looks for matching pattern "\s*probe:inode_permission(?:_\d+)?\s+\(on inode_permission(?:[:\+][0-9A-Fa-f]+)?@.+\)” in result
> where it is expecting "inode_permission:2 at fs/namei.c” . The “@fs/namei.c” info needs debuginfo here.
>
Hi Athira,
Maybe there is a real bug and this patch is ok to go in and we should leave
it as failing. Probe -L shows there is debug info available for inode_permission:
$ ./perf probe -L inode_permission
<inode_permission at linux/fs/namei.c:0>
0 int inode_permission(struct mnt_idmap *idmap,
struct inode *inode, int mask)
... more source code ...
But probe -l has an error which could be related to the following
line not showing the filename details:
$ ./perf probe -l
Failed to find debug information for address 0xffff80008047ac30
probe:inode_permission (on inode_permission)
I'm running a clang kernel and sometimes I see issues with debug
info or toolchain stuff, that could be the reason.
> The function I am using in patch to check for debuginfo (skip_if_no_debuginfo) is from "tests/shell/lib/probe_vfs_getname.sh"
>
> 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
> return 1
> }
>
> So the debuginfo test passes in your case since the log has "Failed to find debug information” which is not present in above grep string.
>
It passes because there is debug info for getname_flags() which is what the
debug info check looks for. After some greps and seds it ultimately does this
which succeeds:
$ perf probe "vfs_getname=getname_flags:72 pathname=result->name:string"
Added new event:
probe:vfs_getname (on getname_flags:72 with pathname=result->name:string)
"Failed to find debug information for address" is only ever printed
with "perf probe -l" when there are probes added. The stderr
of that command is never piped into any grep anyway, which is why I
see it on the test output.
So "probe -L" is working but "probe -l" isn't. Ultimately it looks like a real
issue and we should leave the failure in.
> James,
>
> Only “perf probe -l” subtest fails with debuginfo enabled or other two subtests as well? Can you also share result on how other two subtests behaves ?
>
> 1. Fail 2 :
> perf probe -nf --max-probes=512 -a 'vfs_* $params’
>
>
> 2. Fail 3 :
> perf probe 'vfs_read somenonexistingrandomstuffwhichisalsoprettylongorevenlongertoexceed64'
>
Here's the full output:
$ sudo ./perf test -vvv "testsuite_probe"
84: perftool-testsuite_probe:
--- start ---
test child forked, pid 4872
-- [ 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
Failed to find debug information for address 0xffff80008047ac30
Regexp not found: "\s*probe:inode_permission(?:_\d+)?\s+\(on inode_permission(?:[:\+][0-9A-Fa-f]+)?@.+\)"
-- [ FAIL ] -- perf_probe :: test_adding_kernel :: listing added probe :: perf probe -l (output regexp parsing)
-- [ 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)
Failed to find debug information for address 0xffff80008047ac30
-- [ 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
-- [ PASS ] -- perf_probe :: test_adding_kernel :: wildcard adding support
-- [ PASS ] -- perf_probe :: test_adding_kernel :: non-existing variable
-- [ PASS ] -- perf_probe :: test_adding_kernel :: function with retval :: add
Regexp not found: "^\[\s+perf\s+record:\s+Woken up [0-9\.]+ times? to write data\s+\].*$"
Regexp not found: "^\[\s+perf\s+record:\s+Captured and wrote [0-9\.]+\s*MB\s+(?:[\w\+\.-]*(?:(?:[\w\+\.-]+)?(?:\/[\w\+\.-]+)+)?\/)?perf\.data(?:\.\d+)?\s*\(~?[0-9\.]+ samples\)\s+\].*$"
-- [ FAIL ] -- perf_probe :: test_adding_kernel :: function with retval :: record (command exitcode + output regexp parsing)
zero-sized data (/tmp/perftool-testsuite_probe.VMU/perf_probe/perf.data), nothing to do!
Regexp not found: "\s*cat\s+[0-9\.]+\s+\[[0-9\.]+\]\s+[0-9\.]+:\s+probe:inode_permission\w*:\s+\([0-9A-Fa-f]+\s+<\-\s+[0-9A-Fa-f]+\)\s+arg1=[0-9A-Fa-f]+"
-- [ FAIL ] -- perf_probe :: test_adding_kernel :: function argument probing :: script (command exitcode + output regexp parsing)
## [ FAIL ] ## perf_probe :: test_adding_kernel SUMMARY :: 3 failures found
---- end(-1) ----
84: perftool-testsuite_probe : FAILED!
>
> Also since you mentioned this gets skipped when debuginfo is not enabled, curious to know what is debuginfo message from your setup with debuginfo disabled.
>
$ sudo ./perf probe -L getname_flags
Failed to find the path for the kernel: Invalid ELF file
Error: Failed to show lines.
> Thanks again for checking.
>
> Athira
>
>>
>
>
>>
>>> 2. 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"
>>> -- [ FAIL ] -- perf_probe :: test_adding_kernel :: wildcard adding support (command exitcode + output regexp parsing)
>>>
>>> 3. Regexp not found: "Failed to find"
>>> Regexp not found: "somenonexistingrandomstuffwhichisalsoprettylongorevenlongertoexceed64"
>>> Regexp not found: "in this function|at this address"
>>> Line did not match any pattern: "The /boot/vmlinux file has no debug information."
>>> Line did not match any pattern: "Rebuild with CONFIG_DEBUG_INFO=y, or install an appropriate debuginfo package."
>>>
>>> These three tests depends on kernel debug info.
>>> 1. Fail 1 expects file name along with probe which needs debuginfo
>>> 2. Fail 2 :
>>> perf probe -nf --max-probes=512 -a 'vfs_* $params'
>>> Debuginfo-analysis is not supported.
>>> Error: Failed to add events.
>>>
>>> 3. Fail 3 :
>>> perf probe 'vfs_read somenonexistingrandomstuffwhichisalsoprettylongorevenlongertoexceed64'
>>> Debuginfo-analysis is not supported.
>>> Error: Failed to add events.
>>>
>>> There is already helper function skip_if_no_debuginfo in
>>> lib/probe_vfs_getname.sh which does perf probe and returns
>>> "2" if debug info is not present. Use the skip_if_no_debuginfo
>>> function and skip only the three tests which needs debuginfo
>>> based on the result.
>>>
>>> With the patch:
>>>
>>> 83: perftool-testsuite_probe:
>>> --- start ---
>>> test child forked, pid 3927
>>> -- [ 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
>>> Regexp not found: "\s*probe:inode_permission(?:_\d+)?\s+\(on inode_permission(?:[:\+][0-9A-Fa-f]+)?@.+\)"
>>> -- [ SKIP ] -- perf_probe :: test_adding_kernel :: 2 2 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 :: 2 2 Skipped due to missing debuginfo :: testcase skipped
>>> Regexp not found: "Failed to find"
>>> Regexp not found: "somenonexistingrandomstuffwhichisalsoprettylongorevenlongertoexceed64"
>>> Regexp not found: "in this function|at this address"
>>> Line did not match any pattern: "The /boot/vmlinux file has no debug information."
>>> Line did not match any pattern: "Rebuild with CONFIG_DEBUG_INFO=y, or install an appropriate debuginfo package."
>>> -- [ SKIP ] -- perf_probe :: test_adding_kernel :: 2 2 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
>>> ---- end(0) ----
>>> 83: perftool-testsuite_probe : Ok
>>>
>>> Only the three specific tests are skipped and remaining
>>> ran successfully.
>>>
>>> Signed-off-by: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
>>> ---
>>> .../shell/base_probe/test_adding_kernel.sh | 31 +++++++++++++++++--
>>> 1 file changed, 28 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/tools/perf/tests/shell/base_probe/test_adding_kernel.sh b/tools/perf/tests/shell/base_probe/test_adding_kernel.sh
>>> index 63bb8974b38e..187dc8d4b163 100755
>>> --- a/tools/perf/tests/shell/base_probe/test_adding_kernel.sh
>>> +++ b/tools/perf/tests/shell/base_probe/test_adding_kernel.sh
>>> @@ -21,8 +21,18 @@
>>> THIS_TEST_NAME=`basename $0 .sh`
>>> TEST_RESULT=0
>>>
>>> +# shellcheck source=lib/probe_vfs_getname.sh
>>> +. "$(dirname "$0")/../lib/probe_vfs_getname.sh"
>>> +
>>> TEST_PROBE=${TEST_PROBE:-"inode_permission"}
>>>
>>> +# set NO_DEBUGINFO to skip testcase if debuginfo is not present
>>> +# skip_if_no_debuginfo returns 2 if debuginfo is not present
>>> +skip_if_no_debuginfo
>>> +if [ $? -eq 2 ]; then
>>> + NO_DEBUGINFO=1
>>> +fi
>>> +
>>> check_kprobes_available
>>> if [ $? -ne 0 ]; then
>>> print_overall_skipped
>>> @@ -67,7 +77,12 @@ PERF_EXIT_CODE=$?
>>> ../common/check_all_patterns_found.pl "\s*probe:${TEST_PROBE}(?:_\d+)?\s+\(on ${TEST_PROBE}(?:[:\+]$RE_NUMBER_HEX)?@.+\)" < $LOGS_DIR/adding_kernel_list-l.log
>>> CHECK_EXIT_CODE=$?
>>>
>>> -print_results $PERF_EXIT_CODE $CHECK_EXIT_CODE "listing added probe :: perf probe -l"
>>> +if [ $NO_DEBUGINFO ] ; then
>>> + print_testcase_skipped $NO_DEBUGINFO $NO_DEBUGINFO "Skipped due to missing debuginfo"
>>> +else
>>> + print_results $PERF_EXIT_CODE $CHECK_EXIT_CODE "listing added probe :: perf probe -l"
>>> +fi
>>> +
>>> (( TEST_RESULT += $? ))
>>>
>>>
>>> @@ -208,7 +223,12 @@ PERF_EXIT_CODE=$?
>>> ../common/check_all_patterns_found.pl "probe:vfs_mknod" "probe:vfs_create" "probe:vfs_rmdir" "probe:vfs_link" "probe:vfs_write" < $LOGS_DIR/adding_kernel_adding_wildcard.err
>>> CHECK_EXIT_CODE=$?
>>>
>>> -print_results $PERF_EXIT_CODE $CHECK_EXIT_CODE "wildcard adding support"
>>> +if [ $NO_DEBUGINFO ] ; then
>>> + print_testcase_skipped $NO_DEBUGINFO $NO_DEBUGINFO "Skipped due to missing debuginfo"
>>> +else
>>> + print_results $PERF_EXIT_CODE $CHECK_EXIT_CODE "wildcard adding support"
>>> +fi
>>> +
>>> (( TEST_RESULT += $? ))
>>>
>>>
>>> @@ -232,7 +252,12 @@ CHECK_EXIT_CODE=$?
>>> ../common/check_no_patterns_found.pl "$RE_SEGFAULT" < $LOGS_DIR/adding_kernel_nonexisting.err
>>> (( CHECK_EXIT_CODE += $? ))
>>>
>>> -print_results $PERF_EXIT_CODE $CHECK_EXIT_CODE "non-existing variable"
>>> +if [ $NO_DEBUGINFO ]; then
>>> + print_testcase_skipped $NO_DEBUGINFO $NO_DEBUGINFO "Skipped due to missing debuginfo"
>>> +else
>>> + print_results $PERF_EXIT_CODE $CHECK_EXIT_CODE "non-existing variable"
>>> +fi
>>> +
>>> (( TEST_RESULT += $? ))
>>>
>>>
>
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