Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Link: https://lore.kernel.org/lkml/CA+G9fYtHP+Gg+BrR_GkBMxu2oOi-_e9pATtpb6TVRswv1G... Fixes: f131d9edc29d ("selftests/lkdtm: Don't clear dmesg when running tests") Signed-off-by: Kees Cook keescook@chromium.org --- tools/testing/selftests/lkdtm/run.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh index 8383eb89d88a..5fe23009ae13 100755 --- a/tools/testing/selftests/lkdtm/run.sh +++ b/tools/testing/selftests/lkdtm/run.sh @@ -82,7 +82,7 @@ dmesg > "$DMESG" ($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true
# Record and dump the results -dmesg | diff --changed-group-format='%>' --unchanged-group-format='' "$DMESG" - > "$LOG" || true +dmesg | comm -13 "$DMESG" - > "$LOG" || true
cat "$LOG" # Check for expected output
Kees Cook keescook@chromium.org writes:
Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Although using "comm" requires CONFIG_PRINTK_TIME=y doesn't it?
Which is probably fine, but should be mentioned.
And I guess for completeness you could add:
diff --git a/tools/testing/selftests/lkdtm/config b/tools/testing/selftests/lkdtm/config index d874990e442b..ae88bfb163ff 100644 --- a/tools/testing/selftests/lkdtm/config +++ b/tools/testing/selftests/lkdtm/config @@ -1 +1,2 @@ CONFIG_LKDTM=y +CONFIG_PRINTK_TIME=y
cheers
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Link: https://lore.kernel.org/lkml/CA+G9fYtHP+Gg+BrR_GkBMxu2oOi-_e9pATtpb6TVRswv1G... Fixes: f131d9edc29d ("selftests/lkdtm: Don't clear dmesg when running tests") Signed-off-by: Kees Cook keescook@chromium.org
tools/testing/selftests/lkdtm/run.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh index 8383eb89d88a..5fe23009ae13 100755 --- a/tools/testing/selftests/lkdtm/run.sh +++ b/tools/testing/selftests/lkdtm/run.sh @@ -82,7 +82,7 @@ dmesg > "$DMESG" ($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true # Record and dump the results -dmesg | diff --changed-group-format='%>' --unchanged-group-format='' "$DMESG" - > "$LOG" || true +dmesg | comm -13 "$DMESG" - > "$LOG" || true cat "$LOG"
# Check for expected output
2.25.1
-- Kees Cook
On Sat, Jun 27, 2020 at 09:51:31PM +1000, Michael Ellerman wrote:
Kees Cook keescook@chromium.org writes:
Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Although using "comm" requires CONFIG_PRINTK_TIME=y doesn't it?
No, it doesn't seem to. "comm" doesn't carry about the line prefixes. AIUI, the only reason for a mention of "sort" is because of how "comm" does its line pairing. i.e. as soon as it goes out of sync, it starts accounting for the disjunction between files. But that's exactly what we want it doing, and the prefix doesn't matter.
Kees Cook keescook@chromium.org writes:
On Sat, Jun 27, 2020 at 09:51:31PM +1000, Michael Ellerman wrote:
Kees Cook keescook@chromium.org writes:
Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Although using "comm" requires CONFIG_PRINTK_TIME=y doesn't it?
No, it doesn't seem to. "comm" doesn't carry about the line prefixes. AIUI, the only reason for a mention of "sort" is because of how "comm" does its line pairing. i.e. as soon as it goes out of sync, it starts accounting for the disjunction between files. But that's exactly what we want it doing, and the prefix doesn't matter.
OK, if it works.
cheers
On Fri, Jun 26, 2020 at 01:59:43PM -0700, Kees Cook wrote:
Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Link: https://lore.kernel.org/lkml/CA+G9fYtHP+Gg+BrR_GkBMxu2oOi-_e9pATtpb6TVRswv1G... Fixes: f131d9edc29d ("selftests/lkdtm: Don't clear dmesg when running tests") Signed-off-by: Kees Cook keescook@chromium.org
tools/testing/selftests/lkdtm/run.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh index 8383eb89d88a..5fe23009ae13 100755 --- a/tools/testing/selftests/lkdtm/run.sh +++ b/tools/testing/selftests/lkdtm/run.sh @@ -82,7 +82,7 @@ dmesg > "$DMESG" ($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true # Record and dump the results -dmesg | diff --changed-group-format='%>' --unchanged-group-format='' "$DMESG" - > "$LOG" || true +dmesg | comm -13 "$DMESG" - > "$LOG" || true cat "$LOG" # Check for expected output
I'm not familiar with running lkdtm tests, but I copied the same fixup for the livepatching selftests and "comm" slides in nicely over there, so,
Acked-by: Joe Lawrence joe.lawrence@redhat.com
-- Joe
On Fri, Jun 26, 2020 at 01:59:43PM -0700, Kees Cook wrote:
Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Link: https://lore.kernel.org/lkml/CA+G9fYtHP+Gg+BrR_GkBMxu2oOi-_e9pATtpb6TVRswv1G... Fixes: f131d9edc29d ("selftests/lkdtm: Don't clear dmesg when running tests") Signed-off-by: Kees Cook keescook@chromium.org
Shuah, this really needs to land to fix lkdtm tests on busybox. Can you add this to -next? (Or is it better to direct this to Greg for the lkdtm tree?)
Thanks!
-Kees
tools/testing/selftests/lkdtm/run.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh index 8383eb89d88a..5fe23009ae13 100755 --- a/tools/testing/selftests/lkdtm/run.sh +++ b/tools/testing/selftests/lkdtm/run.sh @@ -82,7 +82,7 @@ dmesg > "$DMESG" ($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true # Record and dump the results -dmesg | diff --changed-group-format='%>' --unchanged-group-format='' "$DMESG" - > "$LOG" || true +dmesg | comm -13 "$DMESG" - > "$LOG" || true cat "$LOG"
# Check for expected output
2.25.1
-- Kees Cook
On 9/9/20 3:49 PM, Kees Cook wrote:
On Fri, Jun 26, 2020 at 01:59:43PM -0700, Kees Cook wrote:
Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Link: https://lore.kernel.org/lkml/CA+G9fYtHP+Gg+BrR_GkBMxu2oOi-_e9pATtpb6TVRswv1G... Fixes: f131d9edc29d ("selftests/lkdtm: Don't clear dmesg when running tests") Signed-off-by: Kees Cook keescook@chromium.org
Shuah, this really needs to land to fix lkdtm tests on busybox. Can you add this to -next? (Or is it better to direct this to Greg for the lkdtm tree?)
Thanks!
-Kees
tools/testing/selftests/lkdtm/run.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh index 8383eb89d88a..5fe23009ae13 100755 --- a/tools/testing/selftests/lkdtm/run.sh +++ b/tools/testing/selftests/lkdtm/run.sh @@ -82,7 +82,7 @@ dmesg > "$DMESG" ($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true # Record and dump the results -dmesg | diff --changed-group-format='%>' --unchanged-group-format='' "$DMESG" - > "$LOG" || true +dmesg | comm -13 "$DMESG" - > "$LOG" || true cat "$LOG"
# Check for expected output
2.25.1
-- Kees Cook
Hi Kees,
You may want to consider a similar follow up to the one Miroslav made to the livepatching equivalent:
https://lore.kernel.org/live-patching/nycvar.YFH.7.76.2008271528000.27422@cb...
basically 'comm' will complain if two lines from dmesg have the same timestamp prefix and their text portions are not sorted.
Regards,
-- Joe
On Wed, Sep 09, 2020 at 04:29:50PM -0400, Joe Lawrence wrote:
On 9/9/20 3:49 PM, Kees Cook wrote:
On Fri, Jun 26, 2020 at 01:59:43PM -0700, Kees Cook wrote:
Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Link: https://lore.kernel.org/lkml/CA+G9fYtHP+Gg+BrR_GkBMxu2oOi-_e9pATtpb6TVRswv1G... Fixes: f131d9edc29d ("selftests/lkdtm: Don't clear dmesg when running tests") Signed-off-by: Kees Cook keescook@chromium.org
Shuah, this really needs to land to fix lkdtm tests on busybox. Can you add this to -next? (Or is it better to direct this to Greg for the lkdtm tree?)
Thanks!
-Kees
tools/testing/selftests/lkdtm/run.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh index 8383eb89d88a..5fe23009ae13 100755 --- a/tools/testing/selftests/lkdtm/run.sh +++ b/tools/testing/selftests/lkdtm/run.sh @@ -82,7 +82,7 @@ dmesg > "$DMESG" ($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true # Record and dump the results -dmesg | diff --changed-group-format='%>' --unchanged-group-format='' "$DMESG" - > "$LOG" || true +dmesg | comm -13 "$DMESG" - > "$LOG" || true cat "$LOG"
# Check for expected output
2.25.1
-- Kees Cook
Hi Kees,
You may want to consider a similar follow up to the one Miroslav made to the livepatching equivalent:
https://lore.kernel.org/live-patching/nycvar.YFH.7.76.2008271528000.27422@cb...
basically 'comm' will complain if two lines from dmesg have the same timestamp prefix and their text portions are not sorted.
Ah-ha! Thank you. I will send a v2. :)
On 9/9/20 1:49 PM, Kees Cook wrote:
On Fri, Jun 26, 2020 at 01:59:43PM -0700, Kees Cook wrote:
Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Link: https://lore.kernel.org/lkml/CA+G9fYtHP+Gg+BrR_GkBMxu2oOi-_e9pATtpb6TVRswv1G... Fixes: f131d9edc29d ("selftests/lkdtm: Don't clear dmesg when running tests") Signed-off-by: Kees Cook keescook@chromium.org
Shuah, this really needs to land to fix lkdtm tests on busybox. Can you add this to -next? (Or is it better to direct this to Greg for the lkdtm tree?)
Kees, Thanks for the ping. I can queue this up in -next
Greg, would you like me to take this through selftest tree?
In case you want to take this through lkdtm tree:
Acked-by: Shuah Khan skhan@linuxfoundation.org
thanks, -- Shuah
On 9/9/20 2:49 PM, Shuah Khan wrote:
On 9/9/20 1:49 PM, Kees Cook wrote:
On Fri, Jun 26, 2020 at 01:59:43PM -0700, Kees Cook wrote:
Instead of full GNU diff (which smaller boot environments may not have), use "comm" which is more available.
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Link: https://lore.kernel.org/lkml/CA+G9fYtHP+Gg+BrR_GkBMxu2oOi-_e9pATtpb6TVRswv1G...
Fixes: f131d9edc29d ("selftests/lkdtm: Don't clear dmesg when running tests") Signed-off-by: Kees Cook keescook@chromium.org
Shuah, this really needs to land to fix lkdtm tests on busybox. Can you add this to -next? (Or is it better to direct this to Greg for the lkdtm tree?)
Kees, Thanks for the ping. I can queue this up in -next
Greg, would you like me to take this through selftest tree?
In case you want to take this through lkdtm tree:
Acked-by: Shuah Khan skhan@linuxfoundation.org
Kees,
Just saw your reply. Will wait for v2.
thanks, -- Shuah
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