2020-03-04 22:20:40

by Seth Forshee

[permalink] [raw]
Subject: [PATCH v2] selftests/ftrace: Use printf instead of echo in kprobe syntax error tests

Test cases which use echo to write strings containing backslashes
fail with some shells, as echo's treatment of backslashes in
strings varies between shell implementations. Use printf instead,
as it should behave consistently across different shells. This
requires adjustments to the strings to escape \ and % characters.
ftrace_errlog_check() must also re-escape these characters after
processing them to remove ^ characters.

Signed-off-by: Seth Forshee <[email protected]>
---
Changes in v2:
- Escape backslashes for a couple of additional tests

.../testing/selftests/ftrace/test.d/functions | 6 +++---
.../test.d/kprobe/kprobe_syntax_errors.tc | 20 +++++++++----------
2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions
index 5d4550591ff9..b38c6eb029e8 100644
--- a/tools/testing/selftests/ftrace/test.d/functions
+++ b/tools/testing/selftests/ftrace/test.d/functions
@@ -114,11 +114,11 @@ yield() {
}

ftrace_errlog_check() { # err-prefix command-with-error-pos-by-^ command-file
- pos=$(echo -n "${2%^*}" | wc -c) # error position
- command=$(echo "$2" | tr -d ^)
+ pos=$(printf "${2%^*}" | wc -c) # error position
+ command=$(printf "$2" | sed -e 's/\^//g' -e 's/%/%%/g' -e 's/\\/\\\\/g')
echo "Test command: $command"
echo > error_log
- (! echo "$command" >> "$3" ) 2> /dev/null
+ (! printf "$command" >> "$3" ) 2> /dev/null
grep "$1: error:" -A 3 error_log
N=$(tail -n 1 error_log | wc -c)
# " Command: " and "^\n" => 13
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
index ef1e9bafb098..039c03d230b9 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
@@ -37,14 +37,14 @@ fi

check_error 'p vfs_read ^$none_var' # BAD_VAR

-check_error 'p vfs_read ^%none_reg' # BAD_REG_NAME
+check_error 'p vfs_read ^%%none_reg' # BAD_REG_NAME
check_error 'p vfs_read ^@12345678abcde' # BAD_MEM_ADDR
check_error 'p vfs_read ^@+10' # FILE_ON_KPROBE

grep -q "imm-value" README && \
-check_error 'p vfs_read arg1=\^x' # BAD_IMM
+check_error 'p vfs_read arg1=\\^x' # BAD_IMM
grep -q "imm-string" README && \
-check_error 'p vfs_read arg1=\"abcd^' # IMMSTR_NO_CLOSE
+check_error 'p vfs_read arg1=\\"abcd^' # IMMSTR_NO_CLOSE

check_error 'p vfs_read ^+0@0)' # DEREF_NEED_BRACE
check_error 'p vfs_read ^+0ab1(@0)' # BAD_DEREF_OFFS
@@ -80,7 +80,7 @@ check_error 'p vfs_read arg1=^' # NO_ARG_BODY
# instruction boundary check is valid on x86 (at this moment)
case $(uname -m) in
x86_64|i[3456]86)
- echo 'p vfs_read' > kprobe_events
+ printf 'p vfs_read' > kprobe_events
if grep -q FTRACE ../kprobes/list ; then
check_error 'p ^vfs_read+3' # BAD_INSN_BNDRY (only if function-tracer is enabled)
fi
@@ -89,13 +89,13 @@ esac

# multiprobe errors
if grep -q "Create/append/" README && grep -q "imm-value" README; then
-echo 'p:kprobes/testevent _do_fork' > kprobe_events
+printf 'p:kprobes/testevent _do_fork' > kprobe_events
check_error '^r:kprobes/testevent do_exit' # DIFF_PROBE_TYPE
-echo 'p:kprobes/testevent _do_fork abcd=\1' > kprobe_events
-check_error 'p:kprobes/testevent _do_fork ^bcd=\1' # DIFF_ARG_TYPE
-check_error 'p:kprobes/testevent _do_fork ^abcd=\1:u8' # DIFF_ARG_TYPE
-check_error 'p:kprobes/testevent _do_fork ^abcd=\"foo"' # DIFF_ARG_TYPE
-check_error '^p:kprobes/testevent _do_fork abcd=\1' # SAME_PROBE
+printf 'p:kprobes/testevent _do_fork abcd=\\1' > kprobe_events
+check_error 'p:kprobes/testevent _do_fork ^bcd=\\1' # DIFF_ARG_TYPE
+check_error 'p:kprobes/testevent _do_fork ^abcd=\\1:u8' # DIFF_ARG_TYPE
+check_error 'p:kprobes/testevent _do_fork ^abcd=\\"foo"'# DIFF_ARG_TYPE
+check_error '^p:kprobes/testevent _do_fork abcd=\\1' # SAME_PROBE
fi

exit 0
--
2.25.0


2020-05-29 20:39:41

by Seth Forshee

[permalink] [raw]
Subject: Re: [PATCH v2] selftests/ftrace: Use printf instead of echo in kprobe syntax error tests

On Wed, Mar 04, 2020 at 04:20:09PM -0600, Seth Forshee wrote:
> Test cases which use echo to write strings containing backslashes
> fail with some shells, as echo's treatment of backslashes in
> strings varies between shell implementations. Use printf instead,
> as it should behave consistently across different shells. This
> requires adjustments to the strings to escape \ and % characters.
> ftrace_errlog_check() must also re-escape these characters after
> processing them to remove ^ characters.
>
> Signed-off-by: Seth Forshee <[email protected]>

Ping. Someone just asked me about this patch, and I noticed that it
hasn't been applied or received any feedback.

> ---
> Changes in v2:
> - Escape backslashes for a couple of additional tests
>
> .../testing/selftests/ftrace/test.d/functions | 6 +++---
> .../test.d/kprobe/kprobe_syntax_errors.tc | 20 +++++++++----------
> 2 files changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions
> index 5d4550591ff9..b38c6eb029e8 100644
> --- a/tools/testing/selftests/ftrace/test.d/functions
> +++ b/tools/testing/selftests/ftrace/test.d/functions
> @@ -114,11 +114,11 @@ yield() {
> }
>
> ftrace_errlog_check() { # err-prefix command-with-error-pos-by-^ command-file
> - pos=$(echo -n "${2%^*}" | wc -c) # error position
> - command=$(echo "$2" | tr -d ^)
> + pos=$(printf "${2%^*}" | wc -c) # error position
> + command=$(printf "$2" | sed -e 's/\^//g' -e 's/%/%%/g' -e 's/\\/\\\\/g')
> echo "Test command: $command"
> echo > error_log
> - (! echo "$command" >> "$3" ) 2> /dev/null
> + (! printf "$command" >> "$3" ) 2> /dev/null
> grep "$1: error:" -A 3 error_log
> N=$(tail -n 1 error_log | wc -c)
> # " Command: " and "^\n" => 13
> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
> index ef1e9bafb098..039c03d230b9 100644
> --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
> @@ -37,14 +37,14 @@ fi
>
> check_error 'p vfs_read ^$none_var' # BAD_VAR
>
> -check_error 'p vfs_read ^%none_reg' # BAD_REG_NAME
> +check_error 'p vfs_read ^%%none_reg' # BAD_REG_NAME
> check_error 'p vfs_read ^@12345678abcde' # BAD_MEM_ADDR
> check_error 'p vfs_read ^@+10' # FILE_ON_KPROBE
>
> grep -q "imm-value" README && \
> -check_error 'p vfs_read arg1=\^x' # BAD_IMM
> +check_error 'p vfs_read arg1=\\^x' # BAD_IMM
> grep -q "imm-string" README && \
> -check_error 'p vfs_read arg1=\"abcd^' # IMMSTR_NO_CLOSE
> +check_error 'p vfs_read arg1=\\"abcd^' # IMMSTR_NO_CLOSE
>
> check_error 'p vfs_read ^+0@0)' # DEREF_NEED_BRACE
> check_error 'p vfs_read ^+0ab1(@0)' # BAD_DEREF_OFFS
> @@ -80,7 +80,7 @@ check_error 'p vfs_read arg1=^' # NO_ARG_BODY
> # instruction boundary check is valid on x86 (at this moment)
> case $(uname -m) in
> x86_64|i[3456]86)
> - echo 'p vfs_read' > kprobe_events
> + printf 'p vfs_read' > kprobe_events
> if grep -q FTRACE ../kprobes/list ; then
> check_error 'p ^vfs_read+3' # BAD_INSN_BNDRY (only if function-tracer is enabled)
> fi
> @@ -89,13 +89,13 @@ esac
>
> # multiprobe errors
> if grep -q "Create/append/" README && grep -q "imm-value" README; then
> -echo 'p:kprobes/testevent _do_fork' > kprobe_events
> +printf 'p:kprobes/testevent _do_fork' > kprobe_events
> check_error '^r:kprobes/testevent do_exit' # DIFF_PROBE_TYPE
> -echo 'p:kprobes/testevent _do_fork abcd=\1' > kprobe_events
> -check_error 'p:kprobes/testevent _do_fork ^bcd=\1' # DIFF_ARG_TYPE
> -check_error 'p:kprobes/testevent _do_fork ^abcd=\1:u8' # DIFF_ARG_TYPE
> -check_error 'p:kprobes/testevent _do_fork ^abcd=\"foo"' # DIFF_ARG_TYPE
> -check_error '^p:kprobes/testevent _do_fork abcd=\1' # SAME_PROBE
> +printf 'p:kprobes/testevent _do_fork abcd=\\1' > kprobe_events
> +check_error 'p:kprobes/testevent _do_fork ^bcd=\\1' # DIFF_ARG_TYPE
> +check_error 'p:kprobes/testevent _do_fork ^abcd=\\1:u8' # DIFF_ARG_TYPE
> +check_error 'p:kprobes/testevent _do_fork ^abcd=\\"foo"'# DIFF_ARG_TYPE
> +check_error '^p:kprobes/testevent _do_fork abcd=\\1' # SAME_PROBE
> fi
>
> exit 0
> --
> 2.25.0
>

2020-05-29 21:30:33

by Shuah Khan

[permalink] [raw]
Subject: Re: [PATCH v2] selftests/ftrace: Use printf instead of echo in kprobe syntax error tests

On 5/29/20 2:37 PM, Seth Forshee wrote:
> On Wed, Mar 04, 2020 at 04:20:09PM -0600, Seth Forshee wrote:
>> Test cases which use echo to write strings containing backslashes
>> fail with some shells, as echo's treatment of backslashes in
>> strings varies between shell implementations. Use printf instead,
>> as it should behave consistently across different shells. This
>> requires adjustments to the strings to escape \ and % characters.
>> ftrace_errlog_check() must also re-escape these characters after
>> processing them to remove ^ characters.
>>
>> Signed-off-by: Seth Forshee <[email protected]>
>
> Ping. Someone just asked me about this patch, and I noticed that it
> hasn't been applied or received any feedback.
>

I pulled in this patch from Masami:

selftests/ftrace: Use printf for backslash included command
https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/commit/?h=next&id=8e923a2168afd221ea26e3d9716f21e9578b5c4d

Looks like a duplicate.

Seth,
Is your patch still needed?

+ Steve and Masami

thanks,
-- Shuah

2020-06-04 22:28:46

by Seth Forshee

[permalink] [raw]
Subject: Re: [PATCH v2] selftests/ftrace: Use printf instead of echo in kprobe syntax error tests

On Fri, May 29, 2020 at 03:26:06PM -0600, Shuah Khan wrote:
> On 5/29/20 2:37 PM, Seth Forshee wrote:
> > On Wed, Mar 04, 2020 at 04:20:09PM -0600, Seth Forshee wrote:
> > > Test cases which use echo to write strings containing backslashes
> > > fail with some shells, as echo's treatment of backslashes in
> > > strings varies between shell implementations. Use printf instead,
> > > as it should behave consistently across different shells. This
> > > requires adjustments to the strings to escape \ and % characters.
> > > ftrace_errlog_check() must also re-escape these characters after
> > > processing them to remove ^ characters.
> > >
> > > Signed-off-by: Seth Forshee <[email protected]>
> >
> > Ping. Someone just asked me about this patch, and I noticed that it
> > hasn't been applied or received any feedback.
> >
>
> I pulled in this patch from Masami:
>
> selftests/ftrace: Use printf for backslash included command
> https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/commit/?h=next&id=8e923a2168afd221ea26e3d9716f21e9578b5c4d
>
> Looks like a duplicate.
>
> Seth,
> Is your patch still needed?

Nope, Masami's patch seems to fix the issues addressed by my patch.
Thanks!