Re: [PATCH libevl 1/2] tests: ptrace-sync: skip SOH and STX in pipe message

Re: [PATCH libevl 1/2] tests: ptrace-sync: skip SOH and STX in pipe message

[Philippe Gerum]

Junxiao Chang <junxiao.chang@intel.com> writes:

> Sometimes there might be SOH(Start of Heading) or STX(Start of
> Text) in be beginning of message. It needs to be skipped, or else
> regex function might return wrong result.

Thanks. A fix [1] addressing the same issue was merged into the -next
branch a couple of hours ago.

https://gitlab.com/Xenomai/xenomai4/libevl/-/commit/a8f7ef7fcfda7edcc1ca4cae9661e0395eeb4674

-- 
Philippe.

Re: [PATCH libevl 2/2] tests: ptrace-sync: only integrate ptrace-sync in debug build

[Philippe Gerum]

Junxiao Chang <junxiao.chang@intel.com> writes:

> ptrace-sync test case needs to load debug symbol in gdb. There is
> debug symbol in debug build. If buildtype is release, this case
> should not be integrated because it doesn't have debug symbol.
>

I don't think so, -g and the optimization level are unrelated in this
day and age (have been at some point though, many, many moons ago).

This is the output log of an x86 build for ptrace-sync.c with
--buildtype release passed to meson, -O2 and -g are both set.

[111/226] x86_64-blade-linux-gcc -m64 -march=nehalem -mtune=generic -mfpmath=sse -msse4.2 -fstack-protector-strong -O2 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Werror=format-security --sysroot=/var/lab/sdk/cpc/x86-corei7/blade-2025.10/sysroots/corei7-64-blade-linux -Itests/ptrace-sync.p -Itests -I../../../../git/xenomai/v4/libevl/tests -Iinclude -I../../../../git/xenomai/v4/libevl/include -I../../../../git/xenomai/v4/libevl/lib/arch/x86/include -fdiagnostics-color=always -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -Wpedantic -Werror -std=gnu11 -O3 -pipe -Wstrict-aliasing -Wno-unused-parameter -Wno-pedantic -D_GNU_SOURCE -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wshadow=local -Wstrict-prototypes -Wmissing-prototypes -O2 -g -pthread -g -MD -MQ tests/ptrace-sync.p/ptrace-sync.c.o -MF tests/ptrace-sync.p/ptrace-sync.c.o.d -o tests/ptrace-sync.p/ptrace-sync.c.o -c ../../../../git/xenomai/v4/libevl/tests/ptrace-sync.c

~# file /usr/libexec/evl/tests/ptrace-sync 
/usr/libexec/evl/tests/ptrace-sync: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-x86-64.so.2, BuildID[sha1]=7b1a13b097bccaf82b65d49b221ef8c0dd450887, for GNU/Linux 5.15.0, with debug_info, not stripped

Stripping the ptrace-sync executable may be the actual cause of the
issue.

-- 
Philippe.

[PATCH libevl 1/2] tests: ptrace-sync: skip SOH and STX in pipe message

[Junxiao Chang]

Sometimes there might be SOH(Start of Heading) or STX(Start of
Text) in be beginning of message. It needs to be skipped, or else
regex function might return wrong result.

This issue could be reproduced with gdb 15.0.50 in ubuntu 24.04.

Signed-off-by: Junxiao Chang <junxiao.chang@intel.com>
---
 tests/ptrace-sync.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tests/ptrace-sync.c b/tests/ptrace-sync.c
index ec6fbb3..68ce353 100644
--- a/tests/ptrace-sync.c
+++ b/tests/ptrace-sync.c
@@ -40,6 +40,8 @@
  */
 
 #define CONCURRENCY  2
+#define SOH          1
+#define STX          2
 
 static struct evl_sem handshake;
 static struct evl_event barrier;
@@ -153,6 +155,7 @@ static int consume_and_match(FILE *fp, const char *expect, bool verbose)
 	int ret = EXIT_FAILURE;
 	char buf[BUFSIZ], *p;
 	regex_t re;
+	size_t len;
 
 	if (verbose)
 		fprintf(stderr, "EXPECT {{ %s }}\n", expect);
@@ -166,8 +169,14 @@ static int consume_and_match(FILE *fp, const char *expect, bool verbose)
 		alarm(0);
 
 		if (p) {
+			len = strlen(p);
+			if (len > 1 && (p[0] == SOH || p[0] == STX)) {
+				/* Ignore SOH(start of header) or STX(start of Text */
+				p++;
+				len--;
+			}
 			if (verbose) {
-				fprintf(stderr, "<- {{ \"%.*s\" }}\n", (int)(strlen(p) - 1), p);
+				fprintf(stderr, "<- {{ \"%.*s\" }}\n", (int)(len - 1), p);
 				fflush(stderr);
 			}
 			if (!regexec(&re, p, 0, NULL, 0)) {
-- 
2.43.0

[PATCH libevl 2/2] tests: ptrace-sync: only integrate ptrace-sync in debug build

[Junxiao Chang]

ptrace-sync test case needs to load debug symbol in gdb. There is
debug symbol in debug build. If buildtype is release, this case
should not be integrated because it doesn't have debug symbol.

Signed-off-by: Junxiao Chang <junxiao.chang@intel.com>
---
 tests/meson.build | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/meson.build b/tests/meson.build
index fb8b291..89e542f 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -64,7 +64,6 @@ test_programs = [
     'proxy-eventfd',
     'proxy-pipe',
     'proxy-poll',
-    'ptrace-sync',
     'rwlock-read',
     'rwlock-write',
     'sched-quota-accuracy',
@@ -80,6 +79,10 @@ test_programs = [
     'thread-mode-bits',
 ]
 
+if get_option('buildtype').startswith('debug')
+   test_programs += 'ptrace-sync'
+endif
+
 foreach t : test_programs
     x = executable(t, t + '.c',
     install : true,
-- 
2.43.0

RE: [PATCH libevl 2/2] tests: ptrace-sync: only integrate ptrace-sync in debug build

[Chang, Junxiao]

Philippe Gerum <rpm@xenomai.org> wrote:
>Junxiao Chang <junxiao.chang@intel.com> writes:
>
>> ptrace-sync test case needs to load debug symbol in gdb. There is
>> debug symbol in debug build. If buildtype is release, this case should
>> not be integrated because it doesn't have debug symbol.
>>
>
>I don't think so, -g and the optimization level are unrelated in this day and age
>(have been at some point though, many, many moons ago).
>
>This is the output log of an x86 build for ptrace-sync.c with --buildtype release
>passed to meson, -O2 and -g are both set.
>
>[111/226] x86_64-blade-linux-gcc -m64 -march=nehalem -mtune=generic -
>mfpmath=sse -msse4.2 -fstack-protector-strong -O2 -D_FORTIFY_SOURCE=2 -
>Wformat -Wformat-security -Werror=format-security --
>sysroot=/var/lab/sdk/cpc/x86-corei7/blade-2025.10/sysroots/corei7-64-blade-
>linux -Itests/ptrace-sync.p -Itests -I../../../../git/xenomai/v4/libevl/tests -
>Iinclude -I../../../../git/xenomai/v4/libevl/include -
>I../../../../git/xenomai/v4/libevl/lib/arch/x86/include -fdiagnostics-color=always
>-D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -Wpedantic -Werror -
>std=gnu11 -O3 -pipe -Wstrict-aliasing -Wno-unused-parameter -Wno-pedantic -
>D_GNU_SOURCE -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wshadow=local
>-Wstrict-prototypes -Wmissing-prototypes -O2 -g -pthread -g -MD -MQ
>tests/ptrace-sync.p/ptrace-sync.c.o -MF tests/ptrace-sync.p/ptrace-sync.c.o.d -
>o tests/ptrace-sync.p/ptrace-sync.c.o -
>c ../../../../git/xenomai/v4/libevl/tests/ptrace-sync.c
>
>~# file /usr/libexec/evl/tests/ptrace-sync
>/usr/libexec/evl/tests/ptrace-sync: ELF 64-bit LSB pie executable, x86-64,
>version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-x86-64.so.2,
>BuildID[sha1]=7b1a13b097bccaf82b65d49b221ef8c0dd450887, for GNU/Linux
>5.15.0, with debug_info, not stripped
>
>Stripping the ptrace-sync executable may be the actual cause of the issue.
>
>--
>Philippe.

My OS is ubuntu 24.04, kernel is latest xenomai 6.18.2. With " -Dbuildtype=release", there is no debug symbol after installing, and the test case failed(with next branch, "remove gdb prompt escape" fix integrated):

intel@intel-NUC13ANHi5:~/code/libevl/build$ readelf --debug-dump=info /usr/libexec/evl/tests/ptrace-sync
intel@intel-NUC13ANHi5:~/code/libevl/build$ sudo /usr/libexec/evl/tests/ptrace-sync
intel@intel-NUC13ANHi5:~/code/libevl/build$ echo $?
1

With "-Dbuildtype=debug" or no buildtype definition, there is debug symbol info. Test case could pass:

intel@intel-NUC13ANHi5:~/code/libevl/build$ readelf --debug-dump=info /usr/libexec/evl/tests/ptrace-sync | more
Contents of the .debug_info section:

  Compilation Unit @ offset 0:
   Length:        0x23d2 (32-bit)
   Version:       5
   Unit Type:     DW_UT_compile (1)
   Abbrev Offset: 0
   Pointer Size:  8
 <0><c>: Abbrev Number: 61 (DW_TAG_compile_unit)
    <d>   DW_AT_producer    : (indirect string, offset: 0x1d7): GNU C11 13.3.0 -mtune=generic -march=x86-64 -g -O2 -std=gnu11 -fasynchronous-unwind-tables -fstack-protector-strong -fstack-clash-protection -
fcf-protection
    <11>   DW_AT_language    : 29       (C11)
    <12>   DW_AT_name        : (indirect line string, offset: 0): ../tests/ptrace-sync.c
...

intel@intel-NUC13ANHi5:~/code/libevl/build$ sudo /usr/libexec/evl/tests/ptrace-sync
intel@intel-NUC13ANHi5:~/code/libevl/build$ echo $?
0

Maybe as you mentioned, debug symbol is stripped during installation.
Thanks,
Junxiao