Samuel Thibault writes:
Hi!
> jann...@gnu.org, le ven. 15 nov. 2024 11:14:39 +0100, a ecrit:
>> As a corollary, using this GDB I found that the statically built tar
>> segfaults on the vtrying to issue the
>>
>> tar: Option --mtime: Treating date '@1' as 1970-01-01 01:00:01
>>
>> warning:
>>
>> WARN ((0, 0, _("Option %s: Treating date '%s' as %s"),
>> p->option, p->date, treated_as));
>>
>> as it looks like, on the
>> 274 vfprintf (stderr, message, args);
>>
>> call. I guess I'll try replacing that with a simple fprintf for the
>> 64bit Hurd,
>
> That's however very worth investigating because something fishy is
> at hand here, and better fix it here where it should be easy to
> investigate, rather than in other places where it'd be way more tricky.
> For a start, are p->option, p->date, and treated_as actually valid
> strings?
Yes
(gdb) p *p
$4 = {next = 0x0, ts = {tv_sec = 1, tv_nsec = 0}, rpl_option = 0x5b0132
"--mtime", date = 0x2000000033e0 "@1"}
Everything looks fine. I'm using the attached patch to work around this
and tested printing errors and warnings; everything works.
This looks like a pretty simple place, but gnulib error reporting functions
are a bit tricky:
--8<---------------cut here---------------start------------->8---
Thread 4 hit Breakpoint 5, __error (status=0, errnum=0, message=0x5aff78
"Option %s: Treating date '%s' as %s") at error.c:274
274 vfprintf (stderr, message, args);
(gdb) p stderr
$6 = (FILE *) 0x608400 <_IO_2_1_stderr_>
(gdb) p message
$7 = 0x5aff78 "Option %s: Treating date '%s' as %s"
(gdb) p args
No symbol "args" in current context.
(gdb) down
Bottom (innermost) frame selected; you cannot go down.
(gdb) up
#1 0x000000000042897b in report_textual_dates (args=0x160fb40) at tar.c:1113
1113 WARN ((0, 0, _("Option %s: Treating date '%s' as %s"),
(gdb) s
__error_internal (status=0, errnum=0, message=0x5aff78 "Option %s: Treating
date '%s' as %s", args=args@entry=0x160f9f8, mode_flags=mode_flags@entry=0) at
error.c:242
242 res = mbsrtowcs (wmessage, &tmp, len, &st);
(gdb) s
243 if (res != len)
(gdb) s
Thread 4 received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) bt
#0 0x0000000000000000 in ?? ()
#1 0x00000000004f532d in __error_internal (status=0, errnum=0,
message=0x5aff78 "Option %s: Treating date '%s' as %s",
args=args@entry=0x160f9f8, mode_flags=mode_flags@entry=0) at error.c:243
#2 0x00000000004f5425 in __error (status=<optimized out>, errnum=<optimized
out>, message=<optimized out>) at error.c:274
#3 0x000000000042897b in report_textual_dates (args=0x160fb40) at tar.c:1113
#4 0x000000000042c418 in decode_options (argc=10, argv=0x200000001270) at
tar.c:2730
#5 0x000000000042c548 in main (argc=8, argv=0x160fcb8) at tar.c:2797
(gdb) up
#1 0x00000000004f532d in __error_internal (status=0, errnum=0,
message=0x5aff78 "Option %s: Treating date '%s' as %s",
args=args@entry=0x160f9f8, mode_flags=mode_flags@entry=0) at error.c:243
243 if (res != len)
(gdb) up
#2 0x00000000004f5425 in __error (status=<optimized out>, errnum=<optimized
out>, message=<optimized out>) at error.c:274
274 vfprintf (stderr, message, args);
--8<---------------cut here---------------end--------------->8---
I don't understand how single-stepping on vfprintf (lne 274) brings me
to line 234, which is inside "#if _LIBC" code.
Greetings,
Janneke
--- ./tar-1.34/lib/paxlib.h.orig 2024-11-15 11:47:57.340427845 +0100
+++ ./tar-1.34/lib/paxlib.h 2024-11-15 12:13:30.554724056 +0100
@@ -42,6 +42,17 @@
single argument of the form ((0, errno, _("FORMAT"), Args...)). errno
is zero when the error is not being detected by the system. */
+#if __GNU__ && __x86_64__
+
+#define PRINT_WARN(x, y, ...) fprintf (stderr, __VA_ARGS__)
+#define WARN(Args) do { PRINT_WARN Args; } while (0)
+
+#define ERROR(Args) do { PRINT_WARN Args , exit (PAXEXIT_FAILURE); } while (0)
+#define FATAL_ERROR(Args) do { PRINT_WARN Args , fatal_exit (); } while (0)
+#define USAGE_ERROR(Args) do { PRINT_WARN Args , usage (PAXEXIT_FAILURE); } while (0)
+
+#else
+
#define WARN(Args) \
do { if (error_hook) error_hook (); error Args; } while (0)
#define ERROR(Args) \
@@ -69,6 +80,8 @@
} \
while (0)
+#endif
+
extern int exit_status;
void pax_decode_mode (mode_t mode, char *string);
--
Janneke Nieuwenhuizen <jann...@gnu.org> | GNU LilyPond https://LilyPond.org
Freelance IT https://www.JoyOfSource.com | Avatar® https://AvatarAcademy.com
