Re: toolchain/59549: gdb is not ctype(3) safe

["Thomas Klausner via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR toolchain/59549; it has been noted by GNATS.

From: Thomas Klausner <wiz%NetBSD.org@localhost>
To: Christos Zoulas <christos%zoulas.com@localhost>
Cc: NetBSD bugtracking <gnats-bugs%NetBSD.org@localhost>
Subject: Re: toolchain/59549: gdb is not ctype(3) safe
Date: Sat, 26 Jul 2025 11:55:29 +0200

 On Fri, Jul 25, 2025 at 08:46:01AM -0400, Christos Zoulas wrote:
 > I am not committing this because it is too intrusive, but see if it helps you.
 
 Thank you!
 
 Now I don't need to double up the gdb's, the gdb running Guitar
 doesn't dump core any longer.
 
 The backtrace of Guitar when it segfaults looks wrong though:
 
 Thread 12 "" received signal SIGSEGV, Segmentation fault.
 [Switching to LWP 26550 of process 27435]
 0x000000000069d346 in __gmtime_r50 (t=0x7cb9f8ffe7f8, tm=0x7cba003bdf80 <tm>) at file/src/gmtime_r.c:13
 warning: 13     file/src/gmtime_r.c: No such file or directory
 (gdb) bt
 #0  0x000000000069d346 in __gmtime_r50 (t=0x7cb9f8ffe7f8, tm=0x7cba003bdf80 <tm>) at file/src/gmtime_r.c:13
 #1  0x000000000069d366 in __gmtime_r50 (t=<optimized out>, tm=0x7cba003bdf80 <tm>) at file/src/gmtime_r.c:14
 #2  0x000000000069d366 in __gmtime_r50 (t=<optimized out>, tm=0x7cba003bdf80 <tm>) at file/src/gmtime_r.c:14
 ... and so on for more than 15000 frames, until I stopped it...
 
 (gdb) p *t
 $1 = 1753523442
 (gdb) p *tm
 $2 = {tm_sec = 42, tm_min = 50, tm_hour = 11, tm_mday = 26, tm_mon = 6, tm_year = 125, tm_wday = 6, tm_yday = 206, tm_isdst = 1, tm_gmtoff = 7200, tm_zone = 0x7cb9fb1d846c "CEST"}
 
 Probably stack corruption, because why else would the same function be there >15000 times.
  Thomas