RE: lib/54272: libedit segfaults on Linux aarch64 build

[christos%zoulas.com@localhost (Christos Zoulas)]

The following reply was made to PR lib/54272; it has been noted by GNATS.

From: christos%zoulas.com@localhost (Christos Zoulas)
To: Mitch Felton <Mitchell.Felton%wdc.com@localhost>, 
	"gnats-bugs%netbsd.org@localhost" <gnats-bugs%netbsd.org@localhost>, 
	"lib-bug-people%netbsd.org@localhost" <lib-bug-people%netbsd.org@localhost>, 
	"gnats-admin%netbsd.org@localhost" <gnats-admin%netbsd.org@localhost>, 
	"netbsd-bugs%netbsd.org@localhost" <netbsd-bugs%netbsd.org@localhost>
Cc: 
Subject: RE: lib/54272: libedit segfaults on Linux aarch64 build
Date: Fri, 7 Jun 2019 10:57:52 -0400

 On Jun 7,  2:40pm, Mitchell.Felton%wdc.com@localhost (Mitch Felton) wrote:
 -- Subject: RE: lib/54272: libedit segfaults on Linux aarch64 build
 
 | I spent some more time debugging this today and you are correct that my fix=
 |  is wrong. It looks like the tgetstr() call that you mentioned is returning=
 |  a pointer to invalid memory. Here's the signature of tgetstr():
 |     char *tgetstr(char *id, char **area);
 | The difference between a good run on my x86_64 system and a bad run on my a=
 | arch64 system seems to be that the return pointer has the upper 16 bits all=
 |  set (0xffff000000000000). For example, it returns 0xfffffffff89b7fa7 inste=
 | ad of 0xfffff89b7fa7 (which is a pointer to the area buffer that it updated=
 | ). So it appears that this is in fact a problem somewhere in tgetstr() and =
 | not with libedit.
 
 Thanks Mitch, I would suggest running this with valgrind or turning on
 the address sanitizer on gcc... Although you might need compile ncurses
 with it, so valgrind is probably easier.
 
 christos