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Fix unlikely core dump in init_tty, and simplify terminfo case.

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* term.c (init_tty) [TERMINFO]: Fix check for buffer overrun.
The old version incorrectly dumped core if malloc returned a
buffer containing only non-NUL bytes.
(init_tty): Do not allocate or free termcap buffers; the
struct does that for us now.
* termchar.h (TERMCAP_BUFFER_SIZE) [!TERMINFO]: New constant.
(struct tty_display_info): Define members termcap_term_buffer and
termcap_strings_buffer only if !TERMINFO, since terminfo doesn't
use them.  Allocate them directly in struct rather than indirectly
via a pointer, to simplify init_tty.
This commit is contained in:
Paul Eggert
2013-08-26 11:10:30 -07:00
parent f5adc984fb
commit 1fc8eb33f5
3 changed files with 34 additions and 16 deletions
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12
src/ChangeLog
View File

@@ -1,5 +1,17 @@
2013-08-26 Paul Eggert <eggert@cs.ucla.edu>
Fix unlikely core dump in init_tty, and simplify terminfo case.
* term.c (init_tty) [TERMINFO]: Fix check for buffer overrun.
The old version incorrectly dumped core if malloc returned a
buffer containing only non-NUL bytes.
(init_tty): Do not allocate or free termcap buffers; the
struct does that for us now.
* termchar.h (TERMCAP_BUFFER_SIZE) [!TERMINFO]: New constant.
(struct tty_display_info): Define members termcap_term_buffer and
termcap_strings_buffer only if !TERMINFO, since terminfo doesn't
use them. Allocate them directly in struct rather than indirectly
via a pointer, to simplify init_tty.
* frame.c (check_minibuf_window): Initialize 'window' properly,
so that Emacs reliably aborts later if 'window' is not initialized.

23
src/term.c
View File

@@ -2934,9 +2934,12 @@ dissociate_if_controlling_tty (int fd)
struct terminal *
init_tty (const char *name, const char *terminal_type, bool must_succeed)
{
char *area = NULL;
#ifdef TERMINFO
char **address = 0;
#else
char *area;
char **address = &area;
int buffer_size = 4096;
#endif
int status;
struct tty_display_info *tty = NULL;
struct terminal *terminal = NULL;
@@ -3024,12 +3027,16 @@ init_tty (const char *name, const char *terminal_type, bool must_succeed)
Wcm_clear (tty);
tty->termcap_term_buffer = xmalloc (buffer_size);
/* On some systems, tgetent tries to access the controlling
terminal. */
block_tty_out_signal ();
#ifdef TERMINFO
status = tgetent (0, terminal_type);
#else
status = tgetent (tty->termcap_term_buffer, terminal_type);
if (tty->termcap_term_buffer[TERMCAP_BUFFER_SIZE - 1])
emacs_abort ();
#endif
unblock_tty_out_signal ();
if (status < 0)
@@ -3061,11 +3068,8 @@ use the Bourne shell command `TERM=... export TERM' (C-shell:\n\
}
#ifndef TERMINFO
if (strlen (tty->termcap_term_buffer) >= buffer_size)
emacs_abort ();
buffer_size = strlen (tty->termcap_term_buffer);
area = tty->termcap_strings_buffer;
#endif
tty->termcap_strings_buffer = area = xmalloc (buffer_size);
tty->TS_ins_line = tgetstr ("al", address);
tty->TS_ins_multi_lines = tgetstr ("AL", address);
tty->TS_bell = tgetstr ("bl", address);
@@ -3481,9 +3485,6 @@ delete_tty (struct terminal *terminal)
xfree (tty->old_tty);
xfree (tty->Wcm);
xfree (tty->termcap_strings_buffer);
xfree (tty->termcap_term_buffer);
xfree (tty);
}

15
src/termchar.h
View File

@@ -28,6 +28,10 @@ struct tty_output
/* There is nothing else here at the moment... */
};
#ifndef TERMINFO
enum { TERMCAP_BUFFER_SIZE = 4096 };
#endif
/* Parameters that are shared between frames on the same tty device. */
struct tty_display_info
@@ -72,14 +76,15 @@ struct tty_display_info
mouse-face. */
Mouse_HLInfo mouse_highlight;
#ifndef TERMINFO
/* Buffer used internally by termcap (see tgetent in the Termcap
manual). Only init_tty and delete_tty should change this. */
char *termcap_term_buffer;
manual). Only init_tty should use this. */
char termcap_term_buffer[TERMCAP_BUFFER_SIZE];
/* Buffer storing terminal description strings (see tgetstr in the
Termcap manual). Only init_tty and delete_tty should change
this. */
char *termcap_strings_buffer;
Termcap manual). Only init_tty should use this. */
char termcap_strings_buffer[TERMCAP_BUFFER_SIZE];
#endif
/* Strings, numbers and flags taken from the termcap entry. */