lwall@sdcrdcf.UUCP (Larry Wall) (11/14/86)
System: patch version 2.0
Patch #: 4
Priority: HIGH
Subject: Certain long hunks are not dynamically allocated correctly
From: Herb Chong and Hokey
Description:
If the pattern portion of a hunk is longer than the initially
allocated maximum hunk size, the hunk is not grown larger in time.
The malloc arena gets stomped on non-4bsd sites. 4bsd sites
generally survive this because more memory is generally allocated
than you asked for.
There was also a minor difficulty with error numbers on new-style
context diffs that require backtracking to parse correctly because
the input line number was not reset along with the file position.
Note that backtracking is VERY rare--you have to have a patch
that ends with a deletion, so that the replacement text is missing,
and at least one line at the place where the replacement text WOULD
have been must look like a replacement line. Only then does
backtracking occur. (Backtracking would be entirely unnecessary
if patches were unambiguously terminated, but they aren't. Note
that the version of patch that comes with 4.3bsd doesn't backtrack
at all.)
Repeat-By:
Compile up patch with a version of malloc that doesn't round up
to a power of two. Apply a patch with more than 125 lines in
the pattern (not the replacement) part of the hunk. Run patch
and watch the fireworks. Delete the core dump.
Fix: From rn, say "| patch -d DIR", where DIR is your patch source
directory. Outside of rn, say "cd DIR; patch <thisarticle".
If you don't have the patch program, apply the following by hand,
or get patch.
If patch indicates that patchlevel is the wrong version, you may need
to apply one or more previous patches, or the patch may already
have been applied. See the patchlevel.h file to find out what has or
has not been applied. In any event, don't continue with the patch.
If you are missing previous patches they can be obtained from me:
Larry Wall
{allegra,burdvax,cbosgd,hplabs,ihnp4,sdcsvax}!sdcrdcf!lwall
If you send a mail message of the following form it will greatly speed
processing:
Subject: Command
@SH mailpatch PATH patch 2.0 NUM ...
where PATH is a return path FROM ME TO YOU in bang notation, and NUM
is the number of one or more patches you need, separated by spaces.
You can also get them by anonymous FTP from sdc-camarillo.arpa.
Index: patchlevel.h
Prereq: 3
1c1
< #define PATCHLEVEL 3
---
> #define PATCHLEVEL 4
Index: pch.c
Prereq: 2.0.1.2
*** pch.c.old Fri Nov 14 10:11:00 1986
*** pch.c Fri Nov 14 10:11:14 1986
***************
*** 1,4
! /* $Header: pch.c,v 2.0.1.2 86/11/03 17:49:52 lwall Exp $
*
* $Log: pch.c,v $
* Revision 2.0.1.2 86/11/03 17:49:52 lwall
--- 1,4 -----
! /* $Header: pch.c,v 2.0.1.3 86/11/14 10:08:33 lwall Exp $
*
* $Log: pch.c,v $
* Revision 2.0.1.3 86/11/14 10:08:33 lwall
***************
*** 1,6
/* $Header: pch.c,v 2.0.1.2 86/11/03 17:49:52 lwall Exp $
*
* $Log: pch.c,v $
* Revision 2.0.1.2 86/11/03 17:49:52 lwall
* New-style delete triggers spurious assertion error.
*
--- 1,10 -----
/* $Header: pch.c,v 2.0.1.3 86/11/14 10:08:33 lwall Exp $
*
* $Log: pch.c,v $
+ * Revision 2.0.1.3 86/11/14 10:08:33 lwall
+ * Fixed problem where a long pattern wouldn't grow the hunk.
+ * Also restored p_input_line when backtracking so error messages are right.
+ *
* Revision 2.0.1.2 86/11/03 17:49:52 lwall
* New-style delete triggers spurious assertion error.
*
***************
*** 401,406
bool repl_missing = FALSE; /* we are now backtracking */
long repl_backtrack_position = 0;
/* file pos of first repl line */
Reg7 LINENUM ptrn_copiable = 0;
/* # of copiable lines in ptrn */
--- 405,411 -----
bool repl_missing = FALSE; /* we are now backtracking */
long repl_backtrack_position = 0;
/* file pos of first repl line */
+ LINENUM repl_patch_line; /* input line number for same */
Reg7 LINENUM ptrn_copiable = 0;
/* # of copiable lines in ptrn */
***************
*** 425,431
}
}
p_input_line++;
! p_char[++p_end] = *buf;
p_line[p_end] = Nullch;
switch (*buf) {
case '*':
--- 430,438 -----
}
}
p_input_line++;
! p_end++;
! assert(p_end < hunkmax);
! p_char[p_end] = *buf;
p_line[p_end] = Nullch;
switch (*buf) {
case '*':
***************
*** 468,473
p_ptrn_lines = 0;
p_first = 1;
}
break;
case '-':
if (buf[1] == '-') {
--- 475,484 -----
p_ptrn_lines = 0;
p_first = 1;
}
+ p_max = p_ptrn_lines + 6; /* we need this much at least */
+ while (p_max >= hunkmax)
+ grow_hunkmax();
+ p_max = hunkmax;
break;
case '-':
if (buf[1] == '-') {
***************
*** 492,497
}
repl_beginning = p_end;
repl_backtrack_position = ftell(pfp);
p_line[p_end] = savestr(buf);
if (out_of_mem) {
p_end--;
--- 503,509 -----
}
repl_beginning = p_end;
repl_backtrack_position = ftell(pfp);
+ repl_patch_line = p_input_line;
p_line[p_end] = savestr(buf);
if (out_of_mem) {
p_end--;
***************
*** 601,606
if (repl_missing) {
/* reset state back to just after --- */
for (p_end--; p_end > repl_beginning; p_end--)
free(p_line[p_end]);
Fseek(pfp, repl_backtrack_position, 0);
--- 613,619 -----
if (repl_missing) {
/* reset state back to just after --- */
+ p_input_line = repl_patch_line;
for (p_end--; p_end > repl_beginning; p_end--)
free(p_line[p_end]);
Fseek(pfp, repl_backtrack_position, 0);netnews@cpesac.UUCP ( netnews login) (11/26/86)
@SH mailpatch burdvax!bpa!cpesac!netnews patch 2.0 1 2 Incase the above does not work please send patch #1 and #2 to version 2.0 of patch to burdvax!bpa!cpesac!netnews thank you Frank Comberiati Norfolk Va.