http://sourceware.org/ml/gdb-patches/2012-04/msg00758.html
Subject: [patch] auto-load safe-path default=$ddir/auto-load [Re: [patch] auto-load safe-path reset back by set ""]
On Sun, 22 Apr 2012 23:26:16 +0200, Doug Evans wrote:
> A thought occurred to me regarding the default value of auto-load-path
> = ${prefix}.
This is unrelated to this patch but thanks for the suggestion.
> So I was wondering if we really want security to be on by default,
> should the default value be gdb's data-directory (e.g.,
> $prefix/share/gdb) + $exec_prefix/lib{,32,64} + ???
Made it therefore $ddir/auto-load, on an ideal system/distro we can change all
the auto-loaded GDB files to be located under $ddir/auto-load. I have filed
for the only remaining violation (/usr/bin/mono-gdb.py) known to me:
https://bugzilla.redhat.com/show_bug.cgi?id=815501
(Sure I will ask about upstreaming of the change.)
> Plus, it seems like at least data-directory should be relocatable.
> Implementing this might be cumbersome unless data-directory was
> represented as something like "$ddir".
Done. Unfortunately this still does not fix the "./gdb" run for a newly built
GDB. Newly built GDB probably could use "-data-directory $PWD/data-directory"
(if GDB's program dir contains "data-directory" sort of relocation).
We could then change current
gdb-gdb.gdb.in -> gdb-gdb.gdb
to
gdb-gdb.gdb.in -> data-directory/auto-load/$PWD/gdb-gdb.gdb
and even install the file (with proper installation directories) as:
/usr/share/gdb/usr/bin/gdb-gdb.gdb
(additionally ensuring for example in Fedora - in its .spec file
@srcdir@ gets substituted right for Fedora *-debuginfo.rpm)
Would it make everyone happy?
Thanks,
Jan
gdb/
2012-04-23 Jan Kratochvil <jan.kratochvil@redhat.com>
Change auto-load safe-path default to $ddir/auto-load.
* auto-load.c (auto_load_safe_path_vec_update): Call
substitute_path_component for $ddir.
* configure: Regenerate.
* configure.ac (--with-auto-load-safe-path): Suggest $ddir syntax.
Change the default to \\\$ddir/auto-load.
* defs.h (substitute_path_component): New declaration.
* utils.c (substitute_path_component): New function.
gdb/doc/
2012-04-23 Jan Kratochvil <jan.kratochvil@redhat.com>
Change auto-load safe-path default to $ddir/auto-load.
* gdb.texinfo (Auto-loading): Change shown safe-path default to
$ddir/auto-load.
(Auto-loading safe path): Change the sample warning to $ddir/auto-load.
Twice. Mention the $ddir substitution.
Index: gdb-7.3.50.20110722/gdb/auto-load.c
===================================================================
--- gdb-7.3.50.20110722.orig/gdb/auto-load.c 2012-04-24 20:37:48.000000000 +0200
+++ gdb-7.3.50.20110722/gdb/auto-load.c 2012-04-24 20:37:53.902703805 +0200
@@ -141,8 +141,12 @@ auto_load_safe_path_vec_update (void)
for (ix = 0; ix < len; ix++)
{
char *dir = VEC_index (char_ptr, auto_load_safe_path_vec, ix);
- char *expanded = tilde_expand (dir);
- char *real_path = gdb_realpath (expanded);
+ char *expanded, *real_path;
+
+ expanded = tilde_expand (dir);
+ substitute_path_component (&expanded, "$ddir", gdb_datadir);
+
+ real_path = gdb_realpath (expanded);
/* Ensure the current entry is at least tilde_expand-ed. */
VEC_replace (char_ptr, auto_load_safe_path_vec, ix, expanded);
Index: gdb-7.3.50.20110722/gdb/configure
===================================================================
--- gdb-7.3.50.20110722.orig/gdb/configure 2012-04-24 20:37:48.000000000 +0200
+++ gdb-7.3.50.20110722/gdb/configure 2012-04-24 20:37:53.904703800 +0200
@@ -1664,7 +1664,8 @@ Optional Packages:
--with-rpm query rpm database for missing debuginfos (yes/no,
def. auto=librpm.so)
--with-auto-load-safe-path=PATH
- directories safe to hold auto-loaded files
+ directories safe to hold auto-loaded files, use
+ '\\\$ddir' for -data-directory
--without-auto-load-safe-path
do not restrict auto-loaded files locations
--with-libunwind use libunwind frame unwinding support
@@ -8392,7 +8393,7 @@ if test "${with_auto_load_safe_path+set}
with_auto_load_safe_path="/"
fi
else
- with_auto_load_safe_path="$prefix"
+ with_auto_load_safe_path='\\\$ddir/auto-load'
fi
Index: gdb-7.3.50.20110722/gdb/configure.ac
===================================================================
--- gdb-7.3.50.20110722.orig/gdb/configure.ac 2012-04-24 20:37:48.000000000 +0200
+++ gdb-7.3.50.20110722/gdb/configure.ac 2012-04-24 20:37:53.904703800 +0200
@@ -303,12 +303,13 @@ fi
AC_MSG_CHECKING([for default auto-load safe-path])
AC_ARG_WITH(auto-load-safe-path,
-AS_HELP_STRING([--with-auto-load-safe-path=PATH], [directories safe to hold auto-loaded files])
+AS_HELP_STRING([--with-auto-load-safe-path=PATH],
+ [directories safe to hold auto-loaded files, use '\\\$ddir' for -data-directory])
AS_HELP_STRING([--without-auto-load-safe-path], [do not restrict auto-loaded files locations]),
[if test "$with_auto_load_safe_path" = "no"; then
with_auto_load_safe_path="/"
fi],
-[with_auto_load_safe_path="$prefix"])
+[with_auto_load_safe_path='\\\$ddir/auto-load'])
AC_DEFINE_DIR(DEFAULT_AUTO_LOAD_SAFE_PATH, with_auto_load_safe_path,
[Directories safe to hold auto-loaded files.])
AC_MSG_RESULT([$with_auto_load_safe_path])
Index: gdb-7.3.50.20110722/gdb/defs.h
===================================================================
--- gdb-7.3.50.20110722.orig/gdb/defs.h 2012-04-24 20:37:47.000000000 +0200
+++ gdb-7.3.50.20110722/gdb/defs.h 2012-04-24 20:38:42.944581730 +0200
@@ -432,6 +432,9 @@ extern const char *gdb_bfd_errmsg (bfd_e
extern int parse_pid_to_attach (char *args);
+extern void substitute_path_component (char **stringp, const char *from,
+ const char *to);
+
/* From demangle.c */
extern void set_demangling_style (char *);
Index: gdb-7.3.50.20110722/gdb/doc/gdb.texinfo
===================================================================
--- gdb-7.3.50.20110722.orig/gdb/doc/gdb.texinfo 2012-04-24 20:37:48.000000000 +0200
+++ gdb-7.3.50.20110722/gdb/doc/gdb.texinfo 2012-04-24 20:37:53.909703788 +0200
@@ -20113,7 +20113,7 @@ libthread-db: Auto-loading of inferior
local-gdbinit: Auto-loading of .gdbinit script from current directory is on.
python-scripts: Auto-loading of Python scripts is on.
safe-path: List of directories from which it is safe to auto-load files
- is /usr/local.
+ is $ddir/auto-load.
@end smallexample
@anchor{info auto-load}
@@ -20315,9 +20315,9 @@ get loaded:
$ ./gdb -q ./gdb
Reading symbols from /home/user/gdb/gdb...done.
warning: File "/home/user/gdb/gdb-gdb.gdb" auto-loading has been
- declined by your `auto-load safe-path' set to "/usr/local".
+ declined by your `auto-load safe-path' set to "$ddir/auto-load".
warning: File "/home/user/gdb/gdb-gdb.py" auto-loading has been
- declined by your `auto-load safe-path' set to "/usr/local".
+ declined by your `auto-load safe-path' set to "$ddir/auto-load".
@end smallexample
The list of trusted directories is controlled by the following commands:
@@ -20349,6 +20349,11 @@ loading and execution of scripts. Multi
host platform directory separator in use.
@end table
+Any used string @file{$ddir} will get replaced by @var{data-directory} which is
+determined at @value{GDBN} startup (@pxref{Data Files}). @file{$ddir} must be
+be placed as a directory component - either alone or delimited by @file{/} or
+@file{\} directory separators, depending on the host platform.
+
Setting this variable to @file{/} disables this security
protection.
This variable is supposed to be set to the system directories writable by the
Index: gdb-7.3.50.20110722/gdb/utils.c
===================================================================
--- gdb-7.3.50.20110722.orig/gdb/utils.c 2012-04-24 20:37:48.000000000 +0200
+++ gdb-7.3.50.20110722/gdb/utils.c 2012-04-24 20:39:12.745507543 +0200
@@ -3797,6 +3797,48 @@ dirnames_to_char_ptr_vec (const char *di
return retval;
}
+/* Substitute all occurences of string FROM by string TO in *STRINGP. *STRINGP
+ must come from xrealloc-compatible allocator and it may be updated. FROM
+ needs to be delimited by IS_DIR_SEPARATOR (or be located at the start or
+ end of *STRINGP. */
+
+void
+substitute_path_component (char **stringp, const char *from, const char *to)
+{
+ char *string = *stringp, *s;
+ const size_t from_len = strlen (from);
+ const size_t to_len = strlen (to);
+
+ for (s = string;;)
+ {
+ s = strstr (s, from);
+ if (s == NULL)
+ break;
+
+ if ((s == string || IS_DIR_SEPARATOR (s[-1]))
+ && (s[from_len] == '\0' || IS_DIR_SEPARATOR (s[from_len])))
+ {
+ char *string_new;
+
+ string_new = xrealloc (string, (strlen (string) + to_len + 1));
+
+ /* Relocate the current S pointer. */
+ s = s - string + string_new;
+ string = string_new;
+
+ /* Replace from by to. */
+ memmove (&s[to_len], &s[from_len], strlen (&s[from_len]) + 1);
+ memcpy (s, to, to_len);
+
+ s += to_len;
+ }
+ else
+ s++;
+ }
+
+ *stringp = string;
+}
+
/* Provide a prototype to silence -Wmissing-prototypes. */
extern initialize_file_ftype _initialize_utils;