Narrow pointer bounds when appropriate

This typically occurs in a storage manager, where the caller
is expected to access only the newly-allocated object,
instead of using the returned value to access unrelated
parts of the heap.
* src/alloc.c (allocate_string, allocate_string_data)
(compact_small_strings, find_string_data_in_pure)
(sweep_strings, setup_on_free_list, allocate_vectorlike
(pure_alloc):
* src/bytecode.c (exec_byte_code):
* src/callint.c (Fcall_interactively):
* src/dispnew.c (scrolling):
* src/editfns.c (styled_format):
* src/frame.c (xrdb_get_resource, x_get_resource_string):
* src/fringe.c (Fdefine_fringe_bitmap):
* src/gmalloc.c (malloc, realloc, aligned_alloc):
Narrow pointer bounds when appropriate.
* src/alloc.c (SDATA_OF_STRING):
* src/lisp.h (make_lisp_symbol) [__CHKP__]:
Widen bounds here, though.
* src/bytecode.c, src/callint.c, src/dispnew.c, src/editfns.c:
* src/emacs.c, src/frame.c, src/fringe.c:
Include ptr-bounds.h.
* src/ptr-bounds.h (ptr_bounds_clip): New function.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/frame.c b/src/frame.c
index 5bafbeddcce..94ec9fbdc7d 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -35,6 +35,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "buffer.h"
 /* These help us bind and responding to switch-frame events.  */
 #include "keyboard.h"
+#include "ptr-bounds.h"
 #include "frame.h"
 #include "blockinput.h"
 #include "termchar.h"
@@ -4812,6 +4813,8 @@ xrdb_get_resource (XrmDatabase rdb, Lisp_Object attribute, Lisp_Object class, Li
   USE_SAFE_ALLOCA;
   char *name_key = SAFE_ALLOCA (name_keysize + class_keysize);
   char *class_key = name_key + name_keysize;
+  name_key = ptr_bounds_clip (name_key, name_keysize);
+  class_key = ptr_bounds_clip (class_key, class_keysize);
 
   /* Start with emacs.FRAMENAME for the name (the specific one)
      and with `Emacs' for the class key (the general one).  */
@@ -4890,6 +4893,8 @@ x_get_resource_string (const char *attribute, const char *class)
   ptrdiff_t class_keysize = sizeof (EMACS_CLASS) - 1 + strlen (class) + 2;
   char *name_key = SAFE_ALLOCA (name_keysize + class_keysize);
   char *class_key = name_key + name_keysize;
+  name_key = ptr_bounds_clip (name_key, name_keysize);
+  class_key = ptr_bounds_clip (class_key, class_keysize);
 
   esprintf (name_key, "%s.%s", SSDATA (Vinvocation_name), attribute);
   sprintf (class_key, "%s.%s", EMACS_CLASS, class);