[glibc/arm/morello/main] cheri: fix __minimal_malloc

[Szabolcs Nagy <nsz@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=b4e28743ec4dbec80c2ebc1f596409ddca60322c

commit b4e28743ec4dbec80c2ebc1f596409ddca60322c
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Tue Mar 1 12:42:26 2022 +0000

    cheri: fix __minimal_malloc
    
    The linker created _end symbol does not have the right bounds, so
    don't try to reuse leftover memory at the end of the .data section.

Diff:
---
 elf/dl-minimal-malloc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/elf/dl-minimal-malloc.c b/elf/dl-minimal-malloc.c
index 7cca54208d..5f5f5554e5 100644
--- a/elf/dl-minimal-malloc.c
+++ b/elf/dl-minimal-malloc.c
@@ -23,6 +23,7 @@
 # pragma GCC visibility push(hidden)
 #endif
 #include <assert.h>
+#include <stdint.h>
 #include <string.h>
 #include <ldsodefs.h>
 #include <malloc/malloc-internal.h>
@@ -33,6 +34,7 @@ static void *alloc_ptr, *alloc_end, *alloc_last_block;
 void *
 __minimal_malloc (size_t n)
 {
+#ifndef __CHERI_PURE_CAPABILITY__
   if (alloc_end == 0)
     {
       /* Consume any unused space in the last page of our data segment.  */
@@ -42,9 +44,10 @@ __minimal_malloc (size_t n)
 				 + GLRO(dl_pagesize) - 1)
 				& ~(GLRO(dl_pagesize) - 1));
     }
+#endif
 
   /* Make sure the allocation pointer is ideally aligned.  */
-  alloc_ptr = (void *) 0 + (((alloc_ptr - (void *) 0) + MALLOC_ALIGNMENT - 1)
+  alloc_ptr = (void *)(((uintptr_t)alloc_ptr + (MALLOC_ALIGNMENT - 1))
 			    & ~(MALLOC_ALIGNMENT - 1));
 
   if (alloc_ptr + n >= alloc_end || n >= -(uintptr_t) alloc_ptr)