[glibc] malloc: Simplify checked_request2size interface

[Florian Weimer <fw@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=7519dee356a0ab21c8990e59ed05dd48a4e573a0

commit 7519dee356a0ab21c8990e59ed05dd48a4e573a0
Author: Florian Weimer <fweimer@redhat.com>
Date:   Tue Jul 5 11:04:45 2022 +0200

    malloc: Simplify checked_request2size interface
    
    In-band signaling avoids an uninitialized variable warning when
    building with -Og and GCC 12.
    
    Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

Diff:
---
 malloc/malloc-check.c |  3 ++-
 malloc/malloc.c       | 30 ++++++++++++++++--------------
 2 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/malloc/malloc-check.c b/malloc/malloc-check.c
index 0299fe99a7..3368532adf 100644
--- a/malloc/malloc-check.c
+++ b/malloc/malloc-check.c
@@ -275,7 +275,8 @@ realloc_check (void *oldmem, size_t bytes)
     malloc_printerr ("realloc(): invalid pointer");
   const INTERNAL_SIZE_T oldsize = chunksize (oldp);
 
-  if (!checked_request2size (rb, &chnb))
+  chnb = checked_request2size (rb);
+  if (chnb == 0)
     {
       __set_errno (ENOMEM);
       goto invert;
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 09e5ff2bce..12908b8f97 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -1333,15 +1333,15 @@ nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    MINSIZE :                                                      \
    ((req) + SIZE_SZ + MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK)
 
-/* Check if REQ overflows when padded and aligned and if the resulting value
-   is less than PTRDIFF_T.  Returns TRUE and the requested size or MINSIZE in
-   case the value is less than MINSIZE on SZ or false if any of the previous
-   check fail.  */
-static inline bool
-checked_request2size (size_t req, size_t *sz) __nonnull (1)
+/* Check if REQ overflows when padded and aligned and if the resulting
+   value is less than PTRDIFF_T.  Returns the requested size or
+   MINSIZE in case the value is less than MINSIZE, or 0 if any of the
+   previous checks fail.  */
+static inline size_t
+checked_request2size (size_t req) __nonnull (1)
 {
   if (__glibc_unlikely (req > PTRDIFF_MAX))
-    return false;
+    return 0;
 
   /* When using tagged memory, we cannot share the end of the user
      block with the header for the next chunk, so ensure that we
@@ -1359,8 +1359,7 @@ checked_request2size (size_t req, size_t *sz) __nonnull (1)
 	    ~(size_t)(__MTAG_GRANULE_SIZE - 1);
     }
 
-  *sz = request2size (req);
-  return true;
+  return request2size (req);
 }
 
 /*
@@ -3295,8 +3294,8 @@ __libc_malloc (size_t bytes)
     ptmalloc_init ();
 #if USE_TCACHE
   /* int_free also calls request2size, be careful to not pad twice.  */
-  size_t tbytes;
-  if (!checked_request2size (bytes, &tbytes))
+  size_t tbytes = checked_request2size (bytes);
+  if (tbytes == 0)
     {
       __set_errno (ENOMEM);
       return NULL;
@@ -3443,7 +3442,8 @@ __libc_realloc (void *oldmem, size_t bytes)
        || __builtin_expect (misaligned_chunk (oldp), 0)))
       malloc_printerr ("realloc(): invalid pointer");
 
-  if (!checked_request2size (bytes, &nb))
+  nb = checked_request2size (bytes);
+  if (nb == 0)
     {
       __set_errno (ENOMEM);
       return NULL;
@@ -3800,7 +3800,8 @@ _int_malloc (mstate av, size_t bytes)
      aligned.
    */
 
-  if (!checked_request2size (bytes, &nb))
+  nb = checked_request2size (bytes);
+  if (nb == 0)
     {
       __set_errno (ENOMEM);
       return NULL;
@@ -4952,7 +4953,8 @@ _int_memalign (mstate av, size_t alignment, size_t bytes)
 
 
 
-  if (!checked_request2size (bytes, &nb))
+  nb = checked_request2size (bytes);
+  if (nb == 0)
     {
       __set_errno (ENOMEM);
       return NULL;