| Message ID | 871qv9ggfe.fsf@oldenburg.str.redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | malloc: Simplify checked_request2size interface | expand |
On 28/06/2022 17:15, Florian Weimer via Libc-alpha wrote: > In-band signaling avoids an uninitialized variable warning when > building with -Og and GCC 12. > > Tested on i686-linux-gnu and x86_64-linux-gnu. Built with > build-many-glibcs.py. LGTM. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> > > --- > 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; >
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;