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author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2021-05-05 08:49:52 +0200 |
---|---|---|
committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2021-05-06 08:03:58 +0200 |
commit | 2c5199bb049efe8e29cd12461dc57bd6e30388e8 (patch) | |
tree | 31086387522ae9803a5a15bb33ee014ed96eeaf8 /cpukit | |
parent | libc: Reimplement posix_memlign() (diff) | |
download | rtems-2c5199bb049efe8e29cd12461dc57bd6e30388e8.tar.bz2 |
Return NULL for zero size allocations
In POSIX, zero size memory allocations are implementation-defined
behaviour. The implementation has two options:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/malloc.html
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_memalign.html
Linux and FreeBSD return a unique pointer for zero size memory
allocations. Return NULL on RTEMS to more likely catch the use of a
zero size memory area by erroneous applications.
Update #4390.
Diffstat (limited to 'cpukit')
-rw-r--r-- | cpukit/libcsupport/src/alignedalloc.c | 4 | ||||
-rw-r--r-- | cpukit/libcsupport/src/calloc.c | 9 | ||||
-rw-r--r-- | cpukit/libcsupport/src/malloc.c | 4 | ||||
-rw-r--r-- | cpukit/libcsupport/src/malloc_deferred.c | 4 | ||||
-rw-r--r-- | cpukit/libcsupport/src/posix_memalign.c | 4 | ||||
-rw-r--r-- | cpukit/libcsupport/src/rtems_memalign.c | 4 | ||||
-rw-r--r-- | cpukit/libcsupport/src/rtemscalloc.c | 9 |
7 files changed, 30 insertions, 8 deletions
diff --git a/cpukit/libcsupport/src/alignedalloc.c b/cpukit/libcsupport/src/alignedalloc.c index b552fc2a0f..9c9ea83bd8 100644 --- a/cpukit/libcsupport/src/alignedalloc.c +++ b/cpukit/libcsupport/src/alignedalloc.c @@ -35,6 +35,10 @@ void *aligned_alloc( size_t alignment, size_t size ) { + if ( size == 0 ) { + return NULL; + } + return rtems_heap_allocate_aligned_with_boundary( size, alignment, 0 ); } diff --git a/cpukit/libcsupport/src/calloc.c b/cpukit/libcsupport/src/calloc.c index 693aa21453..d5cefb382a 100644 --- a/cpukit/libcsupport/src/calloc.c +++ b/cpukit/libcsupport/src/calloc.c @@ -35,14 +35,15 @@ void *calloc( size_t length; if ( nelem == 0 ) { - length = 0; - } else if ( elsize > SIZE_MAX / nelem ) { + return NULL; + } + + if ( elsize > SIZE_MAX / nelem ) { errno = ENOMEM; return NULL; - } else { - length = nelem * elsize; } + length = nelem * elsize; cptr = malloc( length ); RTEMS_OBFUSCATE_VARIABLE( cptr ); if ( RTEMS_PREDICT_FALSE( cptr == NULL ) ) { diff --git a/cpukit/libcsupport/src/malloc.c b/cpukit/libcsupport/src/malloc.c index 795254fbab..3e55a94c83 100644 --- a/cpukit/libcsupport/src/malloc.c +++ b/cpukit/libcsupport/src/malloc.c @@ -30,6 +30,10 @@ void *malloc( { void *return_this; + if ( size == 0 ) { + return NULL; + } + return_this = rtems_heap_allocate_aligned_with_boundary( size, 0, 0 ); if ( !return_this ) { errno = ENOMEM; diff --git a/cpukit/libcsupport/src/malloc_deferred.c b/cpukit/libcsupport/src/malloc_deferred.c index aab76406c7..b319d1213e 100644 --- a/cpukit/libcsupport/src/malloc_deferred.c +++ b/cpukit/libcsupport/src/malloc_deferred.c @@ -106,6 +106,10 @@ void *rtems_heap_allocate_aligned_with_boundary( void *rtems_malloc( size_t size ) { + if ( size == 0 ) { + return NULL; + } + return rtems_heap_allocate_aligned_with_boundary( size, 0, 0 ); } #endif diff --git a/cpukit/libcsupport/src/posix_memalign.c b/cpukit/libcsupport/src/posix_memalign.c index 316ed7315c..4e89413c24 100644 --- a/cpukit/libcsupport/src/posix_memalign.c +++ b/cpukit/libcsupport/src/posix_memalign.c @@ -37,6 +37,10 @@ int posix_memalign( *memptr = NULL; + if ( size == 0 ) { + return 0; + } + if ( alignment < sizeof( void * ) ) { return EINVAL; } diff --git a/cpukit/libcsupport/src/rtems_memalign.c b/cpukit/libcsupport/src/rtems_memalign.c index aa938ac66f..aa67c74a29 100644 --- a/cpukit/libcsupport/src/rtems_memalign.c +++ b/cpukit/libcsupport/src/rtems_memalign.c @@ -40,6 +40,10 @@ int rtems_memalign( *pointer = NULL; + if ( size == 0 ) { + return 0; + } + /* * Perform the aligned allocation requested */ diff --git a/cpukit/libcsupport/src/rtemscalloc.c b/cpukit/libcsupport/src/rtemscalloc.c index 836f1da64d..7e05a14bb1 100644 --- a/cpukit/libcsupport/src/rtemscalloc.c +++ b/cpukit/libcsupport/src/rtemscalloc.c @@ -47,13 +47,14 @@ void *rtems_calloc( size_t nelem, size_t elsize ) void *p; if ( nelem == 0 ) { - length = 0; - } else if ( elsize > SIZE_MAX / nelem ) { return NULL; - } else { - length = nelem * elsize; } + if ( elsize > SIZE_MAX / nelem ) { + return NULL; + } + + length = nelem * elsize; p = rtems_malloc( length ); RTEMS_OBFUSCATE_VARIABLE( p ); if ( RTEMS_PREDICT_FALSE( p == NULL ) ) { |