From d692c62dfbf834c16ef7f171ea3161b3f3fac06b Mon Sep 17 00:00:00 2001 From: Sebastian Huber Date: Mon, 3 May 2021 09:17:33 +0200 Subject: Make zero size allocation result consistent The zero size allocations had no consistent behaviour in RTEMS. For example, malloc( 0 ) returned NULL and posix_memalign( &p, align, 0 ) returned in p a unique pointer (or NULL if no memory is available). 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. Use this approach for RTEMS as well throughout the memory allocation directives Close #4390. --- cpukit/libcsupport/src/malloc.c | 6 -- cpukit/libcsupport/src/malloc_deferred.c | 4 -- cpukit/libcsupport/src/realloc.c | 8 +-- testsuites/libtests/malloctest/init.c | 106 ++++++++++++++++++++++++++++--- 4 files changed, 100 insertions(+), 24 deletions(-) diff --git a/cpukit/libcsupport/src/malloc.c b/cpukit/libcsupport/src/malloc.c index e61128bf8c..795254fbab 100644 --- a/cpukit/libcsupport/src/malloc.c +++ b/cpukit/libcsupport/src/malloc.c @@ -30,12 +30,6 @@ void *malloc( { void *return_this; - /* - * Validate the parameters - */ - if ( !size ) - return (void *) 0; - 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 b319d1213e..aab76406c7 100644 --- a/cpukit/libcsupport/src/malloc_deferred.c +++ b/cpukit/libcsupport/src/malloc_deferred.c @@ -106,10 +106,6 @@ 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/realloc.c b/cpukit/libcsupport/src/realloc.c index 1d9ae45c5d..e28e3fbc33 100644 --- a/cpukit/libcsupport/src/realloc.c +++ b/cpukit/libcsupport/src/realloc.c @@ -53,15 +53,15 @@ void *realloc( void *ptr, size_t size ) uintptr_t old_size; uintptr_t avail_size; + if ( ptr == NULL ) { + return malloc( size ); + } + if ( size == 0 ) { free( ptr ); return NULL; } - if ( ptr == NULL ) { - return malloc( size ); - } - heap = RTEMS_Malloc_Heap; switch ( _Malloc_System_state() ) { diff --git a/testsuites/libtests/malloctest/init.c b/testsuites/libtests/malloctest/init.c index 4d0f421c02..c9dcb63b2c 100644 --- a/testsuites/libtests/malloctest/init.c +++ b/testsuites/libtests/malloctest/init.c @@ -1153,7 +1153,10 @@ static void test_rtems_malloc(void) void *p; p = rtems_malloc(0); - rtems_test_assert(p == NULL); + rtems_test_assert(p != NULL); + + RTEMS_OBFUSCATE_VARIABLE(p); + free(p); errno = 0; p = rtems_malloc(SIZE_MAX / 2); @@ -1163,6 +1166,7 @@ static void test_rtems_malloc(void) p = rtems_malloc(1); rtems_test_assert(p != NULL); + RTEMS_OBFUSCATE_VARIABLE(p); free(p); } @@ -1172,13 +1176,22 @@ static void test_rtems_calloc(void) int *i; p = rtems_calloc(0, 0); - rtems_test_assert(p == NULL); + rtems_test_assert(p != NULL); + + RTEMS_OBFUSCATE_VARIABLE(p); + free(p); p = rtems_calloc(0, 1); - rtems_test_assert(p == NULL); + rtems_test_assert(p != NULL); + + RTEMS_OBFUSCATE_VARIABLE(p); + free(p); p = rtems_calloc(1, 0); - rtems_test_assert(p == NULL); + rtems_test_assert(p != NULL); + + RTEMS_OBFUSCATE_VARIABLE(p); + free(p); errno = 0; p = rtems_calloc(1, SIZE_MAX / 2); @@ -1202,6 +1215,8 @@ static void test_rtems_calloc(void) rtems_test_assert(i != NULL); rtems_test_assert(*i == 0); + + RTEMS_OBFUSCATE_VARIABLE(p); free(i); } @@ -1301,6 +1316,82 @@ static void test_greedy_allocate(void) rtems_test_assert( p == NULL ); } +static void test_alloc_zero_size(void) +{ + size_t size; + void *p; + int eno; + + size = 0; + + RTEMS_OBFUSCATE_VARIABLE( size ); + p = malloc( size ); + rtems_test_assert( p != NULL ); + + RTEMS_OBFUSCATE_VARIABLE( p ); + free( p ); + + RTEMS_OBFUSCATE_VARIABLE( size ); + p = calloc( 1, size ); + rtems_test_assert( p != NULL ); + + RTEMS_OBFUSCATE_VARIABLE( p ); + free( p ); + + RTEMS_OBFUSCATE_VARIABLE( size ); + p = rtems_malloc( size ); + rtems_test_assert( p != NULL ); + + RTEMS_OBFUSCATE_VARIABLE( p ); + free( p ); + + RTEMS_OBFUSCATE_VARIABLE( size ); + p = rtems_calloc( 1, size ); + rtems_test_assert( p != NULL ); + + RTEMS_OBFUSCATE_VARIABLE( p ); + free( p ); + + RTEMS_OBFUSCATE_VARIABLE( size ); + p = NULL; + eno = posix_memalign( &p, 32, size ); + rtems_test_assert( eno == 0 ); + rtems_test_assert( p != NULL ); + + RTEMS_OBFUSCATE_VARIABLE( p ); + free( p ); + + RTEMS_OBFUSCATE_VARIABLE( size ); + p = NULL; + eno = rtems_memalign( &p, 32, size ); + rtems_test_assert( eno == 0 ); + rtems_test_assert( p != NULL ); + + RTEMS_OBFUSCATE_VARIABLE( p ); + free( p ); + + RTEMS_OBFUSCATE_VARIABLE( size ); + p = aligned_alloc( 32, size ); + rtems_test_assert( p != NULL ); + + RTEMS_OBFUSCATE_VARIABLE( p ); + free( p ); + + RTEMS_OBFUSCATE_VARIABLE( size ); + p = realloc( NULL, size ); + rtems_test_assert( p != NULL ); + + RTEMS_OBFUSCATE_VARIABLE( p ); + free( p ); + + RTEMS_OBFUSCATE_VARIABLE( size ); + p = reallocarray( NULL, 1, size ); + rtems_test_assert( p != NULL ); + + RTEMS_OBFUSCATE_VARIABLE( p ); + free( p ); +} + rtems_task Init( rtems_task_argument argument ) @@ -1327,12 +1418,6 @@ rtems_task Init( rtems_test_assert( p1 == NULL ); #pragma GCC diagnostic pop - /* - * Verify error case where malloc of size 0. - */ - p1 = malloc( 0 ); - rtems_test_assert( p1 == NULL ); - test_heap_initialize(); test_heap_block_allocate(); test_heap_allocate(); @@ -1351,6 +1436,7 @@ rtems_task Init( test_rtems_malloc(); test_rtems_calloc(); test_greedy_allocate(); + test_alloc_zero_size(); test_posix_memalign(); -- cgit v1.2.3