diff options
Diffstat (limited to 'erts/emulator/sys/common/erl_mseg.c')
| -rw-r--r-- | erts/emulator/sys/common/erl_mseg.c | 56 |
1 files changed, 54 insertions, 2 deletions
diff --git a/erts/emulator/sys/common/erl_mseg.c b/erts/emulator/sys/common/erl_mseg.c index f4e21bc05f..c859b192f7 100644 --- a/erts/emulator/sys/common/erl_mseg.c +++ b/erts/emulator/sys/common/erl_mseg.c @@ -87,11 +87,22 @@ static int is_cache_check_requested; /* Mmap ... */ #define MMAP_PROT (PROT_READ|PROT_WRITE) + +#if HALFWORD_HEAP +# ifdef MAP_32BIT +# define RANGE_FLAG (MAP_32BIT) +# else +# error "Cannot have halfword heap if unable to restrict mmap areas +# endif +#else +# define RANGE_FLAG (0) +#endif + #ifdef MAP_ANON -# define MMAP_FLAGS (MAP_ANON|MAP_PRIVATE) +# define MMAP_FLAGS (MAP_ANON|MAP_PRIVATE|RANGE_FLAG) # define MMAP_FD (-1) #else -# define MMAP_FLAGS (MAP_PRIVATE) +# define MMAP_FLAGS (MAP_PRIVATE|RANGE_FLAG) # define MMAP_FD mmap_fd static int mmap_fd; #endif @@ -310,6 +321,12 @@ mseg_create(Uint size) MMAP_PROT, MMAP_FLAGS, MMAP_FD, 0); if (seg == (void *) MAP_FAILED) seg = NULL; +#if HALFWORD_HEAP + if ((unsigned long) seg & CHECK_POINTER_MASK) { + erts_fprintf(stderr,"Pointer mask failure (0x%08lx)\n",(unsigned long) seg); + return NULL; + } +#endif #else #error "Missing mseg_create() implementation" #endif @@ -1300,6 +1317,37 @@ erts_mseg_unit_size(void) { return page_size; } +#if HAVE_MMAP && HALFWORD_HEAP +#ifdef MAP_NORESERVE +#define RESERVE_FLAGS (MMAP_FLAGS | MAP_NORESERVE) +#else +#define RESERVE_FLAGS (MMAP_FLAGS) +#endif +static void halfword_reserve(void) +{ +#if 0 + void *ptr, *understack; + unsigned long x = 0x80000000; + long i = 0; + + understack = mmap(NULL,GET_PAGE_SIZE, PROT_NONE, RESERVE_FLAGS, + MMAP_FD, 0); + while (x < (unsigned long) understack) { + ptr = mmap((void *) x, GET_PAGE_SIZE, PROT_NONE, RESERVE_FLAGS, + MMAP_FD, 0); + if ((unsigned long) ptr < 0x80000000) { + munmap(ptr, GET_PAGE_SIZE); + } else { + ++i; + } + x += GET_PAGE_SIZE; + } + erts_fprintf(stderr,"Reserved %ld pages [%d MB]...\n",i, (i*GET_PAGE_SIZE)/1024/1024); +#else + return; +#endif +} +#endif void erts_mseg_init(ErtsMsegInit_t *init) @@ -1328,6 +1376,10 @@ erts_mseg_init(ErtsMsegInit_t *init) erl_exit(ERTS_ABORT_EXIT, "erts_mseg: unable to open /dev/zero\n"); #endif +#if HAVE_MMAP && HALFWORD_HEAP + halfword_reserve(); +#endif + page_size = GET_PAGE_SIZE; page_shift = 1; |