diff options
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c index 7c35ad95f92..b377ce43080 100644 --- a/mm/util.c +++ b/mm/util.c @@ -4,6 +4,10 @@ #include <linux/module.h> #include <linux/err.h> #include <linux/sched.h> +#include <linux/hugetlb.h> +#include <linux/syscalls.h> +#include <linux/mman.h> +#include <linux/file.h> #include <asm/uaccess.h> #define CREATE_TRACE_POINTS @@ -268,6 +272,46 @@ int __attribute__((weak)) get_user_pages_fast(unsigned long start, } EXPORT_SYMBOL_GPL(get_user_pages_fast); +SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, + unsigned long, prot, unsigned long, flags, + unsigned long, fd, unsigned long, pgoff) +{ + struct file * file = NULL; + unsigned long retval = -EBADF; + + if (!(flags & MAP_ANONYMOUS)) { + if (unlikely(flags & MAP_HUGETLB)) + return -EINVAL; + file = fget(fd); + if (!file) + goto out; + } else if (flags & MAP_HUGETLB) { + struct user_struct *user = NULL; + /* + * VM_NORESERVE is used because the reservations will be + * taken when vm_ops->mmap() is called + * A dummy user value is used because we are not locking + * memory so no accounting is necessary + */ + len = ALIGN(len, huge_page_size(&default_hstate)); + file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE, + &user, HUGETLB_ANONHUGE_INODE); + if (IS_ERR(file)) + return PTR_ERR(file); + } + + flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); + + down_write(¤t->mm->mmap_sem); + retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff); + up_write(¤t->mm->mmap_sem); + + if (file) + fput(file); +out: + return retval; +} + /* Tracepoints definitions. */ EXPORT_TRACEPOINT_SYMBOL(kmalloc); EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); |