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Diffstat (limited to 'arch/xtensa/kernel/syscall.c')
-rw-r--r--arch/xtensa/kernel/syscall.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index 54fa8425cee..5d3f7a119ed 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -36,6 +36,10 @@ syscall_t sys_call_table[__NR_syscall_count] /* FIXME __cacheline_aligned */= {
#include <uapi/asm/unistd.h>
};
+#define COLOUR_ALIGN(addr, pgoff) \
+ ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
+ (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
+
asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
{
unsigned long ret;
@@ -52,3 +56,40 @@ asmlinkage long xtensa_fadvise64_64(int fd, int advice,
{
return sys_fadvise64_64(fd, offset, len, advice);
}
+
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
+ unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+ struct vm_area_struct *vmm;
+
+ if (flags & MAP_FIXED) {
+ /* We do not accept a shared mapping if it would violate
+ * cache aliasing constraints.
+ */
+ if ((flags & MAP_SHARED) &&
+ ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
+ return -EINVAL;
+ return addr;
+ }
+
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+ if (!addr)
+ addr = TASK_UNMAPPED_BASE;
+
+ if (flags & MAP_SHARED)
+ addr = COLOUR_ALIGN(addr, pgoff);
+ else
+ addr = PAGE_ALIGN(addr);
+
+ for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
+ /* At this point: (!vmm || addr < vmm->vm_end). */
+ if (TASK_SIZE - len < addr)
+ return -ENOMEM;
+ if (!vmm || addr + len <= vmm->vm_start)
+ return addr;
+ addr = vmm->vm_end;
+ if (flags & MAP_SHARED)
+ addr = COLOUR_ALIGN(addr, pgoff);
+ }
+}