Re: [PATCH v3 21/36] arm64/mm: Implement map_shadow_stack()

The 07/31/2023 14:43, Mark Brown wrote:

+SYSCALL_DEFINE3(map_shadow_stack, unsigned long, addr, unsigned long, size, unsigned int, flags) +{

• unsigned long alloc_size;
• unsigned long __user *cap_ptr;
• unsigned long cap_val;
• int ret;
• if (!system_supports_gcs())

• return -EOPNOTSUPP;
  

• if (flags)

• return -EINVAL;
  

• if (addr % 16)

• return -EINVAL;
  

mmap addr must be page aligned (and there is no align req on size).

i'd expect similar api here.

• if (size == 16 || size % 16)

• return -EINVAL;
  

why %16 and not %8 ?