Re: [PATCH net-next 0/3] vhost: accelerate metadata access through vmap()
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2018-12-14 15:31:28
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Possibly related (same subject, not in this thread)
- 2018-12-26 · Re: [PATCH net-next 0/3] vhost: accelerate metadata access through vmap() · Jason Wang <jasowang@redhat.com>
- 2018-12-25 · Re: [PATCH net-next 0/3] vhost: accelerate metadata access through vmap() · "Michael S. Tsirkin" <mst@redhat.com>
- 2018-12-25 · Re: [PATCH net-next 0/3] vhost: accelerate metadata access through vmap() · Jason Wang <jasowang@redhat.com>
- 2018-12-24 · Re: [PATCH net-next 0/3] vhost: accelerate metadata access through vmap() · "Michael S. Tsirkin" <mst@redhat.com>
- 2018-12-24 · Re: [PATCH net-next 0/3] vhost: accelerate metadata access through vmap() · "Michael S. Tsirkin" <mst@redhat.com>
On Fri, Dec 14, 2018 at 07:33:20AM -0500, Michael S. Tsirkin wrote:
quoted
- unsafe_put_user/unsafe_get_user is not sufficient for accessing structures (e.g accessing descriptor) or arrays (batching).So you want unsafe_copy_xxx_user? I can do this. Hang on will post.
Like this basically? Warning: completely untested. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index b5e58cc0c5e7..d2afd70793ca 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h@@ -728,5 +728,10 @@ do { \ if (unlikely(__gu_err)) goto err_label; \ } while (0) +#define unsafe_copy_from_user(to, from, n) \ + __copy_user_ll(to, (__force const void *)from, n) +#define unsafe_copy_to_user(to, from, n) \ + __copy_user_ll((__force void *)to, from, n) + #endif /* _ASM_X86_UACCESS_H */
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index efe79c1cdd47..b9d515ba2920 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h@@ -271,6 +271,8 @@ extern long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count); #define user_access_end() do { } while (0) #define unsafe_get_user(x, ptr, err) do { if (unlikely(__get_user(x, ptr))) goto err; } while (0) #define unsafe_put_user(x, ptr, err) do { if (unlikely(__put_user(x, ptr))) goto err; } while (0) +#define unsafe_copy_to_user(from, to, n) copy_to_user(from, to, n) +#define unsafe_copy_from_user(from, to, n) copy_from_user(from, to, n) #endif #ifdef CONFIG_HARDENED_USERCOPY