diff options
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 23 | ||||
| -rw-r--r-- | fs/readdir.c | 44 | ||||
| -rw-r--r-- | include/linux/uaccess.h | 6 |
3 files changed, 29 insertions, 44 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 35c225ede0e4..61d93f062a36 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -734,5 +734,28 @@ do { \ if (unlikely(__gu_err)) goto err_label; \ } while (0) +/* + * We want the unsafe accessors to always be inlined and use + * the error labels - thus the macro games. + */ +#define unsafe_copy_loop(dst, src, len, type, label) \ + while (len >= sizeof(type)) { \ + unsafe_put_user(*(type *)src,(type __user *)dst,label); \ + dst += sizeof(type); \ + src += sizeof(type); \ + len -= sizeof(type); \ + } + +#define unsafe_copy_to_user(_dst,_src,_len,label) \ +do { \ + char __user *__ucu_dst = (_dst); \ + const char *__ucu_src = (_src); \ + size_t __ucu_len = (_len); \ + unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u64, label); \ + unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u32, label); \ + unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u16, label); \ + unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u8, label); \ +} while (0) + #endif /* _ASM_X86_UACCESS_H */ diff --git a/fs/readdir.c b/fs/readdir.c index 19bea591c3f1..6e2623e57b2e 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -27,53 +27,13 @@ /* * Note the "unsafe_put_user() semantics: we goto a * label for errors. - * - * Also note how we use a "while()" loop here, even though - * only the biggest size needs to loop. The compiler (well, - * at least gcc) is smart enough to turn the smaller sizes - * into just if-statements, and this way we don't need to - * care whether 'u64' or 'u32' is the biggest size. - */ -#define unsafe_copy_loop(dst, src, len, type, label) \ - while (len >= sizeof(type)) { \ - unsafe_put_user(get_unaligned((type *)src), \ - (type __user *)dst, label); \ - dst += sizeof(type); \ - src += sizeof(type); \ - len -= sizeof(type); \ - } - -/* - * We avoid doing 64-bit copies on 32-bit architectures. They - * might be better, but the component names are mostly small, - * and the 64-bit cases can end up being much more complex and - * put much more register pressure on the code, so it's likely - * not worth the pain of unaligned accesses etc. - * - * So limit the copies to "unsigned long" size. I did verify - * that at least the x86-32 case is ok without this limiting, - * but I worry about random other legacy 32-bit cases that - * might not do as well. - */ -#define unsafe_copy_type(dst, src, len, type, label) do { \ - if (sizeof(type) <= sizeof(unsigned long)) \ - unsafe_copy_loop(dst, src, len, type, label); \ -} while (0) - -/* - * Copy the dirent name to user space, and NUL-terminate - * it. This should not be a function call, since we're doing - * the copy inside a "user_access_begin/end()" section. */ #define unsafe_copy_dirent_name(_dst, _src, _len, label) do { \ char __user *dst = (_dst); \ const char *src = (_src); \ size_t len = (_len); \ - unsafe_copy_type(dst, src, len, u64, label); \ - unsafe_copy_type(dst, src, len, u32, label); \ - unsafe_copy_type(dst, src, len, u16, label); \ - unsafe_copy_type(dst, src, len, u8, label); \ - unsafe_put_user(0, dst, label); \ + unsafe_put_user(0, dst+len, label); \ + unsafe_copy_to_user(dst, src, len, label); \ } while (0) diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index e47d0522a1f4..d4ee6e942562 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -355,8 +355,10 @@ extern long strnlen_unsafe_user(const void __user *unsafe_addr, long count); #ifndef user_access_begin #define user_access_begin(ptr,len) access_ok(ptr, len) #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_op_wrap(op, err) do { if (unlikely(op)) goto err; } while (0) +#define unsafe_get_user(x,p,e) unsafe_op_wrap(__get_user(x,p),e) +#define unsafe_put_user(x,p,e) unsafe_op_wrap(__put_user(x,p),e) +#define unsafe_copy_to_user(d,s,l,e) unsafe_op_wrap(__copy_to_user(d,s,l),e) static inline unsigned long user_access_save(void) { return 0UL; } static inline void user_access_restore(unsigned long flags) { } #endif |