From b5ebb826580742a27d9886b72627afc522bdcc50 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 21 May 2017 15:25:46 -0700 Subject: [PATCH] Clean up x86 unsafe_get/put_user() type handling Al noticed that unsafe_put_user() had type problems, and fixed them in commit 3faf66f46535 ("fix unsafe_put_user()"), which made me look more at those functions. It turns out that unsafe_get_user() had a type issue too: it limited the largest size of the type it could handle to "unsigned long". Which is fine with the current users, but doesn't match our existing normal get_user() semantics, which can also handle "u64" even when that does not fit in a long. While at it, also clean up the type cast in unsafe_put_user(). We actually want to just make it an assignment to the expected type of the pointer, because we actually do want warnings from types that don't convert silently. And it makes the code more readable by not having that one very long and complex line. [ This patch might become stable material if we ever end up back-porting any new users of the unsafe uaccess code, but as things stand now this doesn't matter for any current existing uses. ] Cc: Al Viro Signed-off-by: Linus Torvalds --- arch/x86/include/asm/uaccess.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index d9668c3beb5b4..fc1eb64fdfffd 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -703,14 +703,15 @@ extern struct movsl_mask { #define unsafe_put_user(x, ptr, err_label) \ do { \ int __pu_err; \ - __put_user_size((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), __pu_err, -EFAULT); \ + __typeof__(*(ptr)) __pu_val = (x); \ + __put_user_size(__pu_val, (ptr), sizeof(*(ptr)), __pu_err, -EFAULT); \ if (unlikely(__pu_err)) goto err_label; \ } while (0) #define unsafe_get_user(x, ptr, err_label) \ do { \ int __gu_err; \ - unsigned long __gu_val; \ + __inttype(*(ptr)) __gu_val; \ __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err, -EFAULT); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ if (unlikely(__gu_err)) goto err_label; \ -- 2.39.5