From 9466c1799fa2acb68e505a264dcdf53779101ac6 Mon Sep 17 00:00:00 2001 From: "Christopher M. Riedl" Date: Fri, 26 Feb 2021 19:12:50 -0600 Subject: [PATCH] powerpc/uaccess: Add unsafe_copy_from_user() Use the same approach as unsafe_copy_to_user() but instead call unsafe_get_user() in a loop. Signed-off-by: Christopher M. Riedl Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210227011259.11992-2-cmr@codefail.de --- arch/powerpc/include/asm/uaccess.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 479cb30eabd7..c3d3d178fa0e 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -486,6 +486,27 @@ user_write_access_begin(const void __user *ptr, size_t len) #define unsafe_put_user(x, p, e) \ __unsafe_put_user_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e) +#define unsafe_copy_from_user(d, s, l, e) \ +do { \ + u8 *_dst = (u8 *)(d); \ + const u8 __user *_src = (const u8 __user *)(s); \ + size_t _len = (l); \ + int _i; \ + \ + for (_i = 0; _i < (_len & ~(sizeof(long) - 1)); _i += sizeof(long)) \ + unsafe_get_user(*(long *)(_dst + _i), (long __user *)(_src + _i), e); \ + if (IS_ENABLED(CONFIG_PPC64) && (_len & 4)) { \ + unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \ + _i += 4; \ + } \ + if (_len & 2) { \ + unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \ + _i += 2; \ + } \ + if (_len & 1) \ + unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \ +} while (0) + #define unsafe_copy_to_user(d, s, l, e) \ do { \ u8 __user *_dst = (u8 __user *)(d); \ -- 2.11.0