Re: [PATCH v2 20/40] metag: fix put_user sparse errors
From: James Hogan <hidden>
Date: 2015-01-07 09:55:11
Also in:
lkml
On 06/01/15 15:44, Michael S. Tsirkin wrote:
quoted hunk ↗ jump to hunk
virtio wants to write bitwise types to userspace using put_user. At the moment this triggers sparse errors, since the value is passed through an integer. For example: __le32 __user *p; __le32 x; put_user(x, p); is safe, but currently triggers a sparse warning. Fix that up using __force. This also fixes warnings due to writing a pointer out to userland. Note: this does not suppress any useful sparse checks since callers do a cast (__typeof__(*(ptr))) (x) which in turn forces all the necessary type checks. Suggested-by: James Hogan <redacted> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- arch/metag/include/asm/uaccess.h | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h index c314b45..9627c19 100644 --- a/arch/metag/include/asm/uaccess.h +++ b/arch/metag/include/asm/uaccess.h@@ -107,18 +107,23 @@ extern long __put_user_asm_w(unsigned int x, void __user *addr); extern long __put_user_asm_d(unsigned int x, void __user *addr); extern long __put_user_asm_l(unsigned long long x, void __user *addr); -#define __put_user_size(x, ptr, size, retval) \ -do { \ - retval = 0; \ - switch (size) { \ +#define __put_user_size(x, ptr, size, retval) \ +do { \ + retval = 0; \ + switch (size) { \
On the last 3 lines here you've added a tab after spaces which checkpatch complains about. With that fixed (or converted to tabs properly): Acked-by: James Hogan <redacted> Cheers James
case 1: \ - retval = __put_user_asm_b((unsigned int)x, ptr); break; \ + retval = __put_user_asm_b((__force unsigned int)x, ptr);\ + break; \ case 2: \ - retval = __put_user_asm_w((unsigned int)x, ptr); break; \ + retval = __put_user_asm_w((__force unsigned int)x, ptr);\ + break; \ case 4: \ - retval = __put_user_asm_d((unsigned int)x, ptr); break; \ + retval = __put_user_asm_d((__force unsigned int)x, ptr);\ + break; \ case 8: \ - retval = __put_user_asm_l((unsigned long long)x, ptr); break; \ + retval = __put_user_asm_l((__force unsigned long long)x,\ + ptr); \ + break; \ default: \ __put_user_bad(); \ } \
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