From c693cc4676a055c4126e487b30b0a96ea7ec9936 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 11 Jul 2020 00:27:49 -0400 Subject: saner calling conventions for csum_and_copy_..._user() All callers of these primitives will * discard anything we might've copied in case of error * ignore the csum value in case of error * always pass 0xffffffff as the initial sum, so the resulting csum value (in case of success, that is) will never be 0. That suggest the following calling conventions: * don't pass err_ptr - just return 0 on error. * don't bother with zeroing destination, etc. in case of error * don't pass the initial sum - just use 0xffffffff. This commit does the minimal conversion in the instances of csum_and_copy_...(); the changes of actual asm code behind them are done later in the series. Note that this asm code is often shared with csum_partial_copy_nocheck(); the difference is that csum_partial_copy_nocheck() passes 0 for initial sum while csum_and_copy_..._user() pass 0xffffffff. Fortunately, we are free to pass 0xffffffff in all cases and subsequent patches will use that freedom without any special comments. A part that could be split off: parisc and uml/i386 claimed to have csum_and_copy_to_user() instances of their own, but those were identical to the generic one, so we simply drop them. Not sure if it's worth a separate commit... Signed-off-by: Al Viro --- arch/x86/um/asm/checksum_32.h | 23 ----------------------- 1 file changed, 23 deletions(-) (limited to 'arch/x86/um/asm') diff --git a/arch/x86/um/asm/checksum_32.h b/arch/x86/um/asm/checksum_32.h index b9ac7c9eb72c..0b13c2947ad1 100644 --- a/arch/x86/um/asm/checksum_32.h +++ b/arch/x86/um/asm/checksum_32.h @@ -35,27 +35,4 @@ static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, return csum_fold(sum); } -/* - * Copy and checksum to user - */ -#define HAVE_CSUM_COPY_USER -static __inline__ __wsum csum_and_copy_to_user(const void *src, - void __user *dst, - int len, __wsum sum, int *err_ptr) -{ - if (access_ok(dst, len)) { - if (copy_to_user(dst, src, len)) { - *err_ptr = -EFAULT; - return (__force __wsum)-1; - } - - return csum_partial(src, len, sum); - } - - if (len) - *err_ptr = -EFAULT; - - return (__force __wsum)-1; /* invalid checksum */ -} - #endif -- cgit v1.2.3