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authorAl Viro <viro@zeniv.linux.org.uk>2020-07-11 07:27:49 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2020-08-20 22:45:15 +0300
commitc693cc4676a055c4126e487b30b0a96ea7ec9936 (patch)
tree8f057e3923deeffd1405e40e7ab1c056fa204189 /arch/x86/um
parent99a2c96d52d312b11a943372964226fa134de3b1 (diff)
downloadlinux-c693cc4676a055c4126e487b30b0a96ea7ec9936.tar.xz
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 <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/x86/um')
-rw-r--r--arch/x86/um/asm/checksum_32.h23
1 files changed, 0 insertions, 23 deletions
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