linux-toradex.git/arch/mips/include/asm/checksum.h, branch v5.18

MIPS: Fix inline asm input/output type mismatch in checksum.h used with Clang

2021-01-27T20:59:28+00:00

Fix the following build error when make M=samples/bpf used with Clang:

  CLANG-bpf  samples/bpf/sockex2_kern.o
In file included from samples/bpf/sockex2_kern.c:7:
In file included from ./include/uapi/linux/if_tunnel.h:7:
In file included from ./include/linux/ip.h:16:
In file included from ./include/linux/skbuff.h:28:
In file included from ./include/net/checksum.h:22:
./arch/mips/include/asm/checksum.h:161:9: error: unsupported inline asm: input with type 'unsigned long' matching output with type '__wsum' (aka 'unsigned int')
        : "0" ((__force unsigned long)daddr),
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

This is a known issue on MIPS [1], the changed code can be compiled
successfully by both GCC and Clang.

[1] https://lore.kernel.org/linux-mips/CAG_fn=W0JHf8QyUX==+rQMp8PoULHrsQCa9Htffws31ga8k-iw@mail.gmail.com/

Signed-off-by: Tiezhu Yang 
Signed-off-by: Thomas Bogendoerfer

mips: propagate the calling convention change down into __csum_partial_copy_..._user()

2020-08-20T19:45:20+00:00

and turn the exception handlers into simply returning 0, which
simplifies the hell out of things in csum_partial.S

Signed-off-by: Al Viro

mips: __csum_partial_copy_kernel() has no users left

2020-08-20T19:45:20+00:00

Signed-off-by: Al Viro

mips: csum_and_copy_{to,from}_user() are never called under KERNEL_DS

2020-08-20T19:45:19+00:00

they are only called for iovec-backed iov_iter and under KERNEL_DS an
attempt to create such a beast will yield a kvec-backed one.

Signed-off-by: Al Viro

saner calling conventions for csum_and_copy_..._user()

2020-08-20T19:45:15+00:00

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

csum_partial_copy_nocheck(): drop the last argument

2020-08-20T19:45:14+00:00

It's always 0.  Note that we theoretically could use ~0U as well -
result will be the same modulo 0xffff, _if_ the damn thing did the
right thing for any value of initial sum; later we'll make use of
that when convenient.

However, unlike csum_and_copy_..._user(), there are instances that
did not work for arbitrary initial sums; c6x is one such.

Signed-off-by: Al Viro

unify generic instances of csum_partial_copy_nocheck()

2020-08-20T19:45:14+00:00

quite a few architectures have the same csum_partial_copy_nocheck() -
simply memcpy() the data and then return the csum of the copy.

hexagon, parisc, ia64, s390, um: explicitly spelled out that way.

arc, arm64, csky, h8300, m68k/nommu, microblaze, mips/GENERIC_CSUM, nds32,
nios2, openrisc, riscv, unicore32: end up picking the same thing spelled
out in lib/checksum.h (with varying amounts of perversions along the way).

everybody else (alpha, arm, c6x, m68k/mmu, mips/!GENERIC_CSUM, powerpc,
sh, sparc, x86, xtensa) have non-generic variants.  For all except c6x
the declaration is in their asm/checksum.h.  c6x uses the wrapper
from asm-generic/checksum.h that would normally lead to the lib/checksum.h
instance, but in case of c6x we end up using an asm function from arch/c6x
instead.

Screw that mess - have architectures with private instances define
_HAVE_ARCH_CSUM_AND_COPY in their asm/checksum.h and have the default
one right in net/checksum.h conditional on _HAVE_ARCH_CSUM_AND_COPY
*not* defined.

Signed-off-by: Al Viro

MIPS: checksum: fix sparse flooding on asm/checksum.h

2020-06-25T08:37:23+00:00

csum_fold() in MIPS' asm/checksum.h is another source of sparse flooding
when building different networking source code.
The thing is that only half of __wsum <--> u32 casts inside the function
is forced, which is insufficient.
Add all necessary forced typecasting to stop floods and simplify actual
bug hunting.

Signed-off-by: Alexander Lobakin 
Signed-off-by: Thomas Bogendoerfer

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57+00:00

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds

MIPS: Fix trailing semicolon

2018-01-24T11:17:20+00:00

The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.

Fixes: d0f0f63ac137 ("MIPS: Rewrite csum_fold to plain C.")
Signed-off-by: Luis de Bethencourt 
Cc: Joe Perches 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18517/
Signed-off-by: James Hogan