When UML is compiled under 32-bit x86, it uses its own copy of checksum_32.S, which is terribly out-of-date and doesn't support checksumming unaligned data.

This causes the new "checksum" KUnit test to fail: ./tools/testing/kunit/kunit.py run --kconfig_add CONFIG_64BIT=n --cross_compile i686-linux-gnu- checksum KTAP version 1 # Subtest: checksum 1..3 # test_csum_fixed_random_inputs: ASSERTION FAILED at lib/checksum_kunit.c:243 Expected result == expec, but result == 33316 (0x8224) expec == 33488 (0x82d0) not ok 1 test_csum_fixed_random_inputs # test_csum_all_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:267 Expected result == expec, but result == 65280 (0xff00) expec == 0 (0x0) not ok 2 test_csum_all_carry_inputs # test_csum_no_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:306 Expected result == expec, but result == 65531 (0xfffb) expec == 0 (0x0) not ok 3 test_csum_no_carry_inputs

Sharing the normal implementation in arch/x86/lib both fixes all of these issues and means any further fixes only need to be done once.

x86_64 already seems to share the same implementation between UML and "normal" x86.

Signed-off-by: David Gow davidgow@google.com ---

Note that there is a further issue with the pre-pentium-pro codepath in the shared x86 code, which I'll send a separate fix out for. i686+ works fine with just this series.

--- arch/x86/um/Makefile | 3 +- arch/x86/um/checksum_32.S | 214 -------------------------------------- 2 files changed, 2 insertions(+), 215 deletions(-) delete mode 100644 arch/x86/um/checksum_32.S

diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile index ee89f6bb9242..cb738967a9f5 100644 --- a/arch/x86/um/Makefile +++ b/arch/x86/um/Makefile @@ -17,11 +17,12 @@ obj-y = bugs_$(BITS).o delay.o fault.o ldt.o \

ifeq ($(CONFIG_X86_32),y)

-obj-y += checksum_32.o syscalls_32.o +obj-y += syscalls_32.o obj-$(CONFIG_ELF_CORE) += elfcore.o

subarch-y = ../lib/string_32.o ../lib/atomic64_32.o ../lib/atomic64_cx8_32.o subarch-y += ../lib/cmpxchg8b_emu.o ../lib/atomic64_386_32.o +subarch-y += ../lib/checksum_32.o subarch-y += ../kernel/sys_ia32.o

else diff --git a/arch/x86/um/checksum_32.S b/arch/x86/um/checksum_32.S deleted file mode 100644 index aed782ab7721..000000000000 --- a/arch/x86/um/checksum_32.S +++ /dev/null @@ -1,214 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * INET An implementation of the TCP/IP protocol suite for the LINUX - * operating system. INET is implemented using the BSD Socket - * interface as the means of communication with the user level. - * - * IP/TCP/UDP checksumming routines - * - * Authors: Jorge Cwik, jorge@laser.satlink.net - * Arnt Gulbrandsen, agulbra@nvg.unit.no - * Tom May, ftom@netcom.com - * Pentium Pro/II routines: - * Alexander Kjeldaas astor@guardian.no - * Finn Arne Gangstad finnag@guardian.no - * Lots of code moved from tcp.c and ip.c; see those files - * for more names. - * - * Changes: Ingo Molnar, converted csum_partial_copy() to 2.1 exception - * handling. - * Andi Kleen, add zeroing on error - * converted to pure assembler - */ - -#include <asm/errno.h> -#include <asm/asm.h> -#include <asm/export.h> - -/* - * computes a partial checksum, e.g. for TCP/UDP fragments - */ - -/* -unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum) - */ - -.text -.align 4 -.globl csum_partial - -#ifndef CONFIG_X86_USE_PPRO_CHECKSUM - - /* - * Experiments with Ethernet and SLIP connections show that buff - * is aligned on either a 2-byte or 4-byte boundary. We get at - * least a twofold speedup on 486 and Pentium if it is 4-byte aligned. - * Fortunately, it is easy to convert 2-byte alignment to 4-byte - * alignment for the unrolled loop. - */ -csum_partial: - pushl %esi - pushl %ebx - movl 20(%esp),%eax # Function arg: unsigned int sum - movl 16(%esp),%ecx # Function arg: int len - movl 12(%esp),%esi # Function arg: unsigned char *buff - testl $2, %esi # Check alignment. - jz 2f # Jump if alignment is ok. - subl $2, %ecx # Alignment uses up two bytes. - jae 1f # Jump if we had at least two bytes. - addl $2, %ecx # ecx was < 2. Deal with it. - jmp 4f -1: movw (%esi), %bx - addl $2, %esi - addw %bx, %ax - adcl $0, %eax -2: - movl %ecx, %edx - shrl $5, %ecx - jz 2f - testl %esi, %esi -1: movl (%esi), %ebx - adcl %ebx, %eax - movl 4(%esi), %ebx - adcl %ebx, %eax - movl 8(%esi), %ebx - adcl %ebx, %eax - movl 12(%esi), %ebx - adcl %ebx, %eax - movl 16(%esi), %ebx - adcl %ebx, %eax - movl 20(%esi), %ebx - adcl %ebx, %eax - movl 24(%esi), %ebx - adcl %ebx, %eax - movl 28(%esi), %ebx - adcl %ebx, %eax - lea 32(%esi), %esi - dec %ecx - jne 1b - adcl $0, %eax -2: movl %edx, %ecx - andl $0x1c, %edx - je 4f - shrl $2, %edx # This clears CF -3: adcl (%esi), %eax - lea 4(%esi), %esi - dec %edx - jne 3b - adcl $0, %eax -4: andl $3, %ecx - jz 7f - cmpl $2, %ecx - jb 5f - movw (%esi),%cx - leal 2(%esi),%esi - je 6f - shll $16,%ecx -5: movb (%esi),%cl -6: addl %ecx,%eax - adcl $0, %eax -7: - popl %ebx - popl %esi - RET - -#else - -/* Version for PentiumII/PPro */ - -csum_partial: - pushl %esi - pushl %ebx - movl 20(%esp),%eax # Function arg: unsigned int sum - movl 16(%esp),%ecx # Function arg: int len - movl 12(%esp),%esi # Function arg: const unsigned char *buf - - testl $2, %esi - jnz 30f -10: - movl %ecx, %edx - movl %ecx, %ebx - andl $0x7c, %ebx - shrl $7, %ecx - addl %ebx,%esi - shrl $2, %ebx - negl %ebx - lea 45f(%ebx,%ebx,2), %ebx - testl %esi, %esi - jmp *%ebx - - # Handle 2-byte-aligned regions -20: addw (%esi), %ax - lea 2(%esi), %esi - adcl $0, %eax - jmp 10b - -30: subl $2, %ecx - ja 20b - je 32f - movzbl (%esi),%ebx # csumming 1 byte, 2-aligned - addl %ebx, %eax - adcl $0, %eax - jmp 80f -32: - addw (%esi), %ax # csumming 2 bytes, 2-aligned - adcl $0, %eax - jmp 80f - -40: - addl -128(%esi), %eax - adcl -124(%esi), %eax - adcl -120(%esi), %eax - adcl -116(%esi), %eax - adcl -112(%esi), %eax - adcl -108(%esi), %eax - adcl -104(%esi), %eax - adcl -100(%esi), %eax - adcl -96(%esi), %eax - adcl -92(%esi), %eax - adcl -88(%esi), %eax - adcl -84(%esi), %eax - adcl -80(%esi), %eax - adcl -76(%esi), %eax - adcl -72(%esi), %eax - adcl -68(%esi), %eax - adcl -64(%esi), %eax - adcl -60(%esi), %eax - adcl -56(%esi), %eax - adcl -52(%esi), %eax - adcl -48(%esi), %eax - adcl -44(%esi), %eax - adcl -40(%esi), %eax - adcl -36(%esi), %eax - adcl -32(%esi), %eax - adcl -28(%esi), %eax - adcl -24(%esi), %eax - adcl -20(%esi), %eax - adcl -16(%esi), %eax - adcl -12(%esi), %eax - adcl -8(%esi), %eax - adcl -4(%esi), %eax -45: - lea 128(%esi), %esi - adcl $0, %eax - dec %ecx - jge 40b - movl %edx, %ecx -50: andl $3, %ecx - jz 80f - - # Handle the last 1-3 bytes without jumping - notl %ecx # 1->2, 2->1, 3->0, higher bits are masked - movl $0xffffff,%ebx # by the shll and shrl instructions - shll $3,%ecx - shrl %cl,%ebx - andl -128(%esi),%ebx # esi is 4-aligned so should be ok - addl %ebx,%eax - adcl $0,%eax -80: - popl %ebx - popl %esi - RET - -#endif - EXPORT_SYMBOL(csum_partial)