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A subsequent patch will add additional atomic operations. These new
operations will use the same opcode field as the existing XADD, with
the immediate discriminating different operations.
In preparation, rename the instruction mode BPF_ATOMIC and start
calling the zero immediate BPF_ADD.
This is possible (doesn't break existing valid BPF progs) because the
immediate field is currently reserved MBZ and BPF_ADD is zero.
All uses are removed from the tree but the BPF_XADD definition is
kept around to avoid breaking builds for people including kernel
headers.
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@gmail.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-5-jackmanb@google.com
Commit 716850ab10 ("MIPS: eBPF: Initial eBPF support for MIPS32
architecture.") enabled our eBPF JIT for MIPS32 kernels, whereas it has
previously only been availailable for MIPS64. It was my understanding at
the time that the BPF test suite was passing & JITing a comparable
number of tests to our cBPF JIT [1], but it turns out that was not the
case.
The eBPF JIT has a number of problems on MIPS32:
- Most notably various code paths still result in emission of MIPS64
instructions which will cause reserved instruction exceptions & kernel
panics when run on MIPS32 CPUs.
- The eBPF JIT doesn't account for differences between the O32 ABI used
by MIPS32 kernels versus the N64 ABI used by MIPS64 kernels. Notably
arguments beyond the first 4 are passed on the stack in O32, and this
is entirely unhandled when JITing a BPF_CALL instruction. Stack space
must be reserved for arguments even if they all fit in registers, and
the callee is free to assume that stack space has been reserved for
its use - with the eBPF JIT this is not the case, so calling any
function can result in clobbering values on the stack & unpredictable
behaviour. Function arguments in eBPF are always 64-bit values which
is also entirely unhandled - the JIT still uses a single (32-bit)
register per argument. As a result all function arguments are always
passed incorrectly when JITing a BPF_CALL instruction, leading to
kernel crashes or strange behavior.
- The JIT attempts to bail our on use of ALU64 instructions or 64-bit
memory access instructions. The code doing this at the start of
build_one_insn() incorrectly checks whether BPF_OP() equals BPF_DW,
when it should really be checking BPF_SIZE() & only doing so when
BPF_CLASS() is one of BPF_{LD,LDX,ST,STX}. This results in false
positives that cause more bailouts than intended, and that in turns
hides some of the problems described above.
- The kernel's cBPF->eBPF translation makes heavy use of 64-bit eBPF
instructions that the MIPS32 eBPF JIT bails out on, leading to most
cBPF programs not being JITed at all.
Until these problems are resolved, revert the removal of the cBPF JIT
performed by commit 716850ab10 ("MIPS: eBPF: Initial eBPF support for
MIPS32 architecture."). Together with commit f8fffebdea ("MIPS: BPF:
Disable MIPS32 eBPF JIT") this restores MIPS32 BPF JIT behavior back to
the same state it was prior to the introduction of the broken eBPF JIT
support.
[1] https://lore.kernel.org/linux-mips/MWHPR2201MB13583388481F01A422CE7D66D4410@MWHPR2201MB1358.namprd22.prod.outlook.com/
Signed-off-by: Paul Burton <paulburton@kernel.org>
Fixes: 716850ab10 ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture.")
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Hassan Naveed <hnaveed@wavecomp.com>
Cc: Tony Ambardar <itugrok@yahoo.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Pull MIPS fixes from Paul Burton:
"A collection of MIPS fixes:
- Fill the struct cacheinfo shared_cpu_map field with sensible
values, notably avoiding issues with perf which was unhappy in the
absence of these values.
- A boot fix for Loongson 2E & 2F machines which was fallout from
some refactoring performed this cycle.
- A Kconfig dependency fix for the Loongson CPU HWMon driver.
- A couple of VDSO fixes, ensuring gettimeofday() behaves
appropriately for kernel configurations that don't include support
for a clocksource the VDSO can use & fixing the calling convention
for the n32 & n64 VDSOs which would previously clobber the $gp/$28
register.
- A build fix for vmlinuz compressed images which were
inappropriately building with -fsanitize-coverage despite not being
part of the kernel proper, then failing to link due to the missing
__sanitizer_cov_trace_pc() function.
- A couple of eBPF JIT fixes, including disabling it for MIPS32 due
to a large number of issues with the code generated there &
reflecting ISA dependencies in Kconfig to enforce that systems
which don't support the JIT must include the interpreter"
* tag 'mips_fixes_5.5_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: Avoid VDSO ABI breakage due to global register variable
MIPS: BPF: eBPF JIT: check for MIPS ISA compliance in Kconfig
MIPS: BPF: Disable MIPS32 eBPF JIT
MIPS: Prevent link failure with kcov instrumentation
MIPS: Kconfig: Use correct form for 'depends on'
mips: Fix gettimeofday() in the vdso library
MIPS: Fix boot on Fuloong2 systems
mips: cacheinfo: report shared CPU map
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 315 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull MIPS updates from Paul Burton:
- A set of memblock initialization improvements thanks to Serge Semin,
tidying up after our conversion from bootmem to memblock back in
v4.20.
- Our eBPF JIT the previously supported only MIPS64r2 through MIPS64r5
is improved to also support MIPS64r6. Support for MIPS32 systems is
introduced, with the caveat that it only works for programs that
don't use 64 bit registers or operations - those will bail out & need
to be interpreted.
- Improvements to the allocation & configuration of our exception
vector that should fix issues seen on some platforms using recent
versions of U-Boot.
- Some minor improvements to code generated for jump labels, along with
enabling them by default for generic kernels.
* tag 'mips_5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (27 commits)
mips: Manually call fdt_init_reserved_mem() method
mips: Make sure dt memory regions are valid
mips: Perform early low memory test
mips: Dump memblock regions for debugging
mips: Add reserve-nomap memory type support
mips: Use memblock to reserve the __nosave memory range
mips: Discard post-CMA-init foreach loop
mips: Reserve memory for the kernel image resources
MIPS: Remove duplicate EBase configuration
MIPS: Sync icache for whole exception vector
MIPS: Always allocate exception vector for MIPSr2+
MIPS: Use memblock_phys_alloc() for exception vector
mips: Combine memblock init and memory reservation loops
mips: Discard rudiments from bootmem_init
mips: Make sure kernel .bss exists in boot mem pool
mips: vdso: drop unnecessary cc-ldoption
Revert "MIPS: ralink: fix cpu clock of mt7621 and add dt clk devices"
MIPS: generic: Enable CONFIG_JUMP_LABEL
MIPS: jump_label: Use compact branches for >= r6
MIPS: jump_label: Remove redundant nops
...
Fix sparse warning:
arch/mips/net/ebpf_jit.c:196:5: warning:
symbol 'ebpf_to_mips_reg' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The MIPS eBPF JIT calls flush_icache_range() in order to ensure the
icache observes the code that we just wrote. Unfortunately it gets the
end address calculation wrong due to some bad pointer arithmetic.
The struct jit_ctx target field is of type pointer to u32, and as such
adding one to it will increment the address being pointed to by 4 bytes.
Therefore in order to find the address of the end of the code we simply
need to add the number of 4 byte instructions emitted, but we mistakenly
add the number of instructions multiplied by 4. This results in the call
to flush_icache_range() operating on a memory region 4x larger than
intended, which is always wasteful and can cause crashes if we overrun
into an unmapped page.
Fix this by correcting the pointer arithmetic to remove the bogus
multiplication, and use braces to remove the need for a set of brackets
whilst also making it obvious that the target field is a pointer.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: b6bd53f9c4 ("MIPS: Add missing file for eBPF JIT.")
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
REG_32BIT_ZERO_EX and REG_64BIT are always handled in exactly the same
way, and reg_val_propagate_range() never actually sets any register to
type REG_32BIT_ZERO_EX.
Remove the redundant & unused REG_32BIT_ZERO_EX.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The function prototype used to call JITed eBPF code (ie. the type of the
struct bpf_prog bpf_func field) returns an unsigned int. The MIPS n64
ABI that MIPS64 kernels target defines that 32 bit integers should
always be sign extended when passed in registers as either arguments or
return values.
This means that when returning any value which may not already be sign
extended (ie. of type REG_64BIT or REG_32BIT_ZERO_EX) we need to perform
that sign extension in order to comply with the n64 ABI. Without this we
see strange looking test failures from test_bpf.ko, such as:
test_bpf: #65 ALU64_MOV_X:
dst = 4294967295 jited:1 ret -1 != -1 FAIL (1 times)
Although the return value printed matches the expected value, this is
only because printf is only examining the least significant 32 bits of
the 64 bit register value we returned. The register holding the expected
value is sign extended whilst the v0 register was set to a zero extended
value by our JITed code, so when compared by a conditional branch
instruction the values are not equal.
We already handle this when the return value register is of type
REG_32BIT_ZERO_EX, so simply extend this to also cover REG_64BIT.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: b6bd53f9c4 ("MIPS: Add missing file for eBPF JIT.")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Replace VLAN_TAG_PRESENT with single bit flag and free up
VLAN.CFI overload. Now VLAN.CFI is visible in networking stack
and can be passed around intact.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ool_skb_header_pointer() and size_to_len() is unused same as
tmp_offset, therefore remove all of them.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from mips64 JIT.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The verifier in both cBPF and eBPF reject div/mod by 0 imm,
so this can never load. Remove emitting such test and reject
it from being JITed instead (the latter is actually also not
needed, but given practice in sparc64, ppc64 today, so
doesn't hurt to add it here either).
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Daney <david.daney@cavium.com>
Reviewed-by: David Daney <david.daney@cavium.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since we've changed div/mod exception handling for src_reg in
eBPF verifier itself, remove the leftovers from mips64 JIT.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Daney <david.daney@cavium.com>
Reviewed-by: David Daney <david.daney@cavium.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Having a pure_initcall() callback just to permanently enable BPF
JITs under CONFIG_BPF_JIT_ALWAYS_ON is unnecessary and could leave
a small race window in future where JIT is still disabled on boot.
Since we know about the setting at compilation time anyway, just
initialize it properly there. Also consolidate all the individual
bpf_jit_enable variables into a single one and move them under one
location. Moreover, don't allow for setting unspecified garbage
values on them.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
global bpf_jit_enable variable is tested multiple times in JITs,
blinding and verifier core. The malicious root can try to toggle
it while loading the programs. This race condition was accounted
for and there should be no issues, but it's safer to avoid
this race condition.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Compiling ebpf_jit.c with gcc 4.9 results in a (likely spurious)
compiler warning, as gcc has detected that the variable "target" may be
used uninitialised. Since -Werror is active, this is treated as an error
and causes a kernel build failure whenever CONFIG_MIPS_EBPF_JIT is
enabled.
arch/mips/net/ebpf_jit.c: In function 'build_one_insn':
arch/mips/net/ebpf_jit.c:1118:80: error: 'target' may be used
uninitialized in this function [-Werror=maybe-uninitialized]
emit_instr(ctx, j, target);
^
cc1: all warnings being treated as errors
Fix this by initialising "target" to 0. If it really is used
uninitialised this would result in a jump to 0 and a detectable run time
failure.
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Fixes: b6bd53f9c4 ("MIPS: Add missing file for eBPF JIT.")
Cc: James Hogan <james.hogan@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: <stable@vger.kernel.org> # v4.13+
Patchwork: https://patchwork.linux-mips.org/patch/17375/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
There is a missing break causing a fall-through and setting
ctx.use_bbit_insns to the wrong value. Fix this by adding the
missing break.
Detected with cppcheck:
"Variable 'ctx.use_bbit_insns' is reassigned a value before the old
one has been used. 'break;' missing?"
Fixes: 8d8d18c328 ("MIPS,bpf: Fix using smp_processor_id() in preemptible splat.")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The code looks a little cleaner if we replace BPF_OP(insn->code) with
the local variable bpf_op. Caching the value this way also saves 300
bytes (about 1%) in the code size of the JIT.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the kernel is configured with preemption enabled we were getting
warning stack traces for use of current_cpu_type().
Fix by moving the test between preempt_disable()/preempt_enable() and
caching the results of the CPU type tests for use during code
generation.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Inexplicably, commit f381bf6d82 ("MIPS: Add support for eBPF JIT.")
lost a file somewhere on its path to Linus' tree. Add back the
missing ebpf_jit.c so that we can build with CONFIG_BPF_JIT selected.
This version of ebpf_jit.c is identical to the original except for two
minor change need to resolve conflicts with changes merged from the
BPF branch:
A) Set prog->jited_len = image_size;
B) Use BPF_TAIL_CALL instead of BPF_CALL | BPF_X
Fixes: f381bf6d82 ("MIPS: Add support for eBPF JIT.")
Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for 4.8. Also includes is a
minor SSB cleanup as SSB code traditionally is merged through the MIPS
tree:
ATH25:
- MIPS: Add default configuration for ath25
Boot:
- For zboot, copy appended dtb to the end of the kernel
- store the appended dtb address in a variable
BPF:
- Fix off by one error in offset allocation
Cobalt code:
- Fix typos
Core code:
- debugfs_create_file returns NULL on error, so don't use IS_ERR for
testing for errors.
- Fix double locking issue in RM7000 S-cache code. This would only
affect RM7000 ARC systems on reboot.
- Fix page table corruption on THP permission changes.
- Use compat_sys_keyctl for 32 bit userspace on 64 bit kernels.
David says, there are no compatibility issues raised by this fix.
- Move some signal code around.
- Rewrite r4k count/compare clockevent device registration such that
min_delta_ticks/max_delta_ticks files are guaranteed to be
initialized.
- Only register r4k count/compare as clockevent device if we can
assume the clock to be constant.
- Fix MSA asm warnings in control reg accessors
- uasm and tlbex fixes and tweaking.
- Print segment physical address when EU=1.
- Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO.
- CP: Allow booting by VP other than VP 0
- Cache handling fixes and optimizations for r4k class caches
- Add hotplug support for R6 processors
- Cleanup hotplug bits in kconfig
- traps: return correct si code for accessing nonmapped addresses
- Remove cpu_has_safe_index_cacheops
Lantiq:
- Register IRQ handler for virtual IRQ number
- Fix EIU interrupt loading code
- Use the real EXIN count
- Fix build error.
Loongson 3:
- Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLES
Octeon:
- Delete built-in DTB pruning code for D-Link DSR-1000N.
- Clean up GPIO definitions in dlink_dsr-1000n.dts.
- Add more LEDs to the DSR-100n DTS
- Fix off by one in octeon_irq_gpio_map()
- Typo fixes
- Enable SATA by default in cavium_octeon_defconfig
- Support readq/writeq()
- Remove forced mappings of USB interrupts.
- Ensure DMA descriptors are always in the low 4GB
- Improve USB reset code for OCTEON II.
Pistachio:
- Add maintainers entry for pistachio SoC Support
- Remove plat_setup_iocoherency
Ralink:
- Fix pwm UART in spis group pinmux.
SSB:
- Change bare unsigned to unsigned int to suit coding style
Tools:
- Fix reloc tool compiler warnings.
Other:
- Delete use of ARCH_WANT_OPTIONAL_GPIOLIB"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (61 commits)
MIPS: mm: Fix definition of R6 cache instruction
MIPS: tools: Fix relocs tool compiler warnings
MIPS: Cobalt: Fix typo
MIPS: Octeon: Fix typo
MIPS: Lantiq: Fix build failure
MIPS: Use CPHYSADDR to implement mips32 __pa
MIPS: Octeon: Dlink_dsr-1000n.dts: add more leds.
MIPS: Octeon: Clean up GPIO definitions in dlink_dsr-1000n.dts.
MIPS: Octeon: Delete built-in DTB pruning code for D-Link DSR-1000N.
MIPS: store the appended dtb address in a variable
MIPS: ZBOOT: copy appended dtb to the end of the kernel
MIPS: ralink: fix spis group pinmux
MIPS: Factor o32 specific code into signal_o32.c
MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is present
MIPS: Use per-mm page to execute branch delay slot instructions
MIPS: Modify error handling
MIPS: c-r4k: Use SMP calls for CM indexed cache ops
MIPS: c-r4k: Avoid small flush_icache_range SMP calls
MIPS: c-r4k: Local flush_icache_range cache op override
MIPS: c-r4k: Split r4k_flush_kernel_vmap_range()
...
The SKF_AD_ALU_XOR_X ancillary is not like the other ancillary data
instructions since it XORs A with X while all the others replace A with
some loaded value. All the BPF JITs fail to clear A if this is used as
the first instruction in a filter. This was found using american fuzzy
lop.
Add a helper to determine if A needs to be cleared given the first
instruction in a filter, and use this in the JITs. Except for ARM, the
rest have only been compile-tested.
Fixes: 3480593131 ("net: filter: get rid of BPF_S_* enum")
Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/usb/asix_common.c
net/ipv4/inet_connection_sock.c
net/switchdev/switchdev.c
In the inet_connection_sock.c case the request socket hashing scheme
is completely different in net-next.
The other two conflicts were overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
As we need to add further flags to the bpf_prog structure, lets migrate
both bools to a bitfield representation. The size of the base structure
(excluding insns) remains unchanged at 40 bytes.
Add also tags for the kmemchecker, so that it doesn't throw false
positives. Even in case gcc would generate suboptimal code, it's not
being accessed in performance critical paths.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The entire bpf_jit_asm.S is written in noreorder mode because "we know
better" according to a comment. This also prevented the assembler from
throwing in the required NOPs for MIPS I processors which have no
load-use interlock, thus the load's consumer might end up using the
old value of the register from prior to the load.
Fixed by putting the assembler in reorder mode for just the affected
load instructions. This is not enough for gas to actually try to be
clever by looking at the next instruction and inserting a nop only
when needed but as the comment said "we know better", so getting gas
to unconditionally emit a NOP is just right in this case and prevents
adding further ifdefery.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
FEXPORT also marks the symbol as code using .type symbol, @function.
Without objdump -d will output only a hexdump for code following the
affected symbols.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The rotr, seh and wsbh instructions have been introduced with the R2
ISA. Thus the current BPF code fails to build on pre-R2 little endian
CPUs:
CC arch/mips/net/bpf_jit.o
AS arch/mips/net/bpf_jit_asm.o
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S: Assembler messages:
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:67: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $8,$19'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:68: Error: opcode not supported on this processor: mips32 (mips32) `rotr $19,$8,16'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:83: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $8,$19'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:84: Error: opcode not supported on this processor: mips32 (mips32) `seh $19,$8'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:151: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $8,$12'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:153: Error: opcode not supported on this processor: mips32 (mips32) `rotr $19,$8,16'
/home/aurel32/linux-4.2/arch/mips/net/bpf_jit_asm.S:164: Error: opcode not supported on this processor: mips32 (mips32) `wsbh $19,$12'
/home/aurel32/linux-4.2/scripts/Makefile.build:294: recipe for target 'arch/mips/net/bpf_jit_asm.o' failed
Fix that by providing equivalent code for these CPUs.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: stable@vger.kernel.org # v4.2+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11098/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit introduces BPF ASM helpers for MIPS and MIPS64 kernels.
The purpose of this patch is to twofold:
1) We are now able to handle negative offsets instead of either
falling back to the interpreter or to simply not do anything and
bail out.
2) Optimize reads from the packet header instead of calling the C
helpers
Because of this patch, we are now able to get rid of quite a bit of
code in the JIT generation process by using MIPS optimized assembly
code. The new assembly code makes the test_bpf testsuite happy with
all 60 test passing successfully compared to the previous
implementation where 2 tests were failing.
Doing some basic analysis in the results between the old
implementation and the new one we can obtain the following
summary running current mainline on an ER8 board (+/- 30us delta is
ignored to prevent noise from kernel scheduling or IRQ latencies):
Summary: 22 tests are faster, 7 are slower and 47 saw no improvement
with the most notable improvement being the tcpdump tests. The 7 tests
that seem to be a bit slower is because they all follow the slow path
(bpf_internal_load_pointer_neg_helper) which is meant to be slow so
that's not a problem.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: netdev@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/10530/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
