kernel.git/arch/sparc/net, branch linux-5.4.y

bpf: Introduce BPF nospec instruction for mitigating Spectre v4

2021-09-15T07:47:38Z

commit f5e81d1117501546b7be050c5fbafa6efd2c722c upstream. In case of JITs, each of the JIT backends compiles the BPF nospec instruction /either/ to a machine instruction which emits a speculation barrier /or/ to /no/ machine instruction in case the underlying architecture is not affected by Speculative Store Bypass or has different mitigations in place already. This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence' instruction for mitigation. In case of arm64, we rely on the firmware mitigation as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled, it works for all of the kernel code with no need to provide any additional instructions here (hence only comment in arm64 JIT). Other archs can follow as needed. The BPF nospec instruction is specifically targeting Spectre v4 since i) we don't use a serialization barrier for the Spectre v1 case, and ii) mitigation instructions for v1 and v4 might be different on some archs. The BPF nospec is required for a future commit, where the BPF verifier does annotate intermediate BPF programs with speculation barriers. Co-developed-by: Piotr Krysiuk Co-developed-by: Benedict Schlueter Signed-off-by: Daniel Borkmann Signed-off-by: Piotr Krysiuk Signed-off-by: Benedict Schlueter Acked-by: Alexei Starovoitov Signed-off-by: Sasha Levin [OP: - adjusted context for 5.4 - apply riscv changes to /arch/riscv/net/bpf_jit_comp.c] Signed-off-by: Ovidiu Panait Signed-off-by: Greg Kroah-Hartman

sparc: bpf: eliminate zero extension code-gen

2019-05-25T01:58:38Z

Cc: David S. Miller Signed-off-by: Jiong Wang Signed-off-by: Alexei Starovoitov

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46Z

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 Signed-off-by: Greg Kroah-Hartman

bpf: sparc64: Enable sparc64 jit to provide bpf_line_info

2018-12-20T01:04:53Z

This patch enables sparc64's bpf_int_jit_compile() to provide bpf_line_info by calling bpf_prog_fill_jited_linfo(). Signed-off-by: Martin KaFai Lau Acked-by: David S. Miller Signed-off-by: Daniel Borkmann

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2018-11-29T06:10:54Z

Trivial conflict in net/core/filter.c, a locally computed 'sdif' is now an argument to the function. Signed-off-by: David S. Miller

sparc: Adjust bpf JIT prologue for PSEUDO calls.

2018-11-27T08:46:52Z

Move all arguments into output registers from input registers. This path is exercised by test_verifier.c's "calls: two calls with args" test. Adjust BPF_TAILCALL_PROLOGUE_SKIP as needed. Let's also make the prologue length a constant size regardless of the combination of ->saw_frame_pointer and ->saw_tail_call settings. Signed-off-by: David S. Miller Signed-off-by: Daniel Borkmann

sparc: Correct ctx->saw_frame_pointer logic.

2018-11-27T01:52:29Z

We need to initialize the frame pointer register not just if it is seen as a source operand, but also if it is seen as the destination operand of a store or an atomic instruction (which effectively is a source operand). This is exercised by test_verifier's "non-invalid fp arithmetic" Signed-off-by: David S. Miller Signed-off-by: Alexei Starovoitov

sparc: Fix JIT fused branch convergance.

2018-11-27T01:48:36Z

On T4 and later sparc64 cpus we can use the fused compare and branch instruction. However, it can only be used if the branch destination is in the range of a signed 10-bit immediate offset. This amounts to 1024 instructions forwards or backwards. After the commit referenced in the Fixes: tag, the largest possible size program seen by the JIT explodes by a significant factor. As a result of this convergance takes many more passes since the expanded "BPF_LDX | BPF_MSH | BPF_B" code sequence, for example, contains several embedded branch on condition instructions. On each pass, as suddenly new fused compare and branch instances become valid, this makes thousands more in range for the next pass. And so on and so forth. This is most greatly exemplified by "BPF_MAXINSNS: exec all MSH" which takes 35 passes to converge, and shrinks the image by about 64K. To decrease the cost of this number of convergance passes, do the convergance pass before we have the program image allocated, just like other JITs (such as x86) do. Fixes: e0cea7ce988c ("bpf: implement ld_abs/ld_ind in native bpf") Signed-off-by: David S. Miller Signed-off-by: Alexei Starovoitov

net: remove VLAN_TAG_PRESENT

2018-11-17T03:25:29Z

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 Signed-off-by: David S. Miller

net/bpf_jit: SPARC: split VLAN_PRESENT bit handling from VLAN_TCI

2018-11-17T03:25:28Z

Signed-off-by: Michał Mirosław Signed-off-by: David S. Miller