kernel/linux.git/arch/powerpc/net, branch v5.10.257

powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06

2022-02-01T16:25:45+00:00

[ Upstream commit 3f5f766d5f7f95a69a630da3544a1a0cee1cdddf ] Johan reported the below crash with test_bpf on ppc64 e5500: test_bpf: #296 ALU_END_FROM_LE 64: 0x0123456789abcdef -> 0x67452301 jited:1 Oops: Exception in kernel mode, sig: 4 [#1] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 Modules linked in: test_bpf(+) CPU: 0 PID: 76 Comm: insmod Not tainted 5.14.0-03771-g98c2059e008a-dirty #1 NIP: 8000000000061c3c LR: 80000000006dea64 CTR: 8000000000061c18 REGS: c0000000032d3420 TRAP: 0700 Not tainted (5.14.0-03771-g98c2059e008a-dirty) MSR: 0000000080089000 CR: 88002822 XER: 20000000 IRQMASK: 0 <...> NIP [8000000000061c3c] 0x8000000000061c3c LR [80000000006dea64] .__run_one+0x104/0x17c [test_bpf] Call Trace: .__run_one+0x60/0x17c [test_bpf] (unreliable) .test_bpf_init+0x6a8/0xdc8 [test_bpf] .do_one_initcall+0x6c/0x28c .do_init_module+0x68/0x28c .load_module+0x2460/0x2abc .__do_sys_init_module+0x120/0x18c .system_call_exception+0x110/0x1b8 system_call_common+0xf0/0x210 --- interrupt: c00 at 0x101d0acc <...> ---[ end trace 47b2bf19090bb3d0 ]--- Illegal instruction The illegal instruction turned out to be 'ldbrx' emitted for BPF_FROM_[L|B]E, which was only introduced in ISA v2.06. Guard use of the same and implement an alternative approach for older processors. Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Reported-by: Johan Almbladh Signed-off-by: Naveen N. Rao Tested-by: Johan Almbladh Acked-by: Johan Almbladh Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/d1e51c6fdf572062cf3009a751c3406bda01b832.1641468127.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Sasha Levin

powerpc/bpf: Emit stf barrier instruction sequences for BPF_NOSPEC

2021-11-18T13:04:30+00:00

upstream commit b7540d62509453263604a155bf2d5f0ed450cba2 Emit similar instruction sequences to commit a048a07d7f4535 ("powerpc/64s: Add support for a store forwarding barrier at kernel entry/exit") when encountering BPF_NOSPEC. Mitigations are enabled depending on what the firmware advertises. In particular, we do not gate these mitigations based on current settings, just like in x86. Due to this, we don't need to take any action if mitigations are enabled or disabled at runtime. Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/956570cbc191cd41f8274bed48ee757a86dac62a.1633464148.git.naveen.n.rao@linux.vnet.ibm.com [adjust macros to account for commits 1c9debbc2eb539 and ef909ba954145e. adjust security feature checks to account for commit 84ed26fd00c514] Signed-off-by: Naveen N. Rao Signed-off-by: Greg Kroah-Hartman

powerpc/bpf: Validate branch ranges

2021-11-18T13:04:30+00:00

upstream commit 3832ba4e283d7052b783dab8311df7e3590fed93 Add checks to ensure that we never emit branch instructions with truncated branch offsets. Suggested-by: Michael Ellerman Signed-off-by: Naveen N. Rao Tested-by: Johan Almbladh Reviewed-by: Christophe Leroy Acked-by: Song Liu Acked-by: Johan Almbladh Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/71d33a6b7603ec1013c9734dd8bdd4ff5e929142.1633464148.git.naveen.n.rao@linux.vnet.ibm.com [drop ppc32 changes] Signed-off-by: Naveen N. Rao Signed-off-by: Greg Kroah-Hartman

powerpc/lib: Add helper to check if offset is within conditional branch range

2021-11-18T13:04:29+00:00

upstream commit 4549c3ea3160fa8b3f37dfe2f957657bb265eda9 Add a helper to check if a given offset is within the branch range for a powerpc conditional branch instruction, and update some sites to use the new helper. Signed-off-by: Naveen N. Rao Reviewed-by: Christophe Leroy Acked-by: Song Liu Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/442b69a34ced32ca346a0d9a855f3f6cfdbbbd41.1633464148.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Naveen N. Rao Signed-off-by: Greg Kroah-Hartman

powerpc/bpf: Fix BPF_MOD when imm == 1

2021-11-02T18:48:18+00:00

commit 8bbc9d822421d9ac8ff9ed26a3713c9afc69d6c8 upstream. Only ignore the operation if dividing by 1. Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Signed-off-by: Naveen N. Rao Tested-by: Johan Almbladh Reviewed-by: Christophe Leroy Acked-by: Song Liu Acked-by: Johan Almbladh Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/c674ca18c3046885602caebb326213731c675d06.1633464148.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

powerpc/bpf: Fix BPF_SUB when imm == 0x80000000

2021-10-13T08:04:30+00:00

[ Upstream commit 5855c4c1f415ca3ba1046e77c0b3d3dfc96c9025 ] We aren't handling subtraction involving an immediate value of 0x80000000 properly. Fix the same. Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Signed-off-by: Naveen N. Rao Reviewed-by: Christophe Leroy [mpe: Fold in fix from Naveen to use imm <= 32768] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/fc4b1276eb10761fd7ce0814c8dd089da2815251.1633464148.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Sasha Levin

bpf: Introduce BPF nospec instruction for mitigating Spectre v4

2021-08-04T10:46:44+00:00

[ Upstream commit f5e81d1117501546b7be050c5fbafa6efd2c722c ] 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

bpf, powerpc: Fix misuse of fallthrough in bpf_jit_comp()

2020-09-29T14:39:11+00:00

The user defined label following "fallthrough" is not considered by GCC and causes build failure. kernel-source/include/linux/compiler_attributes.h:208:41: error: attribute 'fallthrough' not preceding a case label or default label [-Werror] 208 define fallthrough _attribute((fallthrough_)) ^~~~~~~~~~~~~ Fixes: df561f6688fe ("treewide: Use fallthrough pseudo-keyword") Signed-off-by: He Zhe Signed-off-by: Daniel Borkmann Cc: Gustavo A. R. Silva Link: https://lore.kernel.org/bpf/20200928090023.38117-1-zhe.he@windriver.com

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

powerpc/ppc-opcode: Consolidate powerpc instructions from bpf_jit.h

2020-07-16T03:12:42+00:00

Move macro definitions of powerpc instructions from bpf_jit.h to ppc-opcode.h and adopt the users of the macros accordingly. `PPC_MR()` is defined twice in bpf_jit.h, remove the duplicate one. Signed-off-by: Balamuruhan S Tested-by: Naveen N. Rao Acked-by: Naveen N. Rao Acked-by: Sandipan Das Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200624113038.908074-5-bala24@linux.ibm.com