powerpc/bpf: Various fixes #1865
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…ch range 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 <naveen.n.rao@linux.vnet.ibm.com>
Add checks to ensure that we never emit branch instructions with truncated branch offsets. Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
SEEN_STACK is unused on PowerPC. Remove it. Also, have SEEN_TAILCALL use 0x40000000. Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
In some scenarios, it is possible that the program epilogue is outside the branch range for a BPF_EXIT instruction. Instead of rejecting such programs, emit an indirect branch. We track the size of the bpf program emitted after the initial run and do a second pass since BPF_EXIT can end up emitting different number of instructions depending on the program size. Suggested-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Only ignore the operation if dividing by 1. Fixes: 156d0e2 ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
We aren't handling subtraction involving an immediate value of 0x80000000 properly. Fix the same. Fixes: 156d0e2 ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
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 <EE,ME> 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: 156d0e2 ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Add a helper to return the stf_barrier type for the current processor. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Emit similar instruction sequences to commit a048a07 ("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 <naveen.n.rao@linux.vnet.ibm.com>
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Master branch: b0e875b |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=556517 irrelevant now. Closing PR. |
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Pull request for series with
subject: powerpc/bpf: Various fixes
version: 1
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=556517