kernel/linux.git/arch/powerpc/net, branch v6.12.103

bpf, arm64, powerpc: Add bpf_jit_bypass_spec_v1/v4()

2026-07-24T14:11:52+00:00

[ Upstream commit 03c68a0f8c68936a0bb915b030693923784724cb ] JITs can set bpf_jit_bypass_spec_v1/v4() if they want the verifier to skip analysis/patching for the respective vulnerability. For v4, this will reduce the number of barriers the verifier inserts. For v1, it allows more programs to be accepted. The primary motivation for this is to not regress unpriv BPF's performance on ARM64 in a future commit where BPF_NOSPEC is also used against Spectre v1. This has the user-visible change that v1-induced rejections on non-vulnerable PowerPC CPUs are avoided. For now, this does not change the semantics of BPF_NOSPEC. It is still a v4-only barrier and must not be implemented if bypass_spec_v4 is always true for the arch. Changing it to a v1 AND v4-barrier is done in a future commit. As an alternative to bypass_spec_v1/v4, one could introduce NOSPEC_V1 AND NOSPEC_V4 instructions and allow backends to skip their lowering as suggested by commit f5e81d111750 ("bpf: Introduce BPF nospec instruction for mitigating Spectre v4"). Adding bpf_jit_bypass_spec_v1/v4() was found to be preferable for the following reason: * bypass_spec_v1/v4 benefits non-vulnerable CPUs: Always performing the same analysis (not taking into account whether the current CPU is vulnerable), needlessly restricts users of CPUs that are not vulnerable. The only use case for this would be portability-testing, but this can later be added easily when needed by allowing users to force bypass_spec_v1/v4 to false. * Portability is still acceptable: Directly disabling the analysis instead of skipping the lowering of BPF_NOSPEC(_V1/V4) might allow programs on non-vulnerable CPUs to be accepted while the program will be rejected on vulnerable CPUs. With the fallback to speculation barriers for Spectre v1 implemented in a future commit, this will only affect programs that do variable stack-accesses or are very complex. For PowerPC, the SEC_FTR checking in bpf_jit_bypass_spec_v4() is based on the check that was previously located in the BPF_NOSPEC case. For LoongArch, it would likely be safe to set both bpf_jit_bypass_spec_v1() and _v4() according to commit a6f6a95f2580 ("LoongArch, bpf: Fix jit to skip speculation barrier opcode"). This is omitted here as I am unable to do any testing for LoongArch. Hari's ack concerns the PowerPC part only. Signed-off-by: Luis Gerhorst Acked-by: Hari Bathini Cc: Henriette Herzog Cc: Maximilian Ott Cc: Milan Stephan Link: https://lore.kernel.org/r/20250603211318.337474-1-luis.gerhorst@fau.de Signed-off-by: Alexei Starovoitov Stable-dep-of: 2f884d371faf ("bpf: Allow LPM map access from sleepable BPF programs") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

bpf: Restrict JIT predictor flush to cBPF

2026-07-24T14:10:39+00:00

commit 0bb99f2cfaae6822d734d69722de30af823efdf3 upstream. Currently predictor flush on memory reuse is done for all BPF JIT allocations, but only cBPF programs can be loaded by an unprivileged user. eBPF is privileged by default, and flushing predictors for all CPUs on every eBPF reuse penalizes the common case for no security benefit. eBPF allocations can be frequent on busy systems, only flush predictors for cBPF programs. Trampoline and dispatcher allocations also skip the flush as they are eBPF-only. [pawan: backport dropped "was_classic" hunk for arches that do not support pack allocator] Signed-off-by: Pawan Gupta Acked-by: Daniel Borkmann Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin

powerpc64/bpf: do not increment tailcall count when prog is NULL

2026-04-02T11:09:49+00:00

commit 521bd39d9d28ce54cbfec7f9b89c94ad4fdb8350 upstream. Do not increment tailcall count, if tailcall did not succeed due to missing BPF program. Fixes: ce0761419fae ("powerpc/bpf: Implement support for tail calls") Cc: stable@vger.kernel.org Tested-by: Venkat Rao Bagalkote Signed-off-by: Hari Bathini Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260303181031.390073-2-hbathini@linux.ibm.com [ Conflict due to missing feature commit 2ed2d8f6fb38 ("powerpc64/bpf: Support tailcalls with subprogs") resolved accordingly. ] Signed-off-by: Hari Bathini Signed-off-by: Greg Kroah-Hartman

powerpc64/bpf: fix kfunc call support

2026-03-25T10:08:48+00:00

[ Upstream commit 01b6ac72729610ae732ca2a66e3a642e23f6cd60 ] Commit 61688a82e047 ("powerpc/bpf: enable kfunc call") inadvertently enabled kfunc call support for 32-bit powerpc but that support will not be possible until ABI mismatch between 32-bit powerpc and eBPF is handled in 32-bit powerpc JIT code. Till then, advertise support only for 64-bit powerpc. Also, in powerpc ABI, caller needs to extend the arguments properly based on signedness. The JIT code is responsible for handling this explicitly for kfunc calls as verifier can't handle this for each architecture-specific ABI needs. But this was not taken care of while kfunc call support was enabled for powerpc. Fix it by handling this with bpf_jit_find_kfunc_model() and using zero_extend() & sign_extend() helper functions. Fixes: 61688a82e047 ("powerpc/bpf: enable kfunc call") Cc: stable@vger.kernel.org Signed-off-by: Hari Bathini Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260303181031.390073-7-hbathini@linux.ibm.com Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc64/bpf: Fold bpf_jit_emit_func_call_hlp() into bpf_jit_emit_func_call_rel()

2026-03-25T10:08:48+00:00

[ Upstream commit 9670f6d2097c4f97e15c67920dfddc664d7ee91c ] Commit 61688a82e047 ("powerpc/bpf: enable kfunc call") enhanced bpf_jit_emit_func_call_hlp() to handle calls out to module region, where bpf progs are generated. The only difference now between bpf_jit_emit_func_call_hlp() and bpf_jit_emit_func_call_rel() is in handling of the initial pass where target function address is not known. Fold that logic into bpf_jit_emit_func_call_hlp() and rename it to bpf_jit_emit_func_call_rel() to simplify bpf function call JIT code. We don't actually need to load/restore TOC across a call out to a different kernel helper or to a different bpf program since they all work with the kernel TOC. We only need to do it if we have to call out to a module function. So, guard TOC load/restore with appropriate conditions. Signed-off-by: Naveen N Rao Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241030070850.1361304-10-hbathini@linux.ibm.com Stable-dep-of: 01b6ac727296 ("powerpc64/bpf: fix kfunc call support") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Merge tag 'powerpc-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2024-07-20T04:00:33+00:00

Pull powerpc updates from Michael Ellerman: - Remove support for 40x CPUs & platforms - Add support to the 64-bit BPF JIT for cpu v4 instructions - Fix PCI hotplug driver crash on powernv - Fix doorbell emulation for KVM on PAPR guests (nestedv2) - Fix KVM nested guest handling of some less used SPRs - Online NUMA nodes with no CPU/memory if they have a PCI device attached - Reduce memory overhead of enabling kfence on 64-bit Radix MMU kernels - Reimplement the iommu table_group_ops for pseries for VFIO SPAPR TCE Thanks to: Anjali K, Artem Savkov, Athira Rajeev, Breno Leitao, Brian King, Celeste Liu, Christophe Leroy, Esben Haabendal, Gaurav Batra, Gautam Menghani, Haren Myneni, Hari Bathini, Jeff Johnson, Krishna Kumar, Krzysztof Kozlowski, Nathan Lynch, Nicholas Piggin, Nick Bowler, Nilay Shroff, Rob Herring (Arm), Shawn Anastasio, Shivaprasad G Bhat, Sourabh Jain, Srikar Dronamraju, Timothy Pearson, Uwe Kleine-König, and Vaibhav Jain. * tag 'powerpc-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (57 commits) Documentation/powerpc: Mention 40x is removed powerpc: Remove 40x leftovers macintosh/therm_windtunnel: fix module unload. powerpc: Check only single values are passed to CPU/MMU feature checks powerpc/xmon: Fix disassembly CPU feature checks powerpc: Drop clang workaround for builtin constant checks powerpc64/bpf: jit support for signed division and modulo powerpc64/bpf: jit support for sign extended mov powerpc64/bpf: jit support for sign extended load powerpc64/bpf: jit support for unconditional byte swap powerpc64/bpf: jit support for 32bit offset jmp instruction powerpc/pci: Hotplug driver bridge support pci/hotplug/pnv_php: Fix hotplug driver crash on Powernv powerpc/configs: Update defconfig with now user-visible CONFIG_FSL_IFC powerpc: add missing MODULE_DESCRIPTION() macros macintosh/mac_hid: add MODULE_DESCRIPTION() KVM: PPC: add missing MODULE_DESCRIPTION() macros powerpc/kexec: Use of_property_read_reg() powerpc/64s/radix/kfence: map __kfence_pool at page granularity powerpc/pseries/iommu: Define spapr_tce_table_group_ops only with CONFIG_IOMMU_API ...

powerpc64/bpf: jit support for signed division and modulo

2024-07-11T05:40:21+00:00

Add jit support for sign division and modulo. Tested using test_bpf module. Signed-off-by: Artem Savkov Signed-off-by: Michael Ellerman Link: https://msgid.link/20240517075650.248801-6-asavkov@redhat.com

powerpc64/bpf: jit support for sign extended mov

2024-07-11T05:40:21+00:00

Add jit support for sign extended mov. Tested using test_bpf module. Signed-off-by: Artem Savkov Signed-off-by: Michael Ellerman Link: https://msgid.link/20240517075650.248801-5-asavkov@redhat.com

powerpc64/bpf: jit support for sign extended load

2024-07-11T05:40:21+00:00

Add jit support for sign extended load. Tested using test_bpf module. Signed-off-by: Artem Savkov Signed-off-by: Michael Ellerman Link: https://msgid.link/20240517075650.248801-4-asavkov@redhat.com

powerpc64/bpf: jit support for unconditional byte swap

2024-07-11T05:40:21+00:00

Add jit support for unconditional byte swap. Tested using BSWAP tests from test_bpf module. Signed-off-by: Artem Savkov Reviewed-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://msgid.link/20240517075650.248801-3-asavkov@redhat.com