kernel.git/arch/powerpc/net, branch linux-5.16.y

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

2022-02-01T16:29:12Z

[ 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: Update ldimm64 instructions during extra pass

2022-02-01T16:29:01Z

commit f9320c49993ca3c0ec0f9a7026b313735306bb8b upstream. These instructions are updated after the initial JIT, so redo codegen during the extra pass. Rename bpf_jit_fixup_subprog_calls() to clarify that this is more than just subprog calls. Fixes: 69c087ba6225b5 ("bpf: Add bpf_for_each_map_elem() helper") Cc: stable@vger.kernel.org # v5.15 Signed-off-by: Naveen N. Rao Tested-by: Jiri Olsa Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/7cc162af77ba918eb3ecd26ec9e7824bc44b1fae.1641468127.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc32/bpf: Fix codegen for bpf-to-bpf calls

2022-02-01T16:29:01Z

commit fab07611fb2e6a15fac05c4583045ca5582fd826 upstream. Pad instructions emitted for BPF_CALL so that the number of instructions generated does not change for different function addresses. This is especially important for calls to other bpf functions, whose address will only be known during extra pass. Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32") Cc: stable@vger.kernel.org # v5.13+ Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/52d8fe51f7620a6f27f377791564d79d75463576.1641468127.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman

bpf: Change value of MAX_TAIL_CALL_CNT from 32 to 33

2022-01-27T11:02:14Z

[ Upstream commit ebf7f6f0a6cdcc17a3da52b81e4b3a98c4005028 ] In the current code, the actual max tail call count is 33 which is greater than MAX_TAIL_CALL_CNT (defined as 32). The actual limit is not consistent with the meaning of MAX_TAIL_CALL_CNT and thus confusing at first glance. We can see the historical evolution from commit 04fd61ab36ec ("bpf: allow bpf programs to tail-call other bpf programs") and commit f9dabe016b63 ("bpf: Undo off-by-one in interpreter tail call count limit"). In order to avoid changing existing behavior, the actual limit is 33 now, this is reasonable. After commit 874be05f525e ("bpf, tests: Add tail call test suite"), we can see there exists failed testcase. On all archs when CONFIG_BPF_JIT_ALWAYS_ON is not set: # echo 0 > /proc/sys/net/core/bpf_jit_enable # modprobe test_bpf # dmesg | grep -w FAIL Tail call error path, max count reached jited:0 ret 34 != 33 FAIL On some archs: # echo 1 > /proc/sys/net/core/bpf_jit_enable # modprobe test_bpf # dmesg | grep -w FAIL Tail call error path, max count reached jited:1 ret 34 != 33 FAIL Although the above failed testcase has been fixed in commit 18935a72eb25 ("bpf/tests: Fix error in tail call limit tests"), it would still be good to change the value of MAX_TAIL_CALL_CNT from 32 to 33 to make the code more readable. The 32-bit x86 JIT was using a limit of 32, just fix the wrong comments and limit to 33 tail calls as the constant MAX_TAIL_CALL_CNT updated. For the mips64 JIT, use "ori" instead of "addiu" as suggested by Johan Almbladh. For the riscv JIT, use RV_REG_TCC directly to save one register move as suggested by Björn Töpel. For the other implementations, no function changes, it does not change the current limit 33, the new value of MAX_TAIL_CALL_CNT can reflect the actual max tail call count, the related tail call testcases in test_bpf module and selftests can work well for the interpreter and the JIT. Here are the test results on x86_64: # uname -m x86_64 # echo 0 > /proc/sys/net/core/bpf_jit_enable # modprobe test_bpf test_suite=test_tail_calls # dmesg | tail -1 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [0/8 JIT'ed] # rmmod test_bpf # echo 1 > /proc/sys/net/core/bpf_jit_enable # modprobe test_bpf test_suite=test_tail_calls # dmesg | tail -1 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [8/8 JIT'ed] # rmmod test_bpf # ./test_progs -t tailcalls #142 tailcalls:OK Summary: 1/11 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Tiezhu Yang Signed-off-by: Daniel Borkmann Tested-by: Johan Almbladh Tested-by: Ilya Leoshkevich Acked-by: Björn Töpel Acked-by: Johan Almbladh Acked-by: Ilya Leoshkevich Link: https://lore.kernel.org/bpf/1636075800-3264-1-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Sasha Levin

Merge tag 'powerpc-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2021-11-05T15:15:46Z

Pull powerpc updates from Michael Ellerman: - Enable STRICT_KERNEL_RWX for Freescale 85xx platforms. - Activate CONFIG_STRICT_KERNEL_RWX by default, while still allowing it to be disabled. - Add support for out-of-line static calls on 32-bit. - Fix oopses doing bpf-to-bpf calls when STRICT_KERNEL_RWX is enabled. - Fix boot hangs on e5500 due to stale value in ESR passed to do_page_fault(). - Fix several bugs on pseries in handling of device tree cache information for hotplugged CPUs, and/or during partition migration. - Various other small features and fixes. Thanks to Alexey Kardashevskiy, Alistair Popple, Anatolij Gustschin, Andrew Donnellan, Athira Rajeev, Bixuan Cui, Bjorn Helgaas, Cédric Le Goater, Christophe Leroy, Daniel Axtens, Daniel Henrique Barboza, Denis Kirjanov, Fabiano Rosas, Frederic Barrat, Gustavo A. R. Silva, Hari Bathini, Jacques de Laval, Joel Stanley, Kai Song, Kajol Jain, Laurent Vivier, Leonardo Bras, Madhavan Srinivasan, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Niklas Schnelle, Oliver O'Halloran, Rob Herring, Russell Currey, Srikar Dronamraju, Stan Johnson, Tyrel Datwyler, Uwe Kleine-König, Vasant Hegde, Wan Jiabing, and Xiaoming Ni, * tag 'powerpc-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (73 commits) powerpc/8xx: Fix Oops with STRICT_KERNEL_RWX without DEBUG_RODATA_TEST powerpc/32e: Ignore ESR in instruction storage interrupt handler powerpc/powernv/prd: Unregister OPAL_MSG_PRD2 notifier during module unload powerpc: Don't provide __kernel_map_pages() without ARCH_SUPPORTS_DEBUG_PAGEALLOC MAINTAINERS: Update powerpc KVM entry powerpc/xmon: fix task state output powerpc/44x/fsp2: add missing of_node_put powerpc/dcr: Use cmplwi instead of 3-argument cmpli KVM: PPC: Tick accounting should defer vtime accounting 'til after IRQ handling powerpc/security: Use a mutex for interrupt exit code patching powerpc/83xx/mpc8349emitx: Make mcu_gpiochip_remove() return void powerpc/fsl_booke: Fix setting of exec flag when setting TLBCAMs powerpc/book3e: Fix set_memory_x() and set_memory_nx() powerpc/nohash: Fix __ptep_set_access_flags() and ptep_set_wrprotect() powerpc/bpf: Fix write protecting JIT code selftests/powerpc: Use date instead of EPOCHSECONDS in mitigation-patching.sh powerpc/64s/interrupt: Fix check_return_regs_valid() false positive powerpc/boot: Set LC_ALL=C in wrapper script powerpc/64s: Default to 64K pages for 64 bit book3s Revert "powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC" ...

powerpc/bpf: Fix write protecting JIT code

2021-10-27T13:08:32Z

Running program with bpf-to-bpf function calls results in data access exception (0x300) with the below call trace: bpf_int_jit_compile+0x238/0x750 (unreliable) bpf_check+0x2008/0x2710 bpf_prog_load+0xb00/0x13a0 __sys_bpf+0x6f4/0x27c0 sys_bpf+0x2c/0x40 system_call_exception+0x164/0x330 system_call_vectored_common+0xe8/0x278 as bpf_int_jit_compile() tries writing to write protected JIT code location during the extra pass. Fix it by holding off write protection of JIT code until the extra pass, where branch target addresses fixup happens. Fixes: 62e3d4210ac9 ("powerpc/bpf: Write protect JIT code") Cc: stable@vger.kernel.org # v5.14+ Signed-off-by: Hari Bathini Reviewed-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211025055649.114728-1-hbathini@linux.ibm.com

powerpc/bpf ppc32: Fix BPF_SUB when imm == 0x80000000

2021-10-07T08:52:59Z

Special case handling of the smallest 32-bit negative number for BPF_SUB. Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32") Signed-off-by: Naveen N. Rao Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/7135360a0cdf70adedbccf9863128b8daef18764.1633464148.git.naveen.n.rao@linux.vnet.ibm.com

powerpc/bpf ppc32: Do not emit zero extend instruction for 64-bit BPF_END

2021-10-07T08:52:59Z

Suppress emitting zero extend instruction for 64-bit BPF_END_FROM_[L|B]E operation. Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32") Signed-off-by: Naveen N. Rao Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b4e3c3546121315a8e2059b19a1bda84971816e4.1633464148.git.naveen.n.rao@linux.vnet.ibm.com

powerpc/bpf ppc32: Fix JMP32_JSET_K

2021-10-07T08:52:58Z

'andi' only takes an unsigned 16-bit value. Correct the imm range used when emitting andi. Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32") Signed-off-by: Naveen N. Rao Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b94489f52831305ec15aca4dd04a3527236be7e8.1633464148.git.naveen.n.rao@linux.vnet.ibm.com

powerpc/bpf ppc32: Fix ALU32 BPF_ARSH operation

2021-10-07T08:52:58Z

Correct the destination register used for ALU32 BPF_ARSH operation. Fixes: 51c66ad849a703 ("powerpc/bpf: Implement extended BPF on PPC32") Signed-off-by: Naveen N. Rao Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/6d24c1f9e79b6f61f5135eaf2ea1e8bcd4dac87b.1633464148.git.naveen.n.rao@linux.vnet.ibm.com