This is v6 of the series posted here: https://lore.kernel.org/all/20240915205648.830121-1-hbathini@xxxxxxxxxxxxx/ This series reworks core ftrace support on powerpc to have the function profiling sequence moved out of line. This enables us to have a single nop at kernel function entry virtually eliminating effect of the function tracer when it is not enabled. The function profile sequence is moved out of line and is allocated at two separate places depending on a new config option. For 64-bit powerpc, the function profiling sequence is also updated to include an additional instruction 'mtlr r0' after the usual two-instruction sequence to fix link stack imbalance (return address predictor) when ftrace is enabled. This showed an improvement of ~10% in null_syscall benchmark (NR_LOOPS=10000000) on a Power 10 system with ftrace enabled. Finally, support for ftrace direct calls is added based on support for DYNAMIC_FTRACE_WITH_CALL_OPS. BPF Trampoline support is added atop this. Support for ftrace direct calls is added for 32-bit powerpc. There is some code to enable bpf trampolines for 32-bit powerpc, but it is not complete and will need to be pursued separately. Patches 1 to 10 are independent of this series and can go in separately though. Rest of the patches depend on the series from Benjamin Gray adding support for patch_uint() and patch_ulong(): https://lore.kernel.org/all/172474280311.31690.1489687786264785049.b4-ty@xxxxxxxxxxxxxx/ Changelog v6: * Shellcheck warnings fixed for arch/powerpc/tools/ftrace_check.sh * Masahiro's suggestions incorporated in appropriate patches: - https://lore.kernel.org/all/CAK7LNATzqVAJHFg6OyVR1+YgNKo7S=nN1M7w5GJVG1Ygn0QhUA@xxxxxxxxxxxxxx/ * Shellcheck warnings fixed for arch/powerpc/tools/ftrace-gen-ool-stubs.sh * Fixed https://lore.kernel.org/all/202409170544.6d1odaN2-lkp@xxxxxxxxx/ * Updated the stale comment describing redzone usage in ppc64 BPF JIT Changelog v5: * Intermediate files named .vmlinux.arch.* instead of .arch.vmlinux.* * Fixed ftrace stack tracer failure due to inadvertent use of 'add r7, r3, MCOUNT_INSN_SIZE' instruction instead of 'addi r7, r3, MCOUNT_INSN_SIZE' * Fixed build error for !CONFIG_MODULES case. * .vmlinux.arch.* files compiled under arch/powerpc/tools * Resolved checkpatch.pl warnings. * Dropped RFC tag. Changelog v4: - Patches 1, 10 and 13 are new. - Address review comments from Nick. Numerous changes throughout the patch series. - Extend support for ftrace ool to vmlinux text up to 64MB (patch 13). - Address remaining TODOs in support for BPF Trampolines. - Update synchronization when patching instructions during trampoline attach/detach. Naveen N Rao (17): powerpc/trace: Account for -fpatchable-function-entry support by toolchain powerpc/kprobes: Use ftrace to determine if a probe is at function entry powerpc64/ftrace: Nop out additional 'std' instruction emitted by gcc v5.x powerpc32/ftrace: Unify 32-bit and 64-bit ftrace entry code powerpc/module_64: Convert #ifdef to IS_ENABLED() powerpc/ftrace: Remove pointer to struct module from dyn_arch_ftrace powerpc/ftrace: Skip instruction patching if the instructions are the same powerpc/ftrace: Move ftrace stub used for init text before _einittext powerpc64/bpf: Fold bpf_jit_emit_func_call_hlp() into bpf_jit_emit_func_call_rel() powerpc/ftrace: Add a postlink script to validate function tracer kbuild: Add generic hook for architectures to use before the final vmlinux link powerpc64/ftrace: Move ftrace sequence out of line powerpc64/ftrace: Support .text larger than 32MB with out-of-line stubs powerpc/ftrace: Add support for DYNAMIC_FTRACE_WITH_CALL_OPS powerpc/ftrace: Add support for DYNAMIC_FTRACE_WITH_DIRECT_CALLS samples/ftrace: Add support for ftrace direct samples on powerpc powerpc64/bpf: Add support for bpf trampolines arch/Kconfig | 6 + arch/powerpc/Kbuild | 2 +- arch/powerpc/Kconfig | 22 +- arch/powerpc/Makefile | 8 + arch/powerpc/Makefile.postlink | 8 + arch/powerpc/include/asm/ftrace.h | 33 +- arch/powerpc/include/asm/module.h | 5 + arch/powerpc/include/asm/ppc-opcode.h | 14 + arch/powerpc/kernel/asm-offsets.c | 11 + arch/powerpc/kernel/kprobes.c | 18 +- arch/powerpc/kernel/module_64.c | 66 +- arch/powerpc/kernel/trace/Makefile | 11 +- arch/powerpc/kernel/trace/ftrace.c | 298 ++++++- arch/powerpc/kernel/trace/ftrace_64_pg.c | 69 +- arch/powerpc/kernel/trace/ftrace_entry.S | 244 ++++-- arch/powerpc/kernel/vmlinux.lds.S | 3 +- arch/powerpc/net/bpf_jit.h | 12 + arch/powerpc/net/bpf_jit_comp.c | 847 +++++++++++++++++++- arch/powerpc/net/bpf_jit_comp32.c | 7 +- arch/powerpc/net/bpf_jit_comp64.c | 72 +- arch/powerpc/tools/.gitignore | 2 + arch/powerpc/tools/Makefile | 10 + arch/powerpc/tools/ftrace-gen-ool-stubs.sh | 49 ++ arch/powerpc/tools/ftrace_check.sh | 50 ++ samples/ftrace/ftrace-direct-modify.c | 85 +- samples/ftrace/ftrace-direct-multi-modify.c | 101 ++- samples/ftrace/ftrace-direct-multi.c | 79 +- samples/ftrace/ftrace-direct-too.c | 83 +- samples/ftrace/ftrace-direct.c | 69 +- scripts/Makefile.vmlinux | 7 + scripts/link-vmlinux.sh | 7 +- 31 files changed, 2096 insertions(+), 202 deletions(-) create mode 100644 arch/powerpc/tools/.gitignore create mode 100644 arch/powerpc/tools/Makefile create mode 100755 arch/powerpc/tools/ftrace-gen-ool-stubs.sh create mode 100755 arch/powerpc/tools/ftrace_check.sh -- 2.47.0
