On 2015/05/28 14:51, Li Bin wrote: > This patchset propose a method for gcc -mfentry feature(profile > before prologue) implementation for arm64, and propose the livepatch > implementation for arm64 based on this feature. > The gcc implementation about this feature will be post to the gcc > community soon. > > With this -mfentry feature, the entry of each function like: > > foo: > mov x9, x30 > bl __fentry__ > mov x30, x9 > [prologue] > ... > > The x9 is a callee corruptible register, and the __fentry__ function > is responsible to protect all registers, so it can be used to protect > the x30. And the added two instructions which is register mov operation > have ralatively small impact on performance.
Hm, this implementation looks good to me :) This also enables us to KPROBES_ON_FTRACE too. Thanks, > > This patchset has been tested on arm64 platform. > > Li Bin (4): > livepatch: ftrace: arm64: Add support for DYNAMIC_FTRACE_WITH_REGS > livepatch: ftrace: add ftrace_function_stub_ip function > livepatch: ftrace: arm64: Add support for -mfentry on arm64 > livepatch: arm64: add support for livepatch on arm64 > > Xie XiuQi (1): > livepatch: arm64: support relocation in a module > > arch/arm64/Kconfig | 5 + > arch/arm64/include/asm/ftrace.h | 9 + > arch/arm64/include/asm/livepatch.h | 45 +++++ > arch/arm64/kernel/Makefile | 1 + > arch/arm64/kernel/arm64ksyms.c | 4 + > arch/arm64/kernel/entry-ftrace.S | 154 +++++++++++++++- > arch/arm64/kernel/ftrace.c | 28 +++- > arch/arm64/kernel/livepatch.c | 41 ++++ > arch/arm64/kernel/module.c | 355 > ++++++++++++++++++------------------ > include/linux/ftrace.h | 1 + > kernel/livepatch/core.c | 17 ++- > kernel/trace/ftrace.c | 32 ++++ > scripts/recordmcount.pl | 2 +- > 13 files changed, 508 insertions(+), 186 deletions(-) > create mode 100644 arch/arm64/include/asm/livepatch.h > create mode 100644 arch/arm64/kernel/livepatch.c > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu...@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
