[PATCH v6 00/28] Initial Prefixed Instruction support
Jordan Niethe
jniethe5 at gmail.com
Wed Apr 29 12:51:58 AEST 2020
On Tue, Apr 28, 2020 at 8:07 PM Balamuruhan S <bala24 at linux.ibm.com> wrote:
>
> On Tue, 2020-04-28 at 11:57 +1000, Jordan Niethe wrote:
> > A future revision of the ISA will introduce prefixed instructions. A
> > prefixed instruction is composed of a 4-byte prefix followed by a
> > 4-byte suffix.
> >
> > All prefixes have the major opcode 1. A prefix will never be a valid
> > word instruction. A suffix may be an existing word instruction or a
> > new instruction.
> >
> > This series enables prefixed instructions and extends the instruction
> > emulation to support them. Then the places where prefixed instructions
> > might need to be emulated are updated.
>
> Hi Jordan,
>
> I tried to test Kprobes with prefixed instruction on this patchset and
> observed that kprobe/uprobe enablement patches are missing from v4.
> Till v3 it were available,
>
> https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20200211053355.21574-11-jniethe5@gmail.com/
>
> https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20200211053355.21574-12-jniethe5@gmail.com/
>
> was it missed for any dependencies/reason ? or will you plan it include in next
> version ?
V4 was when I introduced the data type of prefixed instructions, that
along with helper functions covered a lot of what those enablement
patches were doing.
All of the stuff in that uprobes patch gets done without needing a
specific patch now. I'll add back in the checks for prefix
instructions in arch_prepare_kprobe().
> please let me know if you need help on it.
>
> -- Bala
>
> >
> > v6 is based on feedback from Balamuruhan Suriyakumar, Alistair Popple,
> > Christophe Leroy and Segher Boessenkool.
> > The major changes:
> > - Use the instruction type in more places that had been missed before
> > - Fix issues with ppc32
> > - Introduce new self tests for code patching and feature fixups
> >
> > v5 is based on feedback from Nick Piggins, Michael Ellerman, Balamuruhan
> > Suriyakumar and Alistair Popple.
> > The major changes:
> > - The ppc instruction type is now a struct
> > - Series now just based on next
> > - ppc_inst_masked() dropped
> > - Space for xmon breakpoints allocated in an assembly file
> > - "Add prefixed instructions to instruction data type" patch seperated in
> > to smaller patches
> > - Calling convention for create_branch() is changed
> > - Some places which had not been updated to use the data type are now
> > updated
> >
> > v4 is based on feedback from Nick Piggins, Christophe Leroy and Daniel
> > Axtens.
> > The major changes:
> > - Move xmon breakpoints from data section to text section
> > - Introduce a data type for instructions on powerpc
> >
> > v3 is based on feedback from Christophe Leroy. The major changes:
> > - Completely replacing store_inst() with patch_instruction() in
> > xmon
> > - Improve implementation of mread_instr() to not use mread().
> > - Base the series on top of
> > https://patchwork.ozlabs.org/patch/1232619/ as this will effect
> > kprobes.
> > - Some renaming and simplification of conditionals.
> >
> > v2 incorporates feedback from Daniel Axtens and and Balamuruhan
> > S. The major changes are:
> > - Squashing together all commits about SRR1 bits
> > - Squashing all commits for supporting prefixed load stores
> > - Changing abbreviated references to sufx/prfx -> suffix/prefix
> > - Introducing macros for returning the length of an instruction
> > - Removing sign extension flag from pstd/pld in sstep.c
> > - Dropping patch "powerpc/fault: Use analyse_instr() to check for
> > store with updates to sp" from the series, it did not really fit
> > with prefixed enablement in the first place and as reported by Greg
> > Kurz did not work correctly.
> >
> > Alistair Popple (1):
> > powerpc: Enable Prefixed Instructions
> >
> > Jordan Niethe (27):
> > powerpc/xmon: Remove store_inst() for patch_instruction()
> > powerpc/xmon: Move breakpoint instructions to own array
> > powerpc/xmon: Move breakpoints to text section
> > powerpc/xmon: Use bitwise calculations in_breakpoint_table()
> > powerpc: Change calling convention for create_branch() et. al.
> > powerpc: Use a macro for creating instructions from u32s
> > powerpc: Use an accessor for instructions
> > powerpc: Use a function for getting the instruction op code
> > powerpc: Use a function for byte swapping instructions
> > powerpc: Introduce functions for instruction equality
> > powerpc: Use a datatype for instructions
> > powerpc: Use a function for reading instructions
> > powerpc: Add a probe_user_read_inst() function
> > powerpc: Add a probe_kernel_read_inst() function
> > powerpc/kprobes: Use patch_instruction()
> > powerpc: Define and use __get_user_instr{,inatomic}()
> > powerpc: Introduce a function for reporting instruction length
> > powerpc/xmon: Use a function for reading instructions
> > powerpc/xmon: Move insertion of breakpoint for xol'ing
> > powerpc: Make test_translate_branch() independent of instruction
> > length
> > powerpc: Define new SRR1 bits for a future ISA version
> > powerpc: Add prefixed instructions to instruction data type
> > powerpc: Test prefixed code patching
> > powerpc: Test prefixed instructions in feature fixups
> > powerpc: Support prefixed instructions in alignment handler
> > powerpc sstep: Add support for prefixed load/stores
> > powerpc sstep: Add support for prefixed fixed-point arithmetic
> >
> > arch/powerpc/include/asm/code-patching.h | 37 +-
> > arch/powerpc/include/asm/inst.h | 106 ++++++
> > arch/powerpc/include/asm/kprobes.h | 2 +-
> > arch/powerpc/include/asm/reg.h | 7 +-
> > arch/powerpc/include/asm/sstep.h | 15 +-
> > arch/powerpc/include/asm/uaccess.h | 35 ++
> > arch/powerpc/include/asm/uprobes.h | 7 +-
> > arch/powerpc/kernel/align.c | 13 +-
> > arch/powerpc/kernel/asm-offsets.c | 8 +
> > arch/powerpc/kernel/epapr_paravirt.c | 7 +-
> > arch/powerpc/kernel/hw_breakpoint.c | 5 +-
> > arch/powerpc/kernel/jump_label.c | 5 +-
> > arch/powerpc/kernel/kgdb.c | 9 +-
> > arch/powerpc/kernel/kprobes.c | 24 +-
> > arch/powerpc/kernel/mce_power.c | 5 +-
> > arch/powerpc/kernel/module_64.c | 3 +-
> > arch/powerpc/kernel/optprobes.c | 91 +++--
> > arch/powerpc/kernel/optprobes_head.S | 3 +
> > arch/powerpc/kernel/security.c | 9 +-
> > arch/powerpc/kernel/setup_32.c | 8 +-
> > arch/powerpc/kernel/trace/ftrace.c | 160 ++++----
> > arch/powerpc/kernel/traps.c | 20 +-
> > arch/powerpc/kernel/uprobes.c | 5 +-
> > arch/powerpc/kernel/vecemu.c | 20 +-
> > arch/powerpc/kvm/book3s_hv_nested.c | 2 +-
> > arch/powerpc/kvm/book3s_hv_rm_mmu.c | 2 +-
> > arch/powerpc/kvm/emulate_loadstore.c | 2 +-
> > arch/powerpc/lib/Makefile | 2 +-
> > arch/powerpc/lib/code-patching.c | 305 ++++++++-------
> > arch/powerpc/lib/feature-fixups-test.S | 68 ++++
> > arch/powerpc/lib/feature-fixups.c | 159 ++++++--
> > arch/powerpc/lib/inst.c | 69 ++++
> > arch/powerpc/lib/sstep.c | 461 ++++++++++++++++-------
> > arch/powerpc/lib/test_code-patching.S | 19 +
> > arch/powerpc/lib/test_emulate_step.c | 56 +--
> > arch/powerpc/mm/fault.c | 15 +-
> > arch/powerpc/perf/core-book3s.c | 4 +-
> > arch/powerpc/xmon/Makefile | 2 +-
> > arch/powerpc/xmon/xmon.c | 94 +++--
> > arch/powerpc/xmon/xmon_bpts.S | 11 +
> > arch/powerpc/xmon/xmon_bpts.h | 14 +
> > 41 files changed, 1307 insertions(+), 582 deletions(-)
> > create mode 100644 arch/powerpc/include/asm/inst.h
> > create mode 100644 arch/powerpc/lib/inst.c
> > create mode 100644 arch/powerpc/lib/test_code-patching.S
> > create mode 100644 arch/powerpc/xmon/xmon_bpts.S
> > create mode 100644 arch/powerpc/xmon/xmon_bpts.h
> >
>
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