From: Balamuruhan S <bala24@linux.ibm.com>
To: Nicholas Piggin <npiggin@gmail.com>,
Jordan Niethe <jniethe5@gmail.com>,
linuxppc-dev@lists.ozlabs.org
Cc: alistair@popple.id.au, dja@axtens.net
Subject: Re: [PATCH v4 09/16] powerpc: Use a function for reading instructions
Date: Mon, 23 Mar 2020 14:13:29 +0530 [thread overview]
Message-ID: <bc592c51a195d920a48aaac3c8c42afad76ad488.camel@linux.ibm.com> (raw)
In-Reply-To: <1584946118.tw98vo7hqx.astroid@bobo.none>
On Mon, 2020-03-23 at 18:00 +1000, Nicholas Piggin wrote:
> Jordan Niethe's on March 20, 2020 3:18 pm:
> > Prefixed instructions will mean there are instructions of different
> > length. As a result dereferencing a pointer to an instruction will not
> > necessarily give the desired result. Introduce a function for reading
> > instructions from memory into the instruction data type.
> >
> > Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
> > ---
> > v4: New to series
> > ---
> > arch/powerpc/include/asm/uprobes.h | 4 ++--
> > arch/powerpc/kernel/kprobes.c | 8 ++++----
> > arch/powerpc/kernel/mce_power.c | 2 +-
> > arch/powerpc/kernel/optprobes.c | 6 +++---
> > arch/powerpc/kernel/trace/ftrace.c | 33 +++++++++++++++++++-----------
> > arch/powerpc/kernel/uprobes.c | 2 +-
> > arch/powerpc/lib/code-patching.c | 22 ++++++++++----------
> > arch/powerpc/lib/feature-fixups.c | 6 +++---
> > arch/powerpc/xmon/xmon.c | 6 +++---
> > 9 files changed, 49 insertions(+), 40 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/uprobes.h
> > b/arch/powerpc/include/asm/uprobes.h
> > index 2bbdf27d09b5..fff3c5fc90b5 100644
> > --- a/arch/powerpc/include/asm/uprobes.h
> > +++ b/arch/powerpc/include/asm/uprobes.h
> > @@ -23,8 +23,8 @@ typedef ppc_opcode_t uprobe_opcode_t;
> >
> > struct arch_uprobe {
> > union {
> > - u32 insn;
> > - u32 ixol;
> > + u8 insn[MAX_UINSN_BYTES];
> > + u8 ixol[MAX_UINSN_BYTES];
> > };
> > };
>
> Hmm. I wonder if this should be a different patch. Not sure if raw
> bytes is a good idea here. ppc probes also has a ppc_opcode_t, maybe
> could be replaced with ppc_insn_t and used here instead?
>
> Also can't find where you define ppc_inst_read.
Nick, ppc_inst_read and macro PPC_INST you have asked in patch 4 are defined in
asm/inst.h with patch 3 (powerpc: Use a datatype for instructions)
-- Bala
>
> > diff --git a/arch/powerpc/kernel/trace/ftrace.c
> > b/arch/powerpc/kernel/trace/ftrace.c
> > index 7614a9f537fd..ad451205f268 100644
> > --- a/arch/powerpc/kernel/trace/ftrace.c
> > +++ b/arch/powerpc/kernel/trace/ftrace.c
> > @@ -41,6 +41,12 @@
> > #define NUM_FTRACE_TRAMPS 8
> > static unsigned long ftrace_tramps[NUM_FTRACE_TRAMPS];
> >
> > +static long
> > +read_inst(ppc_inst *inst, const void *src)
> > +{
> > + return probe_kernel_read((void *)inst, src, MCOUNT_INSN_SIZE);
> > +}
>
> Humbly suggest probe_kernel_inst_read.
>
> Thanks,
> Nick
>
next prev parent reply other threads:[~2020-03-23 8:45 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-20 5:17 [PATCH v4 00/16] Initial Prefixed Instruction support Jordan Niethe
2020-03-20 5:17 ` [PATCH v4 01/16] powerpc/xmon: Remove store_inst() for patch_instruction() Jordan Niethe
2020-03-23 6:19 ` Nicholas Piggin
2020-03-20 5:17 ` [PATCH v4 02/16] xmon: Move out-of-line instructions to text section Jordan Niethe
2020-03-23 5:59 ` Balamuruhan S
2020-03-23 6:05 ` Balamuruhan S
2020-03-23 9:26 ` Jordan Niethe
2020-03-23 6:22 ` Nicholas Piggin
2020-03-20 5:17 ` [PATCH v4 03/16] powerpc: Use a datatype for instructions Jordan Niethe
2020-03-23 6:07 ` Balamuruhan S
2020-03-23 6:23 ` Nicholas Piggin
2020-03-23 9:28 ` Jordan Niethe
2020-03-23 9:51 ` Nicholas Piggin
2020-03-24 2:58 ` Michael Ellerman
2020-03-24 3:21 ` Jordan Niethe
2020-04-01 10:32 ` Balamuruhan S
2020-04-01 23:52 ` Jordan Niethe
2020-04-02 23:44 ` Alistair Popple
2020-04-03 0:09 ` Jordan Niethe
2020-03-20 5:17 ` [PATCH v4 04/16] powerpc: Use a macro for creating instructions from u32s Jordan Niethe
2020-03-23 6:26 ` Nicholas Piggin
2020-03-23 9:29 ` Jordan Niethe
2020-03-20 5:17 ` [PATCH v4 05/16] powerpc: Use a function for masking instructions Jordan Niethe
2020-03-23 6:37 ` Nicholas Piggin
2020-03-23 9:31 ` Jordan Niethe
2020-03-20 5:17 ` [PATCH v4 06/16] powerpc: Use a function for getting the instruction op code Jordan Niethe
2020-03-23 6:54 ` Balamuruhan S
2020-03-23 9:35 ` Jordan Niethe
2020-03-20 5:18 ` [PATCH v4 07/16] powerpc: Introduce functions for instruction nullity and equality Jordan Niethe
2020-03-23 6:43 ` Nicholas Piggin
2020-03-23 9:31 ` Jordan Niethe
2020-03-20 5:18 ` [PATCH v4 08/16] powerpc: Use an accessor for word instructions Jordan Niethe
2020-03-23 11:12 ` Balamuruhan S
2020-03-24 3:18 ` Jordan Niethe
2020-03-24 6:22 ` Balamuruhan S
2020-03-20 5:18 ` [PATCH v4 09/16] powerpc: Use a function for reading instructions Jordan Niethe
2020-03-23 8:00 ` Nicholas Piggin
2020-03-23 8:43 ` Balamuruhan S [this message]
2020-03-23 10:09 ` Jordan Niethe
2020-03-23 10:36 ` Nicholas Piggin
2020-03-20 5:18 ` [PATCH v4 10/16] powerpc: Make test_translate_branch() independent of instruction length Jordan Niethe
2020-03-20 5:18 ` [PATCH v4 11/16] powerpc: Enable Prefixed Instructions Jordan Niethe
2020-03-23 7:02 ` Nicholas Piggin
2020-03-20 5:18 ` [PATCH v4 12/16] powerpc: Define new SRR1 bits for a future ISA version Jordan Niethe
2020-03-23 7:03 ` Nicholas Piggin
2020-03-20 5:18 ` [PATCH v4 13/16] powerpc: Support prefixed instructions in alignment handler Jordan Niethe
2020-03-23 7:05 ` Nicholas Piggin
2020-03-23 9:35 ` Jordan Niethe
2020-03-20 5:18 ` [PATCH v4 14/16] powerpc64: Add prefixed instructions to instruction data type Jordan Niethe
2020-03-23 6:58 ` Nicholas Piggin
2020-03-23 7:33 ` Nicholas Piggin
2020-03-23 23:45 ` Jordan Niethe
2020-03-24 5:40 ` Nicholas Piggin
2020-03-30 9:05 ` Alistair Popple
2020-03-30 9:13 ` Jordan Niethe
2020-03-20 5:18 ` [PATCH v4 15/16] powerpc sstep: Add support for prefixed load/stores Jordan Niethe
2020-03-23 8:54 ` Balamuruhan S
2020-03-20 5:18 ` [PATCH v4 16/16] powerpc sstep: Add support for prefixed fixed-point arithmetic Jordan Niethe
2020-03-23 10:05 ` Balamuruhan S
2020-03-23 6:18 ` [PATCH v4 00/16] Initial Prefixed Instruction support Nicholas Piggin
2020-03-23 9:25 ` Jordan Niethe
2020-03-23 10:17 ` Nicholas Piggin
2020-03-24 2:54 ` Jordan Niethe
2020-03-24 2:59 ` Jordan Niethe
2020-03-24 5:44 ` Nicholas Piggin
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