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From: Alistair Popple <alistair@popple•id.au>
To: Jordan Niethe <jniethe5@gmail•com>
Cc: npiggin@gmail•com, bala24@linux•ibm.com,
	naveen.n.rao@linux•vnet.ibm.com, linuxppc-dev@lists•ozlabs.org,
	dja@axtens•net
Subject: Re: [PATCH v7 19/28] powerpc/xmon: Move insertion of breakpoint for xol'ing
Date: Tue, 05 May 2020 12:19:04 +1000	[thread overview]
Message-ID: <2015143.6yaIr3PIRM@townsend> (raw)
In-Reply-To: <20200501034220.8982-20-jniethe5@gmail.com>

I can't see any side-effects from patching both instructions at the same time.

Reviewed-by: Alistair Popple <alistair@popple•id.au>

On Friday, 1 May 2020 1:42:11 PM AEST Jordan Niethe wrote:
> When a new breakpoint is created, the second instruction of that
> breakpoint is patched with a trap instruction. This assumes the length
> of the instruction is always the same. In preparation for prefixed
> instructions, remove this assumption. Insert the trap instruction at the
> same time the first instruction is inserted.
> 
> Signed-off-by: Jordan Niethe <jniethe5@gmail•com>
> ---
>  arch/powerpc/xmon/xmon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> index 1947821e425d..fb2563079046 100644
> --- a/arch/powerpc/xmon/xmon.c
> +++ b/arch/powerpc/xmon/xmon.c
> @@ -878,7 +878,6 @@ static struct bpt *new_breakpoint(unsigned long a)
>  		if (!bp->enabled && atomic_read(&bp->ref_count) == 0) {
>  			bp->address = a;
>  			bp->instr = (void *)(bpt_table + ((bp - bpts) * BPT_WORDS));
> -			patch_instruction(bp->instr + 1, ppc_inst(bpinstr));
>  			return bp;
>  		}
>  	}
> @@ -910,6 +909,7 @@ static void insert_bpts(void)
>  			continue;
>  		}
>  		patch_instruction(bp->instr, instr);
> +		patch_instruction((void *)bp->instr + ppc_inst_len(instr),
> ppc_inst(bpinstr)); if (bp->enabled & BP_CIABR)
>  			continue;
>  		if (patch_instruction((struct ppc_inst *)bp->address,





  reply	other threads:[~2020-05-05  2:20 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-01  3:41 [PATCH v7 00/28] Initial Prefixed Instruction support Jordan Niethe
2020-05-01  3:41 ` [PATCH v7 01/28] powerpc/xmon: Remove store_inst() for patch_instruction() Jordan Niethe
2020-05-01  3:41 ` [PATCH v7 02/28] powerpc/xmon: Move breakpoint instructions to own array Jordan Niethe
2020-05-04  5:41   ` Alistair Popple
2020-05-04  5:52     ` Jordan Niethe
2020-05-01  3:41 ` [PATCH v7 03/28] powerpc/xmon: Move breakpoints to text section Jordan Niethe
2020-05-01  3:41 ` [PATCH v7 04/28] powerpc/xmon: Use bitwise calculations in_breakpoint_table() Jordan Niethe
2020-05-04  5:41   ` Alistair Popple
2020-05-05  7:08   ` Michael Ellerman
2020-05-05  7:31     ` Jordan Niethe
2020-05-01  3:41 ` [PATCH v7 05/28] powerpc: Change calling convention for create_branch() et. al Jordan Niethe
2020-05-04  2:55   ` Alistair Popple
2020-05-01  3:41 ` [PATCH v7 06/28] powerpc: Use a macro for creating instructions from u32s Jordan Niethe
2020-05-04  5:54   ` Alistair Popple
2020-05-01  3:41 ` [PATCH v7 07/28] powerpc: Use an accessor for instructions Jordan Niethe
2020-05-01  3:42 ` [PATCH v7 08/28] powerpc: Use a function for getting the instruction op code Jordan Niethe
2020-05-04  8:01   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 09/28] powerpc: Use a function for byte swapping instructions Jordan Niethe
2020-05-01  3:42 ` [PATCH v7 10/28] powerpc: Introduce functions for instruction equality Jordan Niethe
2020-05-01  3:42 ` [PATCH v7 11/28] powerpc: Use a datatype for instructions Jordan Niethe
2020-05-02 14:29   ` kbuild test robot
2020-05-01  3:42 ` [PATCH v7 12/28] powerpc: Use a function for reading instructions Jordan Niethe
2020-05-04  8:26   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 13/28] powerpc: Add a probe_user_read_inst() function Jordan Niethe
2020-05-04  8:30   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 14/28] powerpc: Add a probe_kernel_read_inst() function Jordan Niethe
2020-05-04  9:24   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 15/28] powerpc/kprobes: Use patch_instruction() Jordan Niethe
2020-05-05  1:41   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 16/28] powerpc: Define and use __get_user_instr{, inatomic}() Jordan Niethe
2020-05-05  1:46   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 17/28] powerpc: Introduce a function for reporting instruction length Jordan Niethe
2020-05-05  2:02   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 18/28] powerpc/xmon: Use a function for reading instructions Jordan Niethe
2020-05-05  2:07   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 19/28] powerpc/xmon: Move insertion of breakpoint for xol'ing Jordan Niethe
2020-05-05  2:19   ` Alistair Popple [this message]
2020-05-01  3:42 ` [PATCH v7 20/28] powerpc: Make test_translate_branch() independent of instruction length Jordan Niethe
2020-05-05  2:40   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 21/28] powerpc: Enable Prefixed Instructions Jordan Niethe
2020-05-01  3:42 ` [PATCH v7 22/28] powerpc: Define new SRR1 bits for a future ISA version Jordan Niethe
2020-05-05  2:49   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 23/28] powerpc: Add prefixed instructions to instruction data type Jordan Niethe
2020-05-05  6:04   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 24/28] powerpc: Test prefixed code patching Jordan Niethe
2020-05-05  6:08   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 25/28] powerpc: Test prefixed instructions in feature fixups Jordan Niethe
2020-05-05  7:15   ` Alistair Popple
2020-05-05  7:34     ` Jordan Niethe
2020-05-01  3:42 ` [PATCH v7 26/28] powerpc: Support prefixed instructions in alignment handler Jordan Niethe
2020-05-05  7:17   ` Alistair Popple
2020-05-01  3:42 ` [PATCH v7 27/28] powerpc sstep: Add support for prefixed load/stores Jordan Niethe
2020-05-01  3:42 ` [PATCH v7 28/28] powerpc sstep: Add support for prefixed fixed-point arithmetic Jordan Niethe

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