[PATCH v5 08/21] powerpc: Introduce functions for instruction equality

Balamuruhan S bala24 at linux.ibm.com
Tue Apr 7 17:37:42 AEST 2020


On Mon, 2020-04-06 at 18:09 +1000, Jordan Niethe wrote:
> In preparation for an instruction data type that can not be directly
> used with the '==' operator use functions for checking equality.

LGTM except one comment below, otherwise

Reviewed-by: Balamuruhan S <bala24 at linux.ibm.com>

> 
> Signed-off-by: Jordan Niethe <jniethe5 at gmail.com>
> ---
> v5: Remove ppc_inst_null()
> ---
>  arch/powerpc/include/asm/inst.h      |  5 +++++
>  arch/powerpc/kernel/trace/ftrace.c   | 15 ++++++++-------
>  arch/powerpc/lib/code-patching.c     | 12 ++++++------
>  arch/powerpc/lib/test_emulate_step.c |  2 +-
>  arch/powerpc/xmon/xmon.c             |  4 ++--
>  5 files changed, 22 insertions(+), 16 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/inst.h
> b/arch/powerpc/include/asm/inst.h
> index 78eb1481f1f6..54ee46b0a7c9 100644
> --- a/arch/powerpc/include/asm/inst.h
> +++ b/arch/powerpc/include/asm/inst.h
> @@ -23,4 +23,9 @@ static inline u32 ppc_inst_swab(u32 x)
>  	return ppc_inst(swab32(ppc_inst_val(x)));
>  }
>  
> +static inline bool ppc_inst_equal(u32 x, u32 y)
> +{
> +	return x == y;
> +}
> +
>  #endif /* _ASM_INST_H */
> diff --git a/arch/powerpc/kernel/trace/ftrace.c
> b/arch/powerpc/kernel/trace/ftrace.c
> index 62ff429bddc4..784b5746cc55 100644
> --- a/arch/powerpc/kernel/trace/ftrace.c
> +++ b/arch/powerpc/kernel/trace/ftrace.c
> @@ -72,7 +72,7 @@ ftrace_modify_code(unsigned long ip, unsigned int old,
> unsigned int new)
>  		return -EFAULT;
>  
>  	/* Make sure it is what we expect it to be */
> -	if (replaced != old) {
> +	if (!ppc_inst_equal(replaced, old)) {
>  		pr_err("%p: replaced (%#x) != old (%#x)",
>  		(void *)ip, ppc_inst_val(replaced), ppc_inst_val(old));
>  		return -EINVAL;
> @@ -170,7 +170,8 @@ __ftrace_make_nop(struct module *mod,
>  	}
>  
>  	/* We expect either a mflr r0, or a std r0, LRSAVE(r1) */
> -	if (op != ppc_inst(PPC_INST_MFLR) && op != ppc_inst(PPC_INST_STD_LR)) {
> +	if (!ppc_inst_equal(op, ppc_inst(PPC_INST_MFLR)) &&
> +	    !ppc_inst_equal(op, ppc_inst(PPC_INST_STD_LR))) {
>  		pr_err("Unexpected instruction %08x around bl _mcount\n",
> ppc_inst_val(op));
>  		return -EINVAL;
>  	}
> @@ -200,7 +201,7 @@ __ftrace_make_nop(struct module *mod,
>  		return -EFAULT;
>  	}
>  
> -	if (op != ppc_inst(PPC_INST_LD_TOC)) {
> +	if (!ppc_inst_equal(op,  ppc_inst(PPC_INST_LD_TOC))) {
>  		pr_err("Expected %08x found %08x\n", PPC_INST_LD_TOC,
> ppc_inst_val(op));
>  		return -EINVAL;
>  	}
> @@ -497,7 +498,7 @@ expected_nop_sequence(void *ip, unsigned int op0,
> unsigned int op1)
>  	 * The load offset is different depending on the ABI. For simplicity
>  	 * just mask it out when doing the compare.
>  	 */
> -	if ((op0 != ppc_inst(0x48000008)) || (ppc_inst_val(op1) & 0xffff0000)
> != 0xe8410000)
> +	if ((!ppc_inst_equal(op0), ppc_inst(0x48000008)) || (ppc_inst_val(op1)
> & 0xffff0000) != 0xe8410000)
>  		return 0;
>  	return 1;
>  }
> @@ -506,7 +507,7 @@ static int
>  expected_nop_sequence(void *ip, unsigned int op0, unsigned int op1)
>  {
>  	/* look for patched "NOP" on ppc64 with -mprofile-kernel */
> -	if (op0 != ppc_inst(PPC_INST_NOP))
> +	if (!ppc_inst_equal(op0, ppc_inst(PPC_INST_NOP)))
>  		return 0;
>  	return 1;
>  }
> @@ -589,7 +590,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long
> addr)
>  		return -EFAULT;
>  
>  	/* It should be pointing to a nop */
> -	if (op != ppc_inst(PPC_INST_NOP)) {
> +	if (!ppc_inst_equal(op,  ppc_inst(PPC_INST_NOP))) {
>  		pr_err("Expected NOP but have %x\n", op);
>  		return -EINVAL;
>  	}
> @@ -646,7 +647,7 @@ static int __ftrace_make_call_kernel(struct dyn_ftrace
> *rec, unsigned long addr)
>  		return -EFAULT;
>  	}
>  
> -	if (op != ppc_inst(PPC_INST_NOP)) {
> +	if (!ppc_inst_equal(op, ppc_inst(PPC_INST_NOP))) {
>  		pr_err("Unexpected call sequence at %p: %x\n", ip,
> ppc_inst_val(op));
>  		return -EINVAL;
>  	}
> diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-
> patching.c
> index 3f88d2a4400c..33654c6334a9 100644
> --- a/arch/powerpc/lib/code-patching.c
> +++ b/arch/powerpc/lib/code-patching.c
> @@ -478,7 +478,7 @@ static void __init test_branch_iform(void)
>  	/* Check flags are masked correctly */
>  	err = create_branch(&instr, &instr, addr, 0xFFFFFFFC);
>  	check(instr_is_branch_to_addr(&instr, addr));
> -	check(instr == ppc_inst(0x48000000));
> +	check(ppc_inst_equal(instr, ppc_inst(0x48000000)));
>  }
>  
>  static void __init test_create_function_call(void)
> @@ -563,7 +563,7 @@ static void __init test_branch_bform(void)
>  	/* Check flags are masked correctly */
>  	err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC);
>  	check(instr_is_branch_to_addr(&instr, addr));
> -	check(instr == ppc_inst(0x43FF0000));
> +	check(ppc_inst_equal(instr, ppc_inst(0x43FF0000)));
>  }
>  
>  static void __init test_translate_branch(void)
> @@ -597,7 +597,7 @@ static void __init test_translate_branch(void)
>  	patch_instruction(q, instr);
>  	check(instr_is_branch_to_addr(p, addr));
>  	check(instr_is_branch_to_addr(q, addr));
> -	check(*q == ppc_inst(0x4a000000));
> +	check(ppc_inst_equal(*q, ppc_inst(0x4a000000)));
>  
>  	/* Maximum positive case, move x to x - 32 MB + 4 */
>  	p = buf + 0x2000000;
> @@ -608,7 +608,7 @@ static void __init test_translate_branch(void)
>  	patch_instruction(q, instr);
>  	check(instr_is_branch_to_addr(p, addr));
>  	check(instr_is_branch_to_addr(q, addr));
> -	check(*q == ppc_inst(0x49fffffc));
> +	check(ppc_inst_equal(*q, ppc_inst(0x49fffffc)));
>  
>  	/* Jump to x + 16 MB moved to x + 20 MB */
>  	p = buf;
> @@ -654,7 +654,7 @@ static void __init test_translate_branch(void)
>  	patch_instruction(q, instr);
>  	check(instr_is_branch_to_addr(p, addr));
>  	check(instr_is_branch_to_addr(q, addr));
> -	check(*q == ppc_inst(0x43ff8000));
> +	check(ppc_inst_equal(*q, ppc_inst(0x43ff8000)));
>  
>  	/* Maximum positive case, move x to x - 32 KB + 4 */
>  	p = buf + 0x8000;
> @@ -666,7 +666,7 @@ static void __init test_translate_branch(void)
>  	patch_instruction(q, instr);
>  	check(instr_is_branch_to_addr(p, addr));
>  	check(instr_is_branch_to_addr(q, addr));
> -	check(*q == ppc_inst(0x43ff7ffc));
> +	check(ppc_inst_equal(*q, ppc_inst(0x43ff7ffc)));
>  
>  	/* Jump to x + 12 KB moved to x + 20 KB */
>  	p = buf;
> diff --git a/arch/powerpc/lib/test_emulate_step.c
> b/arch/powerpc/lib/test_emulate_step.c
> index 60f7eb24d742..16387a9bfda0 100644
> --- a/arch/powerpc/lib/test_emulate_step.c
> +++ b/arch/powerpc/lib/test_emulate_step.c
> @@ -865,7 +865,7 @@ static int __init execute_compute_instr(struct pt_regs
> *regs,
>  	extern int exec_instr(struct pt_regs *regs);
>  	extern s32 patch__exec_instr;
>  
> -	if (!regs || !instr)
> +	if (!regs || !ppc_inst_val(instr))


This change should go in to below patch,

[PATCH v5 06/21] powerpc: Use an accessor for instructions

-- Bala


>  		return -EINVAL;
>  
>  	/* Patch the NOP with the actual instruction */
> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> index 3c1fb46bfacf..f6c87d3d53ea 100644
> --- a/arch/powerpc/xmon/xmon.c
> +++ b/arch/powerpc/xmon/xmon.c
> @@ -950,7 +950,7 @@ static void remove_bpts(void)
>  		if ((bp->enabled & (BP_TRAP|BP_CIABR)) != BP_TRAP)
>  			continue;
>  		if (mread(bp->address, &instr, 4) == 4
> -		    && instr == ppc_inst(bpinstr)
> +		    && ppc_inst_equal(instr, ppc_inst(bpinstr))
>  		    && patch_instruction(
>  			(unsigned int *)bp->address, bp->instr[0]) != 0)
>  			printf("Couldn't remove breakpoint at %lx\n",
> @@ -2860,7 +2860,7 @@ generic_inst_dump(unsigned long adr, long count, int
> praddr,
>  			break;
>  		}
>  		inst = ppc_inst(GETWORD(val));
> -		if (adr > first_adr && inst == last_inst) {
> +		if (adr > first_adr && ppc_inst_equal(inst, last_inst)) {
>  			if (!dotted) {
>  				printf(" ...\n");
>  				dotted = 1;



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