* Re: [PATCH] MIPS: Remove no-op cast in show_regs()
2018-07-02 15:20 ` [PATCH] MIPS: Remove no-op cast in show_regs() Ralf Baechle
@ 2018-07-02 21:00 ` Julia Lawall
2018-07-02 21:39 ` Paul Burton
1 sibling, 0 replies; 3+ messages in thread
From: Julia Lawall @ 2018-07-02 21:00 UTC (permalink / raw)
To: Ralf Baechle; +Cc: Paul Burton, linux-mips, James Hogan, linux-kernel
On Mon, 2 Jul 2018, Ralf Baechle wrote:
> On Fri, Jun 22, 2018 at 11:07:03AM -0700, Paul Burton wrote:
>
> > In show_regs() we have a regs argument of type struct pt_regs *, and we
> > explicitly cast it to that same type as part of calling __show_regs().
> >
> > Casting regs to the same type that it is declared as does nothing at
> > all, so remove the useless cast.
>
> Good catch but there's no dump_stack() in v4.18-rc3 so this doesn't apply.
> That's trivial to patch up but since pointless casts are one of my pet
> peeve I used a semantic patch from a dark local repository to hunt down a
> few more.
>
> @identitycast@
> type T;
> T *A;
> @@
> - (T *) A
> + A
>
> Julia, I guess this isn't bulletproof but maybe something similar should
> be considered for scripts/coccinelle?
Thanks for the suggestion. I will try to put together something. From
the examples, it looks like - (T *)(A) could be better. With that
Coccinelle will also match cases with no parentheses.
julia
>
> Ralf
>
> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
>
> arch/mips/kernel/relocate.c | 2 +-
> arch/mips/kernel/traps.c | 2 +-
> arch/mips/loongson64/loongson-3/smp.c | 10 +++++-----
> arch/mips/pmcs-msp71xx/msp_usb.c | 4 ++--
> arch/mips/sgi-ip22/ip28-berr.c | 2 +-
> 5 files changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/arch/mips/kernel/relocate.c b/arch/mips/kernel/relocate.c
> index cbf4cc0b0b6c..ae7d9cf2c849 100644
> --- a/arch/mips/kernel/relocate.c
> +++ b/arch/mips/kernel/relocate.c
> @@ -146,7 +146,7 @@ int __init do_relocations(void *kbase_old, void *kbase_new, long offset)
> break;
>
> type = (*r >> 24) & 0xff;
> - loc_orig = (void *)(kbase_old + ((*r & 0x00ffffff) << 2));
> + loc_orig = (kbase_old + ((*r & 0x00ffffff) << 2));
> loc_new = RELOCATED(loc_orig);
>
> if (reloc_handlers_rel[type] == NULL) {
> diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
> index d67fa74622ee..2935aa608d2f 100644
> --- a/arch/mips/kernel/traps.c
> +++ b/arch/mips/kernel/traps.c
> @@ -350,7 +350,7 @@ static void __show_regs(const struct pt_regs *regs)
> */
> void show_regs(struct pt_regs *regs)
> {
> - __show_regs((struct pt_regs *)regs);
> + __show_regs(regs);
> }
>
> void show_registers(struct pt_regs *regs)
> diff --git a/arch/mips/loongson64/loongson-3/smp.c b/arch/mips/loongson64/loongson-3/smp.c
> index 8501109bb0f0..e231c2cb4a64 100644
> --- a/arch/mips/loongson64/loongson-3/smp.c
> +++ b/arch/mips/loongson64/loongson-3/smp.c
> @@ -349,7 +349,7 @@ static void loongson3_smp_finish(void)
> write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ);
> local_irq_enable();
> loongson3_ipi_write64(0,
> - (void *)(ipi_mailbox_buf[cpu_logical_map(cpu)]+0x0));
> + (ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0));
> pr_info("CPU#%d finished, CP0_ST=%x\n",
> smp_processor_id(), read_c0_status());
> }
> @@ -416,13 +416,13 @@ static int loongson3_boot_secondary(int cpu, struct task_struct *idle)
> cpu, startargs[0], startargs[1], startargs[2]);
>
> loongson3_ipi_write64(startargs[3],
> - (void *)(ipi_mailbox_buf[cpu_logical_map(cpu)]+0x18));
> + (ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x18));
> loongson3_ipi_write64(startargs[2],
> - (void *)(ipi_mailbox_buf[cpu_logical_map(cpu)]+0x10));
> + (ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x10));
> loongson3_ipi_write64(startargs[1],
> - (void *)(ipi_mailbox_buf[cpu_logical_map(cpu)]+0x8));
> + (ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x8));
> loongson3_ipi_write64(startargs[0],
> - (void *)(ipi_mailbox_buf[cpu_logical_map(cpu)]+0x0));
> + (ipi_mailbox_buf[cpu_logical_map(cpu)] + 0x0));
> return 0;
> }
>
> diff --git a/arch/mips/pmcs-msp71xx/msp_usb.c b/arch/mips/pmcs-msp71xx/msp_usb.c
> index c87c5f810cd1..d38ac70b5a2e 100644
> --- a/arch/mips/pmcs-msp71xx/msp_usb.c
> +++ b/arch/mips/pmcs-msp71xx/msp_usb.c
> @@ -133,13 +133,13 @@ static int __init msp_usb_setup(void)
> * "D" for device-mode. If it works for Ethernet, why not USB...
> * -- hammtrev, 2007/03/22
> */
> - snprintf((char *)&envstr[0], sizeof(envstr), "usbmode");
> + snprintf(&envstr[0], sizeof(envstr), "usbmode");
>
> /* set default host mode */
> val = 1;
>
> /* get environment string */
> - strp = prom_getenv((char *)&envstr[0]);
> + strp = prom_getenv(&envstr[0]);
> if (strp) {
> /* compare string */
> if (!strcmp(strp, "device"))
> diff --git a/arch/mips/sgi-ip22/ip28-berr.c b/arch/mips/sgi-ip22/ip28-berr.c
> index 2ed8e4990b7a..082541d33161 100644
> --- a/arch/mips/sgi-ip22/ip28-berr.c
> +++ b/arch/mips/sgi-ip22/ip28-berr.c
> @@ -464,7 +464,7 @@ void ip22_be_interrupt(int irq)
> die_if_kernel("Oops", regs);
> force_sig(SIGBUS, current);
> } else if (debug_be_interrupt)
> - show_regs((struct pt_regs *)regs);
> + show_regs(regs);
> }
>
> static int ip28_be_handler(struct pt_regs *regs, int is_fixup)
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] MIPS: Remove no-op cast in show_regs()
2018-07-02 15:20 ` [PATCH] MIPS: Remove no-op cast in show_regs() Ralf Baechle
2018-07-02 21:00 ` Julia Lawall
@ 2018-07-02 21:39 ` Paul Burton
1 sibling, 0 replies; 3+ messages in thread
From: Paul Burton @ 2018-07-02 21:39 UTC (permalink / raw)
To: Ralf Baechle; +Cc: linux-mips, James Hogan, Julia Lawall, linux-kernel
Hi Ralf,
On Mon, Jul 02, 2018 at 05:20:29PM +0200, Ralf Baechle wrote:
> On Fri, Jun 22, 2018 at 11:07:03AM -0700, Paul Burton wrote:
>
> > In show_regs() we have a regs argument of type struct pt_regs *, and we
> > explicitly cast it to that same type as part of calling __show_regs().
> >
> > Casting regs to the same type that it is declared as does nothing at
> > all, so remove the useless cast.
>
> Good catch but there's no dump_stack() in v4.18-rc3 so this doesn't apply.
dump_stack() is there in mips-fixes as part of fixing up
arch_trigger_cpumask_backtrace(), so this would apply once the next
fixes pull happens.
But I'm all for cleaning up other instances too.
Thanks,
Paul
^ permalink raw reply [flat|nested] 3+ messages in thread