Re: [REPOST PATCH v6 1/4] kgdb: Remove irq flags from roundup

From: Daniel Thompson
Date: Wed Dec 19 2018 - 11:54:54 EST

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On Tue, Dec 04, 2018 at 07:38:25PM -0800, Douglas Anderson wrote:
> The function kgdb_roundup_cpus() was passed a parameter that was
> documented as:
>
> > the flags that will be used when restoring the interrupts. There is
> > local_irq_save() call before kgdb_roundup_cpus().
>
> Nobody used those flags. Anyone who wanted to temporarily turn on
> interrupts just did local_irq_enable() and local_irq_disable() without
> looking at them. So we can definitely remove the flags.
>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
> Cc: Russell King <linux@xxxxxxxxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Richard Kuo <rkuo@xxxxxxxxxxxxxx>
> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> Cc: Paul Burton <paul.burton@xxxxxxxx>
> Cc: James Hogan <jhogan@xxxxxxxxxx>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
> Cc: Rich Felker <dalias@xxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Acked-by: Will Deacon <will.deacon@xxxxxxx>

I've not heard any objections from the arch/ maintainers so...

Applied! Thanks.

> ---
>
> Changes in v6: None
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2:
> - Removing irq flags separated from fixing lockdep splat.
>
> arch/arc/kernel/kgdb.c | 2 +-
> arch/arm/kernel/kgdb.c | 2 +-
> arch/arm64/kernel/kgdb.c | 2 +-
> arch/hexagon/kernel/kgdb.c | 9 ++-------
> arch/mips/kernel/kgdb.c | 2 +-
> arch/powerpc/kernel/kgdb.c | 2 +-
> arch/sh/kernel/kgdb.c | 2 +-
> arch/sparc/kernel/smp_64.c | 2 +-
> arch/x86/kernel/kgdb.c | 9 ++-------
> include/linux/kgdb.h | 9 ++-------
> kernel/debug/debug_core.c | 2 +-
> 11 files changed, 14 insertions(+), 29 deletions(-)
>
> diff --git a/arch/arc/kernel/kgdb.c b/arch/arc/kernel/kgdb.c
> index 9a3c34af2ae8..0932851028e0 100644
> --- a/arch/arc/kernel/kgdb.c
> +++ b/arch/arc/kernel/kgdb.c
> @@ -197,7 +197,7 @@ static void kgdb_call_nmi_hook(void *ignored)
> kgdb_nmicallback(raw_smp_processor_id(), NULL);
> }
>
> -void kgdb_roundup_cpus(unsigned long flags)
> +void kgdb_roundup_cpus(void)
> {
> local_irq_enable();
> smp_call_function(kgdb_call_nmi_hook, NULL, 0);
> diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
> index caa0dbe3dc61..f21077b077be 100644
> --- a/arch/arm/kernel/kgdb.c
> +++ b/arch/arm/kernel/kgdb.c
> @@ -175,7 +175,7 @@ static void kgdb_call_nmi_hook(void *ignored)
> kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
> }
>
> -void kgdb_roundup_cpus(unsigned long flags)
> +void kgdb_roundup_cpus(void)
> {
> local_irq_enable();
> smp_call_function(kgdb_call_nmi_hook, NULL, 0);
> diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
> index a20de58061a8..12c339ff6e75 100644
> --- a/arch/arm64/kernel/kgdb.c
> +++ b/arch/arm64/kernel/kgdb.c
> @@ -289,7 +289,7 @@ static void kgdb_call_nmi_hook(void *ignored)
> kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
> }
>
> -void kgdb_roundup_cpus(unsigned long flags)
> +void kgdb_roundup_cpus(void)
> {
> local_irq_enable();
> smp_call_function(kgdb_call_nmi_hook, NULL, 0);
> diff --git a/arch/hexagon/kernel/kgdb.c b/arch/hexagon/kernel/kgdb.c
> index 16c24b22d0b2..012e0e230ac2 100644
> --- a/arch/hexagon/kernel/kgdb.c
> +++ b/arch/hexagon/kernel/kgdb.c
> @@ -119,17 +119,12 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
>
> /**
> * kgdb_roundup_cpus - Get other CPUs into a holding pattern
> - * @flags: Current IRQ state
> *
> * On SMP systems, we need to get the attention of the other CPUs
> * and get them be in a known state. This should do what is needed
> * to get the other CPUs to call kgdb_wait(). Note that on some arches,
> * the NMI approach is not used for rounding up all the CPUs. For example,
> - * in case of MIPS, smp_call_function() is used to roundup CPUs. In
> - * this case, we have to make sure that interrupts are enabled before
> - * calling smp_call_function(). The argument to this function is
> - * the flags that will be used when restoring the interrupts. There is
> - * local_irq_save() call before kgdb_roundup_cpus().
> + * in case of MIPS, smp_call_function() is used to roundup CPUs.
> *
> * On non-SMP systems, this is not called.
> */
> @@ -139,7 +134,7 @@ static void hexagon_kgdb_nmi_hook(void *ignored)
> kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
> }
>
> -void kgdb_roundup_cpus(unsigned long flags)
> +void kgdb_roundup_cpus(void)
> {
> local_irq_enable();
> smp_call_function(hexagon_kgdb_nmi_hook, NULL, 0);
> diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c
> index eb6c0d582626..2b05effc17b4 100644
> --- a/arch/mips/kernel/kgdb.c
> +++ b/arch/mips/kernel/kgdb.c
> @@ -219,7 +219,7 @@ static void kgdb_call_nmi_hook(void *ignored)
> set_fs(old_fs);
> }
>
> -void kgdb_roundup_cpus(unsigned long flags)
> +void kgdb_roundup_cpus(void)
> {
> local_irq_enable();
> smp_call_function(kgdb_call_nmi_hook, NULL, 0);
> diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
> index 59c578f865aa..b0e804844be0 100644
> --- a/arch/powerpc/kernel/kgdb.c
> +++ b/arch/powerpc/kernel/kgdb.c
> @@ -124,7 +124,7 @@ static int kgdb_call_nmi_hook(struct pt_regs *regs)
> }
>
> #ifdef CONFIG_SMP
> -void kgdb_roundup_cpus(unsigned long flags)
> +void kgdb_roundup_cpus(void)
> {
> smp_send_debugger_break();
> }
> diff --git a/arch/sh/kernel/kgdb.c b/arch/sh/kernel/kgdb.c
> index 4f04c6638a4d..cc57630f6bf2 100644
> --- a/arch/sh/kernel/kgdb.c
> +++ b/arch/sh/kernel/kgdb.c
> @@ -319,7 +319,7 @@ static void kgdb_call_nmi_hook(void *ignored)
> kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
> }
>
> -void kgdb_roundup_cpus(unsigned long flags)
> +void kgdb_roundup_cpus(void)
> {
> local_irq_enable();
> smp_call_function(kgdb_call_nmi_hook, NULL, 0);
> diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
> index 4792e08ad36b..f45d876983f1 100644
> --- a/arch/sparc/kernel/smp_64.c
> +++ b/arch/sparc/kernel/smp_64.c
> @@ -1014,7 +1014,7 @@ void flush_dcache_page_all(struct mm_struct *mm, struct page *page)
> }
>
> #ifdef CONFIG_KGDB
> -void kgdb_roundup_cpus(unsigned long flags)
> +void kgdb_roundup_cpus(void)
> {
> smp_cross_call(&xcall_kgdb_capture, 0, 0, 0);
> }
> diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
> index 8e36f249646e..ac6291a4178d 100644
> --- a/arch/x86/kernel/kgdb.c
> +++ b/arch/x86/kernel/kgdb.c
> @@ -422,21 +422,16 @@ static void kgdb_disable_hw_debug(struct pt_regs *regs)
> #ifdef CONFIG_SMP
> /**
> * kgdb_roundup_cpus - Get other CPUs into a holding pattern
> - * @flags: Current IRQ state
> *
> * On SMP systems, we need to get the attention of the other CPUs
> * and get them be in a known state. This should do what is needed
> * to get the other CPUs to call kgdb_wait(). Note that on some arches,
> * the NMI approach is not used for rounding up all the CPUs. For example,
> - * in case of MIPS, smp_call_function() is used to roundup CPUs. In
> - * this case, we have to make sure that interrupts are enabled before
> - * calling smp_call_function(). The argument to this function is
> - * the flags that will be used when restoring the interrupts. There is
> - * local_irq_save() call before kgdb_roundup_cpus().
> + * in case of MIPS, smp_call_function() is used to roundup CPUs.
> *
> * On non-SMP systems, this is not called.
> */
> -void kgdb_roundup_cpus(unsigned long flags)
> +void kgdb_roundup_cpus(void)
> {
> apic->send_IPI_allbutself(APIC_DM_NMI);
> }
> diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
> index e465bb15912d..05e5b2eb0d32 100644
> --- a/include/linux/kgdb.h
> +++ b/include/linux/kgdb.h
> @@ -178,21 +178,16 @@ kgdb_arch_handle_exception(int vector, int signo, int err_code,
>
> /**
> * kgdb_roundup_cpus - Get other CPUs into a holding pattern
> - * @flags: Current IRQ state
> *
> * On SMP systems, we need to get the attention of the other CPUs
> * and get them into a known state. This should do what is needed
> * to get the other CPUs to call kgdb_wait(). Note that on some arches,
> * the NMI approach is not used for rounding up all the CPUs. For example,
> - * in case of MIPS, smp_call_function() is used to roundup CPUs. In
> - * this case, we have to make sure that interrupts are enabled before
> - * calling smp_call_function(). The argument to this function is
> - * the flags that will be used when restoring the interrupts. There is
> - * local_irq_save() call before kgdb_roundup_cpus().
> + * in case of MIPS, smp_call_function() is used to roundup CPUs.
> *
> * On non-SMP systems, this is not called.
> */
> -extern void kgdb_roundup_cpus(unsigned long flags);
> +extern void kgdb_roundup_cpus(void);
>
> /**
> * kgdb_arch_set_pc - Generic call back to the program counter
> diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
> index 65c0f1363788..f3cadda45f07 100644
> --- a/kernel/debug/debug_core.c
> +++ b/kernel/debug/debug_core.c
> @@ -593,7 +593,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
>
> /* Signal the other CPUs to enter kgdb_wait() */
> else if ((!kgdb_single_step) && kgdb_do_roundup)
> - kgdb_roundup_cpus(flags);
> + kgdb_roundup_cpus();
> #endif
>
> /*
> --
> 2.20.0.rc1.387.gf8505762e3-goog
>

Next message: Srinivas Pandruvada: "Re: [PATCH] tools/power/x86/intel_pstate_tracer: Fix non root execution for post processing a trace file."
Previous message: Josh Poimboeuf: "Re: [PATCH] kbuild: use -flive-patching when CONFIG_LIVEPATCH is enabled"
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