[v6,1/4] kgdb: Remove irq flags from roundup

Message ID 20181127173839.34328-2-dianders@chromium.org
State New
Headers show
Series
  • kgdb: Fix kgdb_roundup_cpus()
Related show

Commit Message

Doug Anderson Nov. 27, 2018, 5:38 p.m.
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@chromium.org>
Acked-by: Will Deacon <will.deacon@arm.com>
---

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(-)

Comments

Daniel Thompson Dec. 3, 2018, 4 p.m. | #1
On Tue, Nov 27, 2018 at 09:38:36AM -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@chromium.org>
> Acked-by: Will Deacon <will.deacon@arm.com>
> ---
> 
> 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 ++-------

Again, please formally Cc: the arch maintainers in the patch header
(just after your Signed-off-by: if I'm not being explicitly clear).


Daniel.

>  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.rc0.387.gc7a69e6b6c-goog
>

Patch

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
 
 	/*