[PATCH v4 1/4] kgdb: Remove irq flags from roundup

Douglas Anderson
2018-11-12T18:26:55Z

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>
---

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

/*
--
2.19.1.930.g4563a0d9d0-goog