[PATCH] KDB: commandeer vector 0xfe for KDB_VECTOR]]
Jay Lan
jlan at sgi.com
Wed Oct 29 17:37:12 PDT 2008
Jay Lan wrote:
>
> I will let Keith to comment on the logic of your code, but this patch
> will cause IA64 compilation to fail because kdb_giveback_vector()
> is not defined for IA64.
>
> Suggestions:
> 1) change kdb_takeover_vector and kdb_giveback_vector to arch-dependent
> version of kdba_takeover_vector and kdba_giveback_vector.
> 2) extern of kdba_giveback_vector should be moved to arch-dependent
> kdb.h (ie, arch/{ia64,x86}/include/asm/kdb.h.) and the ia64 version
> to be a dummy define.
> 3) kdbmain.c should change accordingly.
Hi Cliff,
Attached below is a revised patch to change your patch with my
suggestions above.
Thanks,
jay
-- Attached file included as plaintext by Ecartis --
-- File: KDB_VECTOR.v2.1
Revised Cliff's KDB_VECTOR patch version 2 to make kdba_takeover_vector
and kdba_giveback_vector arch dependent.
---
arch/ia64/include/asm/kdb.h | 2 ++
arch/x86/kdb/kdbasupport_32.c | 22 ++++++++++++++++++----
arch/x86/kdb/kdbasupport_64.c | 23 +++++++++++++++++++----
include/asm-x86/irq_vectors.h | 11 ++++++-----
include/asm-x86/kdb.h | 2 ++
kdb/kdbmain.c | 2 ++
6 files changed, 49 insertions(+), 13 deletions(-)
Index: linux/arch/x86/kdb/kdbasupport_32.c
===================================================================
--- linux.orig/arch/x86/kdb/kdbasupport_32.c 2008-10-29 17:19:18.000000000 -0700
+++ linux/arch/x86/kdb/kdbasupport_32.c 2008-10-29 17:21:15.944621636 -0700
@@ -883,9 +883,6 @@ kdba_cpu_up(void)
static int __init
kdba_arch_init(void)
{
-#ifdef CONFIG_SMP
- set_intr_gate(KDB_VECTOR, kdb_interrupt);
-#endif
set_intr_gate(KDBENTER_VECTOR, kdb_call);
return 0;
}
@@ -1027,14 +1024,31 @@ kdba_verify_rw(unsigned long addr, size_
#include <mach_ipi.h>
+gate_desc save_idt[NR_VECTORS];
+
+void kdba_takeover_vector(int vector)
+{
+ memcpy(&save_idt[vector], &idt_table[vector], sizeof(gate_desc));
+ set_intr_gate(KDB_VECTOR, kdb_interrupt);
+ return;
+}
+
+void kdba_giveback_vector(int vector)
+{
+ native_write_idt_entry(idt_table, vector, &save_idt[vector]);
+ return;
+}
+
/* When first entering KDB, try a normal IPI. That reduces backtrace problems
* on the other cpus.
*/
void
smp_kdb_stop(void)
{
- if (!KDB_FLAG(NOIPI))
+ if (!KDB_FLAG(NOIPI)) {
+ kdba_takeover_vector(KDB_VECTOR);
send_IPI_allbutself(KDB_VECTOR);
+ }
}
/* The normal KDB IPI handler */
Index: linux/arch/x86/kdb/kdbasupport_64.c
===================================================================
--- linux.orig/arch/x86/kdb/kdbasupport_64.c 2008-10-29 17:19:18.000000000 -0700
+++ linux/arch/x86/kdb/kdbasupport_64.c 2008-10-29 17:21:15.952621783 -0700
@@ -21,6 +21,7 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kdebug.h>
+#include <linux/cpumask.h>
#include <asm/processor.h>
#include <asm/msr.h>
#include <asm/uaccess.h>
@@ -900,9 +901,6 @@ kdba_cpu_up(void)
static int __init
kdba_arch_init(void)
{
-#ifdef CONFIG_SMP
- set_intr_gate(KDB_VECTOR, kdb_interrupt);
-#endif
set_intr_gate(KDBENTER_VECTOR, kdb_call);
return 0;
}
@@ -976,14 +974,31 @@ kdba_set_current_task(const struct task_
#include <mach_ipi.h>
+gate_desc save_idt[NR_VECTORS];
+
+void kdba_takeover_vector(int vector)
+{
+ memcpy(&save_idt[vector], &idt_table[vector], sizeof(gate_desc));
+ set_intr_gate(KDB_VECTOR, kdb_interrupt);
+ return;
+}
+
+void kdba_giveback_vector(int vector)
+{
+ native_write_idt_entry(idt_table, vector, &save_idt[vector]);
+ return;
+}
+
/* When first entering KDB, try a normal IPI. That reduces backtrace problems
* on the other cpus.
*/
void
smp_kdb_stop(void)
{
- if (!KDB_FLAG(NOIPI))
+ if (!KDB_FLAG(NOIPI)) {
+ kdba_takeover_vector(KDB_VECTOR);
send_IPI_allbutself(KDB_VECTOR);
+ }
}
/* The normal KDB IPI handler */
Index: linux/include/asm-x86/irq_vectors.h
===================================================================
--- linux.orig/include/asm-x86/irq_vectors.h 2008-10-29 17:19:18.000000000 -0700
+++ linux/include/asm-x86/irq_vectors.h 2008-10-29 17:22:32.050027567 -0700
@@ -66,7 +66,6 @@
# define RESCHEDULE_VECTOR 0xfc
# define CALL_FUNCTION_VECTOR 0xfb
# define CALL_FUNCTION_SINGLE_VECTOR 0xfa
-#define KDB_VECTOR 0xf9
# define THERMAL_APIC_VECTOR 0xf0
#else
@@ -79,10 +78,6 @@
#define THERMAL_APIC_VECTOR 0xfa
#define THRESHOLD_APIC_VECTOR 0xf9
#define UV_BAU_MESSAGE 0xf8
-/* Overload KDB_VECTOR with UV_BAU_MESSAGE. By the time the UV hardware is
- * ready, we should have moved to a dynamically allocated vector scheme.
- */
-#define KDB_VECTOR 0xf8
#define INVALIDATE_TLB_VECTOR_END 0xf7
#define INVALIDATE_TLB_VECTOR_START 0xf0 /* f0-f7 used for TLB flush */
@@ -91,6 +86,12 @@
#endif
/*
+ * KDB_VECTOR will take over vector 0xfe when it is needed, as in theory
+ * it should not be used anyway.
+ */
+#define KDB_VECTOR 0xfe
+
+/*
* Local APIC timer IRQ vector is on a different priority level,
* to work around the 'lost local interrupt if more than 2 IRQ
* sources per level' errata.
Index: linux/kdb/kdbmain.c
===================================================================
--- linux.orig/kdb/kdbmain.c 2008-10-29 17:19:18.000000000 -0700
+++ linux/kdb/kdbmain.c 2008-10-29 17:21:15.988622448 -0700
@@ -1666,6 +1666,8 @@ kdb_wait_for_cpus(void)
wait == 1 ? " is" : "s are",
wait == 1 ? "its" : "their");
}
+ /* give back the vector we took over in smp_kdb_stop */
+ kdba_giveback_vector(KDB_VECTOR);
#endif /* CONFIG_SMP */
}
Index: linux/arch/ia64/include/asm/kdb.h
===================================================================
--- linux.orig/arch/ia64/include/asm/kdb.h 2008-10-28 17:17:26.000000000 -0700
+++ linux/arch/ia64/include/asm/kdb.h 2008-10-29 17:21:16.008622818 -0700
@@ -43,4 +43,6 @@ kdba_funcptr_value(void *fp)
return *(unsigned long *)fp;
}
+#define kdba_giveback_vector(vector) (0)
+
#endif /* !_ASM_KDB_H */
Index: linux/include/asm-x86/kdb.h
===================================================================
--- linux.orig/include/asm-x86/kdb.h 2008-10-28 17:17:27.000000000 -0700
+++ linux/include/asm-x86/kdb.h 2008-10-29 17:21:16.028623187 -0700
@@ -133,4 +133,6 @@ kdba_funcptr_value(void *fp)
return (unsigned long)fp;
}
+extern void kdba_giveback_vector(int);
+
#endif /* !_ASM_KDB_H */
---------------------------
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