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authorLinus Torvalds <torvalds@linux-foundation.org>2014-01-31 20:59:46 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-31 20:59:46 +0400
commitab5318788c6725b6d5c95aff28e63af4c35a0e2c (patch)
treefb4a81d66ed06828948e3272ebe15088d405ec1e /arch/x86
parent14164b46fc994bcf82963ace00372cf808a31af1 (diff)
parent270750dbc18a71b23d660df110e433ff9616a2d4 (diff)
downloadlinux-ab5318788c6725b6d5c95aff28e63af4c35a0e2c.tar.xz
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core debug changes from Ingo Molnar: "This contains mostly kernel debugging related updates: - make hung_task detection more configurable to distros - add final bits for x86 UV NMI debugging, with related KGDB changes - update the mailing-list of MAINTAINERS entries I'm involved with" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hung_task: Display every hung task warning sysctl: Add neg_one as a standard constraint x86/uv/nmi, kgdb/kdb: Fix UV NMI handler when KDB not configured x86/uv/nmi: Fix Sparse warnings kgdb/kdb: Fix no KDB config problem MAINTAINERS: Restore "L: linux-kernel@vger.kernel.org" entries
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/uv/uv.h2
-rw-r--r--arch/x86/kernel/apic/x2apic_uv_x.c1
-rw-r--r--arch/x86/platform/uv/uv_nmi.c65
3 files changed, 46 insertions, 22 deletions
diff --git a/arch/x86/include/asm/uv/uv.h b/arch/x86/include/asm/uv/uv.h
index 6b964a0b86d1..062921ef34e9 100644
--- a/arch/x86/include/asm/uv/uv.h
+++ b/arch/x86/include/asm/uv/uv.h
@@ -12,7 +12,6 @@ extern enum uv_system_type get_uv_system_type(void);
extern int is_uv_system(void);
extern void uv_cpu_init(void);
extern void uv_nmi_init(void);
-extern void uv_register_nmi_notifier(void);
extern void uv_system_init(void);
extern const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
@@ -26,7 +25,6 @@ static inline enum uv_system_type get_uv_system_type(void) { return UV_NONE; }
static inline int is_uv_system(void) { return 0; }
static inline void uv_cpu_init(void) { }
static inline void uv_system_init(void) { }
-static inline void uv_register_nmi_notifier(void) { }
static inline const struct cpumask *
uv_flush_tlb_others(const struct cpumask *cpumask, struct mm_struct *mm,
unsigned long start, unsigned long end, unsigned int cpu)
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index ad0dc0428baf..d263b1307de1 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -980,7 +980,6 @@ void __init uv_system_init(void)
uv_nmi_setup();
uv_cpu_init();
uv_scir_register_cpu_notifier();
- uv_register_nmi_notifier();
proc_mkdir("sgi_uv", NULL);
/* register Legacy VGA I/O redirection handler */
diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c
index 8eeccba73130..be27da60dc8f 100644
--- a/arch/x86/platform/uv/uv_nmi.c
+++ b/arch/x86/platform/uv/uv_nmi.c
@@ -74,7 +74,6 @@ static atomic_t uv_in_nmi;
static atomic_t uv_nmi_cpu = ATOMIC_INIT(-1);
static atomic_t uv_nmi_cpus_in_nmi = ATOMIC_INIT(-1);
static atomic_t uv_nmi_slave_continue;
-static atomic_t uv_nmi_kexec_failed;
static cpumask_var_t uv_nmi_cpu_mask;
/* Values for uv_nmi_slave_continue */
@@ -149,7 +148,8 @@ module_param_named(retry_count, uv_nmi_retry_count, int, 0644);
* "dump" - dump process stack for each cpu
* "ips" - dump IP info for each cpu
* "kdump" - do crash dump
- * "kdb" - enter KDB/KGDB (default)
+ * "kdb" - enter KDB (default)
+ * "kgdb" - enter KGDB
*/
static char uv_nmi_action[8] = "kdb";
module_param_string(action, uv_nmi_action, sizeof(uv_nmi_action), 0644);
@@ -504,6 +504,7 @@ static void uv_nmi_touch_watchdogs(void)
}
#if defined(CONFIG_KEXEC)
+static atomic_t uv_nmi_kexec_failed;
static void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
{
/* Call crash to dump system state */
@@ -537,18 +538,45 @@ static inline void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
}
#endif /* !CONFIG_KEXEC */
+#ifdef CONFIG_KGDB
#ifdef CONFIG_KGDB_KDB
-/* Call KDB from NMI handler */
-static void uv_call_kdb(int cpu, struct pt_regs *regs, int master)
+static inline int uv_nmi_kdb_reason(void)
{
- int ret;
+ return KDB_REASON_SYSTEM_NMI;
+}
+#else /* !CONFIG_KGDB_KDB */
+static inline int uv_nmi_kdb_reason(void)
+{
+ /* Insure user is expecting to attach gdb remote */
+ if (uv_nmi_action_is("kgdb"))
+ return 0;
+
+ pr_err("UV: NMI error: KDB is not enabled in this kernel\n");
+ return -1;
+}
+#endif /* CONFIG_KGDB_KDB */
+/*
+ * Call KGDB/KDB from NMI handler
+ *
+ * Note that if both KGDB and KDB are configured, then the action of 'kgdb' or
+ * 'kdb' has no affect on which is used. See the KGDB documention for further
+ * information.
+ */
+static void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master)
+{
if (master) {
+ int reason = uv_nmi_kdb_reason();
+ int ret;
+
+ if (reason < 0)
+ return;
+
/* call KGDB NMI handler as MASTER */
- ret = kgdb_nmicallin(cpu, X86_TRAP_NMI, regs,
- &uv_nmi_slave_continue);
+ ret = kgdb_nmicallin(cpu, X86_TRAP_NMI, regs, reason,
+ &uv_nmi_slave_continue);
if (ret) {
- pr_alert("KDB returned error, is kgdboc set?\n");
+ pr_alert("KGDB returned error, is kgdboc set?\n");
atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT);
}
} else {
@@ -567,12 +595,12 @@ static void uv_call_kdb(int cpu, struct pt_regs *regs, int master)
uv_nmi_sync_exit(master);
}
-#else /* !CONFIG_KGDB_KDB */
-static inline void uv_call_kdb(int cpu, struct pt_regs *regs, int master)
+#else /* !CONFIG_KGDB */
+static inline void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master)
{
- pr_err("UV: NMI error: KGDB/KDB is not enabled in this kernel\n");
+ pr_err("UV: NMI error: KGDB is not enabled in this kernel\n");
}
-#endif /* !CONFIG_KGDB_KDB */
+#endif /* !CONFIG_KGDB */
/*
* UV NMI handler
@@ -606,9 +634,9 @@ int uv_handle_nmi(unsigned int reason, struct pt_regs *regs)
if (uv_nmi_action_is("ips") || uv_nmi_action_is("dump"))
uv_nmi_dump_state(cpu, regs, master);
- /* Call KDB if enabled */
- else if (uv_nmi_action_is("kdb"))
- uv_call_kdb(cpu, regs, master);
+ /* Call KGDB/KDB if enabled */
+ else if (uv_nmi_action_is("kdb") || uv_nmi_action_is("kgdb"))
+ uv_call_kgdb_kdb(cpu, regs, master);
/* Clear per_cpu "in nmi" flag */
atomic_set(&uv_cpu_nmi.state, UV_NMI_STATE_OUT);
@@ -634,7 +662,7 @@ int uv_handle_nmi(unsigned int reason, struct pt_regs *regs)
/*
* NMI handler for pulling in CPUs when perf events are grabbing our NMI
*/
-int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs)
+static int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs)
{
int ret;
@@ -651,7 +679,7 @@ int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs)
return ret;
}
-void uv_register_nmi_notifier(void)
+static void uv_register_nmi_notifier(void)
{
if (register_nmi_handler(NMI_UNKNOWN, uv_handle_nmi, 0, "uv"))
pr_warn("UV: NMI handler failed to register\n");
@@ -695,6 +723,5 @@ void uv_nmi_setup(void)
uv_hub_nmi_per(cpu) = uv_hub_nmi_list[nid];
}
BUG_ON(!alloc_cpumask_var(&uv_nmi_cpu_mask, GFP_KERNEL));
+ uv_register_nmi_notifier();
}
-
-