Merge branch 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers into asm-generic

Patches from David Howells <dhowells@redhat.com>:

This is to complete part of the UAPI disintegration for which the
preparatory patches were pulled recently.

Note that there are some fixup patches which are at the base of the
branch aimed at you, plus all arches get the asm-generic branch merged in too.

* 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers:
  UAPI: (Scripted) Disintegrate include/asm-generic
  UAPI: Fix conditional header installation handling (notably kvm_para.h on m68k)
  c6x: remove c6x signal.h
  UAPI: Split compound conditionals containing __KERNEL__ in Arm64
  UAPI: Fix the guards on various asm/unistd.h files

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 42 insertions, 3 deletions

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 0557f24c6bca..17e073c309e6 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -672,6 +672,10 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
 {
         struct kgdb_state kgdb_var;
         struct kgdb_state *ks = &kgdb_var;
+        int ret = 0;
+
+        if (arch_kgdb_ops.enable_nmi)
+                arch_kgdb_ops.enable_nmi(0);
 
         ks->cpu                 = raw_smp_processor_id();
         ks->ex_vector           = evector;
@@ -681,11 +685,15 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
         ks->linux_regs          = regs;
 
         if (kgdb_reenter_check(ks))
-                return 0; /* Ouch, double exception ! */
+                goto out; /* Ouch, double exception ! */
         if (kgdb_info[ks->cpu].enter_kgdb != 0)
-                return 0;
+                goto out;
 
-        return kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
+        ret = kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
+out:
+        if (arch_kgdb_ops.enable_nmi)
+                arch_kgdb_ops.enable_nmi(1);
+        return ret;
 }
 
 int kgdb_nmicallback(int cpu, void *regs)
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 31df1706b9a9..1261dc7eaeb9 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -21,6 +21,7 @@
 #include <linux/smp.h>
 #include <linux/utsname.h>
 #include <linux/vmalloc.h>
+#include <linux/atomic.h>
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/init.h>
@@ -2107,6 +2108,32 @@ static int kdb_dmesg(int argc, const char **argv)
         return 0;
 }
 #endif /* CONFIG_PRINTK */
+
+/* Make sure we balance enable/disable calls, must disable first. */
+static atomic_t kdb_nmi_disabled;
+
+static int kdb_disable_nmi(int argc, const char *argv[])
+{
+        if (atomic_read(&kdb_nmi_disabled))
+                return 0;
+        atomic_set(&kdb_nmi_disabled, 1);
+        arch_kgdb_ops.enable_nmi(0);
+        return 0;
+}
+
+static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
+{
+        if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
+                return -EINVAL;
+        arch_kgdb_ops.enable_nmi(1);
+        return 0;
+}
+
+static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
+        .set = kdb_param_enable_nmi,
+};
+module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
+
 /*
  * kdb_cpu - This function implements the 'cpu' command.
  *      cpu     [<cpunum>]
@@ -2851,6 +2878,10 @@ static void __init kdb_inittab(void)
         kdb_register_repeat("dmesg", kdb_dmesg, "[lines]",
           "Display syslog buffer", 0, KDB_REPEAT_NONE);
 #endif
+        if (arch_kgdb_ops.enable_nmi) {
+                kdb_register_repeat("disable_nmi", kdb_disable_nmi, "",
+                  "Disable NMI entry to KDB", 0, KDB_REPEAT_NONE);
+        }
         kdb_register_repeat("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
           "Define a set of commands, down to endefcmd", 0, KDB_REPEAT_NONE);
         kdb_register_repeat("kill", kdb_kill, "<-signal> <pid>",