kexec: split kexec_load syscall from kexec core code

There are two kexec load syscalls, kexec_load another and kexec_file_load.
 kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
split kexec_load syscall code to kernel/kexec.c.

And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.

The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
kexec_load syscall can bypass the checking.

Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.

Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
kexec_load syscall.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

20 files changed, 32 insertions, 20 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 8f3564930580..4e949e58b192 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -2,6 +2,9 @@
 # General architecture dependent options
 #
 
+config KEXEC_CORE
+        bool
+
 config OPROFILE
         tristate "OProfile system profiling"
         depends on PROFILING
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0d1b717e1eca..72ad724c67ae 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2020,6 +2020,7 @@ config KEXEC
         bool "Kexec system call (EXPERIMENTAL)"
         depends on (!SMP || PM_SLEEP_SMP)
         depends on !CPU_V7M
+        select KEXEC_CORE
         help
           kexec is a system call that implements the ability to shutdown your
           current kernel, and to start another kernel.  It is like a reboot
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 42a91a7aa2b0..eb0249e37981 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -518,6 +518,7 @@ source "drivers/sn/Kconfig"
 config KEXEC
         bool "kexec system call"
         depends on !IA64_HP_SIM && (!SMP || HOTPLUG_CPU)
+        select KEXEC_CORE
         help
           kexec is a system call that implements the ability to shutdown your
           current kernel, and to start another kernel.  It is like a reboot
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 2dd8f63bfbbb..498b567f007b 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -95,6 +95,7 @@ config MMU_SUN3
 config KEXEC
         bool "kexec system call"
         depends on M68KCLASSIC
+        select KEXEC_CORE
         help
           kexec is a system call that implements the ability to shutdown your
           current kernel, and to start another kernel.  It is like a reboot
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 752acca8de1f..e3aa5b0b4ef1 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2597,6 +2597,7 @@ source "kernel/Kconfig.preempt"
 
 config KEXEC
         bool "Kexec system call"
+        select KEXEC_CORE
         help
           kexec is a system call that implements the ability to shutdown your
           current kernel, and to start another kernel.  It is like a reboot
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b447918b9e2c..9a7057ec2154 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -420,6 +420,7 @@ config PPC64_SUPPORTS_MEMORY_FAILURE
 config KEXEC
         bool "kexec system call"
         depends on (PPC_BOOK3S || FSL_BOOKE || (44x && !SMP))
+        select KEXEC_CORE
         help
           kexec is a system call that implements the ability to shutdown your
           current kernel, and to start another kernel.  It is like a reboot
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 4827870f7a6d..1d57000b1b24 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -48,6 +48,7 @@ config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 
 config KEXEC
         def_bool y
+        select KEXEC_CORE
 
 config AUDIT_ARCH
         def_bool y
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 50057fed819d..d514df7e04dd 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -602,6 +602,7 @@ source kernel/Kconfig.hz
 config KEXEC
         bool "kexec system call (EXPERIMENTAL)"
         depends on SUPERH32 && MMU
+        select KEXEC_CORE
         help
           kexec is a system call that implements the ability to shutdown your
           current kernel, and to start another kernel.  It is like a reboot
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 2ba12d761723..106c21bd7f44 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -205,6 +205,7 @@ source "kernel/Kconfig.hz"
 
 config KEXEC
         bool "kexec system call"
+        select KEXEC_CORE
         ---help---
           kexec is a system call that implements the ability to shutdown your
           current kernel, and to start another kernel.  It is like a reboot
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index cc0d73eac047..7aef2d52daa0 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1754,6 +1754,7 @@ source kernel/Kconfig.hz
 
 config KEXEC
         bool "kexec system call"
+        select KEXEC_CORE
         ---help---
           kexec is a system call that implements the ability to shutdown your
           current kernel, and to start another kernel.  It is like a reboot
@@ -1770,8 +1771,8 @@ config KEXEC
 
 config KEXEC_FILE
         bool "kexec file based system call"
+        select KEXEC_CORE
         select BUILD_BIN2C
-        depends on KEXEC
         depends on X86_64
         depends on CRYPTO=y
         depends on CRYPTO_SHA256=y
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 16ef02596db2..2d6b309c8e9a 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -414,7 +414,7 @@ xloadflags:
 # define XLF23 0
 #endif
 
-#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC)
+#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC_CORE)
 # define XLF4 XLF_EFI_KEXEC
 #else
 # define XLF4 0
diff --git a/arch/x86/include/asm/kdebug.h b/arch/x86/include/asm/kdebug.h
index 32ce71375b21..b130d59406fb 100644
--- a/arch/x86/include/asm/kdebug.h
+++ b/arch/x86/include/asm/kdebug.h
@@ -29,7 +29,7 @@ extern void show_trace(struct task_struct *t, struct pt_regs *regs,
 extern void __show_regs(struct pt_regs *regs, int all);
 extern unsigned long oops_begin(void);
 extern void oops_end(unsigned long, struct pt_regs *, int signr);
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 extern int in_crash_kexec;
 #else
 /* no crash dump is ever in progress if no crash kernel can be kexec'd */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 9ffdf25e5b86..b1b78ffe01d0 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -71,8 +71,8 @@ obj-$(CONFIG_LIVEPATCH)		+= livepatch.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
 obj-$(CONFIG_FTRACE_SYSCALLS)   += ftrace.o
 obj-$(CONFIG_X86_TSC)           += trace_clock.o
-obj-$(CONFIG_KEXEC)             += machine_kexec_$(BITS).o
-obj-$(CONFIG_KEXEC)             += relocate_kernel_$(BITS).o crash.o
+obj-$(CONFIG_KEXEC_CORE)        += machine_kexec_$(BITS).o
+obj-$(CONFIG_KEXEC_CORE)        += relocate_kernel_$(BITS).o crash.o
 obj-$(CONFIG_KEXEC_FILE)        += kexec-bzimage64.o
 obj-$(CONFIG_CRASH_DUMP)        += crash_dump_$(BITS).o
 obj-y                           += kprobes/
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 49487b488061..2c7aafa70702 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -200,7 +200,7 @@ static void kvm_setup_secondary_clock(void)
  * kind of shutdown from our side, we unregister the clock by writting anything
  * that does not have the 'enable' bit set in the msr
  */
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 static void kvm_crash_shutdown(struct pt_regs *regs)
 {
         native_write_msr(msr_kvm_system_time, 0, 0);
@@ -259,7 +259,7 @@ void __init kvmclock_init(void)
         x86_platform.save_sched_clock_state = kvm_save_sched_clock_state;
         x86_platform.restore_sched_clock_state = kvm_restore_sched_clock_state;
         machine_ops.shutdown  = kvm_shutdown;
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
         machine_ops.crash_shutdown  = kvm_crash_shutdown;
 #endif
         kvm_get_preset_lpj();
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 86db4bcd7ce5..02693dd9a079 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -673,7 +673,7 @@ struct machine_ops machine_ops = {
         .emergency_restart = native_machine_emergency_restart,
         .restart = native_machine_restart,
         .halt = native_machine_halt,
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
         .crash_shutdown = native_machine_crash_shutdown,
 #endif
 };
@@ -703,7 +703,7 @@ void machine_halt(void)
         machine_ops.halt();
 }
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 void machine_crash_shutdown(struct pt_regs *regs)
 {
         machine_ops.crash_shutdown(regs);
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index baadbf90a7c5..fdb7f2a2d328 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -478,7 +478,7 @@ static void __init memblock_x86_reserve_range_setup_data(void)
  * --------- Crashkernel reservation ------------------------------
  */
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 
 /*
  * Keep the crash kernel below this limit.  On 32 bits earlier kernels
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 00bf300fd846..74e4bf11f562 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -364,7 +364,7 @@ INIT_PER_CPU(irq_stack_union);
 
 #endif /* CONFIG_X86_32 */
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 #include <asm/kexec.h>
 
 . = ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 148ea2016022..d01986832afc 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1264,7 +1264,7 @@ static void vmcs_load(struct vmcs *vmcs)
                        vmcs, phys_addr);
 }
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 /*
  * This bitmap is used to indicate whether the vmclear
  * operation is enabled on all cpus. All disabled by
@@ -1302,7 +1302,7 @@ static void crash_vmclear_local_loaded_vmcss(void)
 #else
 static inline void crash_enable_local_vmclear(int cpu) { }
 static inline void crash_disable_local_vmclear(int cpu) { }
-#endif /* CONFIG_KEXEC */
+#endif /* CONFIG_KEXEC_CORE */
 
 static void __loaded_vmcs_clear(void *arg)
 {
@@ -10411,7 +10411,7 @@ static int __init vmx_init(void)
         if (r)
                 return r;
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
         rcu_assign_pointer(crash_vmclear_loaded_vmcss,
                            crash_vmclear_local_loaded_vmcss);
 #endif
@@ -10421,7 +10421,7 @@ static int __init vmx_init(void)
 
 static void __exit vmx_exit(void)
 {
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
         RCU_INIT_POINTER(crash_vmclear_loaded_vmcss, NULL);
         synchronize_rcu();
 #endif
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index e4308fe6afe8..1db84c0758b7 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -650,7 +650,7 @@ static void __init get_systab_virt_addr(efi_memory_desc_t *md)
 
 static void __init save_runtime_map(void)
 {
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
         efi_memory_desc_t *md;
         void *tmp, *p, *q = NULL;
         int count = 0;
@@ -748,7 +748,7 @@ static void * __init efi_map_regions(int *count, int *pg_shift)
 
 static void __init kexec_enter_virtual_mode(void)
 {
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
         efi_memory_desc_t *md;
         void *p;
 
diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c
index 020c101c255f..5c9f63fa6abf 100644
--- a/arch/x86/platform/uv/uv_nmi.c
+++ b/arch/x86/platform/uv/uv_nmi.c
@@ -492,7 +492,7 @@ static void uv_nmi_touch_watchdogs(void)
         touch_nmi_watchdog();
 }
 
-#if defined(CONFIG_KEXEC)
+#if defined(CONFIG_KEXEC_CORE)
 static atomic_t uv_nmi_kexec_failed;
 static void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
 {
@@ -519,13 +519,13 @@ static void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
         uv_nmi_sync_exit(0);
 }
 
-#else /* !CONFIG_KEXEC */
+#else /* !CONFIG_KEXEC_CORE */
 static inline void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
 {
         if (master)
                 pr_err("UV: NMI kdump: KEXEC not supported in this kernel\n");
 }
-#endif /* !CONFIG_KEXEC */
+#endif /* !CONFIG_KEXEC_CORE */
 
 #ifdef CONFIG_KGDB
 #ifdef CONFIG_KGDB_KDB