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authorVivek Goyal <vgoyal@redhat.com>2014-08-29 15:18:46 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-29 16:28:16 -0700
commit74ca317c26a3f8543203b61d262c0ab2e30c384e (patch)
treee88c78846c33bd3f86034b2ba16616ea38bb2802
parentb38af4721f59d0b564468f623b3e52a638195015 (diff)
downloadlinux-stericsson-74ca317c26a3f8543203b61d262c0ab2e30c384e.tar.gz
kexec: create a new config option CONFIG_KEXEC_FILE for new syscall
Currently new system call kexec_file_load() and all the associated code compiles if CONFIG_KEXEC=y. But new syscall also compiles purgatory code which currently uses gcc option -mcmodel=large. This option seems to be available only gcc 4.4 onwards. Hiding new functionality behind a new config option will not break existing users of old gcc. Those who wish to enable new functionality will require new gcc. Having said that, I am trying to figure out how can I move away from using -mcmodel=large but that can take a while. I think there are other advantages of introducing this new config option. As this option will be enabled only on x86_64, other arches don't have to compile generic kexec code which will never be used. This new code selects CRYPTO=y and CRYPTO_SHA256=y. And all other arches had to do this for CONFIG_KEXEC. Now with introduction of new config option, we can remove crypto dependency from other arches. Now CONFIG_KEXEC_FILE is available only on x86_64. So whereever I had CONFIG_X86_64 defined, I got rid of that. For CONFIG_KEXEC_FILE, instead of doing select CRYPTO=y, I changed it to "depends on CRYPTO=y". This should be safer as "select" is not recursive. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/x86/Kbuild4
-rw-r--r--arch/x86/Kconfig18
-rw-r--r--arch/x86/Makefile5
-rw-r--r--arch/x86/kernel/Makefile2
-rw-r--r--arch/x86/kernel/crash.c6
-rw-r--r--arch/x86/kernel/machine_kexec_64.c11
-rw-r--r--arch/x86/purgatory/Makefile5
-rw-r--r--kernel/kexec.c11
8 files changed, 42 insertions, 20 deletions
diff --git a/arch/x86/Kbuild b/arch/x86/Kbuild
index 61b6d51866f8..3942f74c92d7 100644
--- a/arch/x86/Kbuild
+++ b/arch/x86/Kbuild
@@ -17,6 +17,4 @@ obj-$(CONFIG_IA32_EMULATION) += ia32/
obj-y += platform/
obj-y += net/
-ifeq ($(CONFIG_X86_64),y)
-obj-$(CONFIG_KEXEC) += purgatory/
-endif
+obj-$(CONFIG_KEXEC_FILE) += purgatory/
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5d0bf1aa9dcb..778178f4c7d1 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1585,9 +1585,6 @@ source kernel/Kconfig.hz
config KEXEC
bool "kexec system call"
- select BUILD_BIN2C
- select CRYPTO
- select CRYPTO_SHA256
---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
@@ -1602,9 +1599,22 @@ config KEXEC
interface is strongly in flux, so no good recommendation can be
made.
+config KEXEC_FILE
+ bool "kexec file based system call"
+ select BUILD_BIN2C
+ depends on KEXEC
+ depends on X86_64
+ depends on CRYPTO=y
+ depends on CRYPTO_SHA256=y
+ ---help---
+ This is new version of kexec system call. This system call is
+ file based and takes file descriptors as system call argument
+ for kernel and initramfs as opposed to list of segments as
+ accepted by previous system call.
+
config KEXEC_VERIFY_SIG
bool "Verify kernel signature during kexec_file_load() syscall"
- depends on KEXEC
+ depends on KEXEC_FILE
---help---
This option makes kernel signature verification mandatory for
kexec_file_load() syscall. If kernel is signature can not be
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index c1aa36887843..c96bcec544fc 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -184,11 +184,8 @@ archheaders:
$(Q)$(MAKE) $(build)=arch/x86/syscalls all
archprepare:
-ifeq ($(CONFIG_KEXEC),y)
-# Build only for 64bit. No loaders for 32bit yet.
- ifeq ($(CONFIG_X86_64),y)
+ifeq ($(CONFIG_KEXEC_FILE),y)
$(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c
- endif
endif
###
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index b5ea75c4a4b4..ada2e2d6be3e 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -71,6 +71,7 @@ obj-$(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_FILE) += kexec-bzimage64.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o
obj-y += kprobes/
obj-$(CONFIG_MODULES) += module.o
@@ -118,5 +119,4 @@ ifeq ($(CONFIG_X86_64),y)
obj-$(CONFIG_PCI_MMCONFIG) += mmconf-fam10h_64.o
obj-y += vsmp_64.o
- obj-$(CONFIG_KEXEC) += kexec-bzimage64.o
endif
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 0553a34fa0df..a618fcd2c07d 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -182,8 +182,7 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
crash_save_cpu(regs, safe_smp_processor_id());
}
-#ifdef CONFIG_X86_64
-
+#ifdef CONFIG_KEXEC_FILE
static int get_nr_ram_ranges_callback(unsigned long start_pfn,
unsigned long nr_pfn, void *arg)
{
@@ -696,5 +695,4 @@ int crash_load_segments(struct kimage *image)
return ret;
}
-
-#endif /* CONFIG_X86_64 */
+#endif /* CONFIG_KEXEC_FILE */
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 8b04018e5d1f..485981059a40 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -25,9 +25,11 @@
#include <asm/debugreg.h>
#include <asm/kexec-bzimage64.h>
+#ifdef CONFIG_KEXEC_FILE
static struct kexec_file_ops *kexec_file_loaders[] = {
&kexec_bzImage64_ops,
};
+#endif
static void free_transition_pgtable(struct kimage *image)
{
@@ -178,6 +180,7 @@ static void load_segments(void)
);
}
+#ifdef CONFIG_KEXEC_FILE
/* Update purgatory as needed after various image segments have been prepared */
static int arch_update_purgatory(struct kimage *image)
{
@@ -209,6 +212,12 @@ static int arch_update_purgatory(struct kimage *image)
return ret;
}
+#else /* !CONFIG_KEXEC_FILE */
+static inline int arch_update_purgatory(struct kimage *image)
+{
+ return 0;
+}
+#endif /* CONFIG_KEXEC_FILE */
int machine_kexec_prepare(struct kimage *image)
{
@@ -329,6 +338,7 @@ void arch_crash_save_vmcoreinfo(void)
/* arch-dependent functionality related to kexec file-based syscall */
+#ifdef CONFIG_KEXEC_FILE
int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
unsigned long buf_len)
{
@@ -522,3 +532,4 @@ overflow:
(int)ELF64_R_TYPE(rel[i].r_info), value);
return -ENOEXEC;
}
+#endif /* CONFIG_KEXEC_FILE */
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index 7fde9ee438a4..c4ae06e4ae74 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -24,7 +24,4 @@ $(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE
$(call if_changed,bin2c)
-# No loaders for 32bits yet.
-ifeq ($(CONFIG_X86_64),y)
- obj-$(CONFIG_KEXEC) += kexec-purgatory.o
-endif
+obj-$(CONFIG_KEXEC_FILE) += kexec-purgatory.o
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 0b49a0a58102..2bee072268d9 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -64,7 +64,9 @@ bool kexec_in_progress = false;
char __weak kexec_purgatory[0];
size_t __weak kexec_purgatory_size = 0;
+#ifdef CONFIG_KEXEC_FILE
static int kexec_calculate_store_digests(struct kimage *image);
+#endif
/* Location of the reserved area for the crash kernel */
struct resource crashk_res = {
@@ -341,6 +343,7 @@ out_free_image:
return ret;
}
+#ifdef CONFIG_KEXEC_FILE
static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len)
{
struct fd f = fdget(fd);
@@ -612,6 +615,9 @@ out_free_image:
kfree(image);
return ret;
}
+#else /* CONFIG_KEXEC_FILE */
+static inline void kimage_file_post_load_cleanup(struct kimage *image) { }
+#endif /* CONFIG_KEXEC_FILE */
static int kimage_is_destination_range(struct kimage *image,
unsigned long start,
@@ -1375,6 +1381,7 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
}
#endif
+#ifdef CONFIG_KEXEC_FILE
SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
unsigned long, cmdline_len, const char __user *, cmdline_ptr,
unsigned long, flags)
@@ -1451,6 +1458,8 @@ out:
return ret;
}
+#endif /* CONFIG_KEXEC_FILE */
+
void crash_kexec(struct pt_regs *regs)
{
/* Take the kexec_mutex here to prevent sys_kexec_load
@@ -2006,6 +2015,7 @@ static int __init crash_save_vmcoreinfo_init(void)
subsys_initcall(crash_save_vmcoreinfo_init);
+#ifdef CONFIG_KEXEC_FILE
static int __kexec_add_segment(struct kimage *image, char *buf,
unsigned long bufsz, unsigned long mem,
unsigned long memsz)
@@ -2682,6 +2692,7 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
return 0;
}
+#endif /* CONFIG_KEXEC_FILE */
/*
* Move into place and start executing a preloaded standalone