The patch titled
Subject: kexec: create a new config option CONFIG_KEXEC_FILE for new syscall
has been added to the -mm tree. Its filename is
kexec-create-a-new-config-option-config_kexec_file-for-new-syscall.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kexec-create-a-new-config-option-config_kexec_file-for-new-syscall.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kexec-create-a-new-config-option-config_kexec_file-for-new-syscall.patch
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------------------------------------------------------
From: Vivek Goyal <vgoyal@xxxxxxxxxx>
Subject: 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@xxxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Shaun Ruffell <sruffell@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/Kbuild | 4 +---
arch/x86/Kconfig | 18 ++++++++++++++----
arch/x86/Makefile | 5 +----
arch/x86/kernel/Makefile | 2 +-
arch/x86/kernel/crash.c | 6 ++----
arch/x86/kernel/machine_kexec_64.c | 11 +++++++++++
arch/x86/purgatory/Makefile | 5 +----
kernel/kexec.c | 11 +++++++++++
8 files changed, 42 insertions(+), 20 deletions(-)
diff -puN arch/x86/Kbuild~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall arch/x86/Kbuild
--- a/arch/x86/Kbuild~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall
+++ a/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 -puN arch/x86/Kconfig~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall arch/x86/Kconfig
--- a/arch/x86/Kconfig~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall
+++ a/arch/x86/Kconfig
@@ -1582,9 +1582,6 @@ 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
@@ -1599,9 +1596,22 @@ 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 -puN arch/x86/Makefile~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall arch/x86/Makefile
--- a/arch/x86/Makefile~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall
+++ a/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) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c
- endif
endif
###
diff -puN arch/x86/kernel/Makefile~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall arch/x86/kernel/Makefile
--- a/arch/x86/kernel/Makefile~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall
+++ a/arch/x86/kernel/Makefile
@@ -71,6 +71,7 @@ obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.
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 -puN arch/x86/kernel/crash.c~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall arch/x86/kernel/crash.c
--- a/arch/x86/kernel/crash.c~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall
+++ a/arch/x86/kernel/crash.c
@@ -182,8 +182,7 @@ void native_machine_crash_shutdown(struc
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 *i
return ret;
}
-
-#endif /* CONFIG_X86_64 */
+#endif /* CONFIG_KEXEC_FILE */
diff -puN arch/x86/kernel/machine_kexec_64.c~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall arch/x86/kernel/machine_kexec_64.c
--- a/arch/x86/kernel/machine_kexec_64.c~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall
+++ a/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
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 -puN arch/x86/purgatory/Makefile~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall arch/x86/purgatory/Makefile
--- a/arch/x86/purgatory/Makefile~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall
+++ a/arch/x86/purgatory/Makefile
@@ -24,7 +24,4 @@ $(obj)/kexec-purgatory.c: $(obj)/purgato
$(call if_changed,bin2c)
-# No loaders for 32bits yet.
-ifeq ($(CONFIG_X86_64),y)
- obj-$(CONFIG_KEXEC) += kexec-purgatory.o
-endif
+obj-$(CONFIG_KEXEC_FILE) += kexec-purgatory.o
diff -puN kernel/kexec.c~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall kernel/kexec.c
--- a/kernel/kexec.c~kexec-create-a-new-config-option-config_kexec_file-for-new-syscall
+++ a/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, compa
}
#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_
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(struc
return 0;
}
+#endif /* CONFIG_KEXEC_FILE */
/*
* Move into place and start executing a preloaded standalone
_
Patches currently in -mm which might be from vgoyal@xxxxxxxxxx are
origin.patch
kernel-resourcec-fix-null-deref-with-no-iomem.patch
kexec-create-a-new-config-option-config_kexec_file-for-new-syscall.patch
kexec-remove-config_kexec-dependency-on-crypto.patch
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