[PATCH v8 03/13] kexec_file,x86,powerpc: factor out kexec_file_ops functions

From: AKASHI Takahiro
Date: Thu Feb 22 2018 - 06:19:18 EST

As arch_kexec_kernel_*_{probe,load}(), arch_kimage_file_post_load_cleanup()
and arch_kexec_kernel_verify_sg can be parameterized with a kexec_file_ops
array and now duplicated among some architectures, let's factor them out.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/kexec.h | 2 +-
arch/powerpc/kernel/kexec_elf_64.c | 2 +-
arch/powerpc/kernel/machine_kexec_file_64.c | 39 ++------------------
arch/x86/include/asm/kexec-bzimage64.h | 2 +-
arch/x86/kernel/kexec-bzimage64.c | 2 +-
arch/x86/kernel/machine_kexec_64.c | 45 +----------------------
include/linux/kexec.h | 15 ++++----
kernel/kexec_file.c | 57 +++++++++++++++++++++++++++--
8 files changed, 70 insertions(+), 94 deletions(-)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index d8b1e8e7e035..4a585cba1787 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -95,7 +95,7 @@ static inline bool kdump_in_progress(void)
}

#ifdef CONFIG_KEXEC_FILE
-extern struct kexec_file_ops kexec_elf64_ops;
+extern const struct kexec_file_ops kexec_elf64_ops;

#ifdef CONFIG_IMA_KEXEC
#define ARCH_HAS_KIMAGE_ARCH
diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c
index 9a42309b091a..6c78c11c7faf 100644
--- a/arch/powerpc/kernel/kexec_elf_64.c
+++ b/arch/powerpc/kernel/kexec_elf_64.c
@@ -657,7 +657,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
return ret ? ERR_PTR(ret) : fdt;
}

-struct kexec_file_ops kexec_elf64_ops = {
+const struct kexec_file_ops kexec_elf64_ops = {
.probe = elf64_probe,
.load = elf64_load,
};
diff --git a/arch/powerpc/kernel/machine_kexec_file_64.c b/arch/powerpc/kernel/machine_kexec_file_64.c
index e4395f937d63..a27ec647350c 100644
--- a/arch/powerpc/kernel/machine_kexec_file_64.c
+++ b/arch/powerpc/kernel/machine_kexec_file_64.c
@@ -31,52 +31,19 @@

#define SLAVE_CODE_SIZE 256

-static struct kexec_file_ops *kexec_file_loaders[] = {
+const struct kexec_file_ops * const kexec_file_loaders[] = {
&kexec_elf64_ops,
+ NULL
};

int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
unsigned long buf_len)
{
- int i, ret = -ENOEXEC;
- struct kexec_file_ops *fops;
-
/* We don't support crash kernels yet. */
if (image->type == KEXEC_TYPE_CRASH)
return -ENOTSUPP;

- for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
- fops = kexec_file_loaders[i];
- if (!fops || !fops->probe)
- continue;
-
- ret = fops->probe(buf, buf_len);
- if (!ret) {
- image->fops = fops;
- return ret;
- }
- }
-
- return ret;
-}
-
-void *arch_kexec_kernel_image_load(struct kimage *image)
-{
- if (!image->fops || !image->fops->load)
- return ERR_PTR(-ENOEXEC);
-
- return image->fops->load(image, image->kernel_buf,
- image->kernel_buf_len, image->initrd_buf,
- image->initrd_buf_len, image->cmdline_buf,
- image->cmdline_buf_len);
-}
-
-int arch_kimage_file_post_load_cleanup(struct kimage *image)
-{
- if (!image->fops || !image->fops->cleanup)
- return 0;
-
- return image->fops->cleanup(image->image_loader_data);
+ return _kexec_kernel_image_probe(image, buf, buf_len);
}

/**
diff --git a/arch/x86/include/asm/kexec-bzimage64.h b/arch/x86/include/asm/kexec-bzimage64.h
index 9f07cff43705..df89ee7d3e9e 100644
--- a/arch/x86/include/asm/kexec-bzimage64.h
+++ b/arch/x86/include/asm/kexec-bzimage64.h
@@ -2,6 +2,6 @@
#ifndef _ASM_KEXEC_BZIMAGE64_H
#define _ASM_KEXEC_BZIMAGE64_H

-extern struct kexec_file_ops kexec_bzImage64_ops;
+extern const struct kexec_file_ops kexec_bzImage64_ops;

#endif /* _ASM_KEXE_BZIMAGE64_H */
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index fb095ba0c02f..705654776c0c 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -538,7 +538,7 @@ static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
}
#endif

-struct kexec_file_ops kexec_bzImage64_ops = {
+const struct kexec_file_ops kexec_bzImage64_ops = {
.probe = bzImage64_probe,
.load = bzImage64_load,
.cleanup = bzImage64_cleanup,
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 1f790cf9d38f..2cdd29d64181 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -30,8 +30,9 @@
#include <asm/set_memory.h>

#ifdef CONFIG_KEXEC_FILE
-static struct kexec_file_ops *kexec_file_loaders[] = {
+const struct kexec_file_ops * const kexec_file_loaders[] = {
&kexec_bzImage64_ops,
+ NULL
};
#endif

@@ -363,27 +364,6 @@ 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)
-{
- int i, ret = -ENOEXEC;
- struct kexec_file_ops *fops;
-
- for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
- fops = kexec_file_loaders[i];
- if (!fops || !fops->probe)
- continue;
-
- ret = fops->probe(buf, buf_len);
- if (!ret) {
- image->fops = fops;
- return ret;
- }
- }
-
- return ret;
-}
-
void *arch_kexec_kernel_image_load(struct kimage *image)
{
vfree(image->arch.elf_headers);
@@ -398,27 +378,6 @@ void *arch_kexec_kernel_image_load(struct kimage *image)
image->cmdline_buf_len);
}

-int arch_kimage_file_post_load_cleanup(struct kimage *image)
-{
- if (!image->fops || !image->fops->cleanup)
- return 0;
-
- return image->fops->cleanup(image->image_loader_data);
-}
-
-#ifdef CONFIG_KEXEC_VERIFY_SIG
-int arch_kexec_kernel_verify_sig(struct kimage *image, void *kernel,
- unsigned long kernel_len)
-{
- if (!image->fops || !image->fops->verify_sig) {
- pr_debug("kernel loader does not support signature verification.");
- return -EKEYREJECTED;
- }
-
- return image->fops->verify_sig(kernel, kernel_len);
-}
-#endif
-
/*
* Apply purgatory relocations.
*
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index f16f6ceb3875..325980537125 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -209,7 +209,7 @@ struct kimage {
unsigned long cmdline_buf_len;

/* File operations provided by image loader */
- struct kexec_file_ops *fops;
+ const struct kexec_file_ops *fops;

/* Image loader handling the kernel can store a pointer here */
void *image_loader_data;
@@ -277,12 +277,13 @@ int crash_shrink_memory(unsigned long new_size);
size_t crash_get_memory_size(void);
void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);

-int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
- unsigned long buf_len);
-void * __weak arch_kexec_kernel_image_load(struct kimage *image);
-int __weak arch_kimage_file_post_load_cleanup(struct kimage *image);
-int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
- unsigned long buf_len);
+int _kexec_kernel_image_probe(struct kimage *image, void *buf,
+ unsigned long buf_len);
+void *_kexec_kernel_image_load(struct kimage *image);
+int _kimage_file_post_load_cleanup(struct kimage *image);
+int _kexec_kernel_verify_sig(struct kimage *image, void *buf,
+ unsigned long buf_len);
+
int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
Elf_Shdr *sechdrs, unsigned int relsec);
int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 990adae52151..a6d14a768b3e 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -26,34 +26,83 @@
#include <linux/vmalloc.h>
#include "kexec_internal.h"

+const __weak struct kexec_file_ops * const kexec_file_loaders[] = {NULL};
+
#ifdef CONFIG_ARCH_HAS_KEXEC_PURGATORY
static int kexec_calculate_store_digests(struct kimage *image);
#else
static int kexec_calculate_store_digests(struct kimage *image) { return 0; };
#endif

+int _kexec_kernel_image_probe(struct kimage *image, void *buf,
+ unsigned long buf_len)
+{
+ const struct kexec_file_ops * const *fops;
+ int ret = -ENOEXEC;
+
+ for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops) {
+ ret = (*fops)->probe(buf, buf_len);
+ if (!ret) {
+ image->fops = *fops;
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
/* Architectures can provide this probe function */
int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
unsigned long buf_len)
{
- return -ENOEXEC;
+ return _kexec_kernel_image_probe(image, buf, buf_len);
+}
+
+void *_kexec_kernel_image_load(struct kimage *image)
+{
+ if (!image->fops || !image->fops->load)
+ return ERR_PTR(-ENOEXEC);
+
+ return image->fops->load(image, image->kernel_buf,
+ image->kernel_buf_len, image->initrd_buf,
+ image->initrd_buf_len, image->cmdline_buf,
+ image->cmdline_buf_len);
}

void * __weak arch_kexec_kernel_image_load(struct kimage *image)
{
- return ERR_PTR(-ENOEXEC);
+ return _kexec_kernel_image_load(image);
+}
+
+int _kimage_file_post_load_cleanup(struct kimage *image)
+{
+ if (!image->fops || !image->fops->cleanup)
+ return 0;
+
+ return image->fops->cleanup(image->image_loader_data);
}

int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
{
- return -EINVAL;
+ return _kimage_file_post_load_cleanup(image);
}

#ifdef CONFIG_KEXEC_VERIFY_SIG
+int _kexec_kernel_verify_sig(struct kimage *image, void *buf,
+ unsigned long buf_len)
+{
+ if (!image->fops || !image->fops->verify_sig) {
+ pr_debug("kernel loader does not support signature verification.\n");
+ return -EKEYREJECTED;
+ }
+
+ return image->fops->verify_sig(buf, buf_len);
+}
+
int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
unsigned long buf_len)
{
- return -EKEYREJECTED;
+ return _kexec_kernel_verify_sig(image, buf, buf_len);
}
#endif

--
2.16.2