Re: [PATCH v5 03/10] kexec_file: factor out arch_kexec_kernel_*() from x86, powerpc
From: Julien Thierry
Date: Tue Oct 10 2017 - 07:07:21 EST
Hi Takahiro,
Sorry about the previous message, confidential disclaimer shouldn't have
been there.
Resending comments without disclaimer to avoid confusion.
On 10/10/17 07:36, AKASHI Takahiro wrote:
arch_kexec_kernel_*() and arch_kimage_file_post_load_cleanup can now be
duplicated among some architectures, so 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 | 36 ++----------------
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(+), 91 deletions(-)
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index 25668bc8cb2a..23588952d8bd 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -92,7 +92,7 @@ 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 992c0d258e5d..e7ce78857f0b 100644
--- a/arch/powerpc/kernel/machine_kexec_file_64.c
+++ b/arch/powerpc/kernel/machine_kexec_file_64.c
@@ -31,8 +31,9 @@
#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,
@@ -45,38 +46,7 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
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 d1b5d194e31d..284fd23d133b 100644
--- a/arch/x86/include/asm/kexec-bzimage64.h
+++ b/arch/x86/include/asm/kexec-bzimage64.h
@@ -1,6 +1,6 @@
#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 2b7590f5483a..bfb37665a77f 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -208,7 +208,7 @@ 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;
@@ -276,12 +276,13 @@ 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 9f48f4412297..bbb0177e20ab 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -26,30 +26,79 @@
#include <linux/vmalloc.h>
#include "kexec_internal.h"
+const __weak struct kexec_file_ops * const kexec_file_loaders[] = {NULL};
+
static int kexec_calculate_store_digests(struct kimage *image);
+int _kexec_kernel_image_probe(struct kimage *image, void *buf,
+ unsigned long buf_len)
+{
+ const struct kexec_file_ops *fops;
+ int ret = -ENOEXEC;
+
+ for (fops = kexec_file_loaders[0]; fops && fops->probe; ++fops) {
Hmm, that's not gonna work (and I see that what I said in the previous
patch was not 100% correct either).
'fops' should be of type 'const struct kexec_file_ops **', and the loop
should be:
for (fops = &kexec_file_loaders[0]; *fops && (*fops)->probe; ++fops)
With some additional dereferences in the body of the loop.
Unless you prefer the previous state of the loop (with i and the break
inside), but I still think this looks better.
Cheers,
--
Julien Thierry