[PATCH v4 03/10] kexec_file: factor out arch_kexec_kernel_*() from x86, powerpc

From: Julien Thierry <hidden>
Date: 2017-10-05 10:21:44
Also in: kexec, lkml

Hi Takahiro,

On 02/10/17 07:14, AKASHI Takahiro wrote:

quoted hunk ↗ jump to hunk

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 <redacted>
Cc: Dave Young <redacted>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <redacted>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thiago Jung Bauermann <redacted>
---
  arch/powerpc/kernel/kexec_elf_64.c          |  2 +-
  arch/powerpc/kernel/machine_kexec_file_64.c | 36 ++---------------
  arch/x86/kernel/kexec-bzimage64.c           |  2 +-
  arch/x86/kernel/machine_kexec_64.c          | 45 +--------------------
  include/linux/kexec.h                       | 15 +++----
  kernel/kexec_file.c                         | 63 ++++++++++++++++++++++++++---
  6 files changed, 73 insertions(+), 90 deletions(-)

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/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..c64c29c1fb0e 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 _kexec_kernel_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..130965b28392 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c

@@ -26,30 +26,83 @@
  #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)
+{
+	int i, ret = -ENOEXEC;
+	const struct kexec_file_ops *fops;
+
+	for (i = 0; ; i++) {
+		fops = kexec_file_loaders[i];
+		if (!fops || !fops->probe)
+			break;
+

Could we have something like:

for (fops = &kexec_file_loaders[0]; fops && fops->probe; ++fops) {
	[...]
}

And get rid of i? I think it's nicer to have the condition clearly 
stated in the loop.

Thanks,

+		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 __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
+int _kexec_kernel_post_load_cleanup(struct kimage *image)
  {
-	return -EINVAL;
+	if (!image->fops || !image->fops->cleanup)
+		return 0;
+
+	return image->fops->cleanup(image->image_loader_data);
+}
+
+int __weak arch_kexec_kernel_post_load_cleanup(struct kimage *image)
+{
+	return _kexec_kernel_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

-- 
Julien Thierry

`h`	back out one level
`j`	next message in thread
`k`	previous message in thread
`l`	drill in
`Esc`	close help / fold thread tree
`?`	toggle this help