Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:

 - various hotfixes

 - kexec_file updates and feature work

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (27 commits)
  kernel/kexec_file.c: move purgatories sha256 to common code
  kernel/kexec_file.c: allow archs to set purgatory load address
  kernel/kexec_file.c: remove mis-use of sh_offset field during purgatory load
  kernel/kexec_file.c: remove unneeded variables in kexec_purgatory_setup_sechdrs
  kernel/kexec_file.c: remove unneeded for-loop in kexec_purgatory_setup_sechdrs
  kernel/kexec_file.c: split up __kexec_load_puragory
  kernel/kexec_file.c: use read-only sections in arch_kexec_apply_relocations*
  kernel/kexec_file.c: search symbols in read-only kexec_purgatory
  kernel/kexec_file.c: make purgatory_info->ehdr const
  kernel/kexec_file.c: remove checks in kexec_purgatory_load
  include/linux/kexec.h: silence compile warnings
  kexec_file, x86: move re-factored code to generic side
  x86: kexec_file: clean up prepare_elf64_headers()
  x86: kexec_file: lift CRASH_MAX_RANGES limit on crash_mem buffer
  x86: kexec_file: remove X86_64 dependency from prepare_elf64_headers()
  x86: kexec_file: purge system-ram walking from prepare_elf64_headers()
  kexec_file,x86,powerpc: factor out kexec_file_ops functions
  kexec_file: make use of purgatory optional
  proc: revalidate misc dentries
  mm, slab: reschedule cache_reap() on the same CPU
  ...

2 files changed, 83 insertions, 28 deletions

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 0ebcbeb21056..9e4e638fb505 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -99,21 +99,25 @@ struct compat_kexec_segment {
 
 #ifdef CONFIG_KEXEC_FILE
 struct purgatory_info {
-	/* Pointer to elf header of read only purgatory */
-	Elf_Ehdr *ehdr;
-
-	/* Pointer to purgatory sechdrs which are modifiable */
+	/*
+	 * Pointer to elf header at the beginning of kexec_purgatory.
+	 * Note: kexec_purgatory is read only
+	 */
+	const Elf_Ehdr *ehdr;
+	/*
+	 * Temporary, modifiable buffer for sechdrs used for relocation.
+	 * This memory can be freed post image load.
+	 */
 	Elf_Shdr *sechdrs;
 	/*
-	 * Temporary buffer location where purgatory is loaded and relocated
-	 * This memory can be freed post image load
+	 * Temporary, modifiable buffer for stripped purgatory used for
+	 * relocation. This memory can be freed post image load.
 	 */
 	void *purgatory_buf;
-
-	/* Address where purgatory is finally loaded and is executed from */
-	unsigned long purgatory_load_addr;
 };
 
+struct kimage;
+
 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
 			     unsigned long kernel_len, char *initrd,
@@ -135,6 +139,11 @@ struct kexec_file_ops {
 #endif
 };
 
+extern const struct kexec_file_ops * const kexec_file_loaders[];
+
+int kexec_image_probe_default(struct kimage *image, void *buf,
+			      unsigned long buf_len);
+
 /**
  * struct kexec_buf - parameters for finding a place for a buffer in memory
  * @image:	kexec image in which memory to search.
@@ -159,10 +168,44 @@ struct kexec_buf {
 	bool top_down;
 };
 
+int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf);
+int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
+				   void *buf, unsigned int size,
+				   bool get_value);
+void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name);
+
+int __weak arch_kexec_apply_relocations_add(struct purgatory_info *pi,
+					    Elf_Shdr *section,
+					    const Elf_Shdr *relsec,
+					    const Elf_Shdr *symtab);
+int __weak arch_kexec_apply_relocations(struct purgatory_info *pi,
+					Elf_Shdr *section,
+					const Elf_Shdr *relsec,
+					const Elf_Shdr *symtab);
+
 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 			       int (*func)(struct resource *, void *));
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
+
+/* Alignment required for elf header segment */
+#define ELF_CORE_HEADER_ALIGN   4096
+
+struct crash_mem_range {
+	u64 start, end;
+};
+
+struct crash_mem {
+	unsigned int max_nr_ranges;
+	unsigned int nr_ranges;
+	struct crash_mem_range ranges[0];
+};
+
+extern int crash_exclude_mem_range(struct crash_mem *mem,
+				   unsigned long long mstart,
+				   unsigned long long mend);
+extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
+				       void **addr, unsigned long *sz);
 #endif /* CONFIG_KEXEC_FILE */
 
 struct kimage {
@@ -209,7 +252,7 @@ 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;
@@ -226,14 +269,6 @@ extern void machine_kexec_cleanup(struct kimage *image);
 extern int kernel_kexec(void);
 extern struct page *kimage_alloc_control_pages(struct kimage *image,
 						unsigned int order);
-extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
-				unsigned long max, int top_down,
-				unsigned long *load_addr);
-extern int kexec_purgatory_get_set_symbol(struct kimage *image,
-					  const char *name, void *buf,
-					  unsigned int size, bool get_value);
-extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
-					     const char *name);
 extern void __crash_kexec(struct pt_regs *);
 extern void crash_kexec(struct pt_regs *);
 int kexec_should_crash(struct task_struct *);
@@ -273,16 +308,6 @@ 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 __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,
-					unsigned int relsec);
 void arch_kexec_protect_crashkres(void);
 void arch_kexec_unprotect_crashkres(void);
 
diff --git a/include/linux/sha256.h b/include/linux/sha256.h
new file mode 100644
index 000000000000..244fe01a65fb
--- /dev/null
+++ b/include/linux/sha256.h
@@ -0,0 +1,30 @@
+/*
+ *  Copyright (C) 2014 Red Hat Inc.
+ *
+ *  Author: Vivek Goyal <vgoyal@redhat.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#ifndef SHA256_H
+#define SHA256_H
+
+#include <linux/types.h>
+#include <crypto/sha.h>
+
+/*
+ * Stand-alone implementation of the SHA256 algorithm. It is designed to
+ * have as little dependencies as possible so it can be used in the
+ * kexec_file purgatory. In other cases you should use the implementation in
+ * crypto/.
+ *
+ * For details see lib/sha256.c
+ */
+
+extern int sha256_init(struct sha256_state *sctx);
+extern int sha256_update(struct sha256_state *sctx, const u8 *input,
+			 unsigned int length);
+extern int sha256_final(struct sha256_state *sctx, u8 *hash);
+
+#endif /* SHA256_H */