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 <[email protected]>: (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
  ...

arch/mips/mm/gup.c

@@ -178,6 +178,8 @@ static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end,
 /*
  * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
  * back to the regular GUP.
+ * Note a difference with get_user_pages_fast: this always returns the
+ * number of pages pinned, 0 if no pages were pinned.
  */
 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
 			  struct page **pages)

arch/powerpc/Kconfig

@@ -552,6 +552,9 @@ config KEXEC_FILE
 	  for kernel and initramfs as opposed to a list of segments as is the
 	  case for the older kexec call.
 
+config ARCH_HAS_KEXEC_PURGATORY
+	def_bool KEXEC_FILE
+
 config RELOCATABLE
 	bool "Build a relocatable kernel"
 	depends on PPC64 || (FLATMEM && (44x || FSL_BOOKE))

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

arch/powerpc/kernel/kexec_elf_64.c

@@ -572,14 +572,16 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 {
 	int ret;
 	unsigned int fdt_size;
-	unsigned long kernel_load_addr, purgatory_load_addr;
+	unsigned long kernel_load_addr;
 	unsigned long initrd_load_addr = 0, fdt_load_addr;
 	void *fdt;
 	const void *slave_code;
 	struct elfhdr ehdr;
 	struct elf_info elf_info;
 	struct kexec_buf kbuf = { .image = image, .buf_min = 0,
 				  .buf_max = ppc64_rma_size };
+	struct kexec_buf pbuf = { .image = image, .buf_min = 0,
+				  .buf_max = ppc64_rma_size, .top_down = true };
 
 	ret = build_elf_exec_info(kernel_buf, kernel_len, &ehdr, &elf_info);
 	if (ret)
@@ -591,14 +593,13 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,
 
 	pr_debug("Loaded the kernel at 0x%lx\n", kernel_load_addr);
 
-	ret = kexec_load_purgatory(image, 0, ppc64_rma_size, true,
-				   &purgatory_load_addr);
+	ret = kexec_load_purgatory(image, &pbuf);
 	if (ret) {
 		pr_err("Loading purgatory failed.\n");
 		goto out;
 	}
 
-	pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
+	pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem);
 
 	if (initrd != NULL) {
 		kbuf.buffer = initrd;
@@ -657,7 +658,7 @@ 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,
 };

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 -EOPNOTSUPP;
 
-	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_image_probe_default(image, buf, buf_len);
 }
 
 /**

arch/s390/mm/gup.c

@@ -220,6 +220,8 @@ static inline int gup_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr,
 /*
  * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
  * back to the regular GUP.
+ * Note a difference with get_user_pages_fast: this always returns the
+ * number of pages pinned, 0 if no pages were pinned.
  */
 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
 			  struct page **pages)

arch/sh/mm/gup.c

@@ -160,6 +160,8 @@ static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end,
 /*
  * Like get_user_pages_fast() except its IRQ-safe in that it won't fall
  * back to the regular GUP.
+ * Note a difference with get_user_pages_fast: this always returns the
+ * number of pages pinned, 0 if no pages were pinned.
  */
 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
 			  struct page **pages)

arch/sparc/mm/gup.c

@@ -193,6 +193,10 @@ static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end,
 	return 1;
 }
 
+/*
+ * Note a difference with get_user_pages_fast: this always returns the
+ * number of pages pinned, 0 if no pages were pinned.
+ */
 int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
 			  struct page **pages)
 {

arch/x86/Kconfig

@@ -2008,6 +2008,9 @@ config KEXEC_FILE
 	  for kernel and initramfs as opposed to list of segments as
 	  accepted by previous system call.
 
+config ARCH_HAS_KEXEC_PURGATORY
+	def_bool KEXEC_FILE
+
 config KEXEC_VERIFY_SIG
 	bool "Verify kernel signature during kexec_file_load() syscall"
 	depends on KEXEC_FILE

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 */