kexec_file: Allow archs to handle special regions while locating memory hole

Some architectures may have special memory regions, within the given
memory range, which can't be used for the buffer in a kexec segment.
Implement weak arch_kexec_locate_mem_hole() definition which arch code
may override, to take care of special regions, while trying to locate
a memory hole.

Also, add the missing declarations for arch overridable functions and
and drop the __weak descriptors in the declarations to avoid non-weak
definitions from becoming weak.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602273603.575379.17665852963340380839.stgit@hbathini

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index ea67910ae6b7203bdf69525e87f60bd0c76121c2..9e93bef5296801bd3df4266d534f047ea025d7e9 100644 (file)
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -183,17 +183,24 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
                                   bool get_value);
 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name);
 
-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_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);
+/* Architectures may override the below functions */
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+                                 unsigned long buf_len);
+void *arch_kexec_kernel_image_load(struct kimage *image);
+int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
+                                    Elf_Shdr *section,
+                                    const Elf_Shdr *relsec,
+                                    const Elf_Shdr *symtab);
+int arch_kexec_apply_relocations(struct purgatory_info *pi,
+                                Elf_Shdr *section,
+                                const Elf_Shdr *relsec,
+                                const Elf_Shdr *symtab);
+int arch_kimage_file_post_load_cleanup(struct kimage *image);
+#ifdef CONFIG_KEXEC_SIG
+int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
+                                unsigned long buf_len);
+#endif
+int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
 
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
 int kexec_locate_mem_hole(struct kexec_buf *kbuf);

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index bb05fd52de850ad388cdcd228d62e145804d611e..eb42d2efa16af59928b423219e91185fee87003b 100644 (file)
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -657,6 +657,19 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
        return ret == 1 ? 0 : -EADDRNOTAVAIL;
 }
 
+/**
+ * arch_kexec_locate_mem_hole - Find free memory to place the segments.
+ * @kbuf:                       Parameters for the memory search.
+ *
+ * On success, kbuf->mem will have the start address of the memory region found.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
+{
+       return kexec_locate_mem_hole(kbuf);
+}
+
 /**
  * kexec_add_buffer - place a buffer in a kexec segment
  * @kbuf:      Buffer contents and memory parameters.
@@ -669,7 +682,6 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
  */
 int kexec_add_buffer(struct kexec_buf *kbuf)
 {
-
        struct kexec_segment *ksegment;
        int ret;
 
@@ -697,7 +709,7 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
        kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
 
        /* Walk the RAM ranges and allocate a suitable range for the buffer */
-       ret = kexec_locate_mem_hole(kbuf);
+       ret = arch_kexec_locate_mem_hole(kbuf);
        if (ret)
                return ret;