1 files changed, 54 insertions, 27 deletions

diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index d8f355657171..0c9a897a1fb5 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -64,6 +64,11 @@ static ssize_t copy_page_real(void *buf, void *src, size_t csize)
 }
 
 /*
+ * Pointer to ELF header in new kernel
+ */
+static void *elfcorehdr_newmem;
+
+/*
  * Copy one page from "oldmem"
  *
  * For the kdump reserved memory this functions performs a swap operation:
@@ -368,14 +373,6 @@ static int get_mem_chunk_cnt(void)
 }
 
 /*
- * Relocate pointer in order to allow vmcore code access the data
- */
-static inline unsigned long relocate(unsigned long addr)
-{
-        return OLDMEM_BASE + addr;
-}
-
-/*
  * Initialize ELF loads (new kernel)
  */
 static int loads_init(Elf64_Phdr *phdr, u64 loads_offset)
@@ -426,7 +423,7 @@ static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
         ptr = nt_vmcoreinfo(ptr);
         memset(phdr, 0, sizeof(*phdr));
         phdr->p_type = PT_NOTE;
-        phdr->p_offset = relocate(notes_offset);
+        phdr->p_offset = notes_offset;
         phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
         phdr->p_memsz = phdr->p_filesz;
         return ptr;
@@ -435,7 +432,7 @@ static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
 /*
  * Create ELF core header (new kernel)
  */
-static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz)
+int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
 {
         Elf64_Phdr *phdr_notes, *phdr_loads;
         int mem_chunk_cnt;
@@ -443,6 +440,11 @@ static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz)
         u32 alloc_size;
         u64 hdr_off;
 
+        if (!OLDMEM_BASE)
+                return 0;
+        /* If elfcorehdr= has been passed via cmdline, we use that one */
+        if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
+                return 0;
         mem_chunk_cnt = get_mem_chunk_cnt();
 
         alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
@@ -460,27 +462,52 @@ static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz)
         ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
         /* Init loads */
         hdr_off = PTR_DIFF(ptr, hdr);
-        loads_init(phdr_loads, ((unsigned long) hdr) + hdr_off);
-        *elfcorebuf_sz = hdr_off;
-        *elfcorebuf = (void *) relocate((unsigned long) hdr);
-        BUG_ON(*elfcorebuf_sz > alloc_size);
+        loads_init(phdr_loads, hdr_off);
+        *addr = (unsigned long long) hdr;
+        elfcorehdr_newmem = hdr;
+        *size = (unsigned long long) hdr_off;
+        BUG_ON(elfcorehdr_size > alloc_size);
+        return 0;
 }
 
 /*
- * Create kdump ELF core header in new kernel, if it has not been passed via
- * the "elfcorehdr" kernel parameter
+ * Free ELF core header (new kernel)
  */
-static int setup_kdump_elfcorehdr(void)
+void elfcorehdr_free(unsigned long long addr)
 {
-        size_t elfcorebuf_sz;
-        char *elfcorebuf;
-
-        if (!OLDMEM_BASE || is_kdump_kernel())
-                return -EINVAL;
-        s390_elf_corehdr_create(&elfcorebuf, &elfcorebuf_sz);
-        elfcorehdr_addr = (unsigned long long) elfcorebuf;
-        elfcorehdr_size = elfcorebuf_sz;
-        return 0;
+        if (!elfcorehdr_newmem)
+                return;
+        kfree((void *)(unsigned long)addr);
+}
+
+/*
+ * Read from ELF header
+ */
+ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
+{
+        void *src = (void *)(unsigned long)*ppos;
+
+        src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
+        memcpy(buf, src, count);
+        *ppos += count;
+        return count;
 }
 
-subsys_initcall(setup_kdump_elfcorehdr);
+/*
+ * Read from ELF notes data
+ */
+ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
+{
+        void *src = (void *)(unsigned long)*ppos;
+        int rc;
+
+        if (elfcorehdr_newmem) {
+                memcpy(buf, src, count);
+        } else {
+                rc = copy_from_oldmem(buf, src, count);
+                if (rc)
+                        return rc;
+        }
+        *ppos += count;
+        return count;
+}