This patch now exchanges the old relocate mechanism with the new
arch function call override mechanism that allows to create the ELF
core header in the 2nd kernel.
Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com>
---
arch/s390/kernel/crash_dump.c | 70 ++++++++++++++++++++++++++-----------------
1 file changed, 43 insertions(+), 27 deletions(-)
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index f703d91..a17f8d4 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -22,6 +22,11 @@
#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
/*
+ * 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:
@@ -325,14 +330,6 @@ 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)
@@ -383,7 +380,7 @@ 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;
@@ -392,7 +389,7 @@ 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(void)
{
Elf64_Phdr *phdr_notes, *phdr_loads;
int mem_chunk_cnt;
@@ -400,6 +397,8 @@ static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz)
u32 alloc_size;
u64 hdr_off;
+ if (!OLDMEM_BASE)
+ return -ENOENT;
mem_chunk_cnt = get_mem_chunk_cnt();
alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
@@ -417,27 +416,44 @@ 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);
+ elfcorehdr_addr = (unsigned long long) hdr;
+ elfcorehdr_size = (unsigned long long) hdr_off;
+ elfcorehdr_newmem = hdr;
+ 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(void)
{
- 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;
+ vfree(elfcorehdr_newmem);
+ elfcorehdr_newmem = NULL;
}
-subsys_initcall(setup_kdump_elfcorehdr);
+/*
+ * Read from ELF header
+ */
+ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
+{
+ void *src = (void *)(unsigned long)*ppos;
+
+ if (elfcorehdr_newmem)
+ memcpy(buf, src, count);
+ else
+ copy_from_oldmem(buf, src, count);
+ *ppos += count;
+ return count;
+}
+
+/*
+ * Read from ELF notes data
+ */
+ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
+{
+ return elfcorehdr_read(buf, count, ppos);
+}
--
1.8.1.6
