elf coredump: replace ELF_CORE_EXTRA_* macros by functions

elf_core_dump() and elf_fdpic_core_dump() use #ifdef and the corresponding
macro for hiding _multiline_ logics in functions.  This patch removes
#ifdef and replaces ELF_CORE_EXTRA_* by corresponding functions.  For
architectures not implemeonting ELF_CORE_EXTRA_*, we use weak functions in
order to reduce a range of modification.

This cleanup is for my next patches, but I think this cleanup itself is
worth doing regardless of my firnal purpose.

Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 69 insertions, 43 deletions

diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index 1b549bca4645..804b28dd0328 100644
--- a/arch/um/sys-i386/Makefile
+++ b/arch/um/sys-i386/Makefile
@@ -6,6 +6,8 @@ obj-y = bug.o bugs.o checksum.o delay.o fault.o ksyms.o ldt.o ptrace.o \
         ptrace_user.o setjmp.o signal.o stub.o stub_segv.o syscalls.o sysrq.o \
         sys_call_table.o tls.o
 
+obj-$(CONFIG_BINFMT_ELF) += elfcore.o
+
 subarch-obj-y = lib/semaphore_32.o lib/string_32.o
 subarch-obj-$(CONFIG_HIGHMEM) += mm/highmem_32.o
 subarch-obj-$(CONFIG_MODULES) += kernel/module.o
diff --git a/arch/um/sys-i386/asm/elf.h b/arch/um/sys-i386/asm/elf.h
index 770885472ed4..e64cd41d7bab 100644
--- a/arch/um/sys-i386/asm/elf.h
+++ b/arch/um/sys-i386/asm/elf.h
@@ -116,47 +116,4 @@ do {								\
         }                                                       \
 } while (0)
 
-/*
- * These macros parameterize elf_core_dump in fs/binfmt_elf.c to write out
- * extra segments containing the vsyscall DSO contents.  Dumping its
- * contents makes post-mortem fully interpretable later without matching up
- * the same kernel and hardware config to see what PC values meant.
- * Dumping its extra ELF program headers includes all the other information
- * a debugger needs to easily find how the vsyscall DSO was being used.
- */
-#define ELF_CORE_EXTRA_PHDRS                                                  \
-        (vsyscall_ehdr ? (((struct elfhdr *)vsyscall_ehdr)->e_phnum) : 0 )
-
-#define ELF_CORE_WRITE_EXTRA_PHDRS                                            \
-if ( vsyscall_ehdr ) {                                                        \
-        const struct elfhdr *const ehdrp = (struct elfhdr *)vsyscall_ehdr;    \
-        const struct elf_phdr *const phdrp =                                  \
-                (const struct elf_phdr *) (vsyscall_ehdr + ehdrp->e_phoff);   \
-        int i;                                                                \
-        Elf32_Off ofs = 0;                                                    \
-        for (i = 0; i < ehdrp->e_phnum; ++i) {                                \
-                struct elf_phdr phdr = phdrp[i];                              \
-                if (phdr.p_type == PT_LOAD) {                                 \
-                        ofs = phdr.p_offset = offset;                         \
-                        offset += phdr.p_filesz;                              \
-                }                                                             \
-                else                                                          \
-                        phdr.p_offset += ofs;                                 \
-                phdr.p_paddr = 0; /* match other core phdrs */                \
-                DUMP_WRITE(&phdr, sizeof(phdr));                              \
-        }                                                                     \
-}
-#define ELF_CORE_WRITE_EXTRA_DATA                                             \
-if ( vsyscall_ehdr ) {                                                        \
-        const struct elfhdr *const ehdrp = (struct elfhdr *)vsyscall_ehdr;    \
-        const struct elf_phdr *const phdrp =                                  \
-                (const struct elf_phdr *) (vsyscall_ehdr + ehdrp->e_phoff);   \
-        int i;                                                                \
-        for (i = 0; i < ehdrp->e_phnum; ++i) {                                \
-                if (phdrp[i].p_type == PT_LOAD)                               \
-                        DUMP_WRITE((void *) phdrp[i].p_vaddr,                 \
-                                   phdrp[i].p_filesz);                        \
-        }                                                                     \
-}
-
 #endif
diff --git a/arch/um/sys-i386/elfcore.c b/arch/um/sys-i386/elfcore.c
new file mode 100644
index 000000000000..30cac52a04b4
--- /dev/null
+++ b/arch/um/sys-i386/elfcore.c
@@ -0,0 +1,67 @@
+#include <linux/elf.h>
+#include <linux/coredump.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+
+#include <asm/elf.h>
+
+
+Elf32_Half elf_core_extra_phdrs(void)
+{
+        return vsyscall_ehdr ? (((struct elfhdr *)vsyscall_ehdr)->e_phnum) : 0;
+}
+
+int elf_core_write_extra_phdrs(struct file *file, loff_t offset, size_t *size,
+                               unsigned long limit)
+{
+        if ( vsyscall_ehdr ) {
+                const struct elfhdr *const ehdrp =
+                        (struct elfhdr *) vsyscall_ehdr;
+                const struct elf_phdr *const phdrp =
+                        (const struct elf_phdr *) (vsyscall_ehdr + ehdrp->e_phoff);
+                int i;
+                Elf32_Off ofs = 0;
+
+                for (i = 0; i < ehdrp->e_phnum; ++i) {
+                        struct elf_phdr phdr = phdrp[i];
+
+                        if (phdr.p_type == PT_LOAD) {
+                                ofs = phdr.p_offset = offset;
+                                offset += phdr.p_filesz;
+                        } else {
+                                phdr.p_offset += ofs;
+                        }
+                        phdr.p_paddr = 0; /* match other core phdrs */
+                        *size += sizeof(phdr);
+                        if (*size > limit
+                            || !dump_write(file, &phdr, sizeof(phdr)))
+                                return 0;
+                }
+        }
+        return 1;
+}
+
+int elf_core_write_extra_data(struct file *file, size_t *size,
+                              unsigned long limit)
+{
+        if ( vsyscall_ehdr ) {
+                const struct elfhdr *const ehdrp =
+                        (struct elfhdr *) vsyscall_ehdr;
+                const struct elf_phdr *const phdrp =
+                        (const struct elf_phdr *) (vsyscall_ehdr + ehdrp->e_phoff);
+                int i;
+
+                for (i = 0; i < ehdrp->e_phnum; ++i) {
+                        if (phdrp[i].p_type == PT_LOAD) {
+                                void *addr = (void *) phdrp[i].p_vaddr;
+                                size_t filesz = phdrp[i].p_filesz;
+
+                                *size += filesz;
+                                if (*size > limit
+                                    || !dump_write(file, addr, filesz))
+                                        return 0;
+                        }
+                }
+        }
+        return 1;
+}