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, 66 insertions, 48 deletions

diff --git a/arch/ia64/include/asm/elf.h b/arch/ia64/include/asm/elf.h
index 4c41656..b5298eb 100644
--- a/arch/ia64/include/asm/elf.h
+++ b/arch/ia64/include/asm/elf.h
@@ -219,54 +219,6 @@ do {										\
 	NEW_AUX_ENT(AT_SYSINFO_EHDR, (unsigned long) GATE_EHDR);		\
 } while (0)
 
-
-/*
- * These macros parameterize elf_core_dump in fs/binfmt_elf.c to write out
- * extra segments containing the gate 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 gate DSO was being used.
- */
-#define ELF_CORE_EXTRA_PHDRS		(GATE_EHDR->e_phnum)
-#define ELF_CORE_WRITE_EXTRA_PHDRS						\
-do {										\
-	const struct elf_phdr *const gate_phdrs =			      \
-		(const struct elf_phdr *) (GATE_ADDR + GATE_EHDR->e_phoff);   \
-	int i;									\
-	Elf64_Off ofs = 0;						      \
-	for (i = 0; i < GATE_EHDR->e_phnum; ++i) {				\
-		struct elf_phdr phdr = gate_phdrs[i];			      \
-		if (phdr.p_type == PT_LOAD) {					\
-			phdr.p_memsz = PAGE_ALIGN(phdr.p_memsz);	      \
-			phdr.p_filesz = phdr.p_memsz;			      \
-			if (ofs == 0) {					      \
-				ofs = phdr.p_offset = offset;		      \
-			offset += phdr.p_filesz;				\
-		}							      \
-		else							      \
-				phdr.p_offset = ofs;			      \
-		}							      \
-		else							      \
-			phdr.p_offset += ofs;					\
-		phdr.p_paddr = 0; /* match other core phdrs */			\
-		DUMP_WRITE(&phdr, sizeof(phdr));				\
-	}									\
-} while (0)
-#define ELF_CORE_WRITE_EXTRA_DATA					\
-do {									\
-	const struct elf_phdr *const gate_phdrs =			      \
-		(const struct elf_phdr *) (GATE_ADDR + GATE_EHDR->e_phoff);   \
-	int i;								\
-	for (i = 0; i < GATE_EHDR->e_phnum; ++i) {			\
-		if (gate_phdrs[i].p_type == PT_LOAD) {			      \
-			DUMP_WRITE((void *) gate_phdrs[i].p_vaddr,	      \
-				   PAGE_ALIGN(gate_phdrs[i].p_memsz));	      \
-			break;						      \
-		}							      \
-	}								\
-} while (0)
-
 /*
  * format for entries in the Global Offset Table
  */
diff --git a/arch/ia64/kernel/Makefile b/arch/ia64/kernel/Makefile
index 4138282..db10b1e 100644
--- a/arch/ia64/kernel/Makefile
+++ b/arch/ia64/kernel/Makefile
@@ -45,6 +45,8 @@ endif
 obj-$(CONFIG_DMAR)		+= pci-dma.o
 obj-$(CONFIG_SWIOTLB)		+= pci-swiotlb.o
 
+obj-$(CONFIG_BINFMT_ELF)	+= elfcore.o
+
 # fp_emulate() expects f2-f5,f16-f31 to contain the user-level state.
 CFLAGS_traps.o  += -mfixed-range=f2-f5,f16-f31
 
diff --git a/arch/ia64/kernel/elfcore.c b/arch/ia64/kernel/elfcore.c
new file mode 100644
index 0000000..57a2298
--- /dev/null
+++ b/arch/ia64/kernel/elfcore.c
@@ -0,0 +1,64 @@
+#include <linux/elf.h>
+#include <linux/coredump.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+
+#include <asm/elf.h>
+
+
+Elf64_Half elf_core_extra_phdrs(void)
+{
+	return GATE_EHDR->e_phnum;
+}
+
+int elf_core_write_extra_phdrs(struct file *file, loff_t offset, size_t *size,
+			       unsigned long limit)
+{
+	const struct elf_phdr *const gate_phdrs =
+		(const struct elf_phdr *) (GATE_ADDR + GATE_EHDR->e_phoff);
+	int i;
+	Elf64_Off ofs = 0;
+
+	for (i = 0; i < GATE_EHDR->e_phnum; ++i) {
+		struct elf_phdr phdr = gate_phdrs[i];
+
+		if (phdr.p_type == PT_LOAD) {
+			phdr.p_memsz = PAGE_ALIGN(phdr.p_memsz);
+			phdr.p_filesz = phdr.p_memsz;
+			if (ofs == 0) {
+				ofs = phdr.p_offset = offset;
+				offset += phdr.p_filesz;
+			} else {
+				phdr.p_offset = ofs;
+			}
+		} 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)
+{
+	const struct elf_phdr *const gate_phdrs =
+		(const struct elf_phdr *) (GATE_ADDR + GATE_EHDR->e_phoff);
+	int i;
+
+	for (i = 0; i < GATE_EHDR->e_phnum; ++i) {
+		if (gate_phdrs[i].p_type == PT_LOAD) {
+			void *addr = (void *)gate_phdrs[i].p_vaddr;
+			size_t memsz = PAGE_ALIGN(gate_phdrs[i].p_memsz);
+
+			*size += memsz;
+			if (*size > limit || !dump_write(file, addr, memsz))
+				return 0;
+			break;
+		}
+	}
+	return 1;
+}