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>

13 files changed, 191 insertions, 109 deletions

diff --git a/arch/ia64/include/asm/elf.h b/arch/ia64/include/asm/elf.h
index 4c41656ede87..b5298eb09adb 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 4138282aefa8..db10b1e378b0 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 000000000000..57a2298a8581
--- /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;
+}
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;
+}
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 0bcfbb05c32d..c1a499599b7d 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1878,9 +1878,7 @@ static int elf_core_dump(struct coredump_params *cprm)
          * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
          */
         segs = current->mm->map_count;
-#ifdef ELF_CORE_EXTRA_PHDRS
-        segs += ELF_CORE_EXTRA_PHDRS;
-#endif
+        segs += elf_core_extra_phdrs();
 
         gate_vma = get_gate_vma(current);
         if (gate_vma != NULL)
@@ -1958,9 +1956,8 @@ static int elf_core_dump(struct coredump_params *cprm)
                         goto end_coredump;
         }
 
-#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
-        ELF_CORE_WRITE_EXTRA_PHDRS;
-#endif
+        if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
+                goto end_coredump;
 
         /* write out the notes section */
         if (!write_note_info(&info, cprm->file, &foffset))
@@ -1999,9 +1996,8 @@ static int elf_core_dump(struct coredump_params *cprm)
                 }
         }
 
-#ifdef ELF_CORE_WRITE_EXTRA_DATA
-        ELF_CORE_WRITE_EXTRA_DATA;
-#endif
+        if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
+                goto end_coredump;
 
 end_coredump:
         set_fs(fs);
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 63edf40b569b..952699a86ec3 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1664,9 +1664,7 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
 
         segs = current->mm->map_count;
-#ifdef ELF_CORE_EXTRA_PHDRS
-        segs += ELF_CORE_EXTRA_PHDRS;
-#endif
+        segs += elf_core_extra_phdrs();
 
         /* Set up header */
         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
@@ -1773,9 +1771,8 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
                         goto end_coredump;
         }
 
-#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
-        ELF_CORE_WRITE_EXTRA_PHDRS;
-#endif
+        if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
+                goto end_coredump;
 
         /* write out the notes section */
         for (i = 0; i < numnote; i++)
@@ -1799,9 +1796,8 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
                                     mm_flags) < 0)
                 goto end_coredump;
 
-#ifdef ELF_CORE_WRITE_EXTRA_DATA
-        ELF_CORE_WRITE_EXTRA_DATA;
-#endif
+        if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
+                goto end_coredump;
 
         if (cprm->file->f_pos != offset) {
                 /* Sanity check */
diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index 0adced2f296f..112e45a17e99 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -28,10 +28,12 @@
 
 #undef  elfhdr
 #undef  elf_phdr
+#undef  elf_shdr
 #undef  elf_note
 #undef  elf_addr_t
 #define elfhdr          elf32_hdr
 #define elf_phdr        elf32_phdr
+#define elf_shdr        elf32_shdr
 #define elf_note        elf32_note
 #define elf_addr_t      Elf32_Addr
 
diff --git a/include/linux/elf.h b/include/linux/elf.h
index ad990c5f63f6..ccde3fd45f36 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -396,6 +396,7 @@ extern Elf32_Dyn _DYNAMIC [];
 #define elf_phdr        elf32_phdr
 #define elf_note        elf32_note
 #define elf_addr_t      Elf32_Off
+#define Elf_Half        Elf32_Half
 
 #else
 
@@ -404,6 +405,7 @@ extern Elf64_Dyn _DYNAMIC [];
 #define elf_phdr        elf64_phdr
 #define elf_note        elf64_note
 #define elf_addr_t      Elf64_Off
+#define Elf_Half        Elf64_Half
 
 #endif
 
diff --git a/include/linux/elfcore.h b/include/linux/elfcore.h
index 00d6a68d0421..cfda74f521b5 100644
--- a/include/linux/elfcore.h
+++ b/include/linux/elfcore.h
@@ -8,6 +8,8 @@
 #include <linux/user.h>
 #endif
 #include <linux/ptrace.h>
+#include <linux/elf.h>
+#include <linux/fs.h>
 
 struct elf_siginfo
 {
@@ -150,5 +152,19 @@ static inline int elf_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregse
 
 #endif /* __KERNEL__ */
 
+/*
+ * These functions 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.
+ */
+extern Elf_Half elf_core_extra_phdrs(void);
+extern int
+elf_core_write_extra_phdrs(struct file *file, loff_t offset, size_t *size,
+                           unsigned long limit);
+extern int
+elf_core_write_extra_data(struct file *file, size_t *size, unsigned long limit);
 
 #endif /* _LINUX_ELFCORE_H */
diff --git a/kernel/Makefile b/kernel/Makefile
index 7b974699f8c2..a987aa1676b5 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -91,6 +91,9 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
 obj-$(CONFIG_TRACEPOINTS) += tracepoint.o
 obj-$(CONFIG_LATENCYTOP) += latencytop.o
+obj-$(CONFIG_BINFMT_ELF) += elfcore.o
+obj-$(CONFIG_COMPAT_BINFMT_ELF) += elfcore.o
+obj-$(CONFIG_BINFMT_ELF_FDPIC) += elfcore.o
 obj-$(CONFIG_FUNCTION_TRACER) += trace/
 obj-$(CONFIG_TRACING) += trace/
 obj-$(CONFIG_X86_DS) += trace/
diff --git a/kernel/elfcore.c b/kernel/elfcore.c
new file mode 100644
index 000000000000..5445741f4b4c
--- /dev/null
+++ b/kernel/elfcore.c
@@ -0,0 +1,23 @@
+#include <linux/elf.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+
+#include <asm/elf.h>
+
+
+Elf_Half __weak elf_core_extra_phdrs(void)
+{
+        return 0;
+}
+
+int __weak elf_core_write_extra_phdrs(struct file *file, loff_t offset, size_t *size,
+                                      unsigned long limit)
+{
+        return 1;
+}
+
+int __weak elf_core_write_extra_data(struct file *file, size_t *size,
+                                     unsigned long limit)
+{
+        return 1;
+}