[RESEND][mmotm][PATCH v2, 3/5] elf coredump: replace ELF_CORE_EXTRA_* macros by functions

Daisuke HATAYAMA
2010-01-04T01:20:41Z

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>
---
arch/ia64/ia32/binfmt_elf32.c | 1 +
arch/ia64/ia32/elfcore32.h | 17 ++++++++++
arch/ia64/include/asm/elf.h | 48 -----------------------------
arch/ia64/kernel/Makefile | 2 +
arch/ia64/kernel/elfcore.c | 64 +++++++++++++++++++++++++++++++++++++++
arch/um/sys-i386/Makefile | 2 +
arch/um/sys-i386/asm/elf.h | 43 --------------------------
arch/um/sys-i386/elfcore.c | 67 +++++++++++++++++++++++++++++++++++++++++
fs/binfmt_elf.c | 14 +++-----
fs/binfmt_elf_fdpic.c | 14 +++-----
include/linux/elf.h | 2 +
include/linux/elfcore.h | 16 ++++++++++
kernel/Makefile | 2 +
kernel/elfcore.c | 23 ++++++++++++++
14 files changed, 206 insertions(+), 109 deletions(-)
create mode 100644 arch/ia64/kernel/elfcore.c
create mode 100644 arch/um/sys-i386/elfcore.c
create mode 100644 kernel/elfcore.c

diff --git a/arch/ia64/ia32/binfmt_elf32.c b/arch/ia64/ia32/binfmt_elf32.c
index c69552b..2328f44 100644
--- a/arch/ia64/ia32/binfmt_elf32.c
+++ b/arch/ia64/ia32/binfmt_elf32.c
@@ -43,6 +43,7 @@ randomize_stack_top(unsigned long stack_top);
#undef SET_PERSONALITY
#define SET_PERSONALITY(ex) elf32_set_personality()

+#undef elf_read_implies_exec
#define elf_read_implies_exec(ex, have_pt_gnu_stack) (!(have_pt_gnu_stack))

/* Ugly but avoids duplication */
diff --git a/arch/ia64/ia32/elfcore32.h b/arch/ia64/ia32/elfcore32.h
index 6577257..7877601 100644
--- a/arch/ia64/ia32/elfcore32.h
+++ b/arch/ia64/ia32/elfcore32.h
@@ -8,6 +8,8 @@
#ifndef _ELFCORE32_H_
#define _ELFCORE32_H_

+#include <linux/elf.h>
+
#include <asm/intrinsics.h>
#include <asm/uaccess.h>

@@ -145,4 +147,19 @@ elf_core_copy_task_xfpregs(struct task_struct *tsk, elf_fpxregset_t *xfpu)
return 1;
}

+/*
+ * 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 Elf32_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 /* _ELFCORE32_H_ */
diff --git a/arch/ia64/include/asm/elf.h b/arch/ia64/include/asm/elf.h
index e14108b..60af1ef 100644
--- a/arch/ia64/include/asm/elf.h
+++ b/arch/ia64/include/asm/elf.h
@@ -217,54 +217,6 @@ 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 2a75e93..1b3d65a 100644
--- a/arch/ia64/kernel/Makefile
+++ b/arch/ia64/kernel/Makefile
@@ -51,6 +51,8 @@ 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;
+}
diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index 1b549bc..804b28d 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 7708854..e64cd41 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 0000000..30cac52
--- /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 a0fe475..1b7e9de 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1901,9 +1901,7 @@ 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)
@@ -1981,9 +1979,8 @@ 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))
@@ -2022,9 +2019,8 @@ 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 d928e5f..4c16ff6 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1652,9 +1652,7 @@ 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 */
@@ -1761,9 +1759,8 @@ 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++)
@@ -1787,9 +1784,8 @@ 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 (file->f_pos != offset) {
/* Sanity check */
diff --git a/include/linux/elf.h b/include/linux/elf.h
index 90a4ed0..d103127 100644
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -386,6 +386,7 @@ 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

@@ -394,6 +395,7 @@ 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 00d6a68..cfda74f 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 01435e5..b6d297d 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -102,6 +102,8 @@ obj-$(CONFIG_SLOW_WORK_DEBUG) += slow-work-debugfs.o
obj-$(CONFIG_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o
+obj-$(CONFIG_BINFMT_ELF) += elfcore.o
+obj-$(CONFIG_BINFMT_ELF_FDPIC) += elfcore.o

ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/elfcore.c b/kernel/elfcore.c
new file mode 100644
index 0000000..5445741
--- /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;
+}
--
1.6.5.1