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coredump: move dump_write() and dump_seek() into a header file
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My next patch will replace ELF_CORE_EXTRA_* macros by functions, putting
them into other newly created *.c files.  Then, each files will contain
dump_write(), where each pair of binfmt_*.c and elfcore.c should be the
same.  So, this patch moves them into a header file with dump_seek().
Also, the patch deletes confusing DUMP_WRITE macros in each files.

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>
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Daisuke HATAYAMA authored and torvalds committed Mar 6, 2010
1 parent 05f47fd commit 088e7af
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Showing 4 changed files with 79 additions and 117 deletions.
49 changes: 9 additions & 40 deletions fs/binfmt_aout.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,7 @@
#include <linux/binfmts.h>
#include <linux/personality.h>
#include <linux/init.h>
#include <linux/coredump.h>

#include <asm/system.h>
#include <asm/uaccess.h>
Expand Down Expand Up @@ -59,42 +60,6 @@ static int set_brk(unsigned long start, unsigned long end)
return 0;
}

/*
* These are the only things you should do on a core-file: use only these
* macros to write out all the necessary info.
*/

static int dump_write(struct file *file, const void *addr, int nr)
{
return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
}

static int dump_seek(struct file *file, loff_t off)
{
if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
return 0;
} else {
char *buf = (char *)get_zeroed_page(GFP_KERNEL);
if (!buf)
return 0;
while (off > 0) {
unsigned long n = off;
if (n > PAGE_SIZE)
n = PAGE_SIZE;
if (!dump_write(file, buf, n))
return 0;
off -= n;
}
free_page((unsigned long)buf);
}
return 1;
}

#define DUMP_WRITE(addr, nr) \
if (!dump_write(file, (void *)(addr), (nr))) \
goto end_coredump;

/*
* Routine writes a core dump image in the current directory.
* Currently only a stub-function.
Expand Down Expand Up @@ -146,7 +111,8 @@ static int aout_core_dump(struct coredump_params *cprm)

set_fs(KERNEL_DS);
/* struct user */
DUMP_WRITE(&dump,sizeof(dump));
if (!dump_write(file, &dump, sizeof(dump)))
goto end_coredump;
/* Now dump all of the user data. Include malloced stuff as well */
if (!dump_seek(cprm->file, PAGE_SIZE - sizeof(dump)))
goto end_coredump;
Expand All @@ -156,17 +122,20 @@ static int aout_core_dump(struct coredump_params *cprm)
if (dump.u_dsize != 0) {
dump_start = START_DATA(dump);
dump_size = dump.u_dsize << PAGE_SHIFT;
DUMP_WRITE(dump_start,dump_size);
if (!dump_write(file, dump_start, dump_size))
goto end_coredump;
}
/* Now prepare to dump the stack area */
if (dump.u_ssize != 0) {
dump_start = START_STACK(dump);
dump_size = dump.u_ssize << PAGE_SHIFT;
DUMP_WRITE(dump_start,dump_size);
if (!dump_write(file, dump_start, dump_size))
goto end_coredump;
}
/* Finally dump the task struct. Not be used by gdb, but could be useful */
set_fs(KERNEL_DS);
DUMP_WRITE(current,sizeof(*current));
if (!dump_write(file, current, sizeof(*current)))
goto end_coredump;
end_coredump:
set_fs(fs);
return has_dumped;
Expand Down
52 changes: 14 additions & 38 deletions fs/binfmt_elf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@
#include <linux/random.h>
#include <linux/elf.h>
#include <linux/utsname.h>
#include <linux/coredump.h>
#include <asm/uaccess.h>
#include <asm/param.h>
#include <asm/page.h>
Expand Down Expand Up @@ -1085,36 +1086,6 @@ static int load_elf_library(struct file *file)
* Modelled on fs/exec.c:aout_core_dump()
* Jeremy Fitzhardinge <jeremy@sw.oz.au>
*/
/*
* These are the only things you should do on a core-file: use only these
* functions to write out all the necessary info.
*/
static int dump_write(struct file *file, const void *addr, int nr)
{
return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
}

static int dump_seek(struct file *file, loff_t off)
{
if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
return 0;
} else {
char *buf = (char *)get_zeroed_page(GFP_KERNEL);
if (!buf)
return 0;
while (off > 0) {
unsigned long n = off;
if (n > PAGE_SIZE)
n = PAGE_SIZE;
if (!dump_write(file, buf, n))
return 0;
off -= n;
}
free_page((unsigned long)buf);
}
return 1;
}

/*
* Decide what to dump of a segment, part, all or none.
Expand Down Expand Up @@ -1249,11 +1220,6 @@ static int writenote(struct memelfnote *men, struct file *file,
}
#undef DUMP_WRITE

#define DUMP_WRITE(addr, nr) \
if ((size += (nr)) > cprm->limit || \
!dump_write(cprm->file, (addr), (nr))) \
goto end_coredump;

static void fill_elf_header(struct elfhdr *elf, int segs,
u16 machine, u32 flags, u8 osabi)
{
Expand Down Expand Up @@ -1934,7 +1900,10 @@ static int elf_core_dump(struct coredump_params *cprm)
fs = get_fs();
set_fs(KERNEL_DS);

DUMP_WRITE(elf, sizeof(*elf));
size += sizeof(*elf);
if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
goto end_coredump;

offset += sizeof(*elf); /* Elf header */
offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
foffset = offset;
Expand All @@ -1948,7 +1917,11 @@ static int elf_core_dump(struct coredump_params *cprm)

fill_elf_note_phdr(&phdr, sz, offset);
offset += sz;
DUMP_WRITE(&phdr, sizeof(phdr));

size += sizeof(phdr);
if (size > cprm->limit
|| !dump_write(cprm->file, &phdr, sizeof(phdr)))
goto end_coredump;
}

dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
Expand Down Expand Up @@ -1979,7 +1952,10 @@ static int elf_core_dump(struct coredump_params *cprm)
phdr.p_flags |= PF_X;
phdr.p_align = ELF_EXEC_PAGESIZE;

DUMP_WRITE(&phdr, sizeof(phdr));
size += sizeof(phdr);
if (size > cprm->limit
|| !dump_write(cprm->file, &phdr, sizeof(phdr)))
goto end_coredump;
}

#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
Expand Down
54 changes: 15 additions & 39 deletions fs/binfmt_elf_fdpic.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,7 @@
#include <linux/elf.h>
#include <linux/elf-fdpic.h>
#include <linux/elfcore.h>
#include <linux/coredump.h>

#include <asm/uaccess.h>
#include <asm/param.h>
Expand Down Expand Up @@ -1215,37 +1216,6 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
*/
#ifdef CONFIG_ELF_CORE

/*
* These are the only things you should do on a core-file: use only these
* functions to write out all the necessary info.
*/
static int dump_write(struct file *file, const void *addr, int nr)
{
return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
}

static int dump_seek(struct file *file, loff_t off)
{
if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
return 0;
} else {
char *buf = (char *)get_zeroed_page(GFP_KERNEL);
if (!buf)
return 0;
while (off > 0) {
unsigned long n = off;
if (n > PAGE_SIZE)
n = PAGE_SIZE;
if (!dump_write(file, buf, n))
return 0;
off -= n;
}
free_page((unsigned long)buf);
}
return 1;
}

/*
* Decide whether a segment is worth dumping; default is yes to be
* sure (missing info is worse than too much; etc).
Expand Down Expand Up @@ -1354,11 +1324,6 @@ static int writenote(struct memelfnote *men, struct file *file,
}
#undef DUMP_WRITE

#define DUMP_WRITE(addr, nr) \
if ((size += (nr)) > cprm->limit || \
!dump_write(cprm->file, (addr), (nr))) \
goto end_coredump;

static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
{
memcpy(elf->e_ident, ELFMAG, SELFMAG);
Expand Down Expand Up @@ -1743,7 +1708,11 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
fs = get_fs();
set_fs(KERNEL_DS);

DUMP_WRITE(elf, sizeof(*elf));
size += sizeof(*elf);
if (size > cprm->limit
|| !dump_write(cprm->file, elf, sizeof(*elf)))
goto end_coredump;

offset += sizeof(*elf); /* Elf header */
offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */
foffset = offset;
Expand All @@ -1760,7 +1729,11 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)

fill_elf_note_phdr(&phdr, sz, offset);
offset += sz;
DUMP_WRITE(&phdr, sizeof(phdr));

size += sizeof(phdr);
if (size > cprm->limit
|| !dump_write(cprm->file, &phdr, sizeof(phdr)))
goto end_coredump;
}

/* Page-align dumped data */
Expand Down Expand Up @@ -1794,7 +1767,10 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
phdr.p_flags |= PF_X;
phdr.p_align = ELF_EXEC_PAGESIZE;

DUMP_WRITE(&phdr, sizeof(phdr));
size += sizeof(phdr);
if (size > cprm->limit
|| !dump_write(cprm->file, &phdr, sizeof(phdr)))
goto end_coredump;
}

#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
Expand Down
41 changes: 41 additions & 0 deletions include/linux/coredump.h
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,41 @@
#ifndef _LINUX_COREDUMP_H
#define _LINUX_COREDUMP_H

#include <linux/types.h>
#include <linux/mm.h>
#include <linux/fs.h>

/*
* These are the only things you should do on a core-file: use only these
* functions to write out all the necessary info.
*/
static inline int dump_write(struct file *file, const void *addr, int nr)
{
return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
}

static inline int dump_seek(struct file *file, loff_t off)
{
if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
return 0;
} else {
char *buf = (char *)get_zeroed_page(GFP_KERNEL);

if (!buf)
return 0;
while (off > 0) {
unsigned long n = off;

if (n > PAGE_SIZE)
n = PAGE_SIZE;
if (!dump_write(file, buf, n))
return 0;
off -= n;
}
free_page((unsigned long)buf);
}
return 1;
}

#endif /* _LINUX_COREDUMP_H */

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