Commit ecc8c772 authored by Al Viro's avatar Al Viro
Browse files

new helper: dump_emit()



dump_write() analog, takes core_dump_params instead of file,
keeps track of the amount written in cprm->written and checks for
cprm->limit.  Start using it in binfmt_elf.c...
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 7d2f551f
......@@ -1225,35 +1225,23 @@ static int notesize(struct memelfnote *en)
return sz;
}
#define DUMP_WRITE(addr, nr, foffset) \
do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
static int alignfile(struct file *file, loff_t *foffset)
static int alignfile(struct coredump_params *cprm)
{
static const char buf[4] = { 0, };
DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
return 1;
return dump_emit(cprm, buf, roundup(cprm->written, 4) - cprm->written);
}
static int writenote(struct memelfnote *men, struct file *file,
loff_t *foffset)
static int writenote(struct memelfnote *men, struct coredump_params *cprm)
{
struct elf_note en;
en.n_namesz = strlen(men->name) + 1;
en.n_descsz = men->datasz;
en.n_type = men->type;
DUMP_WRITE(&en, sizeof(en), foffset);
DUMP_WRITE(men->name, en.n_namesz, foffset);
if (!alignfile(file, foffset))
return 0;
DUMP_WRITE(men->data, men->datasz, foffset);
if (!alignfile(file, foffset))
return 0;
return 1;
return dump_emit(cprm, &en, sizeof(en)) &&
dump_emit(cprm, men->name, en.n_namesz) && alignfile(cprm) &&
dump_emit(cprm, men->data, men->datasz) && alignfile(cprm);
}
#undef DUMP_WRITE
static void fill_elf_header(struct elfhdr *elf, int segs,
u16 machine, u32 flags)
......@@ -1702,7 +1690,7 @@ static size_t get_note_info_size(struct elf_note_info *info)
* process-wide notes are interleaved after the first thread-specific note.
*/
static int write_note_info(struct elf_note_info *info,
struct file *file, loff_t *foffset)
struct coredump_params *cprm)
{
bool first = 1;
struct elf_thread_core_info *t = info->thread;
......@@ -1710,22 +1698,22 @@ static int write_note_info(struct elf_note_info *info,
do {
int i;
if (!writenote(&t->notes[0], file, foffset))
if (!writenote(&t->notes[0], cprm))
return 0;
if (first && !writenote(&info->psinfo, file, foffset))
if (first && !writenote(&info->psinfo, cprm))
return 0;
if (first && !writenote(&info->signote, file, foffset))
if (first && !writenote(&info->signote, cprm))
return 0;
if (first && !writenote(&info->auxv, file, foffset))
if (first && !writenote(&info->auxv, cprm))
return 0;
if (first && info->files.data &&
!writenote(&info->files, file, foffset))
!writenote(&info->files, cprm))
return 0;
for (i = 1; i < info->thread_notes; ++i)
if (t->notes[i].data &&
!writenote(&t->notes[i], file, foffset))
!writenote(&t->notes[i], cprm))
return 0;
first = 0;
......@@ -1935,13 +1923,13 @@ static size_t get_note_info_size(struct elf_note_info *info)
}
static int write_note_info(struct elf_note_info *info,
struct file *file, loff_t *foffset)
struct coredump_params *cprm)
{
int i;
struct list_head *t;
for (i = 0; i < info->numnote; i++)
if (!writenote(info->notes + i, file, foffset))
if (!writenote(info->notes + i, cprm))
return 0;
/* write out the thread status notes section */
......@@ -1950,7 +1938,7 @@ static int write_note_info(struct elf_note_info *info,
list_entry(t, struct elf_thread_status, list);
for (i = 0; i < tmp->num_notes; i++)
if (!writenote(&tmp->notes[i], file, foffset))
if (!writenote(&tmp->notes[i], cprm))
return 0;
}
......@@ -2136,13 +2124,10 @@ static int elf_core_dump(struct coredump_params *cprm)
offset = dataoff;
size += sizeof(*elf);
if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
if (!dump_emit(cprm, elf, sizeof(*elf)))
goto end_coredump;
size += sizeof(*phdr4note);
if (size > cprm->limit
|| !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
goto end_coredump;
/* Write program headers for segments dump */
......@@ -2164,19 +2149,20 @@ static int elf_core_dump(struct coredump_params *cprm)
phdr.p_flags |= PF_X;
phdr.p_align = ELF_EXEC_PAGESIZE;
size += sizeof(phdr);
if (size > cprm->limit
|| !dump_write(cprm->file, &phdr, sizeof(phdr)))
if (!dump_emit(cprm, &phdr, sizeof(phdr)))
goto end_coredump;
}
size = cprm->written;
if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
goto end_coredump;
cprm->written = foffset; /* will disappear */
/* write out the notes section */
if (!write_note_info(&info, cprm->file, &foffset))
if (!write_note_info(&info, cprm))
goto end_coredump;
foffset = cprm->written;
if (elf_coredump_extra_notes_write(cprm->file, &foffset))
goto end_coredump;
......
......@@ -693,6 +693,20 @@ int dump_write(struct file *file, const void *addr, int nr)
}
EXPORT_SYMBOL(dump_write);
int dump_emit(struct coredump_params *cprm, const void *addr, int nr)
{
struct file *file = cprm->file;
if (dump_interrupted() || !access_ok(VERIFY_READ, addr, nr))
return 0;
if (cprm->written + nr > cprm->limit)
return 0;
if (file->f_op->write(file, addr, nr, &file->f_pos) != nr)
return 0;
cprm->written += nr;
return 1;
}
EXPORT_SYMBOL(dump_emit);
int dump_seek(struct file *file, loff_t off)
{
int ret = 1;
......
......@@ -61,6 +61,7 @@ struct coredump_params {
struct file *file;
unsigned long limit;
unsigned long mm_flags;
loff_t written;
};
/*
......
......@@ -10,8 +10,10 @@
* These are the only things you should do on a core-file: use only these
* functions to write out all the necessary info.
*/
struct coredump_params;
extern int dump_write(struct file *file, const void *addr, int nr);
extern int dump_seek(struct file *file, loff_t off);
extern int dump_emit(struct coredump_params *cprm, const void *addr, int nr);
#ifdef CONFIG_COREDUMP
extern void do_coredump(siginfo_t *siginfo);
#else
......
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