Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

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

fs/binfmt_elf.c

+23 −37
Original line number Diff line number Diff line
@@ -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;

fs/coredump.c

+14 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/binfmts.h

+1 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ struct coredump_params { 
	struct file *file;

	unsigned long limit;

	unsigned long mm_flags;

	loff_t written;

};



/*

include/linux/coredump.h

+2 −0
Original line number Diff line number Diff line
@@ -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