Commit ba9aadd8 authored by Marcin Slusarz's avatar Marcin Slusarz Committed by Jan Kara
Browse files

udf: reduce stack usage of udf_load_pvoldesc 



Allocate strings with kmalloc.

Checkstack output:
Before: udf_process_sequence:      712
After:  udf_process_sequence:      200

Signed-off-by: default avatarMarcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 97e961fd

fs/udf/super.c

+25 −11
Original line number Diff line number Diff line
@@ -902,14 +902,23 @@ static int udf_find_fileset(struct super_block *sb, 
static int udf_load_pvoldesc(struct super_block *sb, sector_t block)

{

	struct primaryVolDesc *pvoldesc;

	struct ustr instr;

	struct ustr outstr;

	struct ustr *instr, *outstr;

	struct buffer_head *bh;

	uint16_t ident;

	int ret = 1;



	instr = kmalloc(sizeof(struct ustr), GFP_NOFS);

	if (!instr)

		return 1;



	outstr = kmalloc(sizeof(struct ustr), GFP_NOFS);

	if (!outstr)

		goto out1;



	bh = udf_read_tagged(sb, block, block, &ident);

	if (!bh)

		return 1;

		goto out2;



	BUG_ON(ident != TAG_IDENT_PVD);



	pvoldesc = (struct primaryVolDesc *)bh->b_data;
@@ -925,20 +934,25 @@ static int udf_load_pvoldesc(struct super_block *sb, sector_t block) 
#endif

	}



	if (!udf_build_ustr(&instr, pvoldesc->volIdent, 32))

		if (udf_CS0toUTF8(&outstr, &instr)) {

			strncpy(UDF_SB(sb)->s_volume_ident, outstr.u_name,

				outstr.u_len > 31 ? 31 : outstr.u_len);

	if (!udf_build_ustr(instr, pvoldesc->volIdent, 32))

		if (udf_CS0toUTF8(outstr, instr)) {

			strncpy(UDF_SB(sb)->s_volume_ident, outstr->u_name,

				outstr->u_len > 31 ? 31 : outstr->u_len);

			udf_debug("volIdent[] = '%s'\n",

					UDF_SB(sb)->s_volume_ident);

		}



	if (!udf_build_ustr(&instr, pvoldesc->volSetIdent, 128))

		if (udf_CS0toUTF8(&outstr, &instr))

			udf_debug("volSetIdent[] = '%s'\n", outstr.u_name);

	if (!udf_build_ustr(instr, pvoldesc->volSetIdent, 128))

		if (udf_CS0toUTF8(outstr, instr))

			udf_debug("volSetIdent[] = '%s'\n", outstr->u_name);



	brelse(bh);

	return 0;

	ret = 0;

out2:

	kfree(outstr);

out1:

	kfree(instr);

	return ret;

}



static int udf_load_metadata_files(struct super_block *sb, int partition)

CRA Git | Maintained and supported by SUSTech CRA and CCSE