From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id C635B6B004F for ; Tue, 14 Jul 2009 06:24:38 -0400 (EDT) Date: Tue, 14 Jul 2009 13:57:11 +0300 From: Sergey Senozhatsky Subject: Re: kmemleak hexdump proposal Message-ID: <20090714105709.GB2929@localdomain.by> References: <20090629201014.GA5414@localdomain.by> <1247566033.28240.46.camel@pc1117.cambridge.arm.com> <20090714103356.GA2929@localdomain.by> <1247567641.28240.51.camel@pc1117.cambridge.arm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="i9LlY+UWpKt15+FH" Content-Disposition: inline In-Reply-To: <1247567641.28240.51.camel@pc1117.cambridge.arm.com> Sender: owner-linux-mm@kvack.org To: Catalin Marinas Cc: Pekka Enberg , "Paul E. McKenney" , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: --i9LlY+UWpKt15+FH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On (07/14/09 11:34), Catalin Marinas wrote: > On Tue, 2009-07-14 at 13:33 +0300, Sergey Senozhatsky wrote: > > On (07/14/09 11:07), Catalin Marinas wrote: > > Am I understand correct that no way for user to on/off hexdump? > > /* no need for atomic_t kmemleak_hex_dump */ >=20 > Yes. Two lines aren't really too much so we can always have them > displayed. > Agree. diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 5aabd41..f7b74ac 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -161,6 +161,15 @@ struct kmemleak_object { /* flag set on newly allocated objects */ #define OBJECT_NEW (1 << 3) =20 +/* number of bytes to print per line; must be 16 or 32 */ +#define HEX_ROW_SIZE 16 +/* number of bytes to print at a time (1, 2, 4, 8) */ +#define HEX_GROUP_SIZE 1 +/* include ASCII after the hex output */ +#define HEX_ASCII 1 +/* max number of lines to be printed */ +#define HEX_MAX_LINES 2 + /* the list of all allocated objects */ static LIST_HEAD(object_list); /* the list of gray-colored objects (see color_gray comment below) */ @@ -254,6 +263,35 @@ static void kmemleak_disable(void); kmemleak_disable(); \ } while (0) =20 + +/* + * Printing of the objects hex dump to the seq file. The number on lines + * to be printed is limited to HEX_MAX_LINES to prevent seq file spamming. + * The actual number of printed bytes depends on HEX_ROW_SIZE. + * It must be called with the object->lock held. + */ +static void hex_dump_object(struct seq_file *seq, + struct kmemleak_object *object) +{ + const u8 *ptr =3D (const u8 *)object->pointer; + /* Limit the number of lines to HEX_MAX_LINES. */ + int len =3D min(object->size, (size_t)(HEX_MAX_LINES * HEX_ROW_SIZE)); + int i, remaining =3D len; + unsigned char linebuf[200]; + + seq_printf(seq, " hex dump (first %d bytes):\n", len); + + for (i =3D 0; i < len; i +=3D HEX_ROW_SIZE) { + int linelen =3D min(remaining, HEX_ROW_SIZE); + remaining -=3D HEX_ROW_SIZE; + hex_dump_to_buffer(ptr + i, linelen, HEX_ROW_SIZE, + HEX_GROUP_SIZE, linebuf, + sizeof(linebuf), HEX_ASCII); + + seq_printf(seq, " %s\n", linebuf); + } +} + /* * Object colors, encoded with count and min_count: * - white - orphan object, not enough references to it (count < min_count) @@ -304,6 +342,9 @@ static void print_unreferenced(struct seq_file *seq, object->pointer, object->size); seq_printf(seq, " comm \"%s\", pid %d, jiffies %lu\n", object->comm, object->pid, object->jiffies); + + hex_dump_object(seq, object); + seq_printf(seq, " backtrace:\n"); =20 for (i =3D 0; i < object->trace_len; i++) { --i9LlY+UWpKt15+FH Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iJwEAQECAAYFAkpcZIUACgkQfKHnntdSXjQqDwP+OLAZ3uj0XluD6A5BUFoKSSS+ xNNMsNNKlS2cwxVlAdVGmBoUBUOmD2Sq+FksMDyZdRnG2TL5LcUokfcL//LbSo8h hOIssNyv9URqV4PaMIR45E40DBk/rOrz9w6CNCVi8PxeGc5nZjponrwZJq2PCzUg 06KxkqiQ9W215baNQDg= =PwYQ -----END PGP SIGNATURE----- --i9LlY+UWpKt15+FH-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org