From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: droid 4 in v4.18-rc: grep -r adasfasd /sys/ oopses Date: Mon, 9 Jul 2018 12:28:52 +0200 Message-ID: <20180709102852.GA20580@amd> References: <20180708174939.GA10002@amd> <20180708193720.GA13262@amd> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="OXfL5xGRrasGEqWY" Return-path: Content-Disposition: inline In-Reply-To: <20180708193720.GA13262@amd> Sender: linux-kernel-owner@vger.kernel.org To: kernel list , linux-arm-kernel , linux-omap@vger.kernel.org, tony@atomide.com, sre@kernel.org, nekit1000@gmail.com, mpartap@gmx.net, merlijn@wizzup.org Cc: "Rafael J. Wysocki" , Linux-pm mailing list , andriy.shevchenko@linux.intel.com List-Id: linux-pm@vger.kernel.org --OXfL5xGRrasGEqWY Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > grep in /sys produces a nasty oops: > >=20 > > I guess next step is trying to find out which file that is.. >=20 > Let me see... >=20 > openat(6, "suspend", > O_RDONLY|O_NOCTTY|O_NONBLOCK|O_LARGEFILE|O_NOFOLLOW) =3D 4 > fstat64(4, {st_mode=3DS_IFREG|0644, st_size=3D0, ...}) =3D 0 > read(4, 0x4d2000, 32768) =3D -1 EINVAL (Invalid argument) > write(2, "grep: ", 6grep: ) =3D 6 > write(2, "/sys/kernel/debug/pm_debug/cefus"..., > 47/sys/kernel/debug/pm_debug/cefuse_pwrdm/suspend) =3D 47 > write(2, ": Invalid argument", 18: Invalid argument) =3D 18 > write(2, "\n", 1 > ) =3D 1 > close(4) =3D 0 > close(6) =3D 0 > openat(5, "time", O_RDONLY|O_NOCTTY|O_NONBLOCK|O_LARGEFILE|O_NOFOLLOW) > =3D 4 > fstat64(4, {st_mode=3DS_IFREG|0444, st_size=3D0, ...}) =3D 0 > read(4, "cefuse_pwrdm (OFF),OFF:641441757"..., 32768) =3D 849 > read(4, "", 28672) =3D 0 > close(4) =3D 0 > openat(5, "count", > O_RDONLY|O_NOCTTY|O_NONBLOCK|O_LARGEFILE|O_NOFOLLOW) =3D 4 > Connection to usb closed by remote host. > Connection to usb closed. > pavel@half:~$ >=20 > Ok, so it seems to be: >=20 > user@devuan:~$ cat /sys/kernel/debug/pm_debug/count > (oops). >=20 > The file seems to be world-readable. >=20 > user@devuan:~$ ls -al /sys/kernel/debug/pm_debug/count > -r--r--r-- 1 root root 0 Jan 1 1970 /sys/kernel/debug/pm_debug/count >=20 > But on PC, that file does not exist. Ok, it is easier to reproduce like this: sudo mount /dev/zero -t debugfs /sys/kernel/debug/ sudo cat /sys/kernel/debug/pm_debug/count I tried adding debugging like this: diff --git a/arch/arm/mach-omap2/pm-debug.c b/arch/arm/mach-omap2/pm-debug.c index cba72de..ed98da8 100644 --- a/arch/arm/mach-omap2/pm-debug.c +++ b/arch/arm/mach-omap2/pm-debug.c @@ -78,14 +78,17 @@ static int clkdm_dbg_show_counter(struct clockdomain *c= lkdm, void *user) { struct seq_file *s =3D (struct seq_file *)user; =20 + printk("cmp...\n"); if (strcmp(clkdm->name, "emu_clkdm") =3D=3D 0 || strcmp(clkdm->name, "wkup_clkdm") =3D=3D 0 || strncmp(clkdm->name, "dpll", 4) =3D=3D 0) return 0; =20 + printk("printf...\n");=09 seq_printf(s, "%s->%s (%d)\n", clkdm->name, clkdm->pwrdm.ptr->name, clkdm->usecount); =20 + printk("done...\n");=09 return 0; } =20 But it seems to crash outside show_counter function: [ 100.345062] cpcap-usb-phy cpcap-usb-phy.0: connected to USB host [ 102.049743] cmp... [ 102.051910] printf... [ 102.054351] done... [ 102.056579] cmp... [ 102.058685] printf... =2E.. [ 102.319427] printf... [ 102.323211] done... [ 102.326843] ------------[ cut here ]------------ [ 102.333190] WARNING: CPU: 0 PID: 2360 at drivers/bus/omap_l3_noc.c:147 l3_int errupt_handler+0x23c/0x380 [ 102.344696] 44000000.ocp:L3 Custom Error: MASTER MPU TARGET L4PER2 (Read): Da ta Access in User mode during Functional access Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --OXfL5xGRrasGEqWY Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAltDOOQACgkQMOfwapXb+vIxnACcCO51qnvkCTacqdhOUgNSNsNc mI8AoKVarTkhTDuRfXsZgztgrKgS8GjS =sc4Z -----END PGP SIGNATURE----- --OXfL5xGRrasGEqWY--