From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org,
Tony Lindgren <tony@atomide.com>,
Tomi Valkeinen <tomi.valkeinen@ti.com>
Subject: trinity: kernel warning at drivers/video/omap2/dss/manager-sysfs.c:290 manager_alpha_blending_enabled_show+0x3c/0x60()
Date: Wed, 21 Aug 2013 23:33:40 +0100 [thread overview]
Message-ID: <20130821223340.GE25647@n2100.arm.linux.org.uk> (raw)
Trinity found this error on OMAP4430SDP using 3.11-rc4:
WARNING: CPU: 1 PID: 3395 at /home/rmk/git/linux-rmk/drivers/video/omap2/dss/manager-sysfs.c:290 manager_alpha_blending_enabled_show+0x3c/0x60()
Modules linked in:
CPU: 1 PID: 3395 Comm: trinity-child1 Not tainted 3.11.0-rc4+ #487
Backtrace:
[<c0016ca8>] (dump_backtrace+0x0/0x110) from [<c0016e44>] (show_stack+0x18/0x1c)
r6:c03dc0d4 r5:00000009 r4:00000000 r3:00400040
[<c0016e2c>] (show_stack+0x0/0x1c) from [<c03949ec>] (dump_stack+0x74/0x90)
[<c0394978>] (dump_stack+0x0/0x90) from [<c0037a68>] (warn_slowpath_common+0x6c/0x8c)
r4:00000000 r3:deaef800
[<c00379fc>] (warn_slowpath_common+0x0/0x8c) from [<c0037aac>] (warn_slowpath_null+0x24/0x2c)
r8:dd4eb718 r7:c03dc2a0 r6:dd629f70 r5:dd4eb700 r4:dd4af000
[<c0037a88>] (warn_slowpath_null+0x0/0x2c) from [<c01e4744>] (manager_alpha_blending_enabled_show+0x3c/0x60)
[<c01e4708>] (manager_alpha_blending_enabled_show+0x0/0x60) from [<c01e41c0>] (manager_attr_show+0x20/0x2c)
r4:de090cd0
[<c01e41a0>] (manager_attr_show+0x0/0x2c) from [<c0126ee4>] (sysfs_read_file+0xc4/0x14c)
[<c0126e20>] (sysfs_read_file+0x0/0x14c) from [<c00cef2c>] (do_readv_writev+0x118/0x24c)
[<c00cee14>] (do_readv_writev+0x0/0x24c) from [<c00cf140>] (vfs_readv+0x68/0x78)
[<c00cf0d8>] (vfs_readv+0x0/0x78) from [<c00cf19c>] (SyS_readv+0x4c/0x74)
r5:00000000 r4:dd5b7700
[<c00cf150>] (SyS_readv+0x0/0x74) from [<c0013340>] (ret_fast_syscall+0x0/0x48)
Looking at the code:
static ssize_t manager_alpha_blending_enabled_show(
struct omap_overlay_manager *mgr, char *buf)
{
struct omap_overlay_manager_info info;
mgr->get_manager_info(mgr, &info);
WARN_ON(!dss_has_feature(FEAT_ALPHA_FIXED_ZORDER));
-rw-r--r-- 1 root root 4096 Jan 1 00:01 manager0/alpha_blending_enabled
-rw-r--r-- 1 root root 4096 Jan 1 00:01 manager1/alpha_blending_enabled
-rw-r--r-- 1 root root 4096 Jan 1 00:01 manager2/alpha_blending_enabled
So, any program in userspace can open this sysfs file and on read cause
the kernel to print a warning and taint itself if there is no ZORDER
feature? This is not good kernel programming guys. Please audit your
other sysfs files for this bug, thanks.
next reply other threads:[~2013-08-21 22:34 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-21 22:33 Russell King - ARM Linux [this message]
2013-08-27 11:37 ` trinity: kernel warning at drivers/video/omap2/dss/manager-sysfs.c:290 manager_alpha_blending_enabled_show+0x3c/0x60() Tomi Valkeinen
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