A typical code fragment was copied across many dvb-frontend drivers and
causes large stack frames when built with with CONFIG_KASAN on gcc-5/6/7:
drivers/media/dvb-frontends/cxd2841er.c:3225:1: error: the frame size of 3992 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
drivers/media/dvb-frontends/cxd2841er.c:3404:1: error: the frame size of 3136 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
drivers/media/dvb-frontends/stv0367.c:3143:1: error: the frame size of 4016 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
drivers/media/dvb-frontends/stv090x.c:3430:1: error: the frame size of 5312 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
drivers/media/dvb-frontends/stv090x.c:4248:1: error: the frame size of 4872 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]
gcc-8 now solves this by consolidating the stack slots for the argument
variables, but on older compilers we can get the same behavior by taking
the pointer of a local variable rather than the inline function argument.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
While this patch sounded a good idea, unfortunately, it causes
bad dependencies, as drivers that would otherwise work without
the DVB core will now break:
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/tea5767.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/tea5761.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/tda827x.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/tda18218.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/qt1010.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/mt2266.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/mt20xx.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/mt2060.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/mc44s803.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/fc0013.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/fc0012.ko] undefined!
ERROR: "dvb_tuner_simple_release" [drivers/media/tuners/fc0011.ko] undefined!
So, we have to revert it.
Note: as the argument for the release ops changed from "int"
to "void", we needed to change it at the revert patch, to
avoid compilation issues like:
drivers/media/tuners/tea5767.c:437:23: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
.release = tea5767_release,
^~~~~~~~~~~~~~~
This reverts commit 22a613e898.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Most release callback functions are identical: free the "tuner_priv"
and clear it. Let's eliminate some bloat by providing this simple
implementation in the dvb_frontend library.
Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
These structures are only used to copy into other structures, so declare
them as const.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct dvb_tuner_ops i@p = { ... };
@ok1@
identifier r.i;
expression e;
position p;
@@
e = i@p
@ok2@
identifier r.i;
expression e1, e2;
position p;
@@
memcpy(e1, &i@p, e2)
@bad@
position p != {r.p,ok1.p,ok2.p};
identifier r.i;
struct dvb_tuner_ops e;
@@
e@i@p
@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
struct dvb_tuner_ops i = { ... };
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
The stv6110x_devctl structure is never modified, so declare it as
const.
Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
drivers/media/dvb-frontends/bcm3510.c:230:1: warning: 'bcm3510_do_hab_cmd' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/itd1000.c:69:1: warning: 'itd1000_write_regs.constprop.0' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/mt312.c:126:1: warning: 'mt312_write' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/nxt200x.c:111:1: warning: 'nxt200x_writebytes' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/stb6100.c:216:1: warning: 'stb6100_write_reg_range.constprop.3' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/stv6110.c:98:1: warning: 'stv6110_write_regs' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/stv6110x.c:85:1: warning: 'stv6110x_write_regs' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/tda18271c2dd.c:147:1: warning: 'WriteRegs' uses dynamic stack allocation [enabled by default]
drivers/media/dvb-frontends/zl10039.c:119:1: warning: 'zl10039_write' uses dynamic stack allocation [enabled by default]
Instead, let's enforce a limit for the buffer. Considering that I2C
transfers are generally limited, and that devices used on USB has a
max data length of 64 bytes for the control URBs.
So, it seem safe to use 64 bytes as the hard limit for all those devices.
On most cases, the limit is a way lower than that, but this limit
is small enough to not affect the Kernel stack, and it is a no brain
limit, as using smaller ones would require to either carefully each
driver or to take a look on each datasheet.
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Raise the DVB frontends one level up, as the intention is to remove
the drivers/media/dvb directory.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
