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>
These are immutable. Making them "const" allows the compiler to move
them to the "rodata" section.
Note that cxd2841er_t_c_ops cannot be made "const", because
cxd2841er_attach() modifies it. Ouch!
[mchehab@s-opensource.com: fix merge conflicts]
Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Due to the 80-cols restrictions, and latter due to checkpatch
warnings, several strings were broken into multiple lines. This
is not considered a good practice anymore, as it makes harder
to grep for strings at the source code.
As we're right now fixing other drivers due to KERN_CONT, we need
to be able to identify what printk strings don't end with a "\n".
It is a way easier to detect those if we don't break long lines.
So, join those continuation lines.
The patch was generated via the script below, and manually
adjusted if needed.
</script>
use Text::Tabs;
while (<>) {
if ($next ne "") {
$c=$_;
if ($c =~ /^\s+\"(.*)/) {
$c2=$1;
$next =~ s/\"\n$//;
$n = expand($next);
$funpos = index($n, '(');
$pos = index($c2, '",');
if ($funpos && $pos > 0) {
$s1 = substr $c2, 0, $pos + 2;
$s2 = ' ' x ($funpos + 1) . substr $c2, $pos + 2;
$s2 =~ s/^\s+//;
$s2 = ' ' x ($funpos + 1) . $s2 if ($s2 ne "");
print unexpand("$next$s1\n");
print unexpand("$s2\n") if ($s2 ne "");
} else {
print "$next$c2\n";
}
$next="";
next;
} else {
print $next;
}
$next="";
} else {
if (m/\"$/) {
if (!m/\\n\"$/) {
$next=$_;
next;
}
}
}
print $_;
}
</script>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Instead of using the DTV properties cache directly, pass the get
frontend data as an argument. For now, everything should remain
the same, but the next patch will prevent get_frontend to
affect the global cache.
This is needed because several drivers don't care enough to only
change the properties if locked. Due to that, calling
G_PROPERTY before locking on those drivers will make them to
never lock. Ok, those drivers are crap and should never be
merged like that, but the core should not rely that the drivers
would be doing the right thing.
Reviewed-by: Michael Ira Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The DVB API was originally defined using typedefs. This is against
Kernel CodingStyle, and there's no good usage here. While we can't
remove its usage on userspace, we can avoid its usage in Kernelspace.
So, let's do it.
This patch was generated by this shell script:
for j in $(grep typedef include/uapi/linux/dvb/frontend.h |cut -d' ' -f 3); do for i in $(find drivers/media -name '*.[ch]' -type f) $(find drivers/staging/media -name '*.[ch]' -type f); do sed "s,${j}_t,enum $j," <$i >a && mv a $i; done; done
While here, make CodingStyle fixes on the affected lines.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> # for drivers/media/firewire/*
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>
On gcc, enums are generally unsigned, except if a negative value
is declared. Due to that, warnings may happen there:
drivers/media/dvb-frontends/cx22700.c:142:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
drivers/media/dvb-frontends/cx22700.c:155:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
drivers/media/dvb-frontends/cx24123.c:341:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
drivers/media/dvb-frontends/l64781.c:183:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
drivers/media/dvb-frontends/l64781.c:187:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
drivers/media/dvb-frontends/mt312.c:552:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
drivers/media/dvb-frontends/mt312.c:560:2: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
As other compilers might be using signed values, the better is to
keep the checks there, casting the value to avoid the warning.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.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>
Mauro Carvalho Chehab