media: em28xx: split up em28xx_dvb_init to reduce stack size

Browse Source

With CONFIG_KASAN, the init function uses a large amount of kernel stack:

drivers/media/usb/em28xx/em28xx-dvb.c: In function 'em28xx_dvb_init.part.4':
drivers/media/usb/em28xx/em28xx-dvb.c:2061:1: error: the frame size of 3232 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]

Using gcc-7 with -fsanitize-address-use-after-scope makes this even worse:

drivers/media/usb/em28xx/em28xx-dvb.c: In function 'em28xx_dvb_init':
drivers/media/usb/em28xx/em28xx-dvb.c:2069:1: error: the frame size of 4280 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]

By splitting out each part of the switch/case statement that has its own local
variables into a separate function, no single one of them uses more than 500 bytes,
and with a noinline_for_stack annotation we can ensure that they are not merged
back together.

[mchehab@s-opensource.com: fix conflict with changeset
 be7fd3c3a8 ("media: em28xx: Hauppauge DualHD second tuner functionality")]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

...

This commit is contained in:

Arnd Bergmann 2017-12-11 07:05:02 -05:00 committed by Mauro Carvalho Chehab

parent cf68c22f10

commit f410b4093f

1 changed files with 520 additions and 451 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Show Stats Download Patch File Download Diff File Expand all files Collapse all files

961

drivers/media/usb/em28xx/em28xx-dvb.c

View File

File diff suppressed because it is too large Load Diff