__________________________ BRs, Cao, Bingbu > -----Original Message----- > From: Arnd Bergmann [mailto:arnd@xxxxxxxx] > Sent: Tuesday, March 5, 2019 4:28 AM > To: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>; Mauro Carvalho Chehab > <mchehab@xxxxxxxxxx>; Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Arnd Bergmann <arnd@xxxxxxxx>; Zhi, Yong <yong.zhi@xxxxxxxxx>; Cao, > Bingbu <bingbu.cao@xxxxxxxxx>; linux-media@xxxxxxxxxxxxxxx; > devel@xxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: [PATCH] media: staging/intel-ipu3: reduce kernel stack usage > > The imgu_css_queue structure is too large to be put on the kernel stack, > as we can see in 32-bit builds: > > drivers/staging/media/ipu3/ipu3-css.c: In function 'imgu_css_fmt_try': > drivers/staging/media/ipu3/ipu3-css.c:1863:1: error: the frame size of > 1172 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] > > By dynamically allocating this array, the stack usage goes down to an > acceptable 140 bytes for the same x86-32 configuration. > > Fixes: f5f2e4273518 ("media: staging/intel-ipu3: Add css pipeline > programming") > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > drivers/staging/media/ipu3/ipu3-css.c | 25 +++++++++++++++++++------ > 1 file changed, 19 insertions(+), 6 deletions(-) > > diff --git a/drivers/staging/media/ipu3/ipu3-css.c > b/drivers/staging/media/ipu3/ipu3-css.c > index 15ab77e4b766..664c14b7a518 100644 > --- a/drivers/staging/media/ipu3/ipu3-css.c > +++ b/drivers/staging/media/ipu3/ipu3-css.c > @@ -3,6 +3,7 @@ > > #include <linux/device.h> > #include <linux/iopoll.h> > +#include <linux/slab.h> > > #include "ipu3-css.h" > #include "ipu3-css-fw.h" > @@ -1744,7 +1745,7 @@ int imgu_css_fmt_try(struct imgu_css *css, > struct v4l2_rect *const bds = &r[IPU3_CSS_RECT_BDS]; > struct v4l2_rect *const env = &r[IPU3_CSS_RECT_ENVELOPE]; > struct v4l2_rect *const gdc = &r[IPU3_CSS_RECT_GDC]; > - struct imgu_css_queue q[IPU3_CSS_QUEUES]; > + struct imgu_css_queue *q = kcalloc(IPU3_CSS_QUEUES, sizeof(struct > +imgu_css_queue), GFP_KERNEL); Could you use the devm_kcalloc()? > struct v4l2_pix_format_mplane *const in = > &q[IPU3_CSS_QUEUE_IN].fmt.mpix; > struct v4l2_pix_format_mplane *const out = @@ -1753,6 +1754,11 @@ > int imgu_css_fmt_try(struct imgu_css *css, > &q[IPU3_CSS_QUEUE_VF].fmt.mpix; > int i, s, ret; > > + if (!q) { > + ret = -ENOMEM; > + goto out; > + } [Cao, Bingbu] The goto here is wrong, you can just report an error, and I prefer it is next to the alloc. > + > /* Adjust all formats, get statistics buffer sizes and formats */ > for (i = 0; i < IPU3_CSS_QUEUES; i++) { > if (fmts[i]) > @@ -1766,7 +1772,8 @@ int imgu_css_fmt_try(struct imgu_css *css, > IPU3_CSS_QUEUE_TO_FLAGS(i))) { > dev_notice(css->dev, "can not initialize queue %s\n", > qnames[i]); > - return -EINVAL; > + ret = -EINVAL; > + goto out; > } > } > for (i = 0; i < IPU3_CSS_RECTS; i++) { @@ -1788,7 +1795,8 @@ int > imgu_css_fmt_try(struct imgu_css *css, > if (!imgu_css_queue_enabled(&q[IPU3_CSS_QUEUE_IN]) || > !imgu_css_queue_enabled(&q[IPU3_CSS_QUEUE_OUT])) { > dev_warn(css->dev, "required queues are disabled\n"); > - return -EINVAL; > + ret = -EINVAL; > + goto out; > } > > if (!imgu_css_queue_enabled(&q[IPU3_CSS_QUEUE_OUT])) { @@ -1829,7 > +1837,8 @@ int imgu_css_fmt_try(struct imgu_css *css, > ret = imgu_css_find_binary(css, pipe, q, r); > if (ret < 0) { > dev_err(css->dev, "failed to find suitable binary\n"); > - return -EINVAL; > + ret = -EINVAL; > + goto out; > } > css->pipes[pipe].bindex = ret; > > @@ -1843,7 +1852,8 @@ int imgu_css_fmt_try(struct imgu_css *css, > IPU3_CSS_QUEUE_TO_FLAGS(i))) { > dev_err(css->dev, > "final resolution adjustment failed\n"); > - return -EINVAL; > + ret = -EINVAL; > + goto out; > } > *fmts[i] = q[i].fmt.mpix; > } > @@ -1859,7 +1869,10 @@ int imgu_css_fmt_try(struct imgu_css *css, > bds->width, bds->height, gdc->width, gdc->height, > out->width, out->height, vf->width, vf->height); > > - return 0; > + ret = 0; > +out: > + kfree(q); > + return ret; > } > > int imgu_css_fmt_set(struct imgu_css *css, > -- > 2.20.0
