lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 17 Feb 2016 20:20:15 -0600 From: Larry Finger <Larry.Finger@...inger.net> To: Arnd Bergmann <arnd@...db.de>, Florian Schilhabel <florian.c.schilhabel@...glemail.com>, Greg Kroah-Hartman <gregkh@...uxfoundation.org> Cc: linux-arm-kernel@...ts.infradead.org, Luis de Bethencourt <luisbg@....samsung.com>, Joshua Clayton <stillcompiling@...il.com>, devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org Subject: Re: [PATCH] staging: rtl8712: reduce stack usage On 02/17/2016 02:32 AM, Arnd Bergmann wrote: > The "translate_scan" function in rtl8712 uses a lot of stack, and > gets inlined into its single caller, r8711_wx_get_scan, which > in some configurations now blows the 1024 byte stack warning > limit: > > drivers/staging/rtl8712/rtl871x_ioctl_linux.c: In function 'r8711_wx_get_scan': > drivers/staging/rtl8712/rtl871x_ioctl_linux.c:1227:1: error: the frame size of 1032 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] > > This somewhat reduces the stack usage by moving the translate_scan > function out of line with the noinline_for_stack annotation. > It might be possible to modify translate_scan() a little further > to reduce the stack usage, but with this patch, we can build without > the warning, the the call chain to get here is rather predictable > (sys_ioctl->vfs_ioctl->sock_ioctl->dev_ioctl->wext_ioctl-> > r8711_wx_get_scan). > > Signed-off-by: Arnd Bergmann <arnd@...db.de> > --- > drivers/staging/rtl8712/rtl871x_ioctl_linux.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) As there is no reason for translate_scan() to be inlined, this patch seems reasonable The largest user of stack likely comes from the line "struct iw_event iwe". Changing that to a pointer, and using kalloc to acquire the space would likely clear the compile message, but that would require many more changes. Acked-by: Larry Finger <Larry.Finger@...inger.net> Larry > > diff --git a/drivers/staging/rtl8712/rtl871x_ioctl_linux.c b/drivers/staging/rtl8712/rtl871x_ioctl_linux.c > index db2e31bcdd77..a15f3ce70223 100644 > --- a/drivers/staging/rtl8712/rtl871x_ioctl_linux.c > +++ b/drivers/staging/rtl8712/rtl871x_ioctl_linux.c > @@ -137,7 +137,7 @@ static inline void handle_group_key(struct ieee_param *param, > } > } > > -static inline char *translate_scan(struct _adapter *padapter, > +static noinline_for_stack char *translate_scan(struct _adapter *padapter, > struct iw_request_info *info, > struct wlan_network *pnetwork, > char *start, char *stop) >
Powered by blists - more mailing lists