# \[PATCH\]\[next\] fbdev/fb.h: Use struct\_size() helper in kzalloc() - Subsystems: FRAMEBUFFER LAYER, THE REST - Maintainers: Helge Deller, Linus Torvalds - Status: LANDED (17d8dcf5330a ยท 2020-07-10 14:17) - Landed in mainline as 17d8dcf5330a on 2020-07-10. - List: linux-fbdev - 4 messages, 3 authors - Page: https://ratatoskr.run/linux-fbdev/2020/06/6002652/t ## \[PATCH\]\[next\] fbdev/fb.h: Use struct\_size() helper in kzalloc() - From: Gustavo A. R. Silva \ - Date: 2020-06-17 17:51:31 - Message: https://ratatoskr.run/linux-fbdev/2020/06/6002652.md ```text Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. This code was detected with the help of Coccinelle and, audited and fixed manually. Signed-off-by: Gustavo A. R. Silva --- include/linux/fb.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/include/linux/fb.h b/include/linux/fb.h index 3b4b2f0c6994..2b530e6d86e4 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -506,8 +506,9 @@ struct fb_info { }; static inline struct apertures_struct *alloc_apertures(unsigned int max_num) { - struct apertures_struct *a = kzalloc(sizeof(struct apertures_struct) - + max_num * sizeof(struct aperture), GFP_KERNEL); + struct apertures_struct *a; + + a = kzalloc(struct_size(a, ranges, max_num), GFP_KERNEL); if (!a) return NULL; a->count = max_num; -- 2.27.0 ``` ## Re: \[PATCH\]\[next\] fbdev/fb.h: Use struct\_size() helper in kzalloc() - From: Sam Ravnborg \ - Date: 2020-06-20 11:27:27 - Message: https://ratatoskr.run/linux-fbdev/2020/06/6007988.md ```text Hi Gustavo. On Wed, Jun 17, 2020 at 12:56:47PM -0500, Gustavo A. R. Silva wrote: > Make use of the struct_size() helper instead of an open-coded version > in order to avoid any potential type mistakes. > > This code was detected with the help of Coccinelle and, audited and > fixed manually. > > Signed-off-by: Gustavo A. R. Silva struct_size is defined in overflow.h - which is not included by fs.h. So we rely on overflow.h being pulled in by some other header - maybe slab.h in this case. Seems fragile, should this patch add an include of overflow.h? Sam > --- > include/linux/fb.h | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/include/linux/fb.h b/include/linux/fb.h > index 3b4b2f0c6994..2b530e6d86e4 100644 > --- a/include/linux/fb.h > +++ b/include/linux/fb.h > @@ -506,8 +506,9 @@ struct fb_info { > }; > > static inline struct apertures_struct *alloc_apertures(unsigned int max_num) { > - struct apertures_struct *a = kzalloc(sizeof(struct apertures_struct) > - + max_num * sizeof(struct aperture), GFP_KERNEL); > + struct apertures_struct *a; > + > + a = kzalloc(struct_size(a, ranges, max_num), GFP_KERNEL); > if (!a) > return NULL; > a->count = max_num; > -- > 2.27.0 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel ``` ## Re: \[PATCH\]\[next\] fbdev/fb.h: Use struct\_size() helper in kzalloc() - From: Bartlomiej Zolnierkiewicz \ - Date: 2020-07-10 14:23:43 - Message: https://ratatoskr.run/linux-fbdev/2020/07/6032035.md ```text On 6/17/20 7:56 PM, Gustavo A. R. Silva wrote: > Make use of the struct_size() helper instead of an open-coded version > in order to avoid any potential type mistakes. > > This code was detected with the help of Coccinelle and, audited and > fixed manually. > > Signed-off-by: Gustavo A. R. Silva Applied to drm-misc-next tree, thanks. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics > --- > include/linux/fb.h | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/include/linux/fb.h b/include/linux/fb.h > index 3b4b2f0c6994..2b530e6d86e4 100644 > --- a/include/linux/fb.h > +++ b/include/linux/fb.h > @@ -506,8 +506,9 @@ struct fb_info { > }; > > static inline struct apertures_struct *alloc_apertures(unsigned int max_num) { > - struct apertures_struct *a = kzalloc(sizeof(struct apertures_struct) > - + max_num * sizeof(struct aperture), GFP_KERNEL); > + struct apertures_struct *a; > + > + a = kzalloc(struct_size(a, ranges, max_num), GFP_KERNEL); > if (!a) > return NULL; > a->count = max_num; > ``` ## Re: \[PATCH\]\[next\] fbdev/fb.h: Use struct\_size() helper in kzalloc() - From: Bartlomiej Zolnierkiewicz \ - Date: 2020-07-10 14:23:51 - Message: https://ratatoskr.run/linux-fbdev/2020/07/6032037.md ```text On 6/20/20 1:27 PM, Sam Ravnborg wrote: > Hi Gustavo. > > On Wed, Jun 17, 2020 at 12:56:47PM -0500, Gustavo A. R. Silva wrote: >> Make use of the struct_size() helper instead of an open-coded version >> in order to avoid any potential type mistakes. >> >> This code was detected with the help of Coccinelle and, audited and >> fixed manually. >> >> Signed-off-by: Gustavo A. R. Silva > > struct_size is defined in overflow.h - which is not included by fs.h. > So we rely on overflow.h being pulled in by some other header - maybe > slab.h in this case. > Seems fragile, should this patch add an include of overflow.h? $ git grep struct_size drivers/|wc -l 697 $ git grep overflow\\.h drivers/|wc -l 8 $ git grep overflow\\.h include/linux/ include/linux/device.h:#include include/linux/mm.h:#include include/linux/slab.h:#include include/linux/vmalloc.h:#include so I've applied the patch as it is (hoping that the issue is so widespread that no-one tries to remove overflow.h from slab.h without fixing drivers at the same time).. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics > Sam > >> --- >> include/linux/fb.h | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/include/linux/fb.h b/include/linux/fb.h >> index 3b4b2f0c6994..2b530e6d86e4 100644 >> --- a/include/linux/fb.h >> +++ b/include/linux/fb.h >> @@ -506,8 +506,9 @@ struct fb_info { >> }; >> >> static inline struct apertures_struct *alloc_apertures(unsigned int max_num) { >> - struct apertures_struct *a = kzalloc(sizeof(struct apertures_struct) >> - + max_num * sizeof(struct aperture), GFP_KERNEL); >> + struct apertures_struct *a; >> + >> + a = kzalloc(struct_size(a, ranges, max_num), GFP_KERNEL); >> if (!a) >> return NULL; >> a->count = max_num; >> -- >> 2.27.0 >> >> _______________________________________________ >> dri-devel mailing list >> dri-devel@lists.freedesktop.org >> https://protect2.fireeye.com/url?k{ae4d09-26604cda-7bafc646-000babff317b-7eab3a2caa4b8b73&q=1&u=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel ```