Date: Sun, 07 Jan 2018 19:52:59 +0100 From: "Kristof Provost" <kp@FreeBSD.org> To: rgrimes@FreeBSD.org Cc: src-committers@FreeBSD.org, svn-src-all@FreeBSD.org, svn-src-head@FreeBSD.org Subject: Re: svn commit: r327676 - head/sys/compat/linuxkpi/common/include/linux Message-ID: <A30C36F0-BAB5-47B8-AB59-666E3A287FB6@FreeBSD.org> In-Reply-To: <201801071837.w07Ibfxb017914@pdx.rh.CN85.dnsmgr.net> References: <201801071837.w07Ibfxb017914@pdx.rh.CN85.dnsmgr.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On 7 Jan 2018, at 19:37, Rodney W. Grimes wrote: >> On 7 Jan 2018, at 19:02, Rodney W. Grimes wrote: >>>> Author: kp >>>> Date: Sun Jan 7 13:39:12 2018 >>>> New Revision: 327676 >>>> URL: https://svnweb.freebsd.org/changeset/base/327676 >>>> >>>> Log: >>>> linuxkpi: Implement kcalloc() based on mallocarray() >>>> >>>> This means we now get integer overflow protection, which Linux = >>>> code >>>> might expect as it is also provided by kcalloc() in Linux. >>>> >>>> Modified: >>>> head/sys/compat/linuxkpi/common/include/linux/slab.h >>>> >>>> Modified: head/sys/compat/linuxkpi/common/include/linux/slab.h >>>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D >>>> --- head/sys/compat/linuxkpi/common/include/linux/slab.h Sun Jan 7 >>>> 13:35:15 2018 (r327675) >>>> +++ head/sys/compat/linuxkpi/common/include/linux/slab.h Sun Jan 7 >>>> 13:39:12 2018 (r327676) >>>> @@ -46,7 +46,6 @@ MALLOC_DECLARE(M_KMALLOC); >>>> #define kzalloc(size, flags) kmalloc(size, (flags) | __GFP_ZERO) >>>> #define kzalloc_node(size, flags, node) kmalloc(size, (flags) | >>>> __GFP_ZERO) >>>> #define kfree_const(ptr) kfree(ptr) >>>> -#define kcalloc(n, size, flags) kmalloc((n) * (size), >>>> (flags) | __GFP_ZERO) >>> >>> Would not: >>> #define kcalloc(n, size, flags) mallocarray(mallocarray((n), >>> (size), M_KMALLOC, linux_check_m_flags((flags | __GFP_ZERO)) >>> work just fine, saving a call and stack use of about framesize + 32 >>> bytes? >>> >>> >> It would also work, but it?d have to be split up into multiple lines >> then. > > But it would retain the direct macro form, your change changes it > from a #define which is evaluated at pre proc time to a function > call that is evaluated at compile time. The resulting code from > a -O0 well be different because of this. > Indeed. It=E2=80=99s not something I=E2=80=99d worry about as anyone who = cares about = it being fast (as opposed to easier to debug for example) would build it = as -O2/-O3. >> I thought it?d be more readable as a function. > > If that is the only reason I would rather see it retain the > same form as all the other allocs. > How does this look? diff --git a/sys/compat/linuxkpi/common/include/linux/slab.h = b/sys/compat/linuxkpi/common/include/linux/slab.h index 1f8ec82db98..5551211c281 100644 --- a/sys/compat/linuxkpi/common/include/linux/slab.h +++ b/sys/compat/linuxkpi/common/include/linux/slab.h @@ -46,6 +46,9 @@ MALLOC_DECLARE(M_KMALLOC); #define kzalloc(size, flags) kmalloc(size, (flags) | __GFP_ZERO) #define kzalloc_node(size, flags, node) kmalloc(size, (flags) | = __GFP_ZERO) #define kfree_const(ptr) kfree(ptr) +#define kcalloc(n, size, flags) mallocarray((n), (size), \ + M_KMALLOC, \ + linux_check_m_flags((flags | __GFP_ZERO))) #define vzalloc(size) __vmalloc(size, GFP_KERNEL | __GFP_NOWARN | = __GFP_ZERO, 0) #define vfree(arg) kfree(arg) #define kvfree(arg) kfree(arg) @@ -99,13 +102,6 @@ kmalloc(size_t size, gfp_t flags) return (malloc(size, M_KMALLOC, linux_check_m_flags(flags))); } = -static inline void * -kcalloc(size_t n, size_t size, gfp_t flags) -{ - flags |=3D __GFP_ZERO; - return (mallocarray(n, size, M_KMALLOC, linux_check_m_flags(flags))); -} - static inline void * __vmalloc(size_t size, gfp_t flags, int other) { Regards, Kristof
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?A30C36F0-BAB5-47B8-AB59-666E3A287FB6>