On Wed, Apr 28, 2010 at 12:54 AM, white <kyungtak....@gmail.com> wrote: > I want to know more datail about this. > > As I know, android platform is using binder mechanism, and binder is > using mmap mechanism. > Iliyan Malchev fixed mmap size, 4KB -> 32KB. > > Does it affect to platform's performance and security? > > Just I read the comment, that's no related to performance and > security. > And linux kernel recommend 4KB minimal mmap size. > > If there are no issue, I think it's not necessary to change. >
Well it certainly helps. > > [ARM] msm: msm_defconfig: increase mmap_min_addr to 32k 06/14006/2 > author Iliyan Malchev <malc...@google.com> > Wed, 17 Mar 2010 20:58:55 +0000 (13:58 -0700) > committer Iliyan Malchev <malc...@google.com> > Thu, 18 Mar 2010 04:21:29 +0000 (21:21 -0700) > commit f797f5b9a88eb92e7834f0862857d047fc1031cd > tree f07c25347d422a2822d5ef042f2fbb1aa15c52dc tree | snapshot > parent 4a8b102321f02bd4959f4a233535b3c6effa85c4 commit | diff > [ARM] msm: msm_defconfig: increase mmap_min_addr to 32k > > A lot of kernel structures are larger than 4k, and so NULL-pointer > dereferences > could still be exploitable. > > index 46bc204..7a9fe0d 100755 (executable) > --- a/arch/arm/configs/msm_defconfig > +++ b/arch/arm/configs/msm_defconfig > @@ -292,7 +292,7 @@ CONFIG_ZONE_DMA_FLAG=0 > CONFIG_VIRT_TO_BUS=y > CONFIG_UNEVICTABLE_LRU=y > CONFIG_ALIGNMENT_TRAP=y > -CONFIG_DEFAULT_MMAP_MIN_ADDR=4096 > +CONFIG_DEFAULT_MMAP_MIN_ADDR=32768 > > # > # Boot options > > -- > unsubscribe: android-kernel+unsubscr...@googlegroups.com > website: http://groups.google.com/group/android-kernel > -- San Mehat | Staff Software Engineer | Android | Google Inc. 415.366.6172 (s...@google.com) -- unsubscribe: android-kernel+unsubscr...@googlegroups.com website: http://groups.google.com/group/android-kernel
