OpenBSD: Improved Memory Allocation, Beta Testing 3.8, from KernelTrap.

OpenBSD creator Theo de Raadt described a number of modifications to how OpenBSD allocates memory:

• mmap system call return a random memory address, as well ensuring “that two objects are not mapped next to each other; in effect, this creates unallocated memory which we call a ‘guard page’”
• malloc function was updated to use mmap to obtain memory
• free function was updated to immediately return memory to the kernel and un-allocate it from the calling process

Theo points out that these changes have a couple of significant impacts. He explains that for over a decade efforts have been made to find and fix buffer overflows, and more recently bugs have been found in which software is reading before the start of a buffer, or beyond the end of the buffer. With these recent memory allocation changes, such an attempt will cause the application to coredump with a SIGSEGV signal.

Additionally, now that memory is unmapped as soon as it is freed, any attempt to access freed memory will also cause the application to coredump with a SIGSEGV signal.

Popularity: 15% [?]

SSE Performance Programming, from developer.apple.com.

Here is a tutorial about programming SSE in C language, learning how to do SIMD vector programming for MacOS X for Intel CPU.

Popularity: 20% [?]

Mozilla Firefox/Thunderbird Trunk builds (20050901)

• [FX] P1 build for All CPUs support MMX
• [TB] P1 build for All CPUs support MMX

Sepecial Check-in

• Because plugins hosted at update.mozilla.org only support up to 1.0+, not 1.6a1 (limitation in update.mozilla.org ?), I add app.extensions.version as 1.0+ in profile to accept plugins installation

1. checkout finish: Thu Sep 1 00:07:40 DST -0700 UTC 2005
2. All Chech-in, FX Chech-in, TB Chech-in from last build
3. my vs7.1-trunk patch
4. my tweaks profile patch
5. Used branding artwork by JairoB
6. UAO of zh_TW.Big5 Unicode Fix
7. enabled extensions of cookie, xml-rpc, xmlextras, p3p, pref, universalchardet, inspector, transformiix, webservices, xforms, schema-validation, gnomevfs
8. P0/P1/P2/P3 all build with VC7.1
9. P0 build build with /GAL6
10. P1 build build with /GAL6 and mmoy’s MMX patches
11. P2 build build with /GAL6 arch:SSE and mmoy’s SSE patches
12. P3 build build with /GAL7 arch:SSE2 and mmoy’s SSE2 patches

Popularity: 7% [?]