656dd953a8
code like "return g->dlen;" is wrong as we do not hold the qlock of the global segment. another process could come in and override g->dlen making us return the wrong byte count. avoid copying when we already got a kernel address (kernel memory is the same on processes) which is the case with bread()/bwrite(). this is the same optimization that devsd does. also avoid allocating/freeing and copying while holding the qlock. when we copy to/from user memory, we might fault preventing others from accessing the segment while fault handling is in progress. |
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| 68000 | ||
| 68020 | ||
| acme | ||
| adm/timezone | ||
| alpha | ||
| amd64 | ||
| arm | ||
| lib | ||
| mips | ||
| power | ||
| power64 | ||
| rc | ||
| sparc | ||
| sparc64 | ||
| sys | ||
| .hgignore | ||