Messages in this thread |  | | Date | Sun, 20 Aug 2000 12:42:42 -0700 | From | Ralf Baechle <> | Subject | Re: portable way for issuing a far jmp? |
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On Sat, Aug 19, 2000 at 03:46:52AM +0200, Julien Oster wrote:
> Is there any macro or something as a clean way to jump to a function, instead > of calling it? I don't want to use assembler as my modules are fairly > portable by now. > > Sometime I want to _jump_ to a function instead of calling it. e.g., when > wrapping around sys_delete_module, I like to jump to the old handler of > sys_delete_module. The reason is, that when the module wrapping it gets > deleten, the return from the old sys_delete_module gets into the area of the > no longer available module (since the old sys_delete_module deletes it)... > > I could accomplish this with a little bit of assembler, tweaking with the > stack and issueing a "JMP FAR" (on ix86), but that isn't portable in any > way...
There are patches for gcc which implement tail optimization. Afaik very recent gcc's have them implemented but most distributions ship without such a compiler so you'd better not use that possibility. The safer alternative is to arrange for a userprocess to do the module unload.
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