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Bug #15483

open

remove circular from ndi_devi_enter et al

Added by Dan Cross 14 days ago. Updated 7 days ago.

Status:
In Progress
Priority:
Normal
Assignee:
Dan Cross
Category:
kernel
Start date:
Due date:
% Done:

0%

Estimated time:
Difficulty:
Medium
Tags:
Gerrit CR:
2716
External Bug:

Description

#15463 paves the way for removing the `circular` argument completely from ndi_devi_enter, ndi_devi_tryenter, ndi_devi_exit, etc. Removing those has cascading effects across the source base and the delta is fairly large.

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 #1

Updated by Electric Monk 14 days ago

  • Gerrit CR set to 2716
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 #2

Updated by Dan Cross 14 days ago

  • Category set to kernel
  • Status changed from New to In Progress
  • Assignee set to Dan Cross
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 #3

Updated by Dan Cross 7 days ago

A side note: these are private interfaces with no stability guarantees, so removing these parameters is fine.

At Robert's request, I checked the symbol table on the closed binaries to see if they are using any of the effected functions. Exactly one driver (kernel/drv/amd64/mpt) uses the ndi_devi_enter and ndi_devi_exit (and I don't expect to see that symbol anywhere outside of the kernel, since it's a kernel-only function).

However, this should be ok: the way the SYSV ABI works for AMD64, the extra parameter will be stuffed in a caller-save register both both calls, but simply ignored in the callee; assuming that the mpt driver doesn't try to inspect the value of circular after the call (which in all honesty it really shouldn't; I consider the instance we saw of this in the MDI code a bug), these should amount to a nop.

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