Page MenuHomeFreeBSD

[PPC64] Fix trapstk overflow
ClosedPublic

Authored by luporl on Oct 30 2019, 9:27 PM.
Tags
None
Referenced Files
Unknown Object (File)
Thu, Apr 16, 1:13 AM
Unknown Object (File)
Wed, Apr 15, 7:27 AM
Unknown Object (File)
Sat, Apr 11, 5:47 AM
Unknown Object (File)
Wed, Apr 8, 11:26 PM
Unknown Object (File)
Tue, Apr 7, 3:08 AM
Unknown Object (File)
Tue, Apr 7, 1:08 AM
Unknown Object (File)
Sat, Apr 4, 9:54 PM
Unknown Object (File)
Sun, Mar 22, 8:06 PM
Subscribers

Details

Summary

In some scenarios, the 4K trapstk may overflow, corrupting tmpstk.

This was observed during remote debugging, with the following steps:

At remote host (R):

  • enter kdb during boot
  • switch to gdb backend

At local host (L):

  • attach gdb to R
  • try to read an invalid memory position

At R:

  • a DSI trap occurs and kdb restarts (all this occurs on trapstk)
  • while printing the stacktrace, trapstk overflows and corrupts tmpstk

Diff Detail

Repository
rS FreeBSD src repository - subversion
Lint
Lint Not Applicable
Unit
Tests Not Applicable