Messages in this thread | | | Date | Sat, 26 Dec 2009 23:55:19 +0530 | From | "K.Prasad" <> | Subject | [RFC Patch 0/2][Bugfix][x86][hw-breakpoint] Bugfixes for hw_breakpoint_handler |
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Hi All, Please find a patchset of two patches that
Patch 1/2: Clears the arch-reserved bits from debug status register. This helps easy bitwise operations - such as the check for non-trap bits in hw_breakpoint_handler. A check for the same using "if (dr6 & (~DR_TRAP_BITS))" throws incorrect results due to the presence of preset reserved bits.
This patch is copied to maintainers of code (such as kmemcheck, kprobe, ptrace, etc) who make use of local dr6 value in do_debug() that verify and handle exceptions.
Patch 2/2: Return NOTIFY_DONE from hw_breakpoint_handler() for user-space breakpoints only (and not for kernel-space) since this could lead to further processing in do_debug() with undesirable consequences.
Let me know if there are any concerns about the patch.
Thanks, K.Prasad
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