/usr/share/doc/kernel-patch-viewos/README is in kernel-patch-viewos 0.20141201-1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 | The patches here included add the PTRACE_VM/PTRACE_MULTI tagis to the
ptrace system call into the linux kernel of the hosting machine.
From version 2.6.34:
- patchset having -utrace-ptrace* suffix are for kernels including utrace.
(must be used instead of the patch having just -ptrace*)
In this way it is possible to run kmview and optimized umview on the same
kernel.
From version 2.6.25:
- support for x86(32/64) ppc(32/64) um.
VM extensions to PTRACE_SYSCALL/SINGLESTEP/SINGLEBLOCK/CONT instead
of the deprecated PTRACE_SYSVM tag
- separate patches for ptrace_vm and ptrace_multi
The two patches are independent: can be applied in any order.
UMVIEW does not need any patch in the kernel of the hosting computer to
work but with PTRACE_MULTI there is a dramatic increase in performance.
(Tech detail: standard ptrace needs one system call invocation for
each word of memory to be tranferred between the process memory
and the umview memory. System calls like read/write need one context
switch each 4 bytes - on 32bits machine. With PTRACE_MULTI one single
system call invocation suffices).
PT_VM is a more advanced patch.
It is a more efficient support of PTRACE for Virtual Machine.
with PT_VM it is possible to use the PTRACE_SYSVM call instead
of PTRACE_SYSCALL. PTRACE_SYSVM has a parameter that can be set to skip
the syscall execution and/or the after-syscall trace upcall.
PT_SYSVM has been deprecated in favour of extending the syntax of the
standard ptrace tags. This will lead eventually to a simple code both for the
kernel and for applications using this feature.
Credits: Cristian Greco for some patch updates.
As usual:
/* This is part of um-ViewOS
* The user-mode implementation of OSVIEW -- A Process with a View
*
* LINUX KERNEL PATCH for PTRACE_MULTI support.
*
* Copyright 2005 Renzo Davoli
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
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