kernel_optimize_test/drivers/lguest
Rusty Russell 8057d763ed Fix lguest page-pinning logic ("lguest: bad stack page 0xc057a000")
If the stack pointer is 0xc057a000, then the first stack page is at
0xc0579000 (the stack pointer is decremented before use).  Not
calculating this correctly caused guests with CONFIG_DEBUG_PAGEALLOC=y
to be killed with a "bad stack page" message: the initial kernel stack
was just proceeding the .smp_locks section which
CONFIG_DEBUG_PAGEALLOC marks read-only when freeing.

Thanks to Frederik Deweerdt for the bug report!

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-30 09:58:22 -07:00
..
core.c lguest: Fix Malicious Guest GDT Host Crash 2007-08-09 08:14:56 -07:00
hypercalls.c
interrupts_and_traps.c Fix lguest page-pinning logic ("lguest: bad stack page 0xc057a000") 2007-08-30 09:58:22 -07:00
io.c
Kconfig lguest should depend on CONFIG_FUTEX 2007-08-23 21:23:33 -07:00
lg.h
lguest_asm.S
lguest_bus.c lguest files should explicitly include asm/paravirt.h 2007-08-11 15:47:42 -07:00
lguest_user.c
lguest.c i386: Make patching more robust, fix paravirt issue 2007-08-11 15:58:13 -07:00
Makefile
page_tables.c
README
segments.c lguest: Fix Malicious Guest GDT Host Crash 2007-08-09 08:14:56 -07:00
switcher.S lguest: Fix Malicious Guest GDT Host Crash 2007-08-09 08:14:56 -07:00

Welcome, friend reader, to lguest.

Lguest is an adventure, with you, the reader, as Hero.  I can't think of many
5000-line projects which offer both such capability and glimpses of future
potential; it is an exciting time to be delving into the source!

But be warned; this is an arduous journey of several hours or more!  And as we
know, all true Heroes are driven by a Noble Goal.  Thus I offer a Beer (or
equivalent) to anyone I meet who has completed this documentation.

So get comfortable and keep your wits about you (both quick and humorous).
Along your way to the Noble Goal, you will also gain masterly insight into
lguest, and hypervisors and x86 virtualization in general.

Our Quest is in seven parts: (best read with C highlighting turned on)

I) Preparation
	- In which our potential hero is flown quickly over the landscape for a
	  taste of its scope.  Suitable for the armchair coders and other such
	  persons of faint constitution.

II) Guest
	- Where we encounter the first tantalising wisps of code, and come to
	  understand the details of the life of a Guest kernel.

III) Drivers
	- Whereby the Guest finds its voice and become useful, and our
	  understanding of the Guest is completed.

IV) Launcher
	- Where we trace back to the creation of the Guest, and thus begin our
	  understanding of the Host.

V) Host
	- Where we master the Host code, through a long and tortuous journey.
	  Indeed, it is here that our hero is tested in the Bit of Despair.

VI) Switcher
	- Where our understanding of the intertwined nature of Guests and Hosts
	  is completed.

VII) Mastery
	- Where our fully fledged hero grapples with the Great Question:
	  "What next?"

make Preparation!
Rusty Russell.