linux-toradex.git/arch/x86/include/asm/traps.h, branch v3.10.52 Linux kernel for Apalis and Colibri modules x86: Use enum instead of literals for trap values 2012-03-10T00:47:54+00:00 Kees Cook keescook@chromium.org 2012-03-10T00:07:10+00:00 c94082656dac74257f63e91f78d5d458ac781fa5 The traps are referred to by their numbers and it can be difficult to understand them while reading the code without context. This patch adds enumeration of the trap numbers and replaces the numbers with the correct enum for x86. Signed-off-by: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20120310000710.GA32667@www.outflux.net Signed-off-by: H. Peter Anvin <hpa@zytor.com> 
The traps are referred to by their numbers and it can be difficult to
understand them while reading the code without context. This patch adds
enumeration of the trap numbers and replaces the numbers with the correct
enum for x86.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20120310000710.GA32667@www.outflux.net
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
x86-64: Rework vsyscall emulation and add vsyscall= parameter 2011-08-11T00:26:46+00:00 Andy Lutomirski luto@mit.edu 2011-08-10T15:15:32+00:00 3ae36655b97a03fa1decf72f04078ef945647c1a There are three choices: vsyscall=native: Vsyscalls are native code that issues the corresponding syscalls. vsyscall=emulate (default): Vsyscalls are emulated by instruction fault traps, tested in the bad_area path. The actual contents of the vsyscall page is the same as the vsyscall=native case except that it's marked NX. This way programs that make assumptions about what the code in the page does will not be confused when they read that code. vsyscall=none: Trying to execute a vsyscall will segfault. Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/8449fb3abf89851fd6b2260972666a6f82542284.1312988155.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> 
There are three choices:

vsyscall=native: Vsyscalls are native code that issues the
corresponding syscalls.

vsyscall=emulate (default): Vsyscalls are emulated by instruction
fault traps, tested in the bad_area path.  The actual contents of
the vsyscall page is the same as the vsyscall=native case except
that it's marked NX.  This way programs that make assumptions about
what the code in the page does will not be confused when they read
that code.

vsyscall=none: Trying to execute a vsyscall will segfault.

Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/8449fb3abf89851fd6b2260972666a6f82542284.1312988155.git.luto@mit.edu
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86-64: Emulate legacy vsyscalls 2011-06-07T08:02:35+00:00 Andy Lutomirski luto@MIT.EDU 2011-06-05T17:50:24+00:00 5cec93c216db77c45f7ce970d46283bcb1933884 There's a fair amount of code in the vsyscall page. It contains a syscall instruction (in the gettimeofday fallback) and who knows what will happen if an exploit jumps into the middle of some other code. Reduce the risk by replacing the vsyscalls with short magic incantations that cause the kernel to emulate the real vsyscalls. These incantations are useless if entered in the middle. This causes vsyscalls to be a little more expensive than real syscalls. Fortunately sensible programs don't use them. The only exception is time() which is still called by glibc through the vsyscall - but calling time() millions of times per second is not sensible. glibc has this fixed in the development tree. This patch is not perfect: the vread_tsc and vread_hpet functions are still at a fixed address. Fixing that might involve making alternative patching work in the vDSO. Signed-off-by: Andy Lutomirski <luto@mit.edu> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jesper Juhl <jj@chaosbits.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Jan Beulich <JBeulich@novell.com> Cc: richard -rw- weinberger <richard.weinberger@gmail.com> Cc: Mikael Pettersson <mikpe@it.uu.se> Cc: Andi Kleen <andi@firstfloor.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Louis Rilling <Louis.Rilling@kerlabs.com> Cc: Valdis.Kletnieks@vt.edu Cc: pageexec@freemail.hu Link: http://lkml.kernel.org/r/e64e1b3c64858820d12c48fa739efbd1485e79d5.1307292171.git.luto@mit.edu [ Removed the CONFIG option - it's simpler to just do it unconditionally. Tidied up the code as well. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> 
There's a fair amount of code in the vsyscall page.  It contains
a syscall instruction (in the gettimeofday fallback) and who
knows what will happen if an exploit jumps into the middle of
some other code.

Reduce the risk by replacing the vsyscalls with short magic
incantations that cause the kernel to emulate the real
vsyscalls. These incantations are useless if entered in the
middle.

This causes vsyscalls to be a little more expensive than real
syscalls.  Fortunately sensible programs don't use them.
The only exception is time() which is still called by glibc
through the vsyscall - but calling time() millions of times
per second is not sensible. glibc has this fixed in the
development tree.

This patch is not perfect: the vread_tsc and vread_hpet
functions are still at a fixed address.  Fixing that might
involve making alternative patching work in the vDSO.

Signed-off-by: Andy Lutomirski <luto@mit.edu>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/e64e1b3c64858820d12c48fa739efbd1485e79d5.1307292171.git.luto@mit.edu
[ Removed the CONFIG option - it's simpler to just do it unconditionally. Tidied up the code as well. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
KVM: Handle async PF in a guest. 2011-01-12T09:23:16+00:00 Gleb Natapov gleb@redhat.com 2010-10-14T09:22:52+00:00 631bc4878220932fe67fc46fc7cf7cccdb1ec597 When async PF capability is detected hook up special page fault handler that will handle async page fault events and bypass other page faults to regular page fault handler. Also add async PF handling to nested SVM emulation. Async PF always generates exit to L1 where vcpu thread will be scheduled out until page is available. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> 
When async PF capability is detected hook up special page fault handler
that will handle async page fault events and bypass other page faults to
regular page fault handler. Also add async PF handling to nested SVM
emulation. Async PF always generates exit to L1 where vcpu thread will
be scheduled out until page is available.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
x86: Merge simd_math_error() into math_error() 2010-05-03T20:39:29+00:00 Brian Gerst brgerst@gmail.com 2010-03-21T13:00:44+00:00 9b6dba9e0798325dab427b9d60c61630ccc39b28 The only difference between FPU and SIMD exceptions is where the status bits are read from (cwd/swd vs. mxcsr). This also fixes the discrepency introduced by commit adf77bac, which fixed FPU but not SIMD. Signed-off-by: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1269176446-2489-3-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> 
The only difference between FPU and SIMD exceptions is where the
status bits are read from (cwd/swd vs. mxcsr).  This also fixes
the discrepency introduced by commit adf77bac, which fixed FPU
but not SIMD.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1269176446-2489-3-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
x86: Remove unused patch_espfix_desc() 2009-07-19T16:27:52+00:00 Akinobu Mita akinobu.mita@gmail.com 2009-07-18T15:09:56+00:00 fde0312d01b60a3fd5dc56e69a9613defbbc7097 patch_espfix_desc() is not used after commit dc4c2a0aed3b09f6e255bd5c3faa50fe6e0b2ded Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> LKML-Reference: <20090718150955.GB11294@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
patch_espfix_desc() is not used after commit
dc4c2a0aed3b09f6e255bd5c3faa50fe6e0b2ded

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090718150955.GB11294@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge branch 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-10T23:16:27+00:00 Linus Torvalds torvalds@linux-foundation.org 2009-06-10T23:16:27+00:00 be15f9d63b97da0065187696962331de6cd9de9e * 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits) xen: cache cr0 value to avoid trap'n'emulate for read_cr0 xen/x86-64: clean up warnings about IST-using traps xen/x86-64: fix breakpoints and hardware watchpoints xen: reserve Xen start_info rather than e820 reserving xen: add FIX_TEXT_POKE to fixmap lguest: update lazy mmu changes to match lguest's use of kvm hypercalls xen: honour VCPU availability on boot xen: add "capabilities" file xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet xen/sys/hypervisor: change writable_pt to features xen: add /sys/hypervisor support xen/xenbus: export xenbus_dev_changed xen: use device model for suspending xenbus devices xen: remove suspend_cancel hook xen/dev-evtchn: clean up locking in evtchn xen: export ioctl headers to userspace xen: add /dev/xen/evtchn driver xen: add irq_from_evtchn xen: clean up gate trap/interrupt constants xen: set _PAGE_NX in __supported_pte_mask before pagetable construction ... 
* 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits)
  xen: cache cr0 value to avoid trap'n'emulate for read_cr0
  xen/x86-64: clean up warnings about IST-using traps
  xen/x86-64: fix breakpoints and hardware watchpoints
  xen: reserve Xen start_info rather than e820 reserving
  xen: add FIX_TEXT_POKE to fixmap
  lguest: update lazy mmu changes to match lguest's use of kvm hypercalls
  xen: honour VCPU availability on boot
  xen: add "capabilities" file
  xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet
  xen/sys/hypervisor: change writable_pt to features
  xen: add /sys/hypervisor support
  xen/xenbus: export xenbus_dev_changed
  xen: use device model for suspending xenbus devices
  xen: remove suspend_cancel hook
  xen/dev-evtchn: clean up locking in evtchn
  xen: export ioctl headers to userspace
  xen: add /dev/xen/evtchn driver
  xen: add irq_from_evtchn
  xen: clean up gate trap/interrupt constants
  xen: set _PAGE_NX in __supported_pte_mask before pagetable construction
  ...
Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-10T23:13:20+00:00 Linus Torvalds torvalds@linux-foundation.org 2009-06-10T23:13:20+00:00 bb7762961d3ce745688e9050e914c1d3f980268d * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits) x86: fix system without memory on node0 x86, mm: Fix node_possible_map logic mm, x86: remove MEMORY_HOTPLUG_RESERVE related code x86: make sparse mem work in non-NUMA mode x86: process.c, remove useless headers x86: merge process.c a bit x86: use sparse_memory_present_with_active_regions() on UMA x86: unify 64-bit UMA and NUMA paging_init() x86: Allow 1MB of slack between the e820 map and SRAT, not 4GB x86: Sanity check the e820 against the SRAT table using e820 map only x86: clean up and and print out initial max_pfn_mapped x86/pci: remove rounding quirk from e820_setup_gap() x86, e820, pci: reserve extra free space near end of RAM x86: fix typo in address space documentation x86: 46 bit physical address support on 64 bits x86, mm: fault.c, use printk_once() in is_errata93() x86: move per-cpu mmu_gathers to mm/init.c x86: move max_pfn_mapped and max_low_pfn_mapped to setup.c x86: unify noexec handling x86: remove (null) in /sys kernel_page_tables ... 
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits)
  x86: fix system without memory on node0
  x86, mm: Fix node_possible_map logic
  mm, x86: remove MEMORY_HOTPLUG_RESERVE related code
  x86: make sparse mem work in non-NUMA mode
  x86: process.c, remove useless headers
  x86: merge process.c a bit
  x86: use sparse_memory_present_with_active_regions() on UMA
  x86: unify 64-bit UMA and NUMA paging_init()
  x86: Allow 1MB of slack between the e820 map and SRAT, not 4GB
  x86: Sanity check the e820 against the SRAT table using e820 map only
  x86: clean up and and print out initial max_pfn_mapped
  x86/pci: remove rounding quirk from e820_setup_gap()
  x86, e820, pci: reserve extra free space near end of RAM
  x86: fix typo in address space documentation
  x86: 46 bit physical address support on 64 bits
  x86, mm: fault.c, use printk_once() in is_errata93()
  x86: move per-cpu mmu_gathers to mm/init.c
  x86: move max_pfn_mapped and max_low_pfn_mapped to setup.c
  x86: unify noexec handling
  x86: remove (null) in /sys kernel_page_tables
  ...
xen/x86-64: fix breakpoints and hardware watchpoints 2009-05-08T22:51:03+00:00 Jeremy Fitzhardinge jeremy.fitzhardinge@citrix.com 2009-03-30T02:56:29+00:00 6cac5a924668a56c7ccefc345805f1fe0536a90e Native x86-64 uses the IST mechanism to run int3 and debug traps on an alternative stack. Xen does not do this, and so the frames were being misinterpreted by the ptrace code. This change special-cases these two exceptions by using Xen variants which run on the normal kernel stack properly. Impact: avoid crash or bad data when IST trap is invoked under Xen Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> 
Native x86-64 uses the IST mechanism to run int3 and debug traps on
an alternative stack.  Xen does not do this, and so the frames were
being misinterpreted by the ptrace code.  This change special-cases
these two exceptions by using Xen variants which run on the normal
kernel stack properly.

Impact: avoid crash or bad data when IST trap is invoked under Xen
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
x86: avoid multiple declaration of kstack_depth_to_print 2009-04-14T09:45:33+00:00 Jaswinder Singh Rajput jaswinder@kernel.org 2009-04-14T07:48:28+00:00 e7d43a74cb07cbc4b8e9b5e4a914816b33fb0719 Impact: cleanup asm/stacktrace.h is more appropriate so removing other 2 declarations. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> LKML-Reference: <1239695308.3033.34.camel@ht.satnam> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Impact: cleanup

asm/stacktrace.h is more appropriate so removing other 2 declarations.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
LKML-Reference: <1239695308.3033.34.camel@ht.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>