linux-stable.git/arch/x86/kernel/Makefile, branch linux-3.4.y Linux kernel stable tree x86, espfix: Make espfix64 a Kconfig option, fix UML 2014-08-07T19:00:11+00:00 H. Peter Anvin hpa@zytor.com 2014-05-04T17:00:49+00:00 7b6354ea6bfbe20f68c248ee5a846b1d3f76863d commit 197725de65477bc8509b41388157c1a2283542bb upstream. Make espfix64 a hidden Kconfig option. This fixes the x86-64 UML build which had broken due to the non-existence of init_espfix_bsp() in UML: since UML uses its own Kconfig, this option does not appear in the UML build. This also makes it possible to make support for 16-bit segments a configuration option, for the people who want to minimize the size of the kernel. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Richard Weinberger <richard@nod.at> Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 197725de65477bc8509b41388157c1a2283542bb upstream.

Make espfix64 a hidden Kconfig option.  This fixes the x86-64 UML
build which had broken due to the non-existence of init_espfix_bsp()
in UML: since UML uses its own Kconfig, this option does not appear in
the UML build.

This also makes it possible to make support for 16-bit segments a
configuration option, for the people who want to minimize the size of
the kernel.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack 2014-08-07T19:00:10+00:00 H. Peter Anvin hpa@linux.intel.com 2014-04-29T23:46:09+00:00 3989298cbdafdaf0536f23677df9f29bfc44f8ad commit 3891a04aafd668686239349ea58f3314ea2af86b upstream. The IRET instruction, when returning to a 16-bit segment, only restores the bottom 16 bits of the user space stack pointer. This causes some 16-bit software to break, but it also leaks kernel state to user space. We have a software workaround for that ("espfix") for the 32-bit kernel, but it relies on a nonzero stack segment base which is not available in 64-bit mode. In checkin: b3b42ac2cbae x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels we "solved" this by forbidding 16-bit segments on 64-bit kernels, with the logic that 16-bit support is crippled on 64-bit kernels anyway (no V86 support), but it turns out that people are doing stuff like running old Win16 binaries under Wine and expect it to work. This works around this by creating percpu "ministacks", each of which is mapped 2^16 times 64K apart. When we detect that the return SS is on the LDT, we copy the IRET frame to the ministack and use the relevant alias to return to userspace. The ministacks are mapped readonly, so if IRET faults we promote #GP to #DF which is an IST vector and thus has its own stack; we then do the fixup in the #DF handler. (Making #GP an IST exception would make the msr_safe functions unsafe in NMI/MC context, and quite possibly have other effects.) Special thanks to: - Andy Lutomirski, for the suggestion of using very small stack slots and copy (as opposed to map) the IRET frame there, and for the suggestion to mark them readonly and let the fault promote to #DF. - Konrad Wilk for paravirt fixup and testing. - Borislav Petkov for testing help and useful comments. Reported-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Andrew Lutomriski <amluto@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Dirk Hohndel <dirk@hohndel.org> Cc: Arjan van de Ven <arjan.van.de.ven@intel.com> Cc: comex <comexk@gmail.com> Cc: Alexander van Heukelum <heukelum@fastmail.fm> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3891a04aafd668686239349ea58f3314ea2af86b upstream.

The IRET instruction, when returning to a 16-bit segment, only
restores the bottom 16 bits of the user space stack pointer.  This
causes some 16-bit software to break, but it also leaks kernel state
to user space.  We have a software workaround for that ("espfix") for
the 32-bit kernel, but it relies on a nonzero stack segment base which
is not available in 64-bit mode.

In checkin:

    b3b42ac2cbae x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels

we "solved" this by forbidding 16-bit segments on 64-bit kernels, with
the logic that 16-bit support is crippled on 64-bit kernels anyway (no
V86 support), but it turns out that people are doing stuff like
running old Win16 binaries under Wine and expect it to work.

This works around this by creating percpu "ministacks", each of which
is mapped 2^16 times 64K apart.  When we detect that the return SS is
on the LDT, we copy the IRET frame to the ministack and use the
relevant alias to return to userspace.  The ministacks are mapped
readonly, so if IRET faults we promote #GP to #DF which is an IST
vector and thus has its own stack; we then do the fixup in the #DF
handler.

(Making #GP an IST exception would make the msr_safe functions unsafe
in NMI/MC context, and quite possibly have other effects.)

Special thanks to:

- Andy Lutomirski, for the suggestion of using very small stack slots
  and copy (as opposed to map) the IRET frame there, and for the
  suggestion to mark them readonly and let the fault promote to #DF.
- Konrad Wilk for paravirt fixup and testing.
- Borislav Petkov for testing help and useful comments.

Reported-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andrew Lutomriski <amluto@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dirk Hohndel <dirk@hohndel.org>
Cc: Arjan van de Ven <arjan.van.de.ven@intel.com>
Cc: comex <comexk@gmail.com>
Cc: Alexander van Heukelum <heukelum@fastmail.fm>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/kprobes: Split out optprobe related code to kprobes-opt.c 2012-03-06T08:49:49+00:00 Masami Hiramatsu masami.hiramatsu.pt@hitachi.com 2012-03-05T13:32:22+00:00 3f33ab1c0c741bfab2138c14ba1918a7905a1e8b Split out optprobe related code to arch/x86/kernel/kprobes-opt.c for maintenanceability. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Suggested-by: Ingo Molnar <mingo@elte.hu> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: yrl.pp-manager.tt@hitachi.com Cc: systemtap@sourceware.org Cc: anderson@redhat.com Link: http://lkml.kernel.org/r/20120305133222.5982.54794.stgit@localhost.localdomain [ Tidied up the code a tiny bit ] Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Split out optprobe related code to arch/x86/kernel/kprobes-opt.c
for maintenanceability.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: systemtap@sourceware.org
Cc: anderson@redhat.com
Link: http://lkml.kernel.org/r/20120305133222.5982.54794.stgit@localhost.localdomain
[ Tidied up the code a tiny bit ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge branch 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-01-17T02:19:19+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-01-17T02:19:19+00:00 5674124f9f16f196533abb383193bd232c9afc2f * 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Move <asm/asm-offsets.h> from trace_syscalls.c to asm/syscall.h x86, um: Fix typo in 32-bit system call modifications um: Use $(srctree) not $(KBUILD_SRC) x86, um: Mark system call tables readonly x86, um: Use the same style generated syscall tables as native um: Generate headers before generating user-offsets.s um: Run host archheaders, allow use of host generated headers kbuild, headers.sh: Don't make archheaders explicitly x86, syscall: Allow syscall offset to be symbolic x86, syscall: Re-fix typo in comment x86: Simplify syscallhdr.sh x86: Generate system call tables and unistd_*.h from tables checksyscalls: Use arch/x86/syscalls/syscall_32.tbl as source x86: Machine-readable syscall tables and scripts to process them trace: Include <asm/asm-offsets.h> in trace_syscalls.c x86-64, ia32: Move compat_ni_syscall into C and its own file x86-64, syscall: Adjust comment spacing and remove typo kbuild: Add support for an "archheaders" target kbuild: Add support for installing generated asm headers 
* 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Move <asm/asm-offsets.h> from trace_syscalls.c to asm/syscall.h
  x86, um: Fix typo in 32-bit system call modifications
  um: Use $(srctree) not $(KBUILD_SRC)
  x86, um: Mark system call tables readonly
  x86, um: Use the same style generated syscall tables as native
  um: Generate headers before generating user-offsets.s
  um: Run host archheaders, allow use of host generated headers
  kbuild, headers.sh: Don't make archheaders explicitly
  x86, syscall: Allow syscall offset to be symbolic
  x86, syscall: Re-fix typo in comment
  x86: Simplify syscallhdr.sh
  x86: Generate system call tables and unistd_*.h from tables
  checksyscalls: Use arch/x86/syscalls/syscall_32.tbl as source
  x86: Machine-readable syscall tables and scripts to process them
  trace: Include <asm/asm-offsets.h> in trace_syscalls.c
  x86-64, ia32: Move compat_ni_syscall into C and its own file
  x86-64, syscall: Adjust comment spacing and remove typo
  kbuild: Add support for an "archheaders" target
  kbuild: Add support for installing generated asm headers
x86, NMI: Add NMI IPI selftest 2011-12-05T11:00:16+00:00 Don Zickus dzickus@redhat.com 2011-10-13T19:14:26+00:00 99e8b9ca90d688c3ac7d3a141b701c9694a93925 The previous patch modified the stop cpus path to use NMI instead of IRQ as the way to communicate to the other cpus to shutdown. There were some concerns that various machines may have problems with using an NMI IPI. This patch creates a selftest to check if NMI is working at boot. The idea is to help catch any issues before the machine panics and we learn the hard way. Loosely based on the locking-selftest.c file, this separate file runs a couple of simple tests and reports the results. The output looks like: ... Brought up 4 CPUs ---------------- | NMI testsuite: -------------------- remote IPI: ok | local IPI: ok | -------------------- Good, all 2 testcases passed! | --------------------------------- Total of 4 processors activated (21330.61 BogoMIPS). ... Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Richter <robert.richter@amd.com> Cc: seiji.aguchi@hds.com Cc: vgoyal@redhat.com Cc: mjg@redhat.com Cc: tony.luck@intel.com Cc: gong.chen@intel.com Cc: satoru.moriya@hds.com Cc: avi@redhat.com Cc: Andi Kleen <andi@firstfloor.org> Link: http://lkml.kernel.org/r/1318533267-18880-3-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu> 
The previous patch modified the stop cpus path to use NMI
instead of IRQ as the way to communicate to the other cpus to
shutdown.  There were some concerns that various machines may
have problems with using an NMI IPI.

This patch creates a selftest to check if NMI is working at
boot. The idea is to help catch any issues before the machine
panics and we learn the hard way.

Loosely based on the locking-selftest.c file, this separate file
runs a couple of simple tests and reports the results.  The
output looks like:

...
Brought up 4 CPUs
----------------
| NMI testsuite:
--------------------
  remote IPI:  ok  |
   local IPI:  ok  |
--------------------
Good, all   2 testcases passed! |
---------------------------------
Total of 4 processors activated (21330.61 BogoMIPS).
...

Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
Cc: seiji.aguchi@hds.com
Cc: vgoyal@redhat.com
Cc: mjg@redhat.com
Cc: tony.luck@intel.com
Cc: gong.chen@intel.com
Cc: satoru.moriya@hds.com
Cc: avi@redhat.com
Cc: Andi Kleen <andi@firstfloor.org>
Link: http://lkml.kernel.org/r/1318533267-18880-3-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: Generate system call tables and unistd_*.h from tables 2011-11-17T21:35:37+00:00 H. Peter Anvin hpa@linux.intel.com 2011-11-12T00:07:41+00:00 303395ac3bf3e2cb488435537d416bc840438fcb Generate system call tables and unistd_*.h automatically from the tables in arch/x86/syscalls. All other information, like NR_syscalls, is auto-generated, some of which is in asm-offsets_*.c. This allows us to keep all the system call information in one place, and allows for kernel space and user space to see different information; this is currently used for the ia32 system call numbers when building the 64-bit kernel, but will be used by the x32 ABI in the near future. This also removes some gratuitious differences between i386, x86-64 and ia32; in particular, now all system call tables are generated with the same mechanism. Cc: H. J. Lu <hjl.tools@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> 
Generate system call tables and unistd_*.h automatically from the
tables in arch/x86/syscalls.  All other information, like NR_syscalls,
is auto-generated, some of which is in asm-offsets_*.c.

This allows us to keep all the system call information in one place,
and allows for kernel space and user space to see different
information; this is currently used for the ia32 system call numbers
when building the 64-bit kernel, but will be used by the x32 ABI in
the near future.

This also removes some gratuitious differences between i386, x86-64
and ia32; in particular, now all system call tables are generated with
the same mechanism.

Cc: H. J. Lu <hjl.tools@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86, nmi: Split out nmi from traps.c 2011-10-10T04:56:47+00:00 Don Zickus dzickus@redhat.com 2011-09-30T19:06:19+00:00 1d48922c14b6363f6d5febb12464d804bb5cc53f The nmi stuff is changing a lot and adding more functionality. Split it out from the traps.c file so it doesn't continue to pollute that file. This makes it easier to find and expand all the future nmi related work. No real functional changes here. Signed-off-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1317409584-23662-2-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu> 
The nmi stuff is changing a lot and adding more functionality.  Split it
out from the traps.c file so it doesn't continue to pollute that file.

This makes it easier to find and expand all the future nmi related work.

No real functional changes here.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1317409584-23662-2-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-tip 2011-08-13T03:46:24+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-08-13T03:46:24+00:00 06e727d2a5d9d889fabad35223ad77205a9bebb9 * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-tip: x86-64: Rework vsyscall emulation and add vsyscall= parameter x86-64: Wire up getcpu syscall x86: Remove unnecessary compile flag tweaks for vsyscall code x86-64: Add vsyscall:emulate_vsyscall trace event x86-64: Add user_64bit_mode paravirt op x86-64, xen: Enable the vvar mapping x86-64: Work around gold bug 13023 x86-64: Move the "user" vsyscall segment out of the data segment. x86-64: Pad vDSO to a page boundary 
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-tip:
  x86-64: Rework vsyscall emulation and add vsyscall= parameter
  x86-64: Wire up getcpu syscall
  x86: Remove unnecessary compile flag tweaks for vsyscall code
  x86-64: Add vsyscall:emulate_vsyscall trace event
  x86-64: Add user_64bit_mode paravirt op
  x86-64, xen: Enable the vvar mapping
  x86-64: Work around gold bug 13023
  x86-64: Move the "user" vsyscall segment out of the data segment.
  x86-64: Pad vDSO to a page boundary
x86: Remove unnecessary compile flag tweaks for vsyscall code 2011-08-10T23:55:29+00:00 Andy Lutomirski luto@mit.edu 2011-08-10T15:15:30+00:00 f3fb5b7bb70d6e679c15fef85707810a067f5fb6 As of commit 98d0ac38ca7b1b7a552c9a2359174ff84decb600 Author: Andy Lutomirski <luto@mit.edu> Date: Thu Jul 14 06:47:22 2011 -0400 x86-64: Move vread_tsc and vread_hpet into the vDSO user code no longer directly calls into code in arch/x86/kernel/, so we don't need compile flag hacks to make it safe. All vdso code is in the vdso directory now. Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/835cd05a4c7740544d09723d6ba48f4406f9826c.1312988155.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> 
As of commit 98d0ac38ca7b1b7a552c9a2359174ff84decb600
Author: Andy Lutomirski <luto@mit.edu>
Date:   Thu Jul 14 06:47:22 2011 -0400

    x86-64: Move vread_tsc and vread_hpet into the vDSO

user code no longer directly calls into code in arch/x86/kernel/, so
we don't need compile flag hacks to make it safe.  All vdso code is
in the vdso directory now.

Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/835cd05a4c7740544d09723d6ba48f4406f9826c.1312988155.git.luto@mit.edu
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-07-23T00:05:15+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-07-23T00:05:15+00:00 8e204874db000928e37199c2db82b7eb8966cc3c * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86-64, vdso: Do not allocate memory for the vDSO clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option x86, vdso: Drop now wrong comment Document the vDSO and add a reference parser ia64: Replace clocksource.fsys_mmio with generic arch data x86-64: Move vread_tsc and vread_hpet into the vDSO clocksource: Replace vread with generic arch data x86-64: Add --no-undefined to vDSO build x86-64: Allow alternative patching in the vDSO x86: Make alternative instruction pointers relative x86-64: Improve vsyscall emulation CS and RIP handling x86-64: Emulate legacy vsyscalls x86-64: Fill unused parts of the vsyscall page with 0xcc x86-64: Remove vsyscall number 3 (venosys) x86-64: Map the HPET NX x86-64: Remove kernel.vsyscall64 sysctl x86-64: Give vvars their own page x86-64: Document some of entry_64.S x86-64: Fix alignment of jiffies variable 
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-64, vdso: Do not allocate memory for the vDSO
  clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option
  x86, vdso: Drop now wrong comment
  Document the vDSO and add a reference parser
  ia64: Replace clocksource.fsys_mmio with generic arch data
  x86-64: Move vread_tsc and vread_hpet into the vDSO
  clocksource: Replace vread with generic arch data
  x86-64: Add --no-undefined to vDSO build
  x86-64: Allow alternative patching in the vDSO
  x86: Make alternative instruction pointers relative
  x86-64: Improve vsyscall emulation CS and RIP handling
  x86-64: Emulate legacy vsyscalls
  x86-64: Fill unused parts of the vsyscall page with 0xcc
  x86-64: Remove vsyscall number 3 (venosys)
  x86-64: Map the HPET NX
  x86-64: Remove kernel.vsyscall64 sysctl
  x86-64: Give vvars their own page
  x86-64: Document some of entry_64.S
  x86-64: Fix alignment of jiffies variable