kernel/git/stable/linux-stable.git/Documentation/x86, branch linux-3.2.y

x86/pti: Document fix wrong index

2018-03-19T18:58:34+00:00

commit 98f0fceec7f84d80bc053e49e596088573086421 upstream. In section <2. Runtime Cost>, fix wrong index. Signed-off-by: zhenwei.pi Signed-off-by: Thomas Gleixner Cc: dave.hansen@linux.intel.com Link: https://lkml.kernel.org/r/1516237492-27739-1-git-send-email-zhenwei.pi@youruncloud.com Signed-off-by: Ben Hutchings

x86/Documentation: Add PTI description

2018-03-19T18:58:27+00:00

commit 01c9b17bf673b05bb401b76ec763e9730ccf1376 upstream. Add some details about how PTI works, what some of the downsides are, and how to debug it when things go wrong. Also document the kernel parameter: 'pti/nopti'. Signed-off-by: Dave Hansen Signed-off-by: Thomas Gleixner Reviewed-by: Randy Dunlap Reviewed-by: Kees Cook Cc: Moritz Lipp Cc: Daniel Gruss Cc: Michael Schwarz Cc: Richard Fellner Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Hugh Dickins Cc: Andi Lutomirsky Link: https://lkml.kernel.org/r/20180105174436.1BC6FA2B@viggo.jf.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings

x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack

2014-09-13T22:41:51+00:00

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 Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com Cc: Konrad Rzeszutek Wilk Cc: Borislav Petkov Cc: Andrew Lutomriski Cc: Linus Torvalds Cc: Dirk Hohndel Cc: Arjan van de Ven Cc: comex Cc: Alexander van Heukelum Cc: Boris Ostrovsky Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings

x86-64, doc: Remove int 0xcc from entry_64.S documentation

2011-08-16T15:04:08+00:00

Commit 3ae36655b97a03fa1decf72f04078ef945647c1a (x86-64: Rework vsyscall emulation and add vsyscall= parameter) removed the special use of the 0xcc IDT vector. Remove it from Documentation/x86/entry_64.txt also. Signed-off-by: Cesar Eduardo Barros Acked-by: Andy Lutomirski Link: http://lkml.kernel.org/r/1313447210-9149-1-git-send-email-cesarb@cesarb.net Signed-off-by: H. Peter Anvin

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

* '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, doc only: Correct real-mode kernel header offset for init_size

2011-07-13T03:39:11+00:00

The real-mode kernel header init_size field is located at 0x260 per the field listing in th e"REAL-MODE KERNEL HEADER" section. It is listed as 0x25c in the "DETAILS OF HEADER FIELDS" section, which overlaps with pref_address. Correct the details listing to 0x260. Signed-off-by: Darren Hart Link: http://lkml.kernel.org/r/541cf88e2dfe5b8186d8b96b136d892e769a68c1.1310441260.git.dvhart@linux.intel.com CC: H. Peter Anvin Signed-off-by: H. Peter Anvin

x86-64: Document some of entry_64.S

2011-06-05T19:30:32+00:00

Signed-off-by: Andy Lutomirski Cc: Jesper Juhl Cc: Borislav Petkov Cc: Linus Torvalds Cc: Arjan van de Ven Cc: Jan Beulich Cc: richard -rw- weinberger Cc: Mikael Pettersson Cc: Andi Kleen Cc: Brian Gerst Cc: Louis Rilling Cc: Valdis.Kletnieks@vt.edu Cc: pageexec@freemail.hu Link: http://lkml.kernel.org/r/fc134867cc550977cc996866129e11a16ba0f9ea.1307292171.git.luto@mit.edu Signed-off-by: Ingo Molnar

x86, gart: Rename pci-gart_64.c to amd_gart_64.c

2011-05-10T15:22:06+00:00

This file only contains code relevant for the northbridge gart in AMD processors. This patch renames the file to represent this fact in the filename. Signed-off-by: Joerg Roedel

move x86 specific oops=panic to generic code

2011-03-23T00:44:11+00:00

The oops=panic cmdline option is not x86 specific, move it to generic code. Update documentation. Signed-off-by: Olaf Hering Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

x86: Fix misspelling and align params

2011-03-18T09:39:30+00:00

Fix 'upto' misspelling and align parameters. Signed-off-by: Lucas De Marchi Cc: trivial@kernel.org LKML-Reference: <1300389856-1099-2-git-send-email-lucas.demarchi@profusion.mobi> Signed-off-by: Ingo Molnar