summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/fpu
Commit message (Collapse)AuthorAgeFilesLines
* tree-wide: replace config_enabled() with IS_ENABLED()Masahiro Yamada2016-08-041-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Stas Sergeev <stsp@list.ru> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@suse.de> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will Drewry <wad@chromium.org> Cc: Nikolay Martynov <mar.kolya@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Rafal Milecki <zajec5@gmail.com> Cc: James Cowgill <James.Cowgill@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Tony Wu <tung7970@gmail.com> Cc: Huaitong Han <huaitong.han@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Rabin Vincent <rabin@rab.in> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/fpu: Do not BUG_ON() in early FPU codeDave Hansen2016-07-211-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I don't think it is really possible to have a system where CPUID enumerates support for XSAVE but that it does not have FP/SSE (they are "legacy" features and always present). But, I did manage to hit this case in qemu when I enabled its somewhat shaky XSAVE support. The bummer is that the FPU is set up before we parse the command-line or have *any* console support including earlyprintk. That turned what should have been an easy thing to debug in to a bit more of an odyssey. So a BUG() here is worthless. All it does it guarantee that if/when we hit this case we have an empty console. So, remove the BUG() and try to limp along by disabling XSAVE and trying to continue. Add a comment on why we are doing this, and also add a common "out_disable" path for leaving fpu__init_system_xstate(). Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160720194551.63BB2B58@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Re-enable XSAVESYu-cheng Yu2016-07-112-15/+9
| | | | | | | | | | | | | | | | | | | | We did not handle XSAVES instructions correctly. There were issues in converting between standard and compacted format when interfacing with user-space. These issues have been corrected. Add a WARN_ONCE() to make it clear that XSAVES supervisor states are not yet implemented. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <h.peter.anvin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468253937-40008-5-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix fpstate_init() for XRSTORSYu-cheng Yu2016-07-111-0/+8
| | | | | | | | | | | | | | | | | | | | | | | In XSAVES mode if fpstate_init() is used to initialize a task's extended state area, xsave.header.xcomp_bv[63] must be set. Otherwise, when the task is scheduled, a warning is triggered from copy_kernel_to_xregs(). One such test case is: setting an invalid extended state through PTRACE. When xstateregs_set() rejects the syscall and re-initializes the task's extended state area. This triggers the warning mentioned above. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <h.peter.anvin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468253937-40008-4-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Return NULL for disabled xstate component addressYu-cheng Yu2016-07-111-0/+5
| | | | | | | | | | | | | | | | | It is an error to request a disabled XSAVE/XSAVES component address. For that case, make __raw_xsave_addr() return a NULL and issue a warning. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <h.peter.anvin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468253937-40008-3-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix __fpu_restore_sig() for XSAVESYu-cheng Yu2016-07-111-2/+9
| | | | | | | | | | | | | | | | | | | When the kernel is using XSAVES compacted format, we cannot do __copy_from_user() from a signal frame, which has standard-format data. Fix it by using copyin_to_xsaves(), which converts between formats and filters out all supervisor states that we do not allow userspace to write. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <h.peter.anvin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468253937-40008-2-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended xstatesYu-cheng Yu2016-07-101-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | The arrays xstate_offsets[] and xstate_sizes[] record XSAVE standard- format offsets and sizes. Values for non-extended state components fpu and xmm's were not initialized or used. Ptrace format conversion needs them. Fix it. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/cf3ea36cf30e2a99e37da6483e65446d018ff0a7.1466179491.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix XSTATE component offset print outYu-cheng Yu2016-07-101-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | Component offset print out was incorrect for XSAVES. Correct it and move to a separate function. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/86602a8ac400626c6eca7125c3e15934866fc38e.1466179491.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix PTRACE frames for XSAVESYu-cheng Yu2016-07-102-23/+212
| | | | | | | | | | | | | | | | | | | | | | | | | | | XSAVES uses compacted format and is a kernel instruction. The kernel should use standard-format, non-supervisor state data for PTRACE. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> [ Edited away artificial linebreaks. ] Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/de3d80949001305fe389799973b675cab055c457.1466179491.git.yu-cheng.yu@intel.com [ Made various readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Fix supervisor xstate component offsetYu-cheng Yu2016-07-101-23/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPUID function 0x0d, sub function (i, i > 1) returns in ebx the offset of xstate component i. Zero is returned for a supervisor state. A supervisor state can only be saved by XSAVES and XSAVES uses a compacted format. There is no fixed offset for a supervisor state. This patch checks and makes sure a supervisor state offset is not recorded or mis-used. This has no effect in practice as we currently use no supervisor states, but it would be good to fix. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/81b29e40d35d4cec9f2511a856fe769f34935a3f.1466179491.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Align xstate components according to CPUIDYu-cheng Yu2016-07-101-28/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPUID function 0x0d, sub function (i, i > 1) returns in ecx[1] the alignment requirement of component 'i' when the compacted format is used. If ecx[1] is 0, component 'i' is located immediately following the preceding component. If ecx[1] is 1, component 'i' is located on the next 64-byte boundary following the preceding component. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/331e2bef1a0a7a584f06adde095b6bbfbe166472.1466179491.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Copy xstate registers directly to the signal frame when ↵Yu-cheng Yu2016-06-182-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | compacted format is in use XSAVES is a kernel instruction and uses a compacted format. When working with user space, the kernel should provide standard-format, non-supervisor state data. We cannot do __copy_to_user() from a compacted-format kernel xstate area to a signal frame. Dave Hansen proposes this method to simplify copy xstate directly to user. This patch is based on an earlier patch from Fenghua Yu <fenghua.yu@intel.com> Originally-from: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/c36f419d525517d04209a28dd8e1e5af9000036e.1463760376.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Keep init_fpstate.xsave.header.xfeatures as zero for init ↵Fenghua Yu2016-06-181-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | optimization Keep init_fpstate.xsave.header.xfeatures as zero for init optimization. This is important for init optimization that is implemented in processor. If a bit corresponding to an xstate in xstate_bv is 0, it means the xstate is in init status and will not be read from memory to the processor during XRSTOR/XRSTORS instruction. This largely impacts context switch performance. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/2fb4ec7f18b76e8cda057a8c0038def74a9b8044.1463760376.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Rename 'xstate_size' to 'fpu_kernel_xstate_size', to ↵Fenghua Yu2016-06-184-17/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | distinguish it from 'fpu_user_xstate_size' User space uses standard format xsave area. fpstate in signal frame should have standard format size. To explicitly distinguish between xstate size in kernel space and the one in user space, we rename 'xstate_size' to 'fpu_kernel_xstate_size'. Cleanup only, no change in functionality. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> [ Rebased the patch and cleaned up the naming. ] Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/2ecbae347a5152d94be52adf7d0f3b7305d90d99.1463760376.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/xstate: Define and use 'fpu_user_xstate_size'Fenghua Yu2016-06-183-36/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel xstate area can be in standard or compacted format; it is always in standard format for user mode. When XSAVES is enabled, the kernel uses the compacted format and it is necessary to use a separate fpu_user_xstate_size for signal/ptrace frames. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> [ Rebased the patch and cleaned up the naming. ] Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8756ec34dabddfc727cda5743195eb81e8caf91c.1463760376.git.yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Add tracepoints to dump FPU state at key pointsDave Hansen2016-06-082-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've been carrying this patch around for a bit and it's helped me solve at least a couple FPU-related bugs. In addition to using it for debugging, I also drug it out because using AVX (and AVX2/AVX-512) can have serious power consequences for a modern core. It's very important to be able to figure out who is using it. It's also insanely useful to go out and see who is using a given feature, like MPX or Memory Protection Keys. If you, for instance, want to find all processes using protection keys, you can do: echo 'xfeatures & 0x200' > filter Since 0x200 is the protection keys feature bit. Note that this touches the KVM code. KVM did a CREATE_TRACE_POINTS and then included a bunch of random headers. If anyone one of those included other tracepoints, it would have defined the *OTHER* tracepoints. That's bogus, so move it to the right place. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160601174220.3CDFB90E@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Get rid of x87 math exception helpersBorislav Petkov2016-04-131-31/+13
| | | | | | | | | | | | | | | | | | | ... and integrate their functionality into their single user fpu__exception_code(). No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459837795-2588-7-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Remove check_fpu() indirectionBorislav Petkov2016-04-131-11/+5
| | | | | | | | | | | | | | | | | Rename it to fpu__init_check_bugs() and do the CPU feature check at entry, thus getting rid of the old fpu__init_check_bugs() wrapper. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459837795-2588-6-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu/regset: Replace static_cpu_has() usage with boot_cpu_has()Borislav Petkov2016-04-131-2/+2
| | | | | | | | | | | | | | | | | fpregs_{g,s}et() are not sizzling-hot paths to justify the need for static_cpu_has(). Use the normal boot_cpu_has() helper. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459837795-2588-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/cpufeature: Replace cpu_has_xsaves with boot_cpu_has() usageBorislav Petkov2016-04-131-5/+5
| | | | | | | | | | | | | | | Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <kvm@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459801503-15600-11-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/cpufeature: Replace cpu_has_xsave with boot_cpu_has() usageBorislav Petkov2016-04-132-8/+8
| | | | | | | | | | | | | | | Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Link: http://lkml.kernel.org/r/1459801503-15600-10-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/cpufeature: Replace cpu_has_fxsr with boot_cpu_has() usageBorislav Petkov2016-04-133-11/+14
| | | | | | | | | | | | | | Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459801503-15600-9-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/cpufeature: Replace cpu_has_fpu with boot_cpu_has() usageBorislav Petkov2016-04-133-7/+7
| | | | | | | | | | | | | | | | | | | | Use static_cpu_has() in the timing-sensitive paths in fpstate_init() and fpu__copy(). While at it, simplify the use in init_cyrix() and get rid of the ternary operator. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459801503-15600-6-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/cpufeature: Replace cpu_has_xmm with boot_cpu_has() usageBorislav Petkov2016-04-132-2/+2
| | | | | | | | | | | | | | Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1459801503-15600-5-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2016-03-241-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes: - fix hotplug bugs - fix irq live lock - fix various topology handling bugs - fix APIC ACK ordering - fix PV iopl handling - fix speling - fix/tweak memcpy_mcsafe() return value - fix fbcon bug - remove stray prototypes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/msr: Remove unused native_read_tscp() x86/apic: Remove declaration of unused hw_nmi_is_cpu_stuck x86/oprofile/nmi: Add missing hotplug FROZEN handling x86/hpet: Use proper mask to modify hotplug action x86/apic/uv: Fix the hotplug notifier x86/apb/timer: Use proper mask to modify hotplug action x86/topology: Use total_cpus not nr_cpu_ids for logical packages x86/topology: Fix Intel HT disable x86/topology: Fix logical package mapping x86/irq: Cure live lock in fixup_irqs() x86/tsc: Prevent NULL pointer deref in calibrate_delay_is_known() x86/apic: Fix suspicious RCU usage in smp_trace_call_function_interrupt() x86/iopl: Fix iopl capability check on Xen PV x86/iopl/64: Properly context-switch IOPL on Xen PV selftests/x86: Add an iopl test x86/mm, x86/mce: Fix return type/value for memcpy_mcsafe() x86/video: Don't assume all FB devices are PCI devices arch/x86/irq: Purge useless handler declarations from hw_irq.h x86: Fix misspellings in comments
| * Merge branch 'x86/cleanups' into x86/urgentIngo Molnar2016-03-171-1/+1
| |\ | | | | | | | | | | | | | | | Pull in some merge window leftovers. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * x86: Fix misspellings in commentsAdam Buchbinder2016-02-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: trivial@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'mm-pkeys-for-linus' of ↵Linus Torvalds2016-03-202-4/+244
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 protection key support from Ingo Molnar: "This tree adds support for a new memory protection hardware feature that is available in upcoming Intel CPUs: 'protection keys' (pkeys). There's a background article at LWN.net: https://lwn.net/Articles/643797/ The gist is that protection keys allow the encoding of user-controllable permission masks in the pte. So instead of having a fixed protection mask in the pte (which needs a system call to change and works on a per page basis), the user can map a (handful of) protection mask variants and can change the masks runtime relatively cheaply, without having to change every single page in the affected virtual memory range. This allows the dynamic switching of the protection bits of large amounts of virtual memory, via user-space instructions. It also allows more precise control of MMU permission bits: for example the executable bit is separate from the read bit (see more about that below). This tree adds the MM infrastructure and low level x86 glue needed for that, plus it adds a high level API to make use of protection keys - if a user-space application calls: mmap(..., PROT_EXEC); or mprotect(ptr, sz, PROT_EXEC); (note PROT_EXEC-only, without PROT_READ/WRITE), the kernel will notice this special case, and will set a special protection key on this memory range. It also sets the appropriate bits in the Protection Keys User Rights (PKRU) register so that the memory becomes unreadable and unwritable. So using protection keys the kernel is able to implement 'true' PROT_EXEC on x86 CPUs: without protection keys PROT_EXEC implies PROT_READ as well. Unreadable executable mappings have security advantages: they cannot be read via information leaks to figure out ASLR details, nor can they be scanned for ROP gadgets - and they cannot be used by exploits for data purposes either. We know about no user-space code that relies on pure PROT_EXEC mappings today, but binary loaders could start making use of this new feature to map binaries and libraries in a more secure fashion. There is other pending pkeys work that offers more high level system call APIs to manage protection keys - but those are not part of this pull request. Right now there's a Kconfig that controls this feature (CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) that is default enabled (like most x86 CPU feature enablement code that has no runtime overhead), but it's not user-configurable at the moment. If there's any serious problem with this then we can make it configurable and/or flip the default" * 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits) x86/mm/pkeys: Fix mismerge of protection keys CPUID bits mm/pkeys: Fix siginfo ABI breakage caused by new u64 field x86/mm/pkeys: Fix access_error() denial of writes to write-only VMA mm/core, x86/mm/pkeys: Add execute-only protection keys support x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits() for VMA flags x86/mm/pkeys: Allow kernel to modify user pkey rights register x86/fpu: Allow setting of XSAVE state x86/mm: Factor out LDT init from context init mm/core, x86/mm/pkeys: Add arch_validate_pkey() mm/core, arch, powerpc: Pass a protection key in to calc_vm_flag_bits() x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU x86/mm/pkeys: Add Kconfig prompt to existing config option x86/mm/pkeys: Dump pkey from VMA in /proc/pid/smaps x86/mm/pkeys: Dump PKRU with other kernel registers mm/core, x86/mm/pkeys: Differentiate instruction fetches x86/mm/pkeys: Optimize fault handling in access_error() mm/core: Do not enforce PKEY permissions on remote mm access um, pkeys: Add UML arch_*_access_permitted() methods mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys x86/mm/gup: Simplify get_user_pages() PTE bit handling ...
| * | mm/core, x86/mm/pkeys: Add execute-only protection keys supportDave Hansen2016-02-181-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Protection keys provide new page-based protection in hardware. But, they have an interesting attribute: they only affect data accesses and never affect instruction fetches. That means that if we set up some memory which is set as "access-disabled" via protection keys, we can still execute from it. This patch uses protection keys to set up mappings to do just that. If a user calls: mmap(..., PROT_EXEC); or mprotect(ptr, sz, PROT_EXEC); (note PROT_EXEC-only without PROT_READ/WRITE), the kernel will notice this, and set a special protection key on the memory. It also sets the appropriate bits in the Protection Keys User Rights (PKRU) register so that the memory becomes unreadable and unwritable. I haven't found any userspace that does this today. With this facility in place, we expect userspace to move to use it eventually. Userspace _could_ start doing this today. Any PROT_EXEC calls get converted to PROT_READ inside the kernel, and would transparently be upgraded to "true" PROT_EXEC with this code. IOW, userspace never has to do any PROT_EXEC runtime detection. This feature provides enhanced protection against leaking executable memory contents. This helps thwart attacks which are attempting to find ROP gadgets on the fly. But, the security provided by this approach is not comprehensive. The PKRU register which controls access permissions is a normal user register writable from unprivileged userspace. An attacker who can execute the 'wrpkru' instruction can easily disable the protection provided by this feature. The protection key that is used for execute-only support is permanently dedicated at compile time. This is fine for now because there is currently no API to set a protection key other than this one. Despite there being a constant PKRU value across the entire system, we do not set it unless this feature is in use in a process. That is to preserve the PKRU XSAVE 'init state', which can lead to faster context switches. PKRU *is* a user register and the kernel is modifying it. That means that code doing: pkru = rdpkru() pkru |= 0x100; mmap(..., PROT_EXEC); wrpkru(pkru); could lose the bits in PKRU that enforce execute-only permissions. To avoid this, we suggest avoiding ever calling mmap() or mprotect() when the PKRU value is expected to be unstable. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chen Gang <gang.chen.5i5j@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave@sr71.net> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Piotr Kwapulinski <kwapulinski.piotr@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Vladimir Murzin <vladimir.murzin@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: keescook@google.com Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210240.CB4BB5CA@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/mm/pkeys: Allow kernel to modify user pkey rights registerDave Hansen2016-02-181-0/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Protection Key Rights for User memory (PKRU) is a 32-bit user-accessible register. It contains two bits for each protection key: one to write-disable (WD) access to memory covered by the key and another to access-disable (AD). Userspace can read/write the register with the RDPKRU and WRPKRU instructions. But, the register is saved and restored with the XSAVE family of instructions, which means we have to treat it like a floating point register. The kernel needs to write to the register if it wants to implement execute-only memory or if it implements a system call to change PKRU. To do this, we need to create a 'pkru_state' buffer, read the old contents in to it, modify it, and then tell the FPU code that there is modified data in there so it can (possibly) move the buffer back in to the registers. This uses the fpu__xfeature_set_state() function that we defined in the previous patch. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210236.0BE13217@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/fpu: Allow setting of XSAVE stateDave Hansen2016-02-182-2/+159
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to modify the Protection Key rights inside the kernel, so we need to change PKRU's contents. But, if we do a plain 'wrpkru', when we return to userspace we might do an XRSTOR and wipe out the kernel's 'wrpkru'. So, we need to go after PKRU in the xsave buffer. We do this by: 1. Ensuring that we have the XSAVE registers (fpregs) in the kernel FPU buffer (fpstate) 2. Looking up the location of a given state in the buffer 3. Filling in the stat 4. Ensuring that the hardware knows that state is present there (basically that the 'init optimization' is not in place). 5. Copying the newly-modified state back to the registers if necessary. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210235.5A3139BF@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/fpu, x86/mm/pkeys: Add PKRU xsave fields and data structuresDave Hansen2016-02-161-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The protection keys register (PKRU) is saved and restored using xsave. Define the data structure that we will use to access it inside the xsave buffer. Note that we also have to widen the printk of the xsave feature masks since this is feature 0x200 and we only did two characters before. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210204.56DF8F7B@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/fpu: Add placeholder for 'Processor Trace' XSAVE stateDave Hansen2016-02-161-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is an XSAVE state component for Intel Processor Trace (PT). But, we do not currently use it. We add a placeholder in the code for it so it is not a mystery and also so we do not need an explicit enum initialization for Protection Keys in a moment. Why don't we use it? We might end up using this at _some_ point in the future. But, this is a "system" state which requires using the currently unsupported XSAVES feature. Unlike all the other XSAVE states, PT state is also not directly tied to a thread. You might context-switch between threads, but not want to change any of the PT state. Or, you might switch between threads, and *do* want to change PT state, all depending on what is being traced. We currently just manually set some MSRs to do this PT context switching, and it is unclear whether replacing our direct MSR use with XSAVE will be a net win or loss, both in code complexity and performance. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: fenghua.yu@intel.com Cc: linux-mm@kvack.org Cc: yu-cheng.yu@intel.com Link: http://lkml.kernel.org/r/20160212210158.5E4BCAE2@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds2016-03-152-33/+32
|\ \ \ | |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fpu updates from Ingo Molnar: "The biggest change in terms of impact is the changing of the FPU context switch model to 'eagerfpu' for all CPU types, via: commit 58122bf1d856: "x86/fpu: Default eagerfpu=on on all CPUs" This makes all FPU saves and restores synchronous and makes the FPU code a lot more obvious to read. In the next cycle, if this change is problem free, we'll remove the old lazy FPU restore code altogether. This change flushed out some old bugs, which should all be fixed by now, BYMMV" * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu: Default eagerfpu=on on all CPUs x86/fpu: Speed up lazy FPU restores slightly x86/fpu: Fold fpu_copy() into fpu__copy() x86/fpu: Fix FNSAVE usage in eagerfpu mode x86/fpu: Fix math emulation in eager fpu mode
| * | x86/fpu: Default eagerfpu=on on all CPUsAndy Lutomirski2016-02-091-8/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have eager and lazy FPU modes, introduced in: 304bceda6a18 ("x86, fpu: use non-lazy fpu restore for processors supporting xsave") The result is rather messy. There are two code paths in almost all of the FPU code, and only one of them (the eager case) is tested frequently, since most kernel developers have new enough hardware that we use eagerfpu. It seems that, on any remotely recent hardware, eagerfpu is a win: glibc uses SSE2, so laziness is probably overoptimistic, and, in any case, manipulating TS is far slower that saving and restoring the full state. (Stores to CR0.TS are serializing and are poorly optimized.) To try to shake out any latent issues on old hardware, this changes the default to eager on all CPUs. If no performance or functionality problems show up, a subsequent patch could remove lazy mode entirely. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/ac290de61bf08d9cfc2664a4f5080257ffc1075a.1453675014.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/fpu: Fold fpu_copy() into fpu__copy()Andy Lutomirski2016-02-091-21/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Splitting it into two functions needlessly obfuscated the code. While we're at it, improve the comment slightly. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/3eb5a63a9c5c84077b2677a7dfe684eef96fe59e.1453675014.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/fpu: Fix FNSAVE usage in eagerfpu modeAndy Lutomirski2016-02-091-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In eager fpu mode, having deactivated FPU without immediately reloading some other context is illegal. Therefore, to recover from FNSAVE, we can't just deactivate the state -- we need to reload it if we're not actively context switching. We had this wrong in fpu__save() and fpu__copy(). Fix both. __kernel_fpu_begin() was fine -- add a comment. This fixes a warning triggerable with nofxsr eagerfpu=on. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/60662444e13c76f06e23c15c5dcdba31b4ac3d67.1453675014.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | x86/fpu: Fix math emulation in eager fpu modeAndy Lutomirski2016-02-091-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Systems without an FPU are generally old and therefore use lazy FPU switching. Unsurprisingly, math emulation in eager FPU mode is a bit buggy. Fix it. There were two bugs involving kernel code trying to use the FPU registers in eager mode even if they didn't exist and one BUG_ON() that was incorrect. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/b4b8d112436bd6fab866e1b4011131507e8d7fbe.1453675014.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2016-03-151-0/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "This is another big update. Main changes are: - lots of x86 system call (and other traps/exceptions) entry code enhancements. In particular the complex parts of the 64-bit entry code have been migrated to C code as well, and a number of dusty corners have been refreshed. (Andy Lutomirski) - vDSO special mapping robustification and general cleanups (Andy Lutomirski) - cpufeature refactoring, cleanups and speedups (Borislav Petkov) - lots of other changes ..." * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) x86/cpufeature: Enable new AVX-512 features x86/entry/traps: Show unhandled signal for i386 in do_trap() x86/entry: Call enter_from_user_mode() with IRQs off x86/entry/32: Change INT80 to be an interrupt gate x86/entry: Improve system call entry comments x86/entry: Remove TIF_SINGLESTEP entry work x86/entry/32: Add and check a stack canary for the SYSENTER stack x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixup x86/entry: Only allocate space for tss_struct::SYSENTER_stack if needed x86/entry: Vastly simplify SYSENTER TF (single-step) handling x86/entry/traps: Clear DR6 early in do_debug() and improve the comment x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptions x86/entry/32: Restore FLAGS on SYSEXIT x86/entry/32: Filter NT and speed up AC filtering in SYSENTER x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test selftests/x86: In syscall_nt, test NT|TF as well x86/asm-offsets: Remove PARAVIRT_enabled x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled uprobes: __create_xol_area() must nullify xol_mapping.fault x86/cpufeature: Create a new synthetic cpu capability for machine check recovery ...
| * | x86/cpufeature: Enable new AVX-512 featuresFenghua Yu2016-03-121-0/+3
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A few new AVX-512 instruction groups/features are added in cpufeatures.h for enuermation: AVX512DQ, AVX512BW, and AVX512VL. Clear the flags in fpu__xstate_clear_all_cpu_caps(). The specification for latest AVX-512 including the features can be found at: https://software.intel.com/sites/default/files/managed/07/b7/319433-023.pdf Note, I didn't enable the flags in KVM. Hopefully the KVM guys can pick up the flags and enable them in KVM. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Link: http://lkml.kernel.org/r/1457667498-37357-1-git-send-email-fenghua.yu@intel.com [ Added more detailed feature descriptions. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86/fpu: Fix eager-FPU handling on legacy FPU machinesBorislav Petkov2016-03-122-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | i486 derived cores like Intel Quark support only the very old, legacy x87 FPU (FSAVE/FRSTOR, CPUID bit FXSR is not set), and our FPU code wasn't handling the saving and restoring there properly in the 'eagerfpu' case. So after we made eagerfpu the default for all CPU types: 58122bf1d856 x86/fpu: Default eagerfpu=on on all CPUs these old FPU designs broke. First, Andy Shevchenko reported a splat: WARNING: CPU: 0 PID: 823 at arch/x86/include/asm/fpu/internal.h:163 fpu__clear+0x8c/0x160 which was us trying to execute FXRSTOR on those machines even though they don't support it. After taking care of that, Bryan O'Donoghue reported that a simple FPU test still failed because we weren't initializing the FPU state properly on those machines. Take care of all that. Reported-and-tested-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20160311113206.GD4312@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86/fpu: Revert ("x86/fpu: Disable AVX when eagerfpu is off")Yu-cheng Yu2016-03-101-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Leonid Shatz noticed that the SDM interpretation of the following recent commit: 394db20ca240741 ("x86/fpu: Disable AVX when eagerfpu is off") ... is incorrect and that the original behavior of the FPU code was correct. Because AVX is not stated in CR0 TS bit description, it was mistakenly believed to be not supported for lazy context switch. This turns out to be false: Intel Software Developer's Manual Vol. 3A, Sec. 2.5 Control Registers: 'TS Task Switched bit (bit 3 of CR0) -- Allows the saving of the x87 FPU/ MMX/SSE/SSE2/SSE3/SSSE3/SSE4 context on a task switch to be delayed until an x87 FPU/MMX/SSE/SSE2/SSE3/SSSE3/SSE4 instruction is actually executed by the new task.' Intel Software Developer's Manual Vol. 2A, Sec. 2.4 Instruction Exception Specification: 'AVX instructions refer to exceptions by classes that include #NM "Device Not Available" exception for lazy context switch.' So revert the commit. Reported-by: Leonid Shatz <leonid.shatz@ravellosystems.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1457569734-3785-1-git-send-email-yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | x86/fpu: Fix 'no387' regressionAndy Lutomirski2016-03-091-6/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | After fixing FPU option parsing, we now parse the 'no387' boot option too early: no387 clears X86_FEATURE_FPU before it's even probed, so the boot CPU promptly re-enables it. I suspect it gets even more confused on SMP. Fix the probing code to leave X86_FEATURE_FPU off if it's been disabled by setup_clear_cpu_cap(). Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Fixes: 4f81cbafcce2 ("x86/fpu: Fix early FPU command-line parsing") Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Disable AVX when eagerfpu is offyu-cheng yu2016-01-121-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When "eagerfpu=off" is given as a command-line input, the kernel should disable AVX support. The Task Switched bit used for lazy context switching does not support AVX. If AVX is enabled without eagerfpu context switching, one task's AVX state could become corrupted or leak to other tasks. This is a bug and has bad security implications. This only affects systems that have AVX/AVX2/AVX512 and this issue will be found only when one actually uses AVX/AVX2/AVX512 _AND_ does eagerfpu=off. Reference: Intel Software Developer's Manual Vol. 3A Sec. 2.5 Control Registers: TS Task Switched bit (bit 3 of CR0) -- Allows the saving of the x87 FPU/ MMX/SSE/SSE2/SSE3/SSSE3/SSE4 context on a task switch to be delayed until an x87 FPU/MMX/SSE/SSE2/SSE3/SSSE3/SSE4 instruction is actually executed by the new task. Sec. 13.4.1 Using the TS Flag to Control the Saving of the X87 FPU and SSE State When the TS flag is set, the processor monitors the instruction stream for x87 FPU, MMX, SSE instructions. When the processor detects one of these instructions, it raises a device-not-available exeception (#NM) prior to executing the instruction. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/1452119094-7252-5-git-send-email-yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Disable MPX when eagerfpu is offyu-cheng yu2016-01-122-14/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This issue is a fallout from the command-line parsing move. When "eagerfpu=off" is given as a command-line input, the kernel should disable MPX support. The decision for turning off MPX was made in fpu__init_system_ctx_switch(), which is after the selection of the XSAVE format. This patch fixes it by getting that decision done earlier in fpu__init_system_xstate(). Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/1452119094-7252-4-git-send-email-yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Disable XGETBV1 when no XSAVEyu-cheng yu2016-01-121-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When "noxsave" is given as a command-line input, the kernel should disable XGETBV1. This issue currently does not cause any actual problems. XGETBV1 is only useful if we have something using the 'init optimization' (i.e. xsaveopt, xsaves). We already clear both of those in fpu__xstate_clear_all_cpu_caps(). But this is good for completeness. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/1452119094-7252-3-git-send-email-yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Fix early FPU command-line parsingyu-cheng yu2016-01-121-71/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function fpu__init_system() is executed before parse_early_param(). This causes wrong FPU configuration. This patch fixes this issue by parsing boot_command_line in the beginning of fpu__init_system(). With all four patches in this series, each parameter disables features as the following: eagerfpu=off: eagerfpu, avx, avx2, avx512, mpx no387: fpu nofxsr: fxsr, fxsropt, xmm noxsave: xsave, xsaveopt, xsaves, xsavec, avx, avx2, avx512, mpx, xgetbv1 noxsaveopt: xsaveopt noxsaves: xsaves Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi V. Shankar <ravi.v.shankar@intel.com> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/1452119094-7252-2-git-send-email-yu-cheng.yu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds2016-01-112-4/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fpu updates from Ingo Molnar: "This cleans up the FPU fault handling methods to be more robust, and moves eligible variables to .init.data" * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu: Put a few variables in .init.data x86/fpu: Get rid of xstate_fault() x86/fpu: Add an XSTATE_OP() macro
| * x86/fpu: Put a few variables in .init.dataRasmus Villemoes2015-11-272-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These are clearly just used during init. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1447424312-26400-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds2016-01-111-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "The main changes in this cycle were: - code patching and cpu_has cleanups (Borislav Petkov) - paravirt cleanups (Juergen Gross) - TSC cleanup (Thomas Gleixner) - ptrace cleanup (Chen Gang)" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: arch/x86/kernel/ptrace.c: Remove unused arg_offs_table x86/mm: Align macro defines x86/cpu: Provide a config option to disable static_cpu_has x86/cpufeature: Remove unused and seldomly used cpu_has_xx macros x86/cpufeature: Cleanup get_cpu_cap() x86/cpufeature: Move some of the scattered feature bits to x86_capability x86/paravirt: Remove paravirt ops pmd_update[_defer] and pte_update_defer x86/paravirt: Remove unused pv_apic_ops structure x86/tsc: Remove unused tsc_pre_init() hook x86: Remove unused function cpu_has_ht_siblings() x86/paravirt: Kill some unused patching functions
OpenPOWER on IntegriCloud