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2015-03-31x86/mm: Improve AMD Bulldozer ASLR workaroundHector Marco-Gisbert1-0/+1
The ASLR implementation needs to special-case AMD F15h processors by clearing out bits [14:12] of the virtual address in order to avoid I$ cross invalidations and thus performance penalty for certain workloads. For details, see: dfb09f9b7ab0 ("x86, amd: Avoid cache aliasing penalties on AMD family 15h") This special case reduces the mmapped file's entropy by 3 bits. The following output is the run on an AMD Opteron 62xx class CPU processor under x86_64 Linux 4.0.0: $ for i in `seq 1 10`; do cat /proc/self/maps | grep "r-xp.*libc" ; done b7588000-b7736000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 b7570000-b771e000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 b75d0000-b777e000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 b75b0000-b775e000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 b7578000-b7726000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 ... Bits [12:14] are always 0, i.e. the address always ends in 0x8000 or 0x0000. 32-bit systems, as in the example above, are especially sensitive to this issue because 32-bit randomness for VA space is 8 bits (see mmap_rnd()). With the Bulldozer special case, this diminishes to only 32 different slots of mmap virtual addresses. This patch randomizes per boot the three affected bits rather than setting them to zero. Since all the shared pages have the same value at bits [12..14], there is no cache aliasing problems. This value gets generated during system boot and it is thus not known to a potential remote attacker. Therefore, the impact from the Bulldozer workaround gets diminished and ASLR randomness increased. More details at: http://hmarco.org/bugs/AMD-Bulldozer-linux-ASLR-weakness-reducing-mmaped-files-by-eight.html Original white paper by AMD dealing with the issue: http://developer.amd.com/wordpress/media/2012/10/SharedL1InstructionCacheonAMD15hCPU.pdf Mentored-by: Ismael Ripoll <iripoll@disca.upv.es> Signed-off-by: Hector Marco-Gisbert <hecmargi@upv.es> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan-Simon <dl9pf@gmx.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-fsdevel@vger.kernel.org Link: http://lkml.kernel.org/r/1427456301-3764-1-git-send-email-hecmargi@upv.es Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-30KVM: x86: Remove redundant definitionsNadav Amit1-3/+0
Some constants are redfined in emulate.c. Avoid it. s/SELECTOR_RPL_MASK/SEGMENT_RPL_MASK s/SELECTOR_TI_MASK/SEGMENT_TI_MASK No functional change. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Message-Id: <1427635984-8113-3-git-send-email-namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-30KVM: x86: removing redundant eflags bits definitionsNadav Amit1-2/+0
The eflags are redefined (using other defines) in emulate.c. Use the definition from processor-flags.h as some mess already started. No functional change. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Message-Id: <1427635984-8113-2-git-send-email-namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-27Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcuIngo Molnar2-3/+1
Pull RCU updates from Paul E. McKenney: - Documentation updates. - Changes permitting use of call_rcu() and friends very early in boot, for example, before rcu_init() is invoked. - Miscellaneous fixes. - Add in-kernel API to enable and disable expediting of normal RCU grace periods. - Improve RCU's handling of (hotplug-) outgoing CPUs. Note: ARM support is lagging a bit here, and these improved diagnostics might generate (harmless) splats. - NO_HZ_FULL_SYSIDLE fixes. - Tiny RCU updates to make it more tiny. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27x86/irq/tracing: Do not save callee-preserved registers around lockdep_sys_exit_thunkDenys Vlasenko1-2/+0
Internally, lockdep_sys_exit_thunk saves callee-clobbered registers, and calls a C function, lockdep_sys_exit. Thus, callee-preserved registers won't be mangled, there is no need to save them. Patch was run-tested. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1427314468-12763-4-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27x86/irq/tracing: Fold ARCH_LOCKDEP_SYS_EXIT defines into their usersDenys Vlasenko1-9/+7
There is no need to have an extra level of macro indirection here. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1427314468-12763-3-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27x86/irq/tracing: Move ARCH_LOCKDEP_SYS_EXIT defines closer to their usersDenys Vlasenko1-20/+17
This change simply moves defines around (even if it's not obvious in a patch form). Nothing is changed. This is a preparation for folding ARCH_LOCKDEP_SYS_EXIT defines into their users. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1427314468-12763-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27Merge branch 'perf/x86' into perf/core, because it's readyIngo Molnar2-1/+11
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-26KVM: nVMX: Add support for rdtscpJan Kiszka1-0/+1
If the guest CPU is supposed to support rdtscp and the host has rdtscp enabled in the secondary execution controls, we can also expose this feature to L1. Just extend nested_vmx_exit_handled to properly route EXIT_REASON_RDTSCP. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-25Merge 4.0-rc5 into char-misc-nextGreg Kroah-Hartman4-4/+3
We want those fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-24x86/asm: Further improve segment.h readabilityIngo Molnar1-100/+140
- extend/clarify explanations where necessary - move comments from macro values to before the macro, to make them more consistent, and to reduce preprocessor overhead - sort GDT index and selector values likewise by number - use consistent, modern kernel coding style across the file - capitalize consistently - use consistent vertical spacing - remove the unused get_limit() method (noticed by Andy Lutomirski) No change in code (verified with objdump -d): 64-bit defconfig+kvmconfig: 815a129bc1f80de6445c1d8ca5b97cad vmlinux.o.before.asm 815a129bc1f80de6445c1d8ca5b97cad vmlinux.o.after.asm 32-bit defconfig+kvmconfig: e659ef045159ddf41a0771b33a34aae5 vmlinux.o.before.asm e659ef045159ddf41a0771b33a34aae5 vmlinux.o.after.asm Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24x86/asm/entry/64: Rename THREAD_INFO() to ASM_THREAD_INFO()Ingo Molnar1-2/+2
The THREAD_INFO() macro has a somewhat confusingly generic name, defined in a generic .h C header file. It also does not make it clear that it constructs a memory operand for use in assembly code. Rename it to ASM_THREAD_INFO() to make it all glaringly obvious on first glance. Acked-by: Borislav Petkov <bp@suse.de> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/20150324184442.GC14760@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24x86/asm/entry/64: Merge the field offset into the THREAD_INFO() macroIngo Molnar1-2/+2
Before: TI_sysenter_return+THREAD_INFO(%rsp,3*8),%r10d After: movl THREAD_INFO(TI_sysenter_return, %rsp, 3*8), %r10d to turn it into a clear thread_info accessor. No code changed: md5: fb4cb2b3ce05d89940ca304efc8ff183 ia32entry.o.before.asm fb4cb2b3ce05d89940ca304efc8ff183 ia32entry.o.after.asm e39f2958a5d1300158e276e4f7663263 entry_64.o.before.asm e39f2958a5d1300158e276e4f7663263 entry_64.o.after.asm Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/20150324184411.GB14760@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24x86/asm/entry/64: Improve the THREAD_INFO() macro explanationIngo Molnar1-4/+23
Explain the background, and add a real example. Acked-by: Denys Vlasenko <dvlasenk@redhat.com> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Borislav Petkov <bp@suse.de> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/20150324184311.GA14760@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24x86/asm: Deobfuscate segment.hDenys Vlasenko1-70/+53
This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24x86/asm/entry: Get rid of KERNEL_STACK_OFFSETDenys Vlasenko1-3/+2
PER_CPU_VAR(kernel_stack) was set up in a way where it points five stack slots below the top of stack. Presumably, it was done to avoid one "sub $5*8,%rsp" in syscall/sysenter code paths, where iret frame needs to be created by hand. Ironically, none of them benefits from this optimization, since all of them need to allocate additional data on stack (struct pt_regs), so they still have to perform subtraction. This patch eliminates KERNEL_STACK_OFFSET. PER_CPU_VAR(kernel_stack) now points directly to top of stack. pt_regs allocations are adjusted to allocate iret frame as well. Hopefully we can merge it later with 32-bit specific PER_CPU_VAR(cpu_current_top_of_stack) variable... Net result in generated code is that constants in several insns are changed. This change is necessary for changing struct pt_regs creation in SYSCALL64 code path from MOV to PUSH instructions. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1426785469-15125-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24x86/asm/entry/64: Change the THREAD_INFO() definition to not depend on KERNEL_STACK_OFFSETDenys Vlasenko1-3/+5
This changes the THREAD_INFO() definition and all its callsites so that they do not count stack position from (top of stack - KERNEL_STACK_OFFSET), but from top of stack. Semi-mysterious expressions THREAD_INFO(%rsp,RIP) - "why RIP??" are now replaced by more logical THREAD_INFO(%rsp,SIZEOF_PTREGS) - "calculate thread_info's address using information that rsp is SIZEOF_PTREGS bytes below top of stack". While at it, replace "(off)-THREAD_SIZE(reg)" with equivalent "((off)-THREAD_SIZE)(reg)". The form without parentheses falsely looks like we invoke THREAD_SIZE() macro. Improve comment atop THREAD_INFO macro definition. This patch does not change generated code (verified by objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1426785469-15125-1-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24x86/mce: Define mce_severity function pointerAravind Gopalakrishnan1-0/+2
Rename mce_severity() to mce_severity_intel() and assign the mce_severity function pointer to mce_severity_amd() during init on AMD. This way, we can avoid a test to call mce_severity_amd every time we get into mce_severity(). And it's cleaner to do it this way. Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> Suggested-by: Tony Luck <tony.luck@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Chen Yucong <slaoub@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: linux-edac <linux-edac@vger.kernel.org> Link: http://lkml.kernel.org/r/1427125373-2918-3-git-send-email-Aravind.Gopalakrishnan@amd.com Signed-off-by: Borislav Petkov <bp@suse.de>
2015-03-24x86/mce: Add an AMD severities-grading functionAravind Gopalakrishnan1-0/+6
Add a severities function that caters to AMD processors. This allows us to do some vendor-specific work within the function if necessary. Also, introduce a vendor flag bitfield for vendor-specific settings. The severities code uses this to define error scope based on the prescence of the flags field. This is based off of work by Boris Petkov. Testing details: Fam10h, Model 9h (Greyhound) Fam15h: Models 0h-0fh (Orochi), 30h-3fh (Kaveri) and 60h-6fh (Carrizo), Fam16h Model 00h-0fh (Kabini) Boris: Intel SNB AMD K8 (JH-E0) Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Chen Yucong <slaoub@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: linux-edac@vger.kernel.org Link: http://lkml.kernel.org/r/1427125373-2918-2-git-send-email-Aravind.Gopalakrishnan@amd.com [ Fixup build, clean up comments. ] Signed-off-by: Borislav Petkov <bp@suse.de>
2015-03-24lguest: suppress interrupts for single insn, not range.Rusty Russell1-5/+2
The last patch reduced our interrupt-suppression region to one address, so simplify the code somewhat. Also, remove the obsolete undefined instruction ranges and the comment which refers to lguest_guest.S instead of head_32.S. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-23x86: kvm: Revert "remove sched notifier for cross-cpu migrations"Marcelo Tosatti1-0/+1
The following point: 2. per-CPU pvclock time info is updated if the underlying CPU changes. Is not true anymore since "KVM: x86: update pvclock area conditionally, on cpu migration". Add task migration notification back. Problem noticed by Andy Lutomirski. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> CC: stable@kernel.org # 3.11+
2015-03-23Merge 4.0-rc5 into tty-nextGreg Kroah-Hartman4-4/+3
We want the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-23x86/asm/entry: Remove user_mode_vm()Andy Lutomirski1-5/+0
It has no callers anymore. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a594afd6a0bddb1311bd7c92a15201c87fbb8681.1426728647.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/asm/entry: Make user_mode() work correctly if regs came from VM86 modeAndy Lutomirski1-10/+7
user_mode() is now identical to user_mode_vm(). Subsequent patches will change all callers of user_mode_vm() to user_mode() and then delete user_mode_vm(). Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/0dd03eacb5f0a2b5ba0240de25347a31b493c289.1426728647.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/asm/entry: Add user_mode_ignore_vm86()Andy Lutomirski1-0/+17
user_mode() is dangerous and user_mode_vm() has a confusing name. Add user_mode_ignore_vm86() (equivalent to current user_mode()). We'll change the small number of legitimate users of user_mode() to user_mode_ignore_vm86(). Inspired by grsec, although this works rather differently. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/202c56ca63823c338af8e2e54948dbe222da6343.1426728647.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23Merge tag 'v4.0-rc5' into x86/asm, to resolve conflictsIngo Molnar5-21/+14
Conflicts: arch/x86/kernel/entry_64.S Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23Merge branch 'sched/urgent' into sched/core, to pick up fixes before applying new patchesIngo Molnar32-303/+452
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/fpu: Rename drop_init_fpu() to fpu_reset_state()Borislav Petkov1-2/+6
Call it what it does and in accordance with the context where it is used: we reset the FPU state either because we were unable to restore it from the one saved in the task or because we simply want to reset it. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/fpu: Fold __drop_fpu() into its sole userBorislav Petkov1-10/+7
Fold it into drop_fpu(). Phew, one less FPU function to pay attention to. No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/fpu: Introduce restore_init_xstate()Oleg Nesterov1-6/+10
Extract the "use_eager_fpu()" code from drop_init_fpu() into a new, simple helper restore_init_xstate(). The next patch adds another user. - It is not clear why we do not check use_fxsr() like fpu_restore_checking() does. eager_fpu_init_bp() calls setup_init_fpu_buf() too, and we have the "eagerfpu=on" kernel option. - Ignoring the fact that init_xstate_buf is "struct xsave_struct *", not "union thread_xstate *", it is not clear why we can not simply use fpu_restore_checking() and avoid the code duplication. - It is not clear why we can't call setup_init_fpu_buf() unconditionally to always create init_xstate_buf(). Then do_device_not_available() path (at least) could use restore_init_xstate() too. It doesn't need to init fpu->state, its content doesn't matter until unlazy_fpu()/__switch_to()/etc which overwrites this memory anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Link: http://lkml.kernel.org/r/20150311173429.GD5032@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/fpu: Document user_fpu_begin()Oleg Nesterov1-2/+4
Currently, user_fpu_begin() has a single caller and it is not clear why do we actually need it and why we should not worry about preemption right after preempt_enable(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Link: http://lkml.kernel.org/r/20150311173409.GC5032@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23Merge tag 'v4.0-rc5' into x86/fpu, to prevent conflictsIngo Molnar32-303/+452
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23x86/asm/entry: Fix execve() and sigreturn() syscalls to always return via IRETBrian Gerst2-1/+11
Both the execve() and sigreturn() family of syscalls have the ability to change registers in ways that may not be compatabile with the syscall path they were called from. In particular, SYSRET and SYSEXIT can't handle non-default %cs and %ss, and some bits in eflags. These syscalls have stubs that are hardcoded to jump to the IRET path, and not return to the original syscall path. The following commit: 76f5df43cab5e76 ("Always allocate a complete "struct pt_regs" on the kernel stack") recently changed this for some 32-bit compat syscalls, but introduced a bug where execve from a 32-bit program to a 64-bit program would fail because it still returned via SYSRETL. This caused Wine to fail when built for both 32-bit and 64-bit. This patch sets TIF_NOTIFY_RESUME for execve() and sigreturn() so that the IRET path is always taken on exit to userspace. Signed-off-by: Brian Gerst <brgerst@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1426978461-32089-1-git-send-email-brgerst@gmail.com [ Improved the changelog and comments. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-21Merge tag 'pm+acpi-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds1-0/+2
Pull power management and ACPI fixes from Rafael Wysocki: "These are fixes for recent regressions (PCI/ACPI resources and at91 RTC locking), a stable-candidate powercap RAPL driver fix and two ARM cpuidle fixes (one stable-candidate too). Specifics: - Revert a recent PCI commit related to IRQ resources management that introduced a regression for drivers attempting to bind to devices whose previous drivers did not balance pci_enable_device() and pci_disable_device() as expected (Rafael J Wysocki). - Fix a deadlock in at91_rtc_interrupt() introduced by a typo in a recent commit related to wakeup interrupt handling (Dan Carpenter). - Allow the power capping RAPL (Running-Average Power Limit) driver to use different energy units for domains within one CPU package which is necessary to handle Intel Haswell EP processors correctly (Jacob Pan). - Improve the cpuidle mvebu driver's handling of Armada XP SoCs by updating the target residency and exit latency numbers for those chips (Sebastien Rannou). - Prevent the cpuidle mvebu driver from calling cpu_pm_enter() twice in a row before cpu_pm_exit() is called on the same CPU which breaks the core's assumptions regarding the usage of those functions (Gregory Clement)" * tag 'pm+acpi-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: Revert "x86/PCI: Refine the way to release PCI IRQ resources" rtc: at91rm9200: double locking bug in at91_rtc_interrupt() powercap / RAPL: handle domains with different energy units cpuidle: mvebu: Update cpuidle thresholds for Armada XP SOCs cpuidle: mvebu: Fix the CPU PM notifier usage
2015-03-20Revert "x86/PCI: Refine the way to release PCI IRQ resources"Rafael J. Wysocki1-0/+2
Commit b4b55cda5874 (Refine the way to release PCI IRQ resources) introduced a regression in the PCI IRQ resource management by causing the IRQ resource of a device, established when pci_enabled_device() is called on a fully disabled device, to be released when the driver is unbound from the device, regardless of the enable_cnt. This leads to the situation that an ill-behaved driver can now make a device unusable to subsequent drivers by an imbalance in their use of pci_enable/disable_device(). That is a serious problem for secondary drivers like vfio-pci, which are innocent of the transgressions of the previous driver. Since the solution of this problem is not immediate and requires further discussion, revert commit b4b55cda5874 and the issue it was supposed to address (a bug related to xen-pciback) will be taken care of in a different way going forward. Reported-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-18PM / sleep: add pm-trace support for suspending phaseZhonghui Fu1-4/+6
Occasionally, the system can't come back up after suspend/resume due to problems of device suspending phase. This patch make PM_TRACE infrastructure cover device suspending phase of suspend/resume process, and the information in RTC can tell developers which device suspending function make system hang. Signed-off-by: Zhonghui Fu <zhonghui.fu@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-17x86/asm/entry/64: Remove thread_struct::userspIngo Molnar1-1/+0
Nothing uses thread_struct::usersp anymore, so remove it. Originally-from: Denys Vlasenko <dvlasenk@redhat.com> Tested-by: Borislav Petkov <bp@alien8.de> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/asm/entry/64: Simplify 'old_rsp' usageIngo Molnar1-5/+0
Remove all manipulations of PER_CPU(old_rsp) in C code: - it is not used on SYSRET return anymore, and system entries are atomic, so updating it from the fork and context switch paths is pointless. - Tweak a few related comments as well: we no longer have a "partial stack frame" on entry, ever. Based on (split out of) patch from Denys Vlasenko. Originally-from: Denys Vlasenko <dvlasenk@redhat.com> Tested-by: Borislav Petkov <bp@alien8.de> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1426599779-8010-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/asm/entry/32: Document the 32-bit SYSENTER "emergency stack" betterDenys Vlasenko1-2/+2
Before the patch, the 'tss_struct::stack' field was not referenced anywhere. It was used only to set SYSENTER's stack to point after the last byte of tss_struct, thus the trailing field, stack[64], was used. But grep would not know it. You can comment it out, compile, and kernel will even run until an unlucky NMI corrupts io_bitmap[] (which is also not easily detectable). This patch changes code so that the purpose and usage of this field is not mysterious anymore, and can be easily grepped for. This does change generated code, for a subtle reason: since tss_struct is ____cacheline_aligned, there happens to be 5 longs of padding at the end. Old code was using the padding too; new code will strictly use it only for SYSENTER_stack[]. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1425912738-559-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/asm/entry: Simplify task_pt_regs() macro definitionDenys Vlasenko1-14/+6
Before this change, task_pt_regs() was using KSTK_TOP(), and it was the only use of that macro. In turn, KSTK_TOP used THREAD_SIZE_LONGS, and it was the only use of that macro too. Fold these macros into task_pt_regs(). Tweak comment about "- 8" - we now use a symbolic constant, not literal 8. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1426255743-5394-1-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/asm/entry/32: Document our abuse of x86_hw_tss::ss1 and x86_hw_tss::sp1Andy Lutomirski1-3/+18
This has confused me for a while. Now that I figured it out, document it. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> 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: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/b7efc1b7364039824776f68e9ddee9ec1500e894.1426009661.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/asm/entry: Unify and fix initial thread_struct::sp0 valuesAndy Lutomirski1-2/+5
x86_32 and x86_64 need slightly different thread_struct::sp0 values, and x86_32's was incorrect for init. This never mattered -- the init thread never runs user code, so we never used thread_struct::sp0 for anything. Fix it and mostly unify them. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> 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: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1b810c1d2e797e27bb4a7708c426101161edd1f6.1426009661.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/asm/entry: Create and use a 'TOP_OF_KERNEL_STACK_PADDING' macroAndy Lutomirski2-1/+29
x86_32, unlike x86_64, pads the top of the kernel stack, because the hardware stack frame formats are variable in size. Document this padding and give it a name. This should make no change whatsoever to the compiled kernel image. It also doesn't fix any of the current bugs in this area. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/02bf2f54b8dcb76a62a142b6dfe07d4ef7fc582e.1426009661.git.luto@amacapital.net [ Fixed small details, such as a missed magic constant in entry_32.S pointed out by Denys Vlasenko. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/signal/64: Remove 'fs' and 'gs' from sigcontextAndy Lutomirski2-4/+19
As far as I can tell, these fields have been set to zero on save and ignored on restore since Linux was imported into git. Rename them '__pad1' and '__pad2' to avoid confusion. This may also allow us to recycle them some day. This also adds a comment clarifying the history of those fields. I'm intentionally avoiding calling either of them '__pad0': the field formerly known as '__pad0' is now 'ss'. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/844f8490e938780c03355be4c9b69eb4c494bf4e.1426193719.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-17x86/signal/64: Fix SS handling for signals delivered to 64-bit programsAndy Lutomirski2-2/+2
The comment in the signal code says that apps can save/restore other segments on their own. It's true that apps can *save* SS on their own, but there's no way for apps to restore it: SYSCALL effectively resets SS to __USER_DS, so any value that user code tries to load into SS gets lost on entry to sigreturn. This recycles two padding bytes in the segment selector area for SS. While we're at it, we need a second change to make this useful. If the signal we're delivering is caused by a bad SS value, saving that value isn't enough. We need to remove that bad value from the regs before we try to deliver the signal. Oddly, the i386 code already got this right. I suspect that 64-bit programs that try to run 16-bit code and use signals will have a lot of trouble without this. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/405594361340a2ec32f8e2b115c142df0e180d8e.1426193719.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-16Revert "x86/mm/ASLR: Propagate base load address calculation"Borislav Petkov2-3/+0
This reverts commit: f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation") The main reason for the revert is that the new boot flag does not work at all currently, and in order to make this work, we need non-trivial changes to the x86 boot code which we didn't manage to get done in time for merging. And even if we did, they would've been too risky so instead of rushing things and break booting 4.1 on boxes left and right, we will be very strict and conservative and will take our time with this to fix and test it properly. Reported-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Baoquan He <bhe@redhat.com> Cc: H. Peter Anvin <hpa@linux.intel.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Junjie Mao <eternal.n08@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/20150316100628.GD22995@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-16sched/idle/x86: Restore mwait_idle() to fix boot hangs, to improve power savings and to improve performanceLen Brown1-0/+8
In Linux-3.9 we removed the mwait_idle() loop: 69fb3676df33 ("x86 idle: remove mwait_idle() and "idle=mwait" cmdline param") The reasoning was that modern machines should be sufficiently happy during the boot process using the default_idle() HALT loop, until cpuidle loads and either acpi_idle or intel_idle invoke the newer MWAIT-with-hints idle loop. But two machines reported problems: 1. Certain Core2-era machines support MWAIT-C1 and HALT only. MWAIT-C1 is preferred for optimal power and performance. But if they support just C1, cpuidle never loads and so they use the boot-time default idle loop forever. 2. Some laptops will boot-hang if HALT is used, but will boot successfully if MWAIT is used. This appears to be a hidden assumption in BIOS SMI, that is presumably valid on the proprietary OS where the BIOS was validated. https://bugzilla.kernel.org/show_bug.cgi?id=60770 So here we effectively revert the patch above, restoring the mwait_idle() loop. However, we don't bother restoring the idle=mwait cmdline parameter, since it appears to add no value. Maintainer notes: For 3.9, simply revert 69fb3676df for 3.10, patch -F3 applies, fuzz needed due to __cpuinit use in context For 3.11, 3.12, 3.13, this patch applies cleanly Tested-by: Mike Galbraith <bitbucket@online.de> Signed-off-by: Len Brown <len.brown@intel.com> Acked-by: Mike Galbraith <bitbucket@online.de> Cc: <stable@vger.kernel.org> # 3.9+ Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ian Malone <ibmalone@gmail.com> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/345254a551eb5a6a866e048d7ab570fd2193aca4.1389763084.git.len.brown@intel.com [ Ported to recent kernels. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-13x86/fpu: Drop_fpu() should not assume that tsk equals currentOleg Nesterov1-1/+1
drop_fpu() does clear_used_math() and usually this is correct because tsk == current. However switch_fpu_finish()->restore_fpu_checking() is called before __switch_to() updates the "current_task" variable. If it fails, we will wrongly clear the PF_USED_MATH flag of the previous task. So use clear_stopped_child_used_math() instead. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150309171041.GB11388@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-11x86: Use common outgoing-CPU-notification codePaul E. McKenney2-3/+1
This commit removes the open-coded CPU-offline notification with new common code. Among other things, this change avoids calling scheduler code using RCU from an offline CPU that RCU is ignoring. It also allows Xen to notice at online time that the CPU did not go offline correctly. Note that Xen has the surviving CPU carry out some cleanup operations, so if the surviving CPU times out, these cleanup operations might have been carried out while the outgoing CPU was still running. It might therefore be unwise to bring this CPU back online, and this commit avoids doing so. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: <x86@kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: <xen-devel@lists.xenproject.org>
2015-03-11serial, x86: use UPF_* constants for flagsAndy Shevchenko1-4/+4
This patch fixes the following sparse warnings: drivers/tty/serial/8250/8250_core.c:3231:32: warning: incorrect type in assignment (different base types) drivers/tty/serial/8250/8250_core.c:3231:32: expected restricted upf_t [usertype] flags drivers/tty/serial/8250/8250_core.c:3231:32: got unsigned int const [unsigned] flags Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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