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2017-11-02x86/entry/64: Use POP instead of MOV to restore regs on NMI returnAndy Lutomirski1-4/+7
This gets rid of the last user of the old RESTORE_..._REGS infrastructure. Signed-off-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/652a260f17a160789bc6a41d997f98249b73e2ab.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-11-02x86/entry/64: Merge the fast and slow SYSRET pathsAndy Lutomirski1-3/+3
They did almost the same thing. Remove a bunch of pointless instructions (mostly hidden in macros) and reduce cognitive load by merging them. Signed-off-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/1204e20233fcab9130a1ba80b3b1879b5db3fc1f.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-11-02x86/entry/64: Use pop instead of movq in syscall_return_via_sysretAndy Lutomirski1-3/+11
Saves 64 bytes. Signed-off-by: Andy Lutomirski <[email protected]> Reviewed-by: Borislav Petkov <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/6609b7f74ab31c36604ad746e019ea8495aec76c.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-11-02x86/entry/64: Shrink paranoid_exit_restore and make labels localAndy Lutomirski1-8/+5
paranoid_exit_restore was a copy of restore_regs_and_return_to_kernel. Merge them and make the paranoid_exit internal labels local. Keeping .Lparanoid_exit makes the code a bit shorter because it allows a 2-byte jnz instead of a 5-byte jnz. Saves 96 bytes of text. ( This is still a bit suboptimal in a non-CONFIG_TRACE_IRQFLAGS kernel, but fixing that would make the code rather messy. ) Signed-off-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/510d66a1895cda9473c84b1086f0bb974f22de6a.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-11-02x86/entry/64: Simplify reg restore code in the standard IRET pathsAndy Lutomirski2-6/+27
The old code restored all the registers with movq instead of pop. In theory, this was done because some CPUs have higher movq throughput, but any gain there would be tiny and is almost certainly outweighed by the higher text size. This saves 96 bytes of text. Signed-off-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/ad82520a207ccd851b04ba613f4f752b33ac05f7.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-11-02x86/entry/64: Move SWAPGS into the common IRET-to-usermode pathAndy Lutomirski2-20/+15
All of the code paths that ended up doing IRET to usermode did SWAPGS immediately beforehand. Move the SWAPGS into the common code. Signed-off-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/27fd6f45b7cd640de38fb9066fd0349bcd11f8e1.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-11-02x86/entry/64: Split the IRET-to-user and IRET-to-kernel pathsAndy Lutomirski2-10/+26
These code paths will diverge soon. Signed-off-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/dccf8c7b3750199b4b30383c812d4e2931811509.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-11-02x86/entry/64: Remove the restore_c_regs_and_iret labelAndy Lutomirski1-3/+2
The only user was the 64-bit opportunistic SYSRET failure path, and that path didn't really need it. This change makes the opportunistic SYSRET code a bit more straightforward and gets rid of the label. Signed-off-by: Andy Lutomirski <[email protected]> Reviewed-by: Borislav Petkov <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/be3006a7ad3326e3458cf1cc55d416252cbe1986.1509609304.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-10-27x86/build: Beautify build log of syscall headersMasahiro Yamada1-2/+2
This makes the build log look nicer. Before: SYSTBL arch/x86/entry/syscalls/../../include/generated/asm/syscalls_32.h SYSHDR arch/x86/entry/syscalls/../../include/generated/asm/unistd_32_ia32.h SYSHDR arch/x86/entry/syscalls/../../include/generated/asm/unistd_64_x32.h SYSTBL arch/x86/entry/syscalls/../../include/generated/asm/syscalls_64.h SYSHDR arch/x86/entry/syscalls/../../include/generated/uapi/asm/unistd_32.h SYSHDR arch/x86/entry/syscalls/../../include/generated/uapi/asm/unistd_64.h SYSHDR arch/x86/entry/syscalls/../../include/generated/uapi/asm/unistd_x32.h After: SYSTBL arch/x86/include/generated/asm/syscalls_32.h SYSHDR arch/x86/include/generated/asm/unistd_32_ia32.h SYSHDR arch/x86/include/generated/asm/unistd_64_x32.h SYSTBL arch/x86/include/generated/asm/syscalls_64.h SYSHDR arch/x86/include/generated/uapi/asm/unistd_32.h SYSHDR arch/x86/include/generated/uapi/asm/unistd_64.h SYSHDR arch/x86/include/generated/uapi/asm/unistd_x32.h Signed-off-by: Masahiro Yamada <[email protected]> Acked-by: Thomas Gleixner <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland2-2/+2
to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-10-23x86/asm: Don't use the confusing '.ifeq' directiveJosh Poimboeuf1-1/+1
I find the '.ifeq <expression>' directive to be confusing. Reading it quickly seems to suggest its opposite meaning, or that it's missing an argument. Improve readability by replacing all of its x86 uses with '.if <expression> == 0'. Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Andrei Vagin <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/757da028e802c7e98d23fbab8d234b1063e161cf.1508516398.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <[email protected]>
2017-10-23x86/entry: Fix idtentry unwind hintJosh Poimboeuf1-1/+1
This fixes the following ORC warning in the 'int3' entry code: WARNING: can't dereference iret registers at ffff8801c5f17fe0 for ip ffffffff95f0d94b The ORC metadata had the wrong stack offset for the iret registers. Their location on the stack is dependent on whether the exception has an error code. Reported-and-tested-by: Andrei Vagin <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: 8c1f75587a18 ("x86/entry/64: Add unwind hint annotations") Link: http://lkml.kernel.org/r/931d57f0551ed7979d5e7e05370d445c8e5137f8.1508516398.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <[email protected]>
2017-10-19x86: Use ARRAY_SIZEJérémy Lefaure1-1/+2
Using the ARRAY_SIZE macro improves the readability of the code. Found with Coccinelle with the following semantic patch: @r depends on (org || report)@ type T; T[] E; position p; @@ ( (sizeof(E)@p /sizeof(*E)) | (sizeof(E)@p /sizeof(E[...])) | (sizeof(E)@p /sizeof(T)) ) Signed-off-by: Jérémy Lefaure <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: Martin Mares <[email protected]> Cc: Andy Lutomirski <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2017-10-10x86/unwind: Use MSB for frame pointer encoding on 32-bitJosh Poimboeuf1-2/+2
On x86-32, Tetsuo Handa and Fengguang Wu reported unwinder warnings like: WARNING: kernel stack regs at f60bb9c8 in swapper:1 has bad 'bp' value 0ba00000 And also there were some stack dumps with a bunch of unreliable '?' symbols after an apic_timer_interrupt symbol, meaning the unwinder got confused when it tried to read the regs. The cause of those issues is that, with GCC 4.8 (and possibly older), there are cases where GCC misaligns the stack pointer in a leaf function for no apparent reason: c124a388 <acpi_rs_move_data>: c124a388: 55 push %ebp c124a389: 89 e5 mov %esp,%ebp c124a38b: 57 push %edi c124a38c: 56 push %esi c124a38d: 89 d6 mov %edx,%esi c124a38f: 53 push %ebx c124a390: 31 db xor %ebx,%ebx c124a392: 83 ec 03 sub $0x3,%esp ... c124a3e3: 83 c4 03 add $0x3,%esp c124a3e6: 5b pop %ebx c124a3e7: 5e pop %esi c124a3e8: 5f pop %edi c124a3e9: 5d pop %ebp c124a3ea: c3 ret If an interrupt occurs in such a function, the regs on the stack will be unaligned, which breaks the frame pointer encoding assumption. So on 32-bit, use the MSB instead of the LSB to encode the regs. This isn't an issue on 64-bit, because interrupts align the stack before writing to it. Reported-and-tested-by: Tetsuo Handa <[email protected]> Reported-and-tested-by: Fengguang Wu <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Byungchul Park <[email protected]> Cc: LKP <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/279a26996a482ca716605c7dbc7f2db9d8d91e81.1507597785.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <[email protected]>
2017-09-04Merge branch 'x86-apic-for-linus' of ↵Linus Torvalds4-64/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 apic updates from Thomas Gleixner: "This update provides: - Cleanup of the IDT management including the removal of the extra tracing IDT. A first step to cleanup the vector management code. - The removal of the paravirt op adjust_exception_frame. This is a XEN specific issue, but merged through this branch to avoid nasty merge collisions - Prevent dmesg spam about the TSC DEADLINE bug, when the CPU has disabled the TSC DEADLINE timer in CPUID. - Adjust a debug message in the ioapic code to print out the information correctly" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) x86/idt: Fix the X86_TRAP_BP gate x86/xen: Get rid of paravirt op adjust_exception_frame x86/eisa: Add missing include x86/idt: Remove superfluous ALIGNment x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on CPUs without the feature x86/idt: Remove the tracing IDT leftovers x86/idt: Hide set_intr_gate() x86/idt: Simplify alloc_intr_gate() x86/idt: Deinline setup functions x86/idt: Remove unused functions/inlines x86/idt: Move interrupt gate initialization to IDT code x86/idt: Move APIC gate initialization to tables x86/idt: Move regular trap init to tables x86/idt: Move IST stack based traps to table init x86/idt: Move debug stack init to table based x86/idt: Switch early trap init to IDT tables x86/idt: Prepare for table based init x86/idt: Move early IDT setup out of 32-bit asm x86/idt: Move early IDT handler setup to IDT code x86/idt: Consolidate IDT invalidation ...
2017-09-04Merge branch 'x86-syscall-for-linus' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull syscall updates from Ingo Molnar: "Improve the security of set_fs(): we now check the address limit on a number of key platforms (x86, arm, arm64) before returning to user-space - without adding overhead to the typical system call fast path" * 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: arm64/syscalls: Check address limit on user-mode return arm/syscalls: Check address limit on user-mode return x86/syscalls: Check address limit on user-mode return
2017-09-04Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds4-44/+152
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: - Introduce the ORC unwinder, which can be enabled via CONFIG_ORC_UNWINDER=y. The ORC unwinder is a lightweight, Linux kernel specific debuginfo implementation, which aims to be DWARF done right for unwinding. Objtool is used to generate the ORC unwinder tables during build, so the data format is flexible and kernel internal: there's no dependency on debuginfo created by an external toolchain. The ORC unwinder is almost two orders of magnitude faster than the (out of tree) DWARF unwinder - which is important for perf call graph profiling. It is also significantly simpler and is coded defensively: there has not been a single ORC related kernel crash so far, even with early versions. (knock on wood!) But the main advantage is that enabling the ORC unwinder allows CONFIG_FRAME_POINTERS to be turned off - which speeds up the kernel measurably: With frame pointers disabled, GCC does not have to add frame pointer instrumentation code to every function in the kernel. The kernel's .text size decreases by about 3.2%, resulting in better cache utilization and fewer instructions executed, resulting in a broad kernel-wide speedup. Average speedup of system calls should be roughly in the 1-3% range - measurements by Mel Gorman [1] have shown a speedup of 5-10% for some function execution intense workloads. The main cost of the unwinder is that the unwinder data has to be stored in RAM: the memory cost is 2-4MB of RAM, depending on kernel config - which is a modest cost on modern x86 systems. Given how young the ORC unwinder code is it's not enabled by default - but given the performance advantages the plan is to eventually make it the default unwinder on x86. See Documentation/x86/orc-unwinder.txt for more details. - Remove lguest support: its intended role was that of a temporary proof of concept for virtualization, plus its removal will enable the reduction (removal) of the paravirt API as well, so Rusty agreed to its removal. (Juergen Gross) - Clean up and fix FSGS related functionality (Andy Lutomirski) - Clean up IO access APIs (Andy Shevchenko) - Enhance the symbol namespace (Jiri Slaby) * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits) objtool: Handle GCC stack pointer adjustment bug x86/entry/64: Use ENTRY() instead of ALIGN+GLOBAL for stub32_clone() x86/fpu/math-emu: Add ENDPROC to functions x86/boot/64: Extract efi_pe_entry() from startup_64() x86/boot/32: Extract efi_pe_entry() from startup_32() x86/lguest: Remove lguest support x86/paravirt/xen: Remove xen_patch() objtool: Fix objtool fallthrough detection with function padding x86/xen/64: Fix the reported SS and CS in SYSCALL objtool: Track DRAP separately from callee-saved registers objtool: Fix validate_branch() return codes x86: Clarify/fix no-op barriers for text_poke_bp() x86/switch_to/64: Rewrite FS/GS switching yet again to fix AMD CPUs selftests/x86/fsgsbase: Test selectors 1, 2, and 3 x86/fsgsbase/64: Report FSBASE and GSBASE correctly in core dumps x86/fsgsbase/64: Fully initialize FS and GS state in start_thread_common x86/asm: Fix UNWIND_HINT_REGS macro for older binutils x86/asm/32: Fix regs_get_register() on segment registers x86/xen/64: Rearrange the SYSCALL entries x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads ...
2017-08-31x86/xen: Get rid of paravirt op adjust_exception_frameJuergen Gross2-20/+4
When running as Xen pv-guest the exception frame on the stack contains %r11 and %rcx additional to the other data pushed by the processor. Instead of having a paravirt op being called for each exception type prepend the Xen specific code to each exception entry. When running as Xen pv-guest just use the exception entry with prepended instructions, otherwise use the entry without the Xen specific code. [ tglx: Merged through tip to avoid ugly merge conflict ] Signed-off-by: Juergen Gross <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected]
2017-08-29x86/entry/64: Use ENTRY() instead of ALIGN+GLOBAL for stub32_clone()Jiri Slaby1-2/+2
ALIGN+GLOBAL is effectively what ENTRY() does, so use ENTRY() which is dedicated for exactly this purpose -- global functions. Note that stub32_clone() is a C-like leaf function -- it has a standard call frame -- it only switches one argument and continues by jumping into C. Since each ENTRY() should be balanced by some END*() marker, we add a corresponding ENDPROC() to stub32_clone() too. Besides that, x86's custom GLOBAL macro is going to die very soon. Signed-off-by: Jiri Slaby <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-08-29x86/gdt: Use bitfields for initializationThomas Gleixner1-1/+1
The GDT entry related code uses two ways to access entries via union fields: - bitfields - macros which initialize the two 16-bit parts of the entry by magic shift and mask operations. Clean it up and only use the bitfields to initialize and access entries. ( The old access patterns were partly done due to GCC optimizing bitfield accesses in a horrible way - that's mostly fixed these days and clarity of code in such low level accessors is very important. ) Signed-off-by: Thomas Gleixner <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-08-29x86/idt: Remove the tracing IDT completelyThomas Gleixner2-23/+2
No more users of the tracing IDT. All exception tracepoints have been moved into the regular handlers. Get rid of the mess which shouldn't have been created in the first place. Signed-off-by: Thomas Gleixner <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-08-29x86/traps: Simplify pagefault tracing logicThomas Gleixner2-20/+1
Make use of the new irqvector tracing static key and remove the duplicated trace_do_pagefault() implementation. If irq vector tracing is disabled, then the overhead of this is a single NOP5, which is a reasonable tradeoff to avoid duplicated code and the unholy macro mess. Signed-off-by: Thomas Gleixner <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-08-24Merge branch 'linus' into perf/core, to pick up fixesIngo Molnar1-0/+2
Signed-off-by: Ingo Molnar <[email protected]>
2017-08-10irq: Make the irqentry text section unconditionalMasami Hiramatsu1-7/+2
Generate irqentry and softirqentry text sections without any Kconfig dependencies. This will add extra sections, but there should be no performace impact. Suggested-by: Ingo Molnar <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Ananth N Mavinakayanahalli <[email protected]> Cc: Anil S Keshavamurthy <[email protected]> Cc: Chris Zankel <[email protected]> Cc: David S . Miller <[email protected]> Cc: Francis Deslauriers <[email protected]> Cc: Jesper Nilsson <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Max Filippov <[email protected]> Cc: Mikael Starvik <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Yoshinori Sato <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/150172789110.27216.3955739126693102122.stgit@devbox Signed-off-by: Ingo Molnar <[email protected]>
2017-08-10x86/xen/64: Rearrange the SYSCALL entriesAndy Lutomirski2-11/+5
Xen's raw SYSCALL entries are much less weird than native. Rather than fudging them to look like native entries, use the Xen-provided stack frame directly. This lets us eliminate entry_SYSCALL_64_after_swapgs and two uses of the SWAPGS_UNSAFE_STACK paravirt hook. The SYSENTER code would benefit from similar treatment. This makes one change to the native code path: the compat instruction that clears the high 32 bits of %rax is moved slightly later. I'd be surprised if this affects performance at all. Tested-by: Juergen Gross <[email protected]> Signed-off-by: Andy Lutomirski <[email protected]> Reviewed-by: Juergen Gross <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/7c88ed36805d36841ab03ec3b48b4122c4418d71.1502164668.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-08-10Merge branch 'x86/urgent' into x86/asm, to pick up fixesIngo Molnar1-0/+3
Signed-off-by: Ingo Molnar <[email protected]>
2017-08-10x86/asm/64: Clear AC on NMI entriesAndy Lutomirski1-0/+2
This closes a hole in our SMAP implementation. This patch comes from grsecurity. Good catch! Signed-off-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/314cc9f294e8f14ed85485727556ad4f15bb1659.1502159503.git.luto@kernel.org Signed-off-by: Ingo Molnar <[email protected]>
2017-07-26x86: irq: Define a global vector for nested posted interruptsWincy Van1-0/+1
We are using the same vector for nested/non-nested posted interrupts delivery, this may cause interrupts latency in L1 since we can't kick the L2 vcpu out of vmx-nonroot mode. This patch introduces a new vector which is only for nested posted interrupts to solve the problems above. Signed-off-by: Wincy Van <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2017-07-18x86/entry/64: Add unwind hint annotationsJosh Poimboeuf3-11/+66
Add unwind hint annotations to entry_64.S. This will enable the ORC unwinder to unwind through any location in the entry code including syscalls, interrupts, and exceptions. Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/b9f6d478aadf68ba57c739dcfac34ec0dc021c4c.1499786555.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <[email protected]>
2017-07-18x86/entry/64: Initialize the top of the IRQ stack before switching stacksAndy Lutomirski1-1/+23
The OOPS unwinder wants the word at the top of the IRQ stack to point back to the previous stack at all times when the IRQ stack is in use. There's currently a one-instruction window in ENTER_IRQ_STACK during which this isn't the case. Fix it by writing the old RSP to the top of the IRQ stack before jumping. This currently writes the pointer to the stack twice, which is a bit ugly. We could get rid of this by replacing irq_stack_ptr with irq_stack_ptr_minus_eight (better name welcome). OTOH, there may be all kinds of odd microarchitectural considerations in play that affect performance by a few cycles here. Reported-by: Mike Galbraith <[email protected]> Reported-by: Josh Poimboeuf <[email protected]> Signed-off-by: Andy Lutomirski <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/aae7e79e49914808440ad5310ace138ced2179ca.1499786555.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <[email protected]>
2017-07-18x86/entry/64: Refactor IRQ stacks and make them NMI-safeAndy Lutomirski1-24/+61
This will allow IRQ stacks to nest inside NMIs or similar entries that can happen during IRQ stack setup or teardown. The new macros won't work correctly if they're invoked with IRQs on. Add a check under CONFIG_DEBUG_ENTRY to detect that. Signed-off-by: Andy Lutomirski <[email protected]> [ Use %r10 instead of %r11 in xen_do_hypervisor_callback to make objtool and ORC unwinder's lives a little easier. ] Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/b0b2ff5fb97d2da2e1d7e1f380190c92545c8bb5.1499786555.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <[email protected]>
2017-07-08Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds1-3/+0
Pull ARM updates from Russell King: - add support for ftrace-with-registers, which is needed for kgraft and other ftrace tools - support for mremap() for the sigpage/vDSO so that checkpoint/restore can work - add timestamps to each line of the register dump output - remove the unused KTHREAD_SIZE from nommu - align the ARM bitops APIs with the generic API (using unsigned long pointers rather than void pointers) - make the configuration of userspace Thumb support an expert option so that we can default it on, and avoid some hard to debug userspace crashes * 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 8684/1: NOMMU: Remove unused KTHREAD_SIZE definition ARM: 8683/1: ARM32: Support mremap() for sigpage/vDSO ARM: 8679/1: bitops: Align prototypes to generic API ARM: 8678/1: ftrace: Adds support for CONFIG_DYNAMIC_FTRACE_WITH_REGS ARM: make configuration of userspace Thumb support an expert option ARM: 8673/1: Fix __show_regs output timestamps
2017-07-08x86/syscalls: Check address limit on user-mode returnThomas Garnier1-0/+3
Ensure the address limit is a user-mode segment before returning to user-mode. Otherwise a process can corrupt kernel-mode memory and elevate privileges [1]. The set_fs function sets the TIF_SETFS flag to force a slow path on return. In the slow path, the address limit is checked to be USER_DS if needed. The addr_limit_user_check function is added as a cross-architecture function to check the address limit. [1] https://bugs.chromium.org/p/project-zero/issues/detail?id=990 Signed-off-by: Thomas Garnier <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Mark Rutland <[email protected]> Cc: [email protected] Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: David Howells <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Miroslav Benes <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Pratyush Anand <[email protected]> Cc: Russell King <[email protected]> Cc: Petr Mladek <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Kees Cook <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Al Viro <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: [email protected] Cc: Will Drewry <[email protected]> Cc: [email protected] Cc: Oleg Nesterov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Paolo Bonzini <[email protected]> Link: http://lkml.kernel.org/r/[email protected]
2017-06-21ARM: 8683/1: ARM32: Support mremap() for sigpage/vDSODmitry Safonov1-3/+0
CRIU restores application mappings on the same place where they were before Checkpoint. That means, that we need to move vDSO and sigpage during restore on exactly the same place where they were before C/R. Make mremap() code update mm->context.{sigpage,vdso} pointers during VMA move. Sigpage is used for landing after handling a signal - if the pointer is not updated during moving, the application might crash on any signal after mremap(). vDSO pointer on ARM32 is used only for setting auxv at this moment, update it during mremap() in case of future usage. Without those updates, current work of CRIU on ARM32 is not reliable. Historically, we error Checkpointing if we find vDSO page on ARM32 and suggest user to disable CONFIG_VDSO. But that's not correct - it goes from x86 where signal processing is ended in vDSO blob. For arm32 it's sigpage, which is not disabled with `CONFIG_VDSO=n'. Looks like C/R was working by luck - because userspace on ARM32 at this moment always sets SA_RESTORER. Signed-off-by: Dmitry Safonov <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Cc: [email protected] Cc: Will Deacon <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Cyrill Gorcunov <[email protected]> Cc: Pavel Emelyanov <[email protected]> Cc: Christopher Covington <[email protected]> Signed-off-by: Russell King <[email protected]>
2017-06-13x86/asm: Fix comment in return_from_SYSCALL_64()Kirill A. Shutemov1-1/+2
On x86-64 __VIRTUAL_MASK_SHIFT depends on paging mode now. Signed-off-by: Kirill A. Shutemov <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-05-24Revert "x86/entry: Fix the end of the stack for newly forked tasks"Josh Poimboeuf2-18/+23
Petr Mladek reported the following warning when loading the livepatch sample module: WARNING: CPU: 1 PID: 3699 at arch/x86/kernel/stacktrace.c:132 save_stack_trace_tsk_reliable+0x133/0x1a0 ... Call Trace: __schedule+0x273/0x820 schedule+0x36/0x80 kthreadd+0x305/0x310 ? kthread_create_on_cpu+0x80/0x80 ? icmp_echo.part.32+0x50/0x50 ret_from_fork+0x2c/0x40 That warning means the end of the stack is no longer recognized as such for newly forked tasks. The problem was introduced with the following commit: ff3f7e2475bb ("x86/entry: Fix the end of the stack for newly forked tasks") ... which was completely misguided. It only partially fixed the reported issue, and it introduced another bug in the process. None of the other entry code saves the frame pointer before calling into C code, so it doesn't make sense for ret_from_fork to do so either. Contrary to what I originally thought, the original issue wasn't related to newly forked tasks. It was actually related to ftrace. When entry code calls into a function which then calls into an ftrace handler, the stack frame looks different than normal. The original issue will be fixed in the unwinder, in a subsequent patch. Reported-by: Petr Mladek <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Acked-by: Thomas Gleixner <[email protected]> Cc: Dave Jones <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Fixes: ff3f7e2475bb ("x86/entry: Fix the end of the stack for newly forked tasks") Link: http://lkml.kernel.org/r/f350760f7e82f0750c8d1dd093456eb212751caa.1495553739.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <[email protected]>
2017-05-02Merge branch 'for-linus' of ↵Linus Torvalds1-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatch updates from Jiri Kosina: - a per-task consistency model is being added for architectures that support reliable stack dumping (extending this, currently rather trivial set, is currently in the works). This extends the nature of the types of patches that can be applied by live patching infrastructure. The code stems from the design proposal made [1] back in November 2014. It's a hybrid of SUSE's kGraft and RH's kpatch, combining advantages of both: it uses kGraft's per-task consistency and syscall barrier switching combined with kpatch's stack trace switching. There are also a number of fallback options which make it quite flexible. Most of the heavy lifting done by Josh Poimboeuf with help from Miroslav Benes and Petr Mladek [1] https://lkml.kernel.org/r/[email protected] - module load time patch optimization from Zhou Chengming - a few assorted small fixes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: add missing printk newlines livepatch: Cancel transition a safe way for immediate patches livepatch: Reduce the time of finding module symbols livepatch: make klp_mutex proper part of API livepatch: allow removal of a disabled patch livepatch: add /proc/<pid>/patch_state livepatch: change to a per-task consistency model livepatch: store function sizes livepatch: use kstrtobool() in enabled_store() livepatch: move patching functions into patch.c livepatch: remove unnecessary object loaded check livepatch: separate enabled and patched states livepatch/s390: add TIF_PATCH_PENDING thread flag livepatch/s390: reorganize TIF thread flag bits livepatch/powerpc: add TIF_PATCH_PENDING thread flag livepatch/x86: add TIF_PATCH_PENDING thread flag livepatch: create temporary klp_update_patch_state() stub x86/entry: define _TIF_ALLWORK_MASK flags explicitly stacktrace/x86: add function for detecting reliable stack traces
2017-05-02Merge branch 'work.compat' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull fs/compat.c cleanups from Al Viro: "More moving of compat syscalls from fs/compat.c to fs/*.c where the native counterparts live. And death to compat_sys_getdents64() - the only architecture that used to need it was ia64, and _that_ has lost biarch support quite a few years ago" * 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs/compat.c: trim unused includes move compat_rw_copy_check_uvector() over to fs/read_write.c fhandle: move compat syscalls from compat.c open: move compat syscalls from compat.c stat: move compat syscalls from compat.c fcntl: move compat syscalls from compat.c readdir: move compat syscalls from compat.c statfs: move compat syscalls from compat.c utimes: move compat syscalls from compat.c move compat select-related syscalls to fs/select.c Remove compat_sys_getdents64()
2017-05-01Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds2-6/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "The main x86 MM changes in this cycle were: - continued native kernel PCID support preparation patches to the TLB flushing code (Andy Lutomirski) - various fixes related to 32-bit compat syscall returning address over 4Gb in applications, launched from 64-bit binaries - motivated by C/R frameworks such as Virtuozzo. (Dmitry Safonov) - continued Intel 5-level paging enablement: in particular the conversion of x86 GUP to the generic GUP code. (Kirill A. Shutemov) - x86/mpx ABI corner case fixes/enhancements (Joerg Roedel) - ... plus misc updates, fixes and cleanups" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (62 commits) mm, zone_device: Replace {get, put}_zone_device_page() with a single reference to fix pmem crash x86/mm: Fix flush_tlb_page() on Xen x86/mm: Make flush_tlb_mm_range() more predictable x86/mm: Remove flush_tlb() and flush_tlb_current_task() x86/vm86/32: Switch to flush_tlb_mm_range() in mark_screen_rdonly() x86/mm/64: Fix crash in remove_pagetable() Revert "x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation" x86/boot/e820: Remove a redundant self assignment x86/mm: Fix dump pagetables for 4 levels of page tables x86/mpx, selftests: Only check bounds-vs-shadow when we keep shadow x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space Revert "x86/mm/numa: Remove numa_nodemask_from_meminfo()" x86/espfix: Add support for 5-level paging x86/kasan: Extend KASAN to support 5-level paging x86/mm: Add basic defines/helpers for CONFIG_X86_5LEVEL=y x86/paravirt: Add 5-level support to the paravirt code x86/mm: Define virtual memory map for 5-level paging x86/asm: Remove __VIRTUAL_MASK_SHIFT==47 assert x86/boot: Detect 5-level paging support x86/mm/numa: Remove numa_nodemask_from_meminfo() ...
2017-05-01Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds4-1/+36
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso updates from Ingo Molnar: "Add support for vDSO acceleration of the "Hyper-V TSC page", to speed up clock reading on Hyper-V guests" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Add VCLOCK_HVCLOCK vDSO clock read method x86/hyperv: Move TSC reading method to asm/mshyperv.h x86/hyperv: Implement hv_get_tsc_page()
2017-05-01Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2-178/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this cycle were: - unwinder fixes and enhancements - improve ftrace interaction with the unwinder - optimize the code footprint of WARN() and related debugging constructs - ... plus misc updates, cleanups and fixes" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/unwind: Dump all stacks in unwind_dump() x86/unwind: Silence more entry-code related warnings x86/ftrace: Fix ebp in ftrace_regs_caller that screws up unwinder x86/unwind: Remove unused 'sp' parameter in unwind_dump() x86/unwind: Prepend hex mask value with '0x' in unwind_dump() x86/unwind: Properly zero-pad 32-bit values in unwind_dump() x86/unwind: Ensure stack pointer is aligned debug: Avoid setting BUGFLAG_WARNING twice x86/unwind: Silence entry-related warnings x86/unwind: Read stack return address in update_stack_state() x86/unwind: Move common code into update_stack_state() debug: Fix __bug_table[] in arch linker scripts debug: Add _ONCE() logic to report_bug() x86/debug: Define BUG() again for !CONFIG_BUG x86/debug: Implement __WARN() using UD0 x86/ftrace: Use Makefile logic instead of #ifdef for compiling ftrace_*.o x86/ftrace: Add -mfentry support to x86_32 with DYNAMIC_FTRACE set x86/ftrace: Clean up ftrace_regs_caller x86/ftrace: Add stack frame pointer to ftrace_caller x86/ftrace: Move the ftrace specific code out of entry_32.S ...
2017-05-01Merge branch 'x86-process-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pul x86/process updates from Ingo Molnar: "The main change in this cycle was to add the ARCH_[GET|SET]_CPUID prctl() ABI extension to control the availability of the CPUID instruction, analogously to the existing PR_GET|SET_TSC ABI that controls RDTSC. Motivation: the 'rr' user-space record-and-replay execution debugger would like to trap and emulate the CPUID instruction - which instruction is normally unprivileged. Trapping CPUID is possible on IvyBridge and later Intel CPUs - expose this hardware capability" * 'x86-process-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/syscalls/32: Ignore arch_prctl for other architectures um/arch_prctl: Fix fallout from x86 arch_prctl() rework x86/arch_prctl: Add ARCH_[GET|SET]_CPUID x86/cpufeature: Detect CPUID faulting support x86/syscalls/32: Wire up arch_prctl on x86-32 x86/arch_prctl: Add do_arch_prctl_common() x86/arch_prctl/64: Rename do_arch_prctl() to do_arch_prctl_64() x86/arch_prctl/64: Use SYSCALL_DEFINE2 to define sys_arch_prctl() x86/arch_prctl: Rename 'code' argument to 'option' x86/msr: Rename MISC_FEATURE_ENABLES to MISC_FEATURES_ENABLES x86/process: Optimize TIF_NOTSC switch x86/process: Correct and optimize TIF_BLOCKSTEP switch x86/process: Optimize TIF checks in __switch_to_xtra()
2017-04-17Remove compat_sys_getdents64()Al Viro1-1/+1
Unlike normal compat syscall variants, it is needed only for biarch architectures that have different alignement requirements for u64 in 32bit and 64bit ABI *and* have __put_user() that won't handle a store of 64bit value at 32bit-aligned address. We used to have one such (ia64), but its biarch support has been gone since 2010 (after being broken in 2008, which went unnoticed since nobody had been using it). It had escaped removal at the same time only because back in 2004 a patch that switched several syscalls on amd64 from private wrappers to generic compat ones had switched to use of compat_sys_getdents64(), which hadn't needed (or used) a compat wrapper on amd64. Let's bury it - it's at least 7 years overdue. Signed-off-by: Al Viro <[email protected]>
2017-04-10x86/vdso: Ensure vdso32_enabled gets set to valid values onlyMathias Krause1-2/+9
vdso_enabled can be set to arbitrary integer values via the kernel command line 'vdso32=' parameter or via 'sysctl abi.vsyscall32'. load_vdso32() only maps VDSO if vdso_enabled == 1, but ARCH_DLINFO_IA32 merily checks for vdso_enabled != 0. As a consequence the AT_SYSINFO_EHDR auxiliary vector for the VDSO_ENTRY is emitted with a NULL pointer which causes a segfault when the application tries to use the VDSO. Restrict the valid arguments on the command line and the sysctl to 0 and 1. Fixes: b0b49f2673f0 ("x86, vdso: Remove compat vdso support") Signed-off-by: Mathias Krause <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: [email protected] Cc: Roland McGrath <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2017-04-04x86/asm: Remove __VIRTUAL_MASK_SHIFT==47 assertKirill A. Shutemov1-5/+2
We don't need the assert anymore, as: 17be0aec74fb ("x86/asm/entry/64: Implement better check for canonical addresses") made canonical address checks generic wrt. address width. Signed-off-by: Kirill A. Shutemov <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2017-03-24x86/ftrace: Move the ftrace specific code out of entry_32.SSteven Rostedt (VMware)1-169/+0
The function tracing hook code for ftrace is not an entry point from userspace and does not belong in the entry_*.S files. It has already been moved out of entry_64.S. Move it out of entry_32.S into its own ftrace_32.S file. Signed-off-by: Steven Rostedt (VMware) <[email protected]> Reviewed-by: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2017-03-23Merge branch 'x86/process' into x86/mm, to create new base for further patchesIngo Molnar1-0/+1
Signed-off-by: Ingo Molnar <[email protected]>
2017-03-23Merge branch 'linus' into x86/asm, to refresh the topic tree with fixesIngo Molnar5-0/+6
Signed-off-by: Ingo Molnar <[email protected]>
2017-03-20x86/syscalls/32: Wire up arch_prctl on x86-32Kyle Huey1-0/+1
Hook up arch_prctl to call do_arch_prctl() on x86-32, and in 32 bit compat mode on x86-64. This allows to have arch_prctls that are not specific to 64 bits. On UML, simply stub out this syscall. Signed-off-by: Kyle Huey <[email protected]> Cc: Grzegorz Andrejczuk <[email protected]> Cc: [email protected] Cc: Radim Krčmář <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Andi Kleen <[email protected]> Cc: [email protected] Cc: Nadav Amit <[email protected]> Cc: Robert O'Callahan <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Len Brown <[email protected]> Cc: Shuah Khan <[email protected]> Cc: [email protected] Cc: Jeff Dike <[email protected]> Cc: Alexander Viro <[email protected]> Cc: [email protected] Cc: David Matlack <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: [email protected] Cc: Paolo Bonzini <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2017-03-16x86: Remap GDT tables in the fixmap sectionThomas Garnier1-1/+1
Each processor holds a GDT in its per-cpu structure. The sgdt instruction gives the base address of the current GDT. This address can be used to bypass KASLR memory randomization. With another bug, an attacker could target other per-cpu structures or deduce the base of the main memory section (PAGE_OFFSET). This patch relocates the GDT table for each processor inside the fixmap section. The space is reserved based on number of supported processors. For consistency, the remapping is done by default on 32 and 64-bit. Each processor switches to its remapped GDT at the end of initialization. For hibernation, the main processor returns with the original GDT and switches back to the remapping at completion. This patch was tested on both architectures. Hibernation and KVM were both tested specially for their usage of the GDT. Thanks to Boris Ostrovsky <[email protected]> for testing and recommending changes for Xen support. Signed-off-by: Thomas Garnier <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Chris Wilson <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Joerg Roedel <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Kees Cook <[email protected]> Cc: Len Brown <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Lorenzo Stoakes <[email protected]> Cc: Luis R . Rodriguez <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Paul Gortmaker <[email protected]> Cc: Pavel Machek <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Radim Krčmář <[email protected]> Cc: Rafael J . Wysocki <[email protected]> Cc: Rusty Russell <[email protected]> Cc: Stanislaw Gruszka <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tim Chen <[email protected]> Cc: Vitaly Kuznetsov <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: zijun_hu <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
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