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* x86/fpu: Use validate_xstate_header() to validate the xstate_header in ↵Eric Biggers2017-09-261-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | __fpu__restore_sig() Tighten the checks in __fpu__restore_sig() and update comments. Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-4-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Use validate_xstate_header() to validate the xstate_header in ↵Eric Biggers2017-09-261-13/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | xstateregs_set() Tighten the checks in xstateregs_set(). Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-3-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Introduce validate_xstate_header()Eric Biggers2017-09-262-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move validation of user-supplied xstate_header into a helper function, in preparation of calling it from both the ptrace and sigreturn syscall paths. The new function also considers it to be an error if *any* reserved bits are set, whereas before we were just clearing most of them silently. This should reduce the chance of bugs that fail to correctly validate user-supplied XSAVE areas. It also will expose any broken userspace programs that set the other reserved bits; this is desirable because such programs will lose compatibility with future CPUs and kernels if those bits are ever used for anything. (There shouldn't be any such programs, and in fact in the case where the compacted format is in use we were already validating xfeatures. But you never know...) Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170924105913.9157-2-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Rename fpu__activate_fpstate_read/write() to ↵Ingo Molnar2017-09-263-10/+10
| | | | | | | | | | | | | | | | | | | | | | | fpu__prepare_[read|write]() As per the new nomenclature we don't 'activate' the FPU state anymore, we initialize it. So drop the _activate_fpstate name from these functions, which were a bit of a mouthful anyway, and name them: fpu__prepare_read() fpu__prepare_write() Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Rename fpu__activate_curr() to fpu__initialize()Ingo Molnar2017-09-265-8/+8
| | | | | | | | | | | | | | | | | | | | | Rename this function to better express that it's all about initializing the FPU state of a task which goes hand in hand with the fpu::initialized field. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-33-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Simplify and speed up fpu__copy()Ingo Molnar2017-09-261-12/+3
| | | | | | | | | | | | | | | | | | | | | | | | | fpu__copy() has a preempt_disable()/enable() pair, which it had to do to be able to atomically unlazy the current task when doing an FNSAVE. But we don't unlazy tasks anymore, we always do direct saves/restores of FPU context. So remove both the unnecessary critical section, and update the comments. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-32-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Fix stale comments about lazy FPU logicIngo Molnar2017-09-261-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We don't do any lazy restore anymore, what we have are two pieces of optimization: - no-FPU tasks that don't save/restore the FPU context (kernel threads are such) - cached FPU registers maintained via the fpu->last_cpu field. This means that if an FPU task context switches to a non-FPU task then we can maintain the FPU registers as an in-FPU copies (cache), and skip the restoration of them once we switch back to the original FPU-using task. Update all the comments that still referred to old 'lazy' and 'unlazy' concepts. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-31-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Rename fpu::fpstate_active to fpu::initializedIngo Molnar2017-09-2611-35/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The x86 FPU code used to have a complex state machine where both the FPU registers and the FPU state context could be 'active' (or inactive) independently of each other - which enabled features like lazy FPU restore. Much of this complexity is gone in the current code: now we basically can have FPU-less tasks (kernel threads) that don't use (and save/restore) FPU state at all, plus full FPU users that save/restore directly with no laziness whatsoever. But the fpu::fpstate_active still carries bits of the old complexity - meanwhile this flag has become a simple flag that shows whether the FPU context saving area in the thread struct is initialized and used, or not. Rename it to fpu::initialized to express this simplicity in the name as well. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-30-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Remove fpu__current_fpstate_write_begin/end()Ingo Molnar2017-09-262-65/+0
| | | | | | | | | | | | | | | | | | | | These functions are not used anymore, so remove them. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Bobby Powers <bobbypowers@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-29-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Fix fpu__activate_fpstate_read() and update commentsIngo Molnar2017-09-261-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | fpu__activate_fpstate_read() can be called for the current task when coredumping - or for stopped tasks when ptrace-ing. Implement this properly in the code and update the comments. This also fixes an incorrect (but harmless) warning introduced by one of the earlier patches. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-28-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Reinitialize FPU registers if restoring FPU state failsEric Biggers2017-09-252-36/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Userspace can change the FPU state of a task using the ptrace() or rt_sigreturn() system calls. Because reserved bits in the FPU state can cause the XRSTOR instruction to fail, the kernel has to carefully validate that no reserved bits or other invalid values are being set. Unfortunately, there have been bugs in this validation code. For example, we were not checking that the 'xcomp_bv' field in the xstate_header was 0. As-is, such bugs are exploitable to read the FPU registers of other processes on the system. To do so, an attacker can create a task, assign to it an invalid FPU state, then spin in a loop and monitor the values of the FPU registers. Because the task's FPU registers are not being restored, sometimes the FPU registers will have the values from another process. This is likely to continue to be a problem in the future because the validation done by the CPU instructions like XRSTOR is not immediately visible to kernel developers. Nor will invalid FPU states ever be encountered during ordinary use --- they will only be seen during fuzzing or exploits. There can even be reserved bits outside the xstate_header which are easy to forget about. For example, the MXCSR register contains reserved bits, which were not validated by the KVM_SET_XSAVE ioctl until commit a575813bfe4b ("KVM: x86: Fix load damaged SSEx MXCSR register"). Therefore, mitigate this class of vulnerability by restoring the FPU registers from init_fpstate if restoring from the task's state fails. We actually used to do this, but it was (perhaps unwisely) removed by commit 9ccc27a5d297 ("x86/fpu: Remove error return values from copy_kernel_to_*regs() functions"). This new patch is also a bit different. First, it only clears the registers, not also the bad in-memory state; this is simpler and makes it easier to make the mitigation cover all callers of __copy_kernel_to_fpregs(). Second, it does the register clearing in an exception handler so that no extra instructions are added to context switches. In fact, we *remove* instructions, since previously we were always zeroing the register containing 'err' even if CONFIG_X86_DEBUG_FPU was disabled. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/20170922174156.16780-4-ebiggers3@gmail.com Link: http://lkml.kernel.org/r/20170923130016.21448-27-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Don't let userspace set bogus xcomp_bvEric Biggers2017-09-252-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On x86, userspace can use the ptrace() or rt_sigreturn() system calls to set a task's extended state (xstate) or "FPU" registers. ptrace() can set them for another task using the PTRACE_SETREGSET request with NT_X86_XSTATE, while rt_sigreturn() can set them for the current task. In either case, registers can be set to any value, but the kernel assumes that the XSAVE area itself remains valid in the sense that the CPU can restore it. However, in the case where the kernel is using the uncompacted xstate format (which it does whenever the XSAVES instruction is unavailable), it was possible for userspace to set the xcomp_bv field in the xstate_header to an arbitrary value. However, all bits in that field are reserved in the uncompacted case, so when switching to a task with nonzero xcomp_bv, the XRSTOR instruction failed with a #GP fault. This caused the WARN_ON_FPU(err) in copy_kernel_to_xregs() to be hit. In addition, since the error is otherwise ignored, the FPU registers from the task previously executing on the CPU were leaked. Fix the bug by checking that the user-supplied value of xcomp_bv is 0 in the uncompacted case, and returning an error otherwise. The reason for validating xcomp_bv rather than simply overwriting it with 0 is that we want userspace to see an error if it (incorrectly) provides an XSAVE area in compacted format rather than in uncompacted format. Note that as before, in case of error we clear the task's FPU state. This is perhaps non-ideal, especially for PTRACE_SETREGSET; it might be better to return an error before changing anything. But it seems the "clear on error" behavior is fine for now, and it's a little tricky to do otherwise because it would mean we couldn't simply copy the full userspace state into kernel memory in one __copy_from_user(). This bug was found by syzkaller, which hit the above-mentioned WARN_ON_FPU(): WARNING: CPU: 1 PID: 0 at ./arch/x86/include/asm/fpu/internal.h:373 __switch_to+0x5b5/0x5d0 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.13.0 #453 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff9ba2bc8e42c0 task.stack: ffffa78cc036c000 RIP: 0010:__switch_to+0x5b5/0x5d0 RSP: 0000:ffffa78cc08bbb88 EFLAGS: 00010082 RAX: 00000000fffffffe RBX: ffff9ba2b8bf2180 RCX: 00000000c0000100 RDX: 00000000ffffffff RSI: 000000005cb10700 RDI: ffff9ba2b8bf36c0 RBP: ffffa78cc08bbbd0 R08: 00000000929fdf46 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9ba2bc8e42c0 R13: 0000000000000000 R14: ffff9ba2b8bf3680 R15: ffff9ba2bf5d7b40 FS: 00007f7e5cb10700(0000) GS:ffff9ba2bf400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004005cc CR3: 0000000079fd5000 CR4: 00000000001406e0 Call Trace: Code: 84 00 00 00 00 00 e9 11 fd ff ff 0f ff 66 0f 1f 84 00 00 00 00 00 e9 e7 fa ff ff 0f ff 66 0f 1f 84 00 00 00 00 00 e9 c2 fa ff ff <0f> ff 66 0f 1f 84 00 00 00 00 00 e9 d4 fc ff ff 66 66 2e 0f 1f Here is a C reproducer. The expected behavior is that the program spin forever with no output. However, on a buggy kernel running on a processor with the "xsave" feature but without the "xsaves" feature (e.g. Sandy Bridge through Broadwell for Intel), within a second or two the program reports that the xmm registers were corrupted, i.e. were not restored correctly. With CONFIG_X86_DEBUG_FPU=y it also hits the above kernel warning. #define _GNU_SOURCE #include <stdbool.h> #include <inttypes.h> #include <linux/elf.h> #include <stdio.h> #include <sys/ptrace.h> #include <sys/uio.h> #include <sys/wait.h> #include <unistd.h> int main(void) { int pid = fork(); uint64_t xstate[512]; struct iovec iov = { .iov_base = xstate, .iov_len = sizeof(xstate) }; if (pid == 0) { bool tracee = true; for (int i = 0; i < sysconf(_SC_NPROCESSORS_ONLN) && tracee; i++) tracee = (fork() != 0); uint32_t xmm0[4] = { [0 ... 3] = tracee ? 0x00000000 : 0xDEADBEEF }; asm volatile(" movdqu %0, %%xmm0\n" " mov %0, %%rbx\n" "1: movdqu %%xmm0, %0\n" " mov %0, %%rax\n" " cmp %%rax, %%rbx\n" " je 1b\n" : "+m" (xmm0) : : "rax", "rbx", "xmm0"); printf("BUG: xmm registers corrupted! tracee=%d, xmm0=%08X%08X%08X%08X\n", tracee, xmm0[0], xmm0[1], xmm0[2], xmm0[3]); } else { usleep(100000); ptrace(PTRACE_ATTACH, pid, 0, 0); wait(NULL); ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov); xstate[65] = -1; ptrace(PTRACE_SETREGSET, pid, NT_X86_XSTATE, &iov); ptrace(PTRACE_CONT, pid, 0, 0); wait(NULL); } return 1; } Note: the program only tests for the bug using the ptrace() system call. The bug can also be reproduced using the rt_sigreturn() system call, but only when called from a 32-bit program, since for 64-bit programs the kernel restores the FPU state from the signal frame by doing XRSTOR directly from userspace memory (with proper error checking). Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: <stable@vger.kernel.org> [v3.17+] Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Fixes: 0b29643a5843 ("x86/xsaves: Change compacted format xsave area header") Link: http://lkml.kernel.org/r/20170922174156.16780-2-ebiggers3@gmail.com Link: http://lkml.kernel.org/r/20170923130016.21448-25-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Turn WARN_ON() in context switch into WARN_ON_FPU()Andi Kleen2017-09-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | copy_xregs_to_kernel checks if the alternatives have been already patched. This WARN_ON() is always executed in every context switch. All the other checks in fpu internal.h are WARN_ON_FPU(), but this one is plain WARN_ON(). I assume it was forgotten to switch it. So switch it to WARN_ON_FPU() too to avoid some unnecessary code in the context switch, and a potentially expensive cache line miss for the global variable. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170329062605.4970-1-andi@firstfloor.org Link: http://lkml.kernel.org/r/20170923130016.21448-24-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Fix boolreturn.cocci warningskbuild test robot2017-09-241-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | arch/x86/kernel/fpu/xstate.c:931:9-10: WARNING: return of 0/1 in function 'xfeatures_mxcsr_quirk' with return type bool Return statements in functions returning bool should use true/false instead of 1/0. Generated by: scripts/coccinelle/misc/boolreturn.cocci Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kbuild-all@01.org Cc: tipbuild@zytor.com Link: http://lkml.kernel.org/r/20170306004553.GA25764@lkp-wsm-ep1 Link: http://lkml.kernel.org/r/20170923130016.21448-23-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Add FPU state copying quirk to handle XRSTOR failure on Intel ↵Rik van Riel2017-09-242-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Skylake CPUs On Skylake CPUs I noticed that XRSTOR is unable to deal with states created by copyout_from_xsaves() if the xstate has only SSE/YMM state, and no FP state. That is, xfeatures had XFEATURE_MASK_SSE set, but not XFEATURE_MASK_FP. The reason is that part of the SSE/YMM state lives in the MXCSR and MXCSR_FLAGS fields of the FP state. Ensure that whenever we copy SSE or YMM state around, the MXCSR and MXCSR_FLAGS fields are also copied around. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170210085445.0f1cc708@annuminas.surriel.com Link: http://lkml.kernel.org/r/20170923130016.21448-22-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Remove struct fpu::fpregs_activeIngo Molnar2017-09-245-43/+1
| | | | | | | | | | | | | | | | | | | | | | The previous changes paved the way for the removal of the fpu::fpregs_active state flag - we now only have the fpu::fpstate_active and fpu::last_cpu fields left. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-21-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Decouple fpregs_activate()/fpregs_deactivate() from fpu->fpregs_activeIngo Molnar2017-09-242-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The fpregs_activate()/fpregs_deactivate() are currently called in such a pattern: if (!fpu->fpregs_active) fpregs_activate(fpu); ... if (fpu->fpregs_active) fpregs_deactivate(fpu); But note that it's actually safe to call them without checking the flag first. This further decouples the fpu->fpregs_active flag from actual FPU logic. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-20-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Change fpu->fpregs_active users to fpu->fpstate_activeIngo Molnar2017-09-244-10/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to simplify the FPU state machine by eliminating fpu->fpregs_active, and we can do that because the two state flags (::fpregs_active and ::fpstate_active) are set essentially together. The old lazy FPU switching code used to make a distinction - but there's no lazy switching code anymore, we always switch in an 'eager' fashion. Do this by first changing all substantial uses of fpu->fpregs_active to fpu->fpstate_active and adding a few debug checks to double check our assumption is correct. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-19-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Split the state handling in fpu__drop()Ingo Molnar2017-09-241-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prepare fpu__drop() to use fpu->fpregs_active. There are two distinct usecases for fpu__drop() in this context: exit_thread() when called for 'current' in exit(), and when called for another task in fork(). This patch does not change behavior, it only adds a couple of debug checks and structures the code to make the ->fpregs_active change more obviously correct. All the complications will be removed later on. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-18-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Make the fpu state change in fpu__clear() scheduler-atomicIngo Molnar2017-09-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | Do this temporarily only, to make it easier to change the FPU state machine, in particular this change couples the fpu->fpregs_active and fpu->fpstate_active states: they are only set/cleared together (as far as the scheduler sees them). This will be removed by later patches. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-17-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Simplify fpu->fpregs_active useIngo Molnar2017-09-244-22/+8
| | | | | | | | | | | | | | | | | | | | | | | | The fpregs_active() inline function is pretty pointless - in almost all the callsites it can be replaced with a direct fpu->fpregs_active access. Do so and eliminate the extra layer of obfuscation. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-16-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Flip the parameter order in copy_*_to_xstate()Ingo Molnar2017-09-244-7/+7
| | | | | | | | | | | | | | | | | | | | | | | Make it more consistent with regular memcpy() semantics, where the destination argument comes first. No change in functionality. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-15-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Remove 'kbuf' parameter from the copy_user_to_xstate() APIIngo Molnar2017-09-244-23/+11
| | | | | | | | | | | | | | | | | | | | No change in functionality. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-14-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Remove 'ubuf' parameter from the copy_kernel_to_xstate() APIIngo Molnar2017-09-243-16/+5
| | | | | | | | | | | | | | | | | | | | No change in functionality. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-13-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Split copy_user_to_xstate() into copy_kernel_to_xstate() & ↵Ingo Molnar2017-09-243-6/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | copy_user_to_xstate() Similar to: x86/fpu: Split copy_xstate_to_user() into copy_xstate_to_kernel() & copy_xstate_to_user() No change in functionality. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-12-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Simplify __copy_xstate_to_kernel() return valuesIngo Molnar2017-09-241-12/+5
| | | | | | | | | | | | | | | | | | | | | | | __copy_xstate_to_kernel() can only return 0 (because kernel copies cannot fail), simplify the code throughout. No change in functionality. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-11-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Change 'size_total' parameter to unsigned and standardize the size ↵Ingo Molnar2017-09-241-17/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | checks in copy_xstate_to_*() 'size_total' is derived from an unsigned input parameter - and then converted to 'int' and checked for negative ranges: if (size_total < 0 || offset < size_total) { This conversion and the checks are unnecessary obfuscation, reject overly large requested copy sizes outright and simplify the underlying code. Reported-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-10-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Clarify parameter names in the copy_xstate_to_*() methodsIngo Molnar2017-09-242-24/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now there's a confusing mixture of 'offset' and 'size' parameters: - __copy_xstate_to_*() input parameter 'end_pos' not not really an offset, but the full size of the copy to be performed. - input parameter 'count' to copy_xstate_to_*() shadows that of __copy_xstate_to_*()'s 'count' parameter name - but the roles are different: the first one is the total number of bytes to be copied, while the second one is a partial copy size. To unconfuse all this, use a consistent set of parameter names: - 'size' is the partial copy size within a single xstate component - 'size_total' is the total copy requested - 'offset_start' is the requested starting offset. - 'offset' is the offset within an xstate component. No change in functionality. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-9-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Remove the 'start_pos' parameter from the __copy_xstate_to_*() ↵Ingo Molnar2017-09-241-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | functions 'start_pos' is always 0, so remove it and remove the pointless check of 'pos < 0' which can not ever be true as 'pos' is unsigned ... No change in functionality. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-8-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Clean up the parameter definitions of copy_xstate_to_*()Ingo Molnar2017-09-241-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Remove pointless 'const' of non-pointer input parameter. Remove unnecessary parenthesis that shows uncertainty about arithmetic operator precedence. Clarify copy_xstate_to_user() description. No change in functionality. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-7-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Clean up parameter order in the copy_xstate_to_*() APIsIngo Molnar2017-09-243-17/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Parameter ordering is weird: int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf, struct xregs_state *xsave); int copy_xstate_to_user(unsigned int pos, unsigned int count, void __user *ubuf, struct xregs_state *xsave); 'pos' and 'count', which are attributes of the destination buffer, are listed before the destination buffer itself ... List them after the primary arguments instead. This makes the code more similar to regular memcpy() variant APIs. No change in functionality. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-6-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Remove 'kbuf' parameter from the copy_xstate_to_user() APIsIngo Molnar2017-09-243-20/+9
| | | | | | | | | | | | | | | | | | | | | | The 'kbuf' parameter is unused in the _user() side of the API, remove it. This simplifies the code and makes it easier to think about. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-5-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Remove 'ubuf' parameter from the copy_xstate_to_kernel() APIsIngo Molnar2017-09-243-17/+8
| | | | | | | | | | | | | | | | | | | | | | The 'ubuf' parameter is unused in the _kernel() side of the API, remove it. This simplifies the code and makes it easier to think about. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-4-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Split copy_xstate_to_user() into copy_xstate_to_kernel() & ↵Ingo Molnar2017-09-243-10/+109
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | copy_xstate_to_user() copy_xstate_to_user() is a weird API - in part due to a bad API inherited from the regset APIs. But don't propagate that bad API choice into the FPU code - so as a first step split the API into kernel and user buffer handling routines. (Also split the xstate_copyout() internal helper.) The split API is a dumb duplication that should be obviously correct, the real splitting will be done in the next patch. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-3-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/fpu: Rename copyin_to_xsaves()/copyout_from_xsaves() to ↵Ingo Molnar2017-09-244-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | copy_user_to_xstate()/copy_xstate_to_user() The 'copyin/copyout' nomenclature needlessly departs from what the modern FPU code uses, which is: copy_fpregs_to_fpstate() copy_fpstate_to_sigframe() copy_fregs_to_user() copy_fxregs_to_kernel() copy_fxregs_to_user() copy_kernel_to_fpregs() copy_kernel_to_fregs() copy_kernel_to_fxregs() copy_kernel_to_xregs() copy_user_to_fregs() copy_user_to_fxregs() copy_user_to_xregs() copy_xregs_to_kernel() copy_xregs_to_user() I.e. according to this pattern, the following rename should be done: copyin_to_xsaves() -> copy_user_to_xstate() copyout_from_xsaves() -> copy_xstate_to_user() or, if we want to be pedantic, denote that that the user-space format is ptrace: copyin_to_xsaves() -> copy_user_ptrace_to_xstate() copyout_from_xsaves() -> copy_xstate_to_user_ptrace() But I'd suggest the shorter, non-pedantic name. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-2-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge tag 'acpi-4.14-rc2' of ↵Linus Torvalds2017-09-224-20/+36
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI fixes from Rafael Wysocki: "These fix the initialization of resources in the ACPI WDAT watchdog driver, a recent regression in the ACPI device properties handling, a recent change in behavior causing the ACPI_HANDLE() macro to only work for GPL code and create a MAINTAINERS entry for ACPI PMIC drivers in order to specify the official reviewers for that code. Specifics: - Fix the initialization of resources in the ACPI WDAT watchdog driver that uses unititialized memory which causes compiler warnings to be triggered (Arnd Bergmann). - Fix a recent regression in the ACPI device properties handling that causes some device properties data to be skipped during enumeration (Sakari Ailus). - Fix a recent change in behavior that caused the ACPI_HANDLE() macro to stop working for non-GPL code which is a problem for the NVidia binary graphics driver, for example (John Hubbard). - Add a MAINTAINERS entry for the ACPI PMIC drivers to specify the official reviewers for that code (Rafael Wysocki)" * tag 'acpi-4.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: properties: Return _DSD hierarchical extension (data) sub-nodes correctly ACPI / bus: Make ACPI_HANDLE() work for non-GPL code again ACPI / watchdog: properly initialize resources ACPI / PMIC: Add code reviewers to MAINTAINERS
| *---. Merge branches 'acpi-pmic', 'acpi-bus', 'acpi-wdat' and 'acpi-properties'Rafael J. Wysocki2017-09-223-20/+24
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * acpi-pmic: ACPI / PMIC: Add code reviewers to MAINTAINERS * acpi-bus: ACPI / bus: Make ACPI_HANDLE() work for non-GPL code again * acpi-wdat: ACPI / watchdog: properly initialize resources * acpi-properties: ACPI: properties: Return _DSD hierarchical extension (data) sub-nodes correctly
| | | | * ACPI: properties: Return _DSD hierarchical extension (data) sub-nodes correctlySakari Ailus2017-09-191-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recently merged patch "ACPI: Prepare for constifying acpi_get_next_subnode() fwnode argument" was part of a patchset constifying the fwnode arguments across the fwnode property API. The purpose of the patch was to allow returning non-const fwnodes from a data structure the root of which is const. Unfortunately the patch introduced the functionality, in particular when starting parsed from an ACPI device node, the hierarchical data extension nodes would not be enumerated. Restore the old behaviour while still retaining constness properties of the patch. Fixes: 01c1da289791 "ACPI: Prepare for constifying acpi_get_next_subnode() fwnode argument" Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| | | * | ACPI / watchdog: properly initialize resourcesArnd Bergmann2017-09-191-1/+1
| | | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We copy a local resource structure into a list, but only initialize some of its members, as pointed out by gcc-4.4: drivers/acpi/acpi_watchdog.c: In function 'acpi_watchdog_init': drivers/acpi/acpi_watchdog.c:105: error: 'res.child' may be used uninitialized in this function drivers/acpi/acpi_watchdog.c:105: error: 'res.sibling' may be used uninitialized in this function drivers/acpi/acpi_watchdog.c:105: error: 'res.parent' may be used uninitialized in this function drivers/acpi/acpi_watchdog.c:105: error: 'res.desc' may be used uninitialized in this function drivers/acpi/acpi_watchdog.c:105: error: 'res.name' may be used uninitialized in this function Newer compilers can presumably optimize the uninitialized access away entirely and don't warn at all, but rely on the kzalloc() to zero the structure first. This adds an explicit initialization to force consistent behavior. Fixes: 058dfc767008 (ACPI / watchdog: Add support for WDAT hardware watchdog) Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| | * / ACPI / bus: Make ACPI_HANDLE() work for non-GPL code againJohn Hubbard2017-09-192-14/+17
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to commit db3e50f3234b (device property: Get rid of struct fwnode_handle type field), ACPI_HANDLE() inadvertently became a GPL-only call. The call path that led to that was: ACPI_HANDLE() ACPI_COMPANION() to_acpi_device_node() is_acpi_device_node() acpi_device_fwnode_ops DECLARE_ACPI_FWNODE_OPS(acpi_device_fwnode_ops); ...and the new DECLARE_ACPI_FWNODE_OPS() includes EXPORT_SYMBOL_GPL, whereas previously it was a static struct. In order to avoid changing any of that, let's instead provide ever so slightly better encapsulation of those struct fwnode_operations instances. Those do not really need to be directly used in inline function calls in header files. Simply moving two small functions (is_acpi_device_node and is_acpi_data_node) out of acpi_bus.h, and into a .c file, does that. That leaves the internals of struct fwnode_operations as GPL-only (which I think was the intent all along), but un-breaks any driver code out there that relies on the ACPI subsystem's being (historically) an EXPORT_SYMBOL-usable system. By that, I mean, ACPI_HANDLE() and other basic ACPI calls were non-GPL-protected. Also, while I'm there, remove a tiny bit of redundancy that was missed in the earlier commit, by having is_acpi_node() use the other two routines, instead of checking fwnode directly. Fixes: db3e50f3234b (device property: Get rid of struct fwnode_handle type field) Signed-off-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * / ACPI / PMIC: Add code reviewers to MAINTAINERSRafael Wysocki2017-09-181-0/+12
| |/ | | | | | | | | | | | | | | | | | | | | Andy and Mika review code changes under drivers/acpi/pmic/ on a regular basis and I rely on their help with that, so add them as code reviwewers for that part of the kernel. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Lee Jones <lee.jones@linaro.org> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
* | Merge tag 'pm-4.14-rc2' of ↵Linus Torvalds2017-09-227-13/+30
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These fix a cpufreq regression introduced by recent changes related to the generic DT driver, an initialization time memory leak in cpuidle on ARM, a PM core bug that may cause system suspend/resume to fail on some systems, a request type validation issue in the PM QoS framework and two documentation-related issues. Specifics: - Fix a regression in cpufreq on systems using DT as the source of CPU configuration information where two different code paths attempt to create the cpufreq-dt device object (there can be only one) and fix up the "compatible" matching for some TI platforms on top of that (Viresh Kumar, Dave Gerlach). - Fix an initialization time memory leak in cpuidle on ARM which occurs if the cpuidle driver initialization fails (Stefan Wahren). - Fix a PM core function that checks whether or not there are any system suspend/resume callbacks for a device, but forgets to check legacy callbacks which then may be skipped incorrectly and the system may crash and/or the device may become unusable after a suspend-resume cycle (Rafael Wysocki). - Fix request type validation for latency tolerance PM QoS requests which may lead to unexpected behavior (Jan Schönherr). - Fix a broken link to PM documentation from a header file and a typo in a PM document (Geert Uytterhoeven, Rafael Wysocki)" * tag 'pm-4.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpufreq: ti-cpufreq: Support additional am43xx platforms ARM: cpuidle: Avoid memleak if init fail cpufreq: dt-platdev: Add some missing platforms to the blacklist PM: core: Fix device_pm_check_callbacks() PM: docs: Drop an excess character from devices.rst PM / QoS: Use the correct variable to check the QoS request type driver core: Fix link to device power management documentation
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| *-. \ Merge branches 'pm-cpufreq' and 'pm-cpuidle'Rafael J. Wysocki2017-09-223-3/+17
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-cpufreq: cpufreq: ti-cpufreq: Support additional am43xx platforms cpufreq: dt-platdev: Add some missing platforms to the blacklist * pm-cpuidle: ARM: cpuidle: Avoid memleak if init fail
| | | * | ARM: cpuidle: Avoid memleak if init failStefan Wahren2017-09-191-2/+4
| | | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case there are no DT idle states defined or cpuidle_register_driver() fails, the copy of the idle driver is leaked: unreferenced object 0xede0dc00 (size 1024): comm "swapper/0", pid 1, jiffies 4294937431 (age 744.510s) hex dump (first 32 bytes): 94 9e 0b c1 00 00 00 00 00 00 00 00 00 00 00 00 ................ 57 46 49 00 00 00 00 00 00 00 00 00 00 00 00 00 WFI............. backtrace: [<c1295f04>] arm_idle_init+0x44/0x1ac [<c0301e6c>] do_one_initcall+0x3c/0x16c [<c1200d70>] kernel_init_freeable+0x110/0x1d0 [<c0cb3624>] kernel_init+0x8/0x114 [<c0307a98>] ret_from_fork+0x14/0x3c So fix this by freeing the unregistered copy in error case. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Fixes: d50a7d8acd78 (ARM: cpuidle: Support asymmetric idle definition) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| | * | cpufreq: ti-cpufreq: Support additional am43xx platformsDave Gerlach2017-09-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than letting the ti-cpufreq driver match against 'ti,am4372' machine compatible during probe let's match against 'ti,am43' so that we can support both 'ti,am4372' and 'ti,am438x' platforms which both match to this compatible. Signed-off-by: Dave Gerlach <d-gerlach@ti.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| | * | cpufreq: dt-platdev: Add some missing platforms to the blacklistViresh Kumar2017-09-191-0/+12
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit edeec420de24 (cpufreq: dt-platdev: Automatically create cpufreq device with OPP v2) missed adding few platforms to the blacklist which create the cpufreq-dt device from their own drivers, after some dependencies are sorted out. And for those platforms, both the platform specific driver and the cpufreq-dt-platdev driver try to create the cpufreq-dt device now. Fix that by including those platforms in the blacklist. This doesn't include the TI platforms, for which there is a separate patch. Fixes: edeec420de24 (cpufreq: dt-cpufreq: platdev Automatically create device with OPP v2) Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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| *-. \ Merge branches 'pm-core', 'pm-qos' and 'pm-docs'Rafael J. Wysocki2017-09-223-7/+7
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-core: PM: core: Fix device_pm_check_callbacks() * pm-qos: PM / QoS: Use the correct variable to check the QoS request type * pm-docs: PM: docs: Drop an excess character from devices.rst driver core: Fix link to device power management documentation
| | | * | PM: docs: Drop an excess character from devices.rstRafael J. Wysocki2017-09-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Drop an excess "`" from Documentation/driver-api/pm/devices.rst. Fixes: 2728b2d2e5be (PM / core / docs: Convert sleep states API document to reST) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| | | * | driver core: Fix link to device power management documentationGeert Uytterhoeven2017-09-181-1/+1
| | | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Correct location as of commit 2728b2d2e5be4b82 (PM / core / docs: Convert sleep states API document to reST). Fixes: 2728b2d2e5be4b82 (PM / core / docs: Convert sleep states API document to reST) Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| | * / PM / QoS: Use the correct variable to check the QoS request typeJan H. Schönherr2017-09-181-5/+5
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | Use the actual function argument for the validation of the request type, instead of the type field in a fresh (supposedly zero-initialized) request structure. Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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