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2020-11-04Merge branch 'core/urgent' into core/entryThomas Gleixner
Pick up the entry fix before further modifications.
2020-10-29entry: Add support for TIF_NOTIFY_SIGNALJens Axboe
Add TIF_NOTIFY_SIGNAL handling in the generic entry code, which if set, will return true if signal_pending() is used in a wait loop. That causes an exit of the loop so that notify_signal tracehooks can be run. If the wait loop is currently inside a system call, the system call is restarted once task_work has been processed. In preparation for only having arch_do_signal() handle syscall restarts if _TIF_SIGPENDING isn't set, rename it to arch_do_signal_or_restart(). Pass in a boolean that tells the architecture specific signal handler if it should attempt to get a signal, or just process a potential syscall restart. For !CONFIG_GENERIC_ENTRY archs, add the TIF_NOTIFY_SIGNAL handling to get_signal(). This is done to minimize the needed architecture changes to support this feature. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20201026203230.386348-3-axboe@kernel.dk
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-24x86/entry: Use generic syscall exit functionalityThomas Gleixner
Replace the x86 variant with the generic version. Provide the relevant architecture specific helper functions and defines. Use a temporary define for idtentry_exit_user which will be cleaned up seperately. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20200722220520.494648601@linutronix.de
2020-06-01Merge branch 'work.set_fs-exec' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull uaccess/coredump updates from Al Viro: "set_fs() removal in coredump-related area - mostly Christoph's stuff..." * 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: binfmt_elf_fdpic: remove the set_fs(KERNEL_DS) in elf_fdpic_core_dump binfmt_elf: remove the set_fs(KERNEL_DS) in elf_core_dump binfmt_elf: remove the set_fs in fill_siginfo_note signal: refactor copy_siginfo_to_user32 powerpc/spufs: simplify spufs core dumping powerpc/spufs: stop using access_ok powerpc/spufs: fix copy_to_user while atomic
2020-05-13x86/fpu/xstate: Define new functions for clearing fpregs and xstatesFenghua Yu
Currently, fpu__clear() clears all fpregs and xstates. Once XSAVES supervisor states are introduced, supervisor settings (e.g. CET xstates) must remain active for signals; It is necessary to have separate functions: - Create fpu__clear_user_states(): clear only user settings for signals; - Create fpu__clear_all(): clear both user and supervisor settings in flush_thread(). Also modify copy_init_fpstate_to_fpregs() to take a mask from above two functions. Remove obvious side-comment in fpu__clear(), while at it. [ bp: Make the second argument of fpu__clear() bool after requesting it a bunch of times during review. - Add a comment about copy_init_fpstate_to_fpregs() locking needs. ] Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20200512145444.15483-6-yu-cheng.yu@intel.com
2020-05-05signal: refactor copy_siginfo_to_user32Christoph Hellwig
Factor out a copy_siginfo_to_external32 helper from copy_siginfo_to_user32 that fills out the compat_siginfo, but does so on a kernel space data structure. With that we can let architectures override copy_siginfo_to_user32 with their own implementations using copy_siginfo_to_external32. That allows moving the x32 SIGCHLD purely to x86 architecture code. As a nice side effect copy_siginfo_to_external32 also comes in handy for avoiding a set_fs() call in the coredump code later on. Contains improvements from Eric W. Biederman <ebiederm@xmission.com> and Arnd Bergmann <arnd@arndb.de>. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-31Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "This topic tree contains more commits than usual: - most of it are uaccess cleanups/reorganization by Al - there's a bunch of prototype declaration (--Wmissing-prototypes) cleanups - misc other cleanups all around the map" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/mm/set_memory: Fix -Wmissing-prototypes warnings x86/efi: Add a prototype for efi_arch_mem_reserve() x86/mm: Mark setup_emu2phys_nid() static x86/jump_label: Move 'inline' keyword placement x86/platform/uv: Add a missing prototype for uv_bau_message_interrupt() kill uaccess_try() x86: unsafe_put-style macro for sigmask x86: x32_setup_rt_frame(): consolidate uaccess areas x86: __setup_rt_frame(): consolidate uaccess areas x86: __setup_frame(): consolidate uaccess areas x86: setup_sigcontext(): list user_access_{begin,end}() into callers x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit) x86: ia32_setup_rt_frame(): consolidate uaccess areas x86: ia32_setup_frame(): consolidate uaccess areas x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers x86/alternatives: Mark text_poke_loc_init() static x86/cpu: Fix a -Wmissing-prototypes warning for init_ia32_feat_ctl() x86/mm: Drop pud_mknotpresent() x86: Replace setup_irq() by request_irq() x86/configs: Slightly reduce defconfigs ...
2020-03-26x86: unsafe_put-style macro for sigmaskAl Viro
regularizes things a bit Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-26x86: x32_setup_rt_frame(): consolidate uaccess areasAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-26x86: __setup_rt_frame(): consolidate uaccess areasAl Viro
reorder copy_siginfo_to_user() calls a bit Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-26x86: __setup_frame(): consolidate uaccess areasAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-26x86: setup_sigcontext(): list user_access_{begin,end}() into callersAl Viro
Similar to ia32_setup_sigcontext() change several commits ago, make it __always_inline. In cases when there is a user_access_{begin,end}() section nearby, just move the call over there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-26x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit)Al Viro
Straightforward, except for save_altstack_ex() stuck in those. Replace that thing with an analogue that would use unsafe_put_user() instead of put_user_ex() (called compat_save_altstack()) and be done with that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-21x86: Remove unneeded includesBrian Gerst
Clean up includes of and in <asm/syscalls.h> Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200313195144.164260-19-brgerst@gmail.com
2020-03-21x86/entry/64: Use syscall wrappers for x32_rt_sigreturnBrian Gerst
Add missing syscall wrapper for x32_rt_sigreturn(). Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20200313195144.164260-6-brgerst@gmail.com
2020-03-19x86: get rid of put_user_try in {ia32,x32}_setup_rt_frame()Al Viro
Straightforward, except for compat_save_altstack_ex() stuck in those. Replace that thing with an analogue that would use unsafe_put_user() instead of put_user_ex() (called unsafe_compat_save_altstack()) and be done with that... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-18x86: switch setup_sigcontext() to unsafe_put_user()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-18x86: get rid of get_user_ex() in restore_sigcontext()Al Viro
Just do copyin into a local struct and be done with that - we are on a shallow stack here. [reworked by tglx, removing the macro horrors while we are touching that] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-18x86: switch sigframe sigset handling to explict __get_user()/__put_user()Al Viro
... and consolidate the definition of sigframe_ia32->extramask - it's always a 1-element array of 32bit unsigned. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-01-08x86: Remove force_iret()Brian Gerst
force_iret() was originally intended to prevent the return to user mode with the SYSRET or SYSEXIT instructions, in cases where the register state could have been changed to be incompatible with those instructions. The entry code has been significantly reworked since then, and register state is validated before SYSRET or SYSEXIT are used. force_iret() no longer serves its original purpose and can be eliminated. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20191219115812.102620-1-brgerst@gmail.com
2019-07-12x86: use static_cpu_has in uaccess region to avoid instrumentationMarco Elver
This patch is a pre-requisite for enabling KASAN bitops instrumentation; using static_cpu_has instead of boot_cpu_has avoids instrumentation of test_bit inside the uaccess region. With instrumentation, the KASAN check would otherwise be flagged by objtool. For consistency, kernel/signal.c was changed to mirror this change, however, is never instrumented with KASAN (currently unsupported under x86 32bit). Link: http://lkml.kernel.org/r/20190613125950.197667-3-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Suggested-by: H. Peter Anvin <hpa@zytor.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-27signal: Remove task parameter from force_sigEric W. Biederman
All of the remaining callers pass current into force_sig so remove the task parameter to make this obvious and to make misuse more difficult in the future. This also makes it clear force_sig passes current into force_sig_info. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-05-07Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 FPU state handling updates from Borislav Petkov: "This contains work started by Rik van Riel and brought to fruition by Sebastian Andrzej Siewior with the main goal to optimize when to load FPU registers: only when returning to userspace and not on every context switch (while the task remains in the kernel). In addition, this optimization makes kernel_fpu_begin() cheaper by requiring registers saving only on the first invocation and skipping that in following ones. What is more, this series cleans up and streamlines many aspects of the already complex FPU code, hopefully making it more palatable for future improvements and simplifications. Finally, there's a __user annotations fix from Jann Horn" * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits) x86/fpu: Fault-in user stack if copy_fpstate_to_sigframe() fails x86/pkeys: Add PKRU value to init_fpstate x86/fpu: Restore regs in copy_fpstate_to_sigframe() in order to use the fastpath x86/fpu: Add a fastpath to copy_fpstate_to_sigframe() x86/fpu: Add a fastpath to __fpu__restore_sig() x86/fpu: Defer FPU state load until return to userspace x86/fpu: Merge the two code paths in __fpu__restore_sig() x86/fpu: Restore from kernel memory on the 64-bit path too x86/fpu: Inline copy_user_to_fpregs_zeroing() x86/fpu: Update xstate's PKRU value on write_pkru() x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD x86/fpu: Always store the registers in copy_fpstate_to_sigframe() x86/entry: Add TIF_NEED_FPU_LOAD x86/fpu: Eager switch PKRU state x86/pkeys: Don't check if PKRU is zero before writing it x86/fpu: Only write PKRU if it is different from current x86/pkeys: Provide *pkru() helpers x86/fpu: Use a feature number instead of mask in two more helpers x86/fpu: Make __raw_xsave_addr() use a feature number instead of mask x86/fpu: Add an __fpregs_load_activate() internal helper ...
2019-05-06Merge branch 'core-rseq-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull rseq updates from Ingo Molnar: "A cleanup and a fix to comments" * 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rseq: Remove superfluous rseq_len from task_struct rseq: Clean up comments by reflecting removal of event counter
2019-04-19rseq: Clean up comments by reflecting removal of event counterMathieu Desnoyers
The "event counter" was removed from rseq before it was merged upstream. However, a few comments in the source code still refer to it. Adapt the comments to match reality. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ben Maurer <bmaurer@fb.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Lameter <cl@linux.com> Cc: Dave Watson <davejwatson@fb.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Link: http://lkml.kernel.org/r/20190305194755.2602-2-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-10x86/fpu: Remove fpu->initializedSebastian Andrzej Siewior
The struct fpu.initialized member is always set to one for user tasks and zero for kernel tasks. This avoids saving/restoring the FPU registers for kernel threads. The ->initialized = 0 case for user tasks has been removed in previous changes, for instance, by doing an explicit unconditional init at fork() time for FPU-less systems which was otherwise delayed until the emulated opcode. The context switch code (switch_fpu_prepare() + switch_fpu_finish()) can't unconditionally save/restore registers for kernel threads. Not only would it slow down the switch but also load a zeroed xcomp_bv for XSAVES. For kernel_fpu_begin() (+end) the situation is similar: EFI with runtime services uses this before alternatives_patched is true. Which means that this function is used too early and it wasn't the case before. For those two cases, use current->mm to distinguish between user and kernel thread. For kernel_fpu_begin() skip save/restore of the FPU registers. During the context switch into a kernel thread don't do anything. There is no reason to save the FPU state of a kernel thread. The reordering in __switch_to() is important because the current() pointer needs to be valid before switch_fpu_finish() is invoked so ->mm is seen of the new task instead the old one. N.B.: fpu__save() doesn't need to check ->mm because it is called by user tasks only. [ bp: Massage. ] Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Aubrey Li <aubrey.li@intel.com> Cc: Babu Moger <Babu.Moger@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: Dmitry Safonov <dima@arista.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: kvm ML <kvm@vger.kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-8-bigeasy@linutronix.de
2019-04-03x86/fpu: Fix __user annotationsJann Horn
In save_xstate_epilog(), use __user when type-casting userspace pointers. In setup_sigcontext() and x32_setup_rt_frame(), cast the userspace pointers to 'unsigned long __user *' before writing into them. These pointers are originally '__u32 __user *' or '__u64 __user *', causing sparse to complain when a userspace pointer is written into them. The casts are okay because the pointers always point to pointer-sized values. Thanks to Luc Van Oostenryck and Al Viro for explaining this to me. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mukesh Ojha <mojha@codeaurora.org> Cc: Qiaowei Ren <qiaowei.ren@intel.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190329214652.258477-3-jannh@google.com
2019-04-03x86/uaccess, signal: Fix AC=1 bloatPeter Zijlstra
Occasionally GCC is less agressive with inlining and the following is observed: arch/x86/kernel/signal.o: warning: objtool: restore_sigcontext()+0x3cc: call to force_valid_ss.isra.5() with UACCESS enabled arch/x86/kernel/signal.o: warning: objtool: do_signal()+0x384: call to frame_uc_flags.isra.0() with UACCESS enabled Cure this by moving this code out of the AC=1 region, since it really isn't needed for the user access. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-22rseq: Avoid infinite recursion when delivering SIGSEGVWill Deacon
When delivering a signal to a task that is using rseq, we call into __rseq_handle_notify_resume() so that the registers pushed in the sigframe are updated to reflect the state of the restartable sequence (for example, ensuring that the signal returns to the abort handler if necessary). However, if the rseq management fails due to an unrecoverable fault when accessing userspace or certain combinations of RSEQ_CS_* flags, then we will attempt to deliver a SIGSEGV. This has the potential for infinite recursion if the rseq code continuously fails on signal delivery. Avoid this problem by using force_sigsegv() instead of force_sig(), which is explicitly designed to reset the SEGV handler to SIG_DFL in the case of a recursive fault. In doing so, remove rseq_signal_deliver() from the internal rseq API and have an optional struct ksignal * parameter to rseq_handle_notify_resume() instead. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: peterz@infradead.org Cc: paulmck@linux.vnet.ibm.com Cc: boqun.feng@gmail.com Link: https://lkml.kernel.org/r/1529664307-983-1-git-send-email-will.deacon@arm.com
2018-06-06x86: Add support for restartable sequencesMathieu Desnoyers
Call the rseq_handle_notify_resume() function on return to userspace if TIF_NOTIFY_RESUME thread flag is set. Perform fixup on the pre-signal frame when a signal is delivered on top of a restartable sequence critical section. Check that system calls are not invoked from within rseq critical sections by invoking rseq_signal() from syscall_return_slowpath(). With CONFIG_DEBUG_RSEQ, such behavior results in termination of the process with SIGSEGV. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Joel Fernandes <joelaf@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Watson <davejwatson@fb.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Chris Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Hunter <ahh@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Maurer <bmaurer@fb.com> Cc: linux-api@vger.kernel.org Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20180602124408.8430-7-mathieu.desnoyers@efficios.com
2018-04-02x86/sigreturn: use SYSCALL_DEFINE0Tautschnig, Michael
All definitions of syscalls in x86 except for those patched here have already been using the appropriate SYSCALL_DEFINE*. Signed-off-by: Michael Tautschnig <tautschn@amazon.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jaswinder Singh <jaswinder@infradead.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: x86@kernel.org Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02x86: fix sys_sigreturn() return type to be long, not unsigned longDominik Brodowski
Same as with other system calls, sys_sigreturn() should return a value of type long, not unsigned long. This also matches the behaviour for IA32_EMULATION, see sys32_sigreturn() in arch/x86/ia32/ia32_signal.c . Cc: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: x86@kernel.org Cc: Michael Tautschnig <tautschn@amazon.co.uk> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-01-30x86/asm: Move 'status' from thread_struct to thread_infoAndy Lutomirski
The TS_COMPAT bit is very hot and is accessed from code paths that mostly also touch thread_info::flags. Move it into struct thread_info to improve cache locality. The only reason it was in thread_struct is that there was a brief period during which arch-specific fields were not allowed in struct thread_info. Linus suggested further changing: ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED); to: if (unlikely(ti->status & (TS_COMPAT|TS_I386_REGS_POKED))) ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED); on the theory that frequently dirtying the cacheline even in pure 64-bit code that never needs to modify status hurts performance. That could be a reasonable followup patch, but I suspect it matters less on top of this patch. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Link: https://lkml.kernel.org/r/03148bcc1b217100e6e8ecf6a5468c45cf4304b6.1517164461.git.luto@kernel.org
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-26x86/fpu: Rename fpu::fpstate_active to fpu::initializedIngo Molnar
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>
2017-07-30x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment readsAndy Lutomirski
Now that pt_regs properly defines segment fields as 16-bit on 32-bit CPUs, there's no need to mask off the high word. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-11x86/debug: Fix the printk() debug output of signal_fault(), do_trap() and ↵Markus Trippelsdorf
do_general_protection() Since commit: 4bcc595ccd80 "printk: reinstate KERN_CONT for printing" ... the debug output of signal_fault(), do_trap() and do_general_protection() looks garbled, e.g.: traps: conftest[9335] trap invalid opcode ip:400428 sp:7ffeaba1b0d8 error:0 in conftest[400000+1000] (note the unintended line break.) Fix the bug by adding KERN_CONTs. Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-03Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso updates from Ingo Molnar: "The main changes in this cycle centered around adding support for 32-bit compatible C/R of the vDSO on 64-bit kernels, by Dmitry Safonov" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Use CONFIG_X86_X32_ABI to enable vdso prctl x86/vdso: Only define map_vdso_randomized() if CONFIG_X86_64 x86/vdso: Only define prctl_map_vdso() if CONFIG_CHECKPOINT_RESTORE x86/signal: Add SA_{X32,IA32}_ABI sa_flags x86/ptrace: Down with test_thread_flag(TIF_IA32) x86/coredump: Use pr_reg size, rather that TIF_IA32 flag x86/arch_prctl/vdso: Add ARCH_MAP_VDSO_* x86/vdso: Replace calculate_addr in map_vdso() with addr x86/vdso: Unmap vdso blob on vvar mapping failure
2016-09-15x86/asm: Move the thread_info::status field to thread_structAndy Lutomirski
Because sched.h and thread_info.h are a tangled mess, I turned in_compat_syscall() into a macro. If we had current_thread_struct() or similar and we could use it from thread_info.h, then this would be a bit cleaner. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/ccc8a1b2f41f9c264a41f771bb4a6539a642ad72.1473801993.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-14x86/signal: Add SA_{X32,IA32}_ABI sa_flagsDmitry Safonov
Introduce new flags that defines which ABI to use on creating sigframe. Those flags kernel will set according to sigaction syscall ABI, which set handler for the signal being delivered. So that will drop the dependency on TIF_IA32/TIF_X32 flags on signal deliver. Those flags will be used only under CONFIG_COMPAT. Similar way ARM uses sa_flags to differ in which mode deliver signal for 26-bit applications (look at SA_THIRYTWO). Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: 0x7f454c46@gmail.com Cc: oleg@redhat.com Cc: linux-mm@kvack.org Cc: gorcunov@openvz.org Cc: xemul@virtuozzo.com Link: http://lkml.kernel.org/r/20160905133308.28234-7-dsafonov@virtuozzo.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-08-06Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Two fixes and a cleanup-fix, to the syscall entry code and to ptrace" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/syscalls/64: Add compat_sys_keyctl for 32-bit userspace x86/ptrace: Stop setting TS_COMPAT in ptrace code x86/vdso: Error out if the vDSO isn't a valid DSO
2016-08-04tree-wide: replace config_enabled() with IS_ENABLED()Masahiro Yamada
The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Stas Sergeev <stsp@list.ru> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@suse.de> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will Drewry <wad@chromium.org> Cc: Nikolay Martynov <mar.kolya@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Rafal Milecki <zajec5@gmail.com> Cc: James Cowgill <James.Cowgill@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Tony Wu <tung7970@gmail.com> Cc: Huaitong Han <huaitong.han@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Rabin Vincent <rabin@rab.in> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-27x86/ptrace: Stop setting TS_COMPAT in ptrace codeAndy Lutomirski
Setting TS_COMPAT in ptrace is wrong: if we happen to do it during syscall entry, then we'll confuse seccomp and audit. (The former isn't a security problem: seccomp is currently entirely insecure if a malicious ptracer is attached.) As a minimal fix, this patch adds a new flag TS_I386_REGS_POKED that handles the ptrace special case. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/5383ebed38b39fa37462139e337aff7f2314d1ca.1469599803.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-16Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
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: - MSR access API fixes and enhancements (Andy Lutomirski) - early exception handling improvements (Andy Lutomirski) - user-space FS/GS prctl usage fixes and improvements (Andy Lutomirski) - Remove the cpu_has_*() APIs and replace them with equivalents (Borislav Petkov) - task switch micro-optimization (Brian Gerst) - 32-bit entry code simplification (Denys Vlasenko) - enhance PAT handling in enumated CPUs (Toshi Kani) ... and lots of other cleanups/fixlets" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) x86/arch_prctl/64: Restore accidentally removed put_cpu() in ARCH_SET_GS x86/entry/32: Remove asmlinkage_protect() x86/entry/32: Remove GET_THREAD_INFO() from entry code x86/entry, sched/x86: Don't save/restore EFLAGS on task switch x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs selftests/x86/ldt_gdt: Test set_thread_area() deletion of an active segment x86/tls: Synchronize segment registers in set_thread_area() x86/asm/64: Rename thread_struct's fs and gs to fsbase and gsbase x86/arch_prctl/64: Remove FSBASE/GSBASE < 4G optimization x86/segments/64: When load_gs_index fails, clear the base x86/segments/64: When loadsegment(fs, ...) fails, clear the base x86/asm: Make asm/alternative.h safe from assembly x86/asm: Stop depending on ptrace.h in alternative.h x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall() x86/asm: Make sure verify_cpu() has a good stack x86/extable: Add a comment about early exception handlers x86/msr: Set the return value to zero when native_rdmsr_safe() fails x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y x86/paravirt: Add paravirt_{read,write}_msr() x86/msr: Carry on after a non-"safe" MSR access fails ...
2016-05-03signals/sigaltstack, x86/signals: Unify the x86 sigaltstack check with other ↵Stas Sergeev
architectures Currently x86's get_sigframe() checks for "current->sas_ss_size" to determine whether there is a need to switch to sigaltstack. The common practice used by all other arches is to check for sas_ss_flags(sp) == 0 This patch makes the code consistent with other architectures. The slight complexity of the patch is added by the optimization on !sigstack check that was requested by Andy Lutomirski: sas_ss_flags(sp)==0 already implies that we are not on a sigstack, so the code is shuffled to avoid the duplicate checking. This patch should have no user-visible impact. Signed-off-by: Stas Sergeev <stsp@list.ru> Cc: Al Viro <viro@zeniv.linux.org.uk> 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: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-api@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1460665206-13646-2-git-send-email-stsp@list.ru Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-19x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall()Dmitry Safonov
The is_ia32_task()/is_x32_task() function names are a big misnomer: they suggests that the compat-ness of a system call is a task property, which is not true, the compatness of a system call purely depends on how it was invoked through the system call layer. A task may call 32-bit and 64-bit and x32 system calls without changing any of its kernel visible state. This specific minomer is also actively dangerous, as it might cause kernel developers to use the wrong kind of security checks within system calls. So rename it to in_{ia32,x32}_syscall(). Suggested-by: Andy Lutomirski <luto@amacapital.net> Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com> [ Expanded the changelog. ] Acked-by: Andy Lutomirski <luto@kernel.org> Cc: 0x7f454c46@gmail.com Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1460987025-30360-1-git-send-email-dsafonov@virtuozzo.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13x86/cpufeature: Replace cpu_has_xsave with boot_cpu_has() usageBorislav Petkov
Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Link: http://lkml.kernel.org/r/1459801503-15600-10-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>