- 12 Apr, 2019 7 commits
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Sebastian Andrzej Siewior authored
The task's initial PKRU value is set partly for fpu__clear()/ copy_init_pkru_to_fpregs(). It is not part of init_fpstate.xsave and instead it is set explicitly. If the user removes the PKRU state from XSAVE in the signal handler then __fpu__restore_sig() will restore the missing bits from `init_fpstate' and initialize the PKRU value to 0. Add the `init_pkru_value' to `init_fpstate' so it is set to the init value in such a case. In theory copy_init_pkru_to_fpregs() could be removed because restoring the PKRU at return-to-userland should be enough. 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: Andi Kleen <ak@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-28-bigeasy@linutronix.de
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Sebastian Andrzej Siewior authored
If a task is scheduled out and receives a signal then it won't be able to take the fastpath because the registers aren't available. The slowpath is more expensive compared to XRSTOR + XSAVE which usually succeeds. Here are some clock_gettime() numbers from a bigger box with AVX512 during bootup: - __fpregs_load_activate() takes 140ns - 350ns. If it was the most recent FPU context on the CPU then the optimisation in __fpregs_load_activate() will skip the load (which was disabled during the test). - copy_fpregs_to_sigframe() takes 200ns - 450ns if it succeeds. On a pagefault it is 1.8us - 3us usually in the 2.6us area. - The slowpath takes 1.5us - 6us. Usually in the 2.6us area. My testcases (including lat_sig) take the fastpath without __fpregs_load_activate(). I expect this to be the majority. Since the slowpath is in the >1us area it makes sense to load the registers and attempt to save them directly. The direct save may fail but should only happen on the first invocation or after fork() while the page is read-only. [ bp: Massage a bit. ] Signed-off-by:
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Sebastian Andrzej Siewior authored
Try to save the FPU registers directly to the userland stack frame if the CPU holds the FPU registers for the current task. This has to be done with the pagefault disabled because we can't fault (while the FPU registers are locked) and therefore the operation might fail. If it fails try the slowpath which can handle faults. [ bp: Massage a bit. ] Signed-off-by:
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Sebastian Andrzej Siewior authored
The previous commits refactor the restoration of the FPU registers so that they can be loaded from in-kernel memory. This overhead can be avoided if the load can be performed without a pagefault. Attempt to restore FPU registers by invoking copy_user_to_fpregs_zeroing(). If it fails try the slowpath which can handle pagefaults. [ bp: Add a comment over the fastpath to be able to find one's way around the function. ] Signed-off-by:
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Rik van Riel authored
Defer loading of FPU state until return to userspace. This gives the kernel the potential to skip loading FPU state for tasks that stay in kernel mode, or for tasks that end up with repeated invocations of kernel_fpu_begin() & kernel_fpu_end(). The fpregs_lock/unlock() section ensures that the registers remain unchanged. Otherwise a context switch or a bottom half could save the registers to its FPU context and the processor's FPU registers would became random if modified at the same time. KVM swaps the host/guest registers on entry/exit path. This flow has been kept as is. First it ensures that the registers are loaded and then saves the current (host) state before it loads the guest's registers. The swap is done at the very end with disabled interrupts so it should not change anymore before theg guest is entered. The read/save version seems to be cheaper compared to memcpy() in a micro benchmark. Each thread gets TIF_NEED_FPU_LOAD set as part of fork() / fpu__copy(). For kernel threads, this flag gets never cleared which avoids saving / restoring the FPU state for kernel threads and during in-kernel usage of the FPU registers. [ bp: Correct and update commit message and fix checkpatch warnings. s/register/registers/ where it is used in plural. minor comment corrections. remove unused trace_x86_fpu_activate_state() TP. ] Signed-off-by:
Rik van Riel <riel@surriel.com> Signed-off-by:
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Sebastian Andrzej Siewior authored
The ia32_fxstate case (32bit with fxsr) and the other (64bit frames or 32bit frames without fxsr) restore both from kernel memory and sanitize the content. The !ia32_fxstate version restores missing xstates from "init state" while the ia32_fxstate doesn't and skips it. Merge the two code paths and keep the !ia32_fxstate one. Copy only the user_i387_ia32_struct data structure in the ia32_fxstate. Signed-off-by:
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Sebastian Andrzej Siewior authored
The 64-bit case (both 64-bit and 32-bit frames) loads the new state from user memory. However, doing this is not desired if the FPU state is going to be restored on return to userland: it would be required to disable preemption in order to avoid a context switch which would set TIF_NEED_FPU_LOAD. If this happens before the restore operation then the loaded registers would become volatile. Furthermore, disabling preemption while accessing user memory requires to disable the pagefault handler. An error during FXRSTOR would then mean that either a page fault occurred (and it would have to be retried with enabled page fault handler) or a #GP occurred because the xstate is bogus (after all, the signal handler can modify it). In order to avoid that mess, copy the FPU state from userland, validate it and then load it. The copy_kernel_…() helpers are basically just like the old helpers except that they operate on kernel memory and the fault handler just sets the error value and the caller handles it. copy_user_to_fpregs_zeroing() and its helpers remain and will be used later for a fastpath optimisation. [ bp: Clarify commit message. ] Signed-off-by:
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- 11 Apr, 2019 9 commits
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Sebastian Andrzej Siewior authored
Start refactoring __fpu__restore_sig() by inlining copy_user_to_fpregs_zeroing(). The original function remains and will be used to restore from userland memory if possible. Signed-off-by:
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Sebastian Andrzej Siewior authored
During the context switch the xstate is loaded which also includes the PKRU value. If xstate is restored on return to userland it is required that the PKRU value in xstate is the same as the one in the CPU. Save the PKRU in xstate during modification. Signed-off-by:
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Rik van Riel authored
The FPU registers need only to be saved if TIF_NEED_FPU_LOAD is not set. Otherwise this has been already done and can be skipped. [ bp: Massage a bit. ] Signed-off-by:
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Rik van Riel authored
copy_fpstate_to_sigframe() stores the registers directly to user space. This is okay because the FPU registers are valid and saving them directly avoids saving them into kernel memory and making a copy. However, this cannot be done anymore if the FPU registers are going to be restored on the return to userland. It is possible that the FPU registers will be invalidated in the middle of the save operation and this should be done with disabled preemption / BH. Save the FPU registers to the task's FPU struct and copy them to the user memory later on. Signed-off-by:
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Sebastian Andrzej Siewior authored
Add TIF_NEED_FPU_LOAD. This flag is used for loading the FPU registers before returning to userland. It must not be set on systems without a FPU. If this flag is cleared, the CPU's FPU registers hold the latest, up-to-date content of the current task's (current()) FPU registers. The in-memory copy (union fpregs_state) is not valid. If this flag is set, then all of CPU's FPU registers may hold a random value (except for PKRU) and it is required to load the content of the FPU registers on return to userland. Introduce it now as a preparatory change before adding the main feature. Signed-off-by:
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Rik van Riel authored
While most of a task's FPU state is only needed in user space, the protection keys need to be in place immediately after a context switch. The reason is that any access to userspace memory while running in kernel mode also needs to abide by the memory permissions specified in the protection keys. The "eager switch" is a preparation for loading the FPU state on return to userland. Instead of decoupling PKRU state from xstate, update PKRU within xstate on write operations by the kernel. For user tasks the PKRU should be always read from the xsave area and it should not change anything because the PKRU value was loaded as part of FPU restore. For kernel threads the default "init_pkru_value" will be written. Before this commit, the kernel thread would end up with a random value which it inherited from the previous user task. [ bigeasy: save pkru to xstate, no cache, don't use __raw_xsave_addr() ] [ bp: update commit message, sort headers properly in asm/fpu/xstate.h ] Signed-off-by:
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Sebastian Andrzej Siewior authored
write_pkru() checks if the current value is the same as the expected value. So instead of just checking if the current and new value is zero (and skip the write in such a case) we can benefit from that. Remove the zero check of PKRU, __write_pkru() provides such a check now. Signed-off-by:
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Sebastian Andrzej Siewior authored
According to Dave Hansen, WRPKRU is more expensive than RDPKRU. It has a higher cycle cost and it's also practically a (light) speculation barrier. As an optimisation read the current PKRU value and only write the new one if it is different. Signed-off-by:
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Sebastian Andrzej Siewior authored
Dave Hansen asked for __read_pkru() and __write_pkru() to be symmetrical. As part of the series __write_pkru() will read back the value and only write it if it is different. In order to make both functions symmetrical, move the function containing only the opcode asm into a function called like the instruction itself. __write_pkru() will just invoke wrpkru() but in a follow-up patch will also read back the value. [ bp: Convert asm opcode wrapper names to rd/wrpkru(). ] Suggested-by:
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- 10 Apr, 2019 6 commits
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Sebastian Andrzej Siewior authored
After changing the argument of __raw_xsave_addr() from a mask to number Dave suggested to check if it makes sense to do the same for get_xsave_addr(). As it turns out it does. Only get_xsave_addr() needs the mask to check if the requested feature is part of what is supported/saved and then uses the number again. The shift operation is cheaper compared to fls64() (find last bit set). Also, the feature number uses less opcode space compared to the mask. :) Make the get_xsave_addr() argument a xfeature number instead of a mask and fix up its callers. Furthermore, use xfeature_nr and xfeature_mask consistently. This results in the following changes to the kvm code: feature -> xfeature_mask index -> xfeature_nr Suggested-by:
Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by:
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Sebastian Andrzej Siewior authored
Most users of __raw_xsave_addr() use a feature number, shift it to a mask and then __raw_xsave_addr() shifts it back to the feature number. Make __raw_xsave_addr() use the feature number as an argument. Signed-off-by:
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Rik van Riel authored
Add a helper function that ensures the floating point registers for the current task are active. Use with preemption disabled. While at it, add fpregs_lock/unlock() helpers too, to be used in later patches. [ bp: Add a comment about its intended usage. ] Signed-off-by:
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Sebastian Andrzej Siewior authored
user_fpu_begin() sets fpu_fpregs_owner_ctx to task's fpu struct. This is always the case since there is no lazy FPU anymore. fpu_fpregs_owner_ctx is used during context switch to decide if it needs to load the saved registers or if the currently loaded registers are valid. It could be skipped during a taskA -> kernel thread -> taskA switch because the switch to the kernel thread would not alter the CPU's sFPU tate. Since this field is always updated during context switch and never invalidated, setting it manually (in user context) makes no difference. A kernel thread with kernel_fpu_begin() block could set fpu_fpregs_owner_ctx to NULL but a kernel thread does not use user_fpu_begin(). This is a leftover from the lazy-FPU time. Remove user_fpu_begin(), it does not change fpu_fpregs_owner_ctx's content. Signed-off-by:
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Sebastian Andrzej Siewior authored
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:
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Sebastian Andrzej Siewior authored
In commit 72a671ce ("x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels") the 32bit and 64bit path of the signal delivery code were merged. The 32bit version: int save_i387_xstate_ia32(void __user *buf) … if (cpu_has_xsave) return save_i387_xsave(fp); if (cpu_has_fxsr) return save_i387_fxsave(fp); The 64bit version: int save_i387_xstate(void __user *buf) … if (user_has_fpu()) { if (use_xsave()) err = xsave_user(buf); else err = fxsave_user(buf); if (unlikely(err)) { __clear_user(buf, xstate_size); return err; The merge: int save_xstate_sig(void __user *buf, void __user *buf_fx, int size) … if (user_has_fpu()) { /* Save the live register state to the user directly. */ if (save_user_xstate(buf_fx)) return -1; /* Update the thread's fxstate to save the fsave header. */ if (ia32_fxstate) fpu_fxsave(&tsk->thread.fpu); I don't think that we needed to save the FPU registers to ->thread.fpu because the registers were stored in buf_fx. Today the state will be restored from buf_fx after the signal was handled (I assume that this was also the case with lazy-FPU). Since commit 66463db4 ("x86, fpu: shift drop_init_fpu() from save_xstate_sig() to handle_signal()") it is ensured that the signal handler starts with clear/fresh set of FPU registers which means that the previous store is futile. Remove the copy_fxregs_to_kernel() call because task's FPU state is cleared later in handle_signal() via fpu__clear(). Signed-off-by:
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- 09 Apr, 2019 5 commits
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Sebastian Andrzej Siewior authored
With lazy-FPU support the (now named variable) ->initialized was set to true if the CPU's FPU registers were holding a valid state of the FPU registers for the active process. If it was set to false then the FPU state was saved in fpu->state and the FPU was deactivated. With lazy-FPU gone, ->initialized is always true for user threads and kernel threads never call this function so ->initialized is always true in copy_fpstate_to_sigframe(). The using_compacted_format() check is also a leftover from the lazy-FPU time. In the ->initialized == false case copy_to_user() would copy the compacted buffer while userland would expect the non-compacted format instead. So in order to save the FPU state in the non-compacted form it issues XSAVE to save the *current* FPU state. If the FPU is not enabled, the attempt raises the FPU trap, the trap restores the FPU contents and re-enables the FPU and XSAVE is invoked again and succeeds. *This* does not longer work since commit bef8b6da ("x86/fpu: Handle #NM without FPU emulation as an error") Remove the check for ->initialized because it is always true and remove the false condition. Update the comment to reflect that the state is always live. [ bp: Massage. ] Signed-off-by:
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Sebastian Andrzej Siewior authored
fpu__clear() only initializes the state if the CPU has FPU support. This initialisation is also required for FPU-less systems and takes place in math_emulate(). Since fpu__initialize() only performs the initialization if ->initialized is zero it does not matter that it is invoked each time an opcode is emulated. It makes the removal of ->initialized easier if the struct is also initialized in the FPU-less case at the same time. Move fpu__initialize() before the FPU feature check so it is also performed in the FPU-less case too. [ bp: Massage a bit. ] Signed-off-by:
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Sebastian Andrzej Siewior authored
The preempt_disable() section was introduced in commit a10b6a16 ("x86/fpu: Make the fpu state change in fpu__clear() scheduler-atomic") and it was said to be temporary. fpu__initialize() initializes the FPU struct to its initial value and then sets ->initialized to 1. The last part is the important one. The content of the state does not matter because it gets set via copy_init_fpstate_to_fpregs(). A preemption here has little meaning because the registers will always be set to the same content after copy_init_fpstate_to_fpregs(). A softirq with a kernel_fpu_begin() could also force to save FPU's registers after fpu__initialize() without changing the outcome here. Remove the preempt_disable() section in fpu__clear(), preemption here does not hurt. Signed-off-by:
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Sebastian Andrzej Siewior authored
There are no users of fpu__restore() so it is time to remove it. The comment regarding fpu__restore() and TS bit is stale since commit b3b0870e ("i387: do not preload FPU state at task switch time") and has no meaning since. Signed-off-by:
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Sebastian Andrzej Siewior authored
This is a preparation for the removal of the ->initialized member in the fpu struct. __fpu__restore_sig() is deactivating the FPU via fpu__drop() and then setting manually ->initialized followed by fpu__restore(). The result is that it is possible to manipulate fpu->state and the state of registers won't be saved/restored on a context switch which would overwrite fpu->state: fpu__drop(fpu): ... fpu->initialized = 0; preempt_enable(); <--- context switch Don't access the fpu->state while the content is read from user space and examined/sanitized. Use a temporary kmalloc() buffer for the preparation of the FPU registers and once the state is considered okay, load it. Should something go wrong, return with an error and without altering the original FPU registers. The removal of fpu__initialize() is a nop because fpu->initialized is already set for the user task. [ bp: Massage a bit. ] Signed-off-by:
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- 03 Apr, 2019 1 commit
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Jann Horn authored
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:
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- 31 Mar, 2019 9 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull KVM fixes from Paolo Bonzini: "A collection of x86 and ARM bugfixes, and some improvements to documentation. On top of this, a cleanup of kvm_para.h headers, which were exported by some architectures even though they not support KVM at all. This is responsible for all the Kbuild changes in the diffstat" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits) Documentation: kvm: clarify KVM_SET_USER_MEMORY_REGION KVM: doc: Document the life cycle of a VM and its resources KVM: selftests: complete IO before migrating guest state KVM: selftests: disable stack protector for all KVM tests KVM: selftests: explicitly disable PIE for tests KVM: selftests: assert on exit reason in CR4/cpuid sync test KVM: x86: update %rip after emulating IO x86/kvm/hyper-v: avoid spurious pending stimer on vCPU init kvm/x86: Move MSR_IA32_ARCH_CAPABILITIES to array emulated_msrs KVM: x86: Emulate MSR_IA32_ARCH_CAPABILITIES on AMD hosts kvm: don't redefine flags as something else kvm: mmu: Used range based flushing in slot_handle_level_range KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported KVM: x86: remove check on nr_mmu_pages in kvm_arch_commit_memory_region() kvm: nVMX: Add a vmentry check for HOST_SYSENTER_ESP and HOST_SYSENTER_EIP fields KVM: SVM: Workaround errata#1096 (insn_len maybe zero on SMAP violation) KVM: Reject device ioctls from processes other than the VM's creator KVM: doc: Fix incorrect word ordering regarding supported use of APIs KVM: x86: fix handling of role.cr4_pae and rename it to 'gpte_size' KVM: nVMX: Do not inherit quadrant and invalid for the root shadow EPT ...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Thomas Gleixner: "A pile of x86 updates: - Prevent exceeding he valid physical address space in the /dev/mem limit checks. - Move all header content inside the header guard to prevent compile failures. - Fix the bogus __percpu annotation in this_cpu_has() which makes sparse very noisy. - Disable switch jump tables completely when retpolines are enabled. - Prevent leaking the trampoline address" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/realmode: Make set_real_mode_mem() static inline x86/cpufeature: Fix __percpu annotation in this_cpu_has() x86/mm: Don't exceed the valid physical address space x86/retpolines: Disable switch jump tables when retpolines are enabled x86/realmode: Don't leak the trampoline kernel address x86/boot: Fix incorrect ifdeffery scope x86/resctrl: Remove unused variable -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf tooling fixes from Thomas Gleixner: "Core libraries: - Fix max perf_event_attr.precise_ip detection. - Fix parser error for uncore event alias - Fixup ordering of kernel maps after obtaining the main kernel map address. Intel PT: - Fix TSC slip where A TSC packet can slip past MTC packets so that the timestamp appears to go backwards. - Fixes for exported-sql-viewer GUI conversion to python3. ARM coresight: - Fix the build by adding a missing case value for enumeration value introduced in newer library, that now is the required one. tool headers: - Syncronize kernel headers with the kernel, getting new io_uring and pidfd_send_signal syscalls so that 'perf trace' can handle them" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf pmu: Fix parser error for uncore event alias perf scripts python: exported-sql-viewer.py: Fix python3 support perf scripts python: exported-sql-viewer.py: Fix never-ending loop perf machine: Update kernel map address and re-order properly tools headers uapi: Sync powerpc's asm/kvm.h copy with the kernel sources tools headers: Update x86's syscall_64.tbl and uapi/asm-generic/unistd tools headers uapi: Update drm/i915_drm.h tools arch x86: Sync asm/cpufeatures.h with the kernel sources tools headers uapi: Sync linux/fcntl.h to get the F_SEAL_FUTURE_WRITE addition tools headers uapi: Sync asm-generic/mman-common.h and linux/mman.h perf evsel: Fix max perf_event_attr.precise_ip detection perf intel-pt: Fix TSC slip perf cs-etm: Add missing case value -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull CPU hotplug fixes from Thomas Gleixner: "Two SMT/hotplug related fixes: - Prevent crash when HOTPLUG_CPU is disabled and the CPU bringup aborts. This is triggered with the 'nosmt' command line option, but can happen by any abort condition. As the real unplug code is not compiled in, prevent the fail by keeping the CPU in zombie state. - Enforce HOTPLUG_CPU for SMP on x86 to avoid the above situation completely. With 'nosmt' being a popular option it's required to unplug the half brought up sibling CPUs (due to the MCE wreckage) completely" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/smp: Enforce CONFIG_HOTPLUG_CPU when SMP=y cpu/hotplug: Prevent crash when CPU bringup fails on CONFIG_HOTPLUG_CPU=n -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull locking fixlet from Thomas Gleixner: "Trivial update to the maintainers file" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: MAINTAINERS: Remove deleted file from futex file pattern
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull core fixes from Thomas Gleixner: "A small set of core updates: - Make the watchdog respect the selected CPU mask again. That was broken by the rework of the watchdog thread management and caused inconsistent state and NMI watchdog being unstoppable. - Ensure that the objtool build can find the libelf location. - Remove dead kcore stub code" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: watchdog: Respect watchdog cpumask on CPU hotplug objtool: Query pkg-config for libelf location proc/kcore: Remove unused kclist_add_remap() -
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc fixes from Michael Ellerman: "Three non-regression fixes. - Our optimised memcmp could read past the end of one of the buffers and potentially trigger a page fault leading to an oops. - Some of our code to read energy management data on PowerVM had an endian bug leading to bogus results. - When reporting a machine check exception we incorrectly reported TLB multihits as D-Cache multhits due to a missing entry in the array of causes. Thanks to: Chandan Rajendra, Gautham R. Shenoy, Mahesh Salgaonkar, Segher Boessenkool, Vaidyanathan Srinivasan" * tag 'powerpc-5.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/pseries/mce: Fix misleading print for TLB mutlihit powerpc/pseries/energy: Use OF accessor functions to read ibm,drc-indexes powerpc/64: Fix memcmp reading past the end of src/dest -
git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds authored
Pull dmaengine fixes from Vinod Koul: - Revert "dmaengine: stm32-mdma: Add a check on read_u32_array" as that caused regression - Fix MAINTAINER file uniphier-mdmac.c file path * tag 'dmaengine-fix-5.1-rc3' of git://git.infradead.org/users/vkoul/slave-dma: MAINTAINERS: Fix uniphier-mdmac.c file path dmaengine: stm32-mdma: Revert "dmaengine: stm32-mdma: Add a check on read_u32_array"
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- 30 Mar, 2019 3 commits
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Linus Torvalds authored
Merge tag 'led-fixes-for-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds Pull LED fixes from Jacek Anaszewski: - fix refcnt leak on interface rename - use memcpy in device_name_store() to avoid including garbage from a previous, longer value in the device_name - fix a potential NULL pointer dereference in case of_match_device() cannot find a match * tag 'led-fixes-for-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds: leds: trigger: netdev: use memcpy in device_name_store leds: pca9532: fix a potential NULL pointer dereference leds: trigger: netdev: fix refcnt leak on interface rename
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git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpioLinus Torvalds authored
Pull GPIO fixes from Linus Walleij: "As you can see [in the git history] I was away on leave and Bartosz kindly stepped in and collected a slew of fixes, I pulled them into my tree in two sets and merged some two more fixes (fixing my own caused bugs) on top. Summary: - Revert the extended use of gpio_set_config() and think about how we can do this properly. - Fix up the SPI CS GPIO handling so it now works properly on the SPI bus children, as intended. - Error paths and driver fixes" * tag 'gpio-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: gpio: mockup: use simple_read_from_buffer() in debugfs read callback gpio: of: Fix of_gpiochip_add() error path gpio: of: Check for "spi-cs-high" in child instead of parent node gpio: of: Check propname before applying "cs-gpios" quirks gpio: mockup: fix debugfs read Revert "gpio: use new gpio_set_config() helper in more places" gpio: aspeed: fix a potential NULL pointer dereference gpio: amd-fch: Fix bogus SPDX identifier gpio: adnp: Fix testing wrong value in adnp_gpio_direction_input gpio: exar: add a check for the return value of ida_simple_get fails -
Rasmus Villemoes authored
If userspace doesn't end the input with a newline (which can easily happen if the write happens from a C program that does write(fd, iface, strlen(iface))), we may end up including garbage from a previous, longer value in the device_name. For example # cat device_name # printf 'eth12' > device_name # cat device_name eth12 # printf 'eth3' > device_name # cat device_name eth32 I highly doubt anybody is relying on this behaviour, so switch to simply copying the bytes (we've already checked that size is < IFNAMSIZ) and unconditionally zero-terminate it; of course, we also still have to strip a trailing newline. This is also preparation for future patches. Fixes: 06f502f5 ("leds: trigger: Introduce a NETDEV trigger") Signed-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by:
Pavel Machek <pavel@ucw.cz> Signed-off-by:
Jacek Anaszewski <jacek.anaszewski@gmail.com>
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