From 2619da73bb2f10d88f7e1087125c40144fdf0987 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Thu, 5 Mar 2026 20:49:55 +0100 Subject: KVM: x86: Use __DECLARE_FLEX_ARRAY() for UAPI structures with VLAs Commit 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with flexible-array members") broke the userspace API for C++. These structures ending in VLAs are typically a *header*, which can be followed by an arbitrary number of entries. Userspace typically creates a larger structure with some non-zero number of entries, for example in QEMU's kvm_arch_get_supported_msr_feature(): struct { struct kvm_msrs info; struct kvm_msr_entry entries[1]; } msr_data = {}; While that works in C, it fails in C++ with an error like: flexible array member 'kvm_msrs::entries' not at end of 'struct msr_data' Fix this by using __DECLARE_FLEX_ARRAY() for the VLA, which uses [0] for C++ compilation. Fixes: 94dfc73e7cf4 ("treewide: uapi: Replace zero-length arrays with flexible-array members") Cc: stable@vger.kernel.org Signed-off-by: David Woodhouse Link: https://patch.msgid.link/3abaf6aefd6e5efeff3b860ac38421d9dec908db.camel@infradead.org [sean: tag for stable@] Signed-off-by: Sean Christopherson --- include/uapi/linux/kvm.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 80364d4dbebb..3f0d8d3c3daf 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -542,7 +543,7 @@ struct kvm_coalesced_mmio { struct kvm_coalesced_mmio_ring { __u32 first, last; - struct kvm_coalesced_mmio coalesced_mmio[]; + __DECLARE_FLEX_ARRAY(struct kvm_coalesced_mmio, coalesced_mmio); }; #define KVM_COALESCED_MMIO_MAX \ @@ -592,7 +593,7 @@ struct kvm_clear_dirty_log { /* for KVM_SET_SIGNAL_MASK */ struct kvm_signal_mask { __u32 len; - __u8 sigset[]; + __DECLARE_FLEX_ARRAY(__u8, sigset); }; /* for KVM_TPR_ACCESS_REPORTING */ @@ -1051,7 +1052,7 @@ struct kvm_irq_routing_entry { struct kvm_irq_routing { __u32 nr; __u32 flags; - struct kvm_irq_routing_entry entries[]; + __DECLARE_FLEX_ARRAY(struct kvm_irq_routing_entry, entries); }; #define KVM_IRQFD_FLAG_DEASSIGN (1 << 0) @@ -1142,7 +1143,7 @@ struct kvm_dirty_tlb { struct kvm_reg_list { __u64 n; /* number of regs */ - __u64 reg[]; + __DECLARE_FLEX_ARRAY(__u64, reg); }; struct kvm_one_reg { @@ -1608,7 +1609,7 @@ struct kvm_stats_desc { #ifdef __KERNEL__ char name[KVM_STATS_NAME_SIZE]; #else - char name[]; + __DECLARE_FLEX_ARRAY(char, name); #endif }; -- cgit v1.2.3 From 45065a5095c7773fb98c35d60c20c3b513540597 Mon Sep 17 00:00:00 2001 From: Akshai Murari Date: Fri, 27 Mar 2026 06:54:45 +0000 Subject: Input: add keycodes for contextual AI usages (HUTRR119) HUTRR119 introduces new usages for keys intended to invoke AI agents based on the current context. These are useful with the increasing number of operating systems with integrated Large Language Models Add new key definitions for KEY_ACTION_ON_SELECTION, KEY_CONTEXTUAL_INSERT and KEY_CONTEXTUAL_QUERY Signed-off-by: Akshai Murari Acked-by: Dmitry Torokhov Signed-off-by: Jiri Kosina --- include/uapi/linux/input-event-codes.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h index 4bdb6a165987..3528168f7c6d 100644 --- a/include/uapi/linux/input-event-codes.h +++ b/include/uapi/linux/input-event-codes.h @@ -643,6 +643,10 @@ #define KEY_EPRIVACY_SCREEN_ON 0x252 #define KEY_EPRIVACY_SCREEN_OFF 0x253 +#define KEY_ACTION_ON_SELECTION 0x254 /* AL Action on Selection (HUTRR119) */ +#define KEY_CONTEXTUAL_INSERT 0x255 /* AL Contextual Insertion (HUTRR119) */ +#define KEY_CONTEXTUAL_QUERY 0x256 /* AL Contextual Query (HUTRR119) */ + #define KEY_KBDINPUTASSIST_PREV 0x260 #define KEY_KBDINPUTASSIST_NEXT 0x261 #define KEY_KBDINPUTASSIST_PREVGROUP 0x262 -- cgit v1.2.3 From 08ee1559052be302f1d3752f48360b89517d9f8d Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Sat, 4 Apr 2026 18:40:58 -0600 Subject: prctl: cfi: change the branch landing pad prctl()s to be more descriptive Per Linus' comments requesting the replacement of "INDIR_BR_LP" in the indirect branch tracking prctl()s with something more readable, and suggesting the use of the speculation control prctl()s as an exemplar, reimplement the prctl()s and related constants that control per-task forward-edge control flow integrity. This primarily involves two changes. First, the prctls are restructured to resemble the style of the speculative execution workaround control prctls PR_{GET,SET}_SPECULATION_CTRL, to make them easier to extend in the future. Second, the "indir_br_lp" abbrevation is expanded to "branch_landing_pads" to be less telegraphic. The kselftest and documentation is adjusted accordingly. Link: https://lore.kernel.org/linux-riscv/CAHk-=whhSLGZAx3N5jJpb4GLFDqH_QvS07D+6BnkPWmCEzTAgw@mail.gmail.com/ Cc: Deepak Gupta Cc: Linus Torvalds Cc: Mark Brown Signed-off-by: Paul Walmsley --- include/uapi/linux/prctl.h | 37 +++++++++++++++---------------------- 1 file changed, 15 insertions(+), 22 deletions(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index 55b0446fff9d..b6ec6f693719 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -397,30 +397,23 @@ struct prctl_mm_map { # define PR_RSEQ_SLICE_EXT_ENABLE 0x01 /* - * Get the current indirect branch tracking configuration for the current - * thread, this will be the value configured via PR_SET_INDIR_BR_LP_STATUS. + * Get or set the control flow integrity (CFI) configuration for the + * current thread. + * + * Some per-thread control flow integrity settings are not yet + * controlled through this prctl(); see for example + * PR_{GET,SET,LOCK}_SHADOW_STACK_STATUS */ -#define PR_GET_INDIR_BR_LP_STATUS 80 - +#define PR_GET_CFI 80 +#define PR_SET_CFI 81 /* - * Set the indirect branch tracking configuration. PR_INDIR_BR_LP_ENABLE will - * enable cpu feature for user thread, to track all indirect branches and ensure - * they land on arch defined landing pad instruction. - * x86 - If enabled, an indirect branch must land on an ENDBRANCH instruction. - * arch64 - If enabled, an indirect branch must land on a BTI instruction. - * riscv - If enabled, an indirect branch must land on an lpad instruction. - * PR_INDIR_BR_LP_DISABLE will disable feature for user thread and indirect - * branches will no more be tracked by cpu to land on arch defined landing pad - * instruction. - */ -#define PR_SET_INDIR_BR_LP_STATUS 81 -# define PR_INDIR_BR_LP_ENABLE (1UL << 0) - -/* - * Prevent further changes to the specified indirect branch tracking - * configuration. All bits may be locked via this call, including - * undefined bits. + * Forward-edge CFI variants (excluding ARM64 BTI, which has its own + * prctl()s). */ -#define PR_LOCK_INDIR_BR_LP_STATUS 82 +#define PR_CFI_BRANCH_LANDING_PADS 0 +/* Return and control values for PR_{GET,SET}_CFI */ +# define PR_CFI_ENABLE _BITUL(0) +# define PR_CFI_DISABLE _BITUL(1) +# define PR_CFI_LOCK _BITUL(2) #endif /* _LINUX_PRCTL_H */ -- cgit v1.2.3