forked from mirrors/linux
		
	Following the pattern of io_uring, perf, skb, and bpf, iommfd will use user->locked_vm for accounting pinned pages. Ensure the value is included in the struct and export free_uid() as iommufd is modular. user->locked_vm is the good accounting to use for ulimit because it is per-user, and the security sandboxing of locked pages is not supposed to be per-process. Other places (vfio, vdpa and infiniband) have used mm->pinned_vm and/or mm->locked_vm for accounting pinned pages, but this is only per-process and inconsistent with the new FOLL_LONGTERM users in the kernel. Concurrent work is underway to try to put this in a cgroup, so everything can be consistent and the kernel can provide a FOLL_LONGTERM limit that actually provides security. Link: https://lore.kernel.org/r/7-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Yi Liu <yi.l.liu@intel.com> Tested-by: Lixiao Yang <lixiao.yang@intel.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
		
			
				
	
	
		
			56 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			56 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_SCHED_USER_H
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#define _LINUX_SCHED_USER_H
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#include <linux/uidgid.h>
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#include <linux/atomic.h>
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#include <linux/percpu_counter.h>
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#include <linux/refcount.h>
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#include <linux/ratelimit.h>
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/*
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 * Some day this will be a full-fledged user tracking system..
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 */
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struct user_struct {
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	refcount_t __count;	/* reference count */
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#ifdef CONFIG_EPOLL
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	struct percpu_counter epoll_watches; /* The number of file descriptors currently watched */
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#endif
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	unsigned long unix_inflight;	/* How many files in flight in unix sockets */
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	atomic_long_t pipe_bufs;  /* how many pages are allocated in pipe buffers */
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	/* Hash table maintenance information */
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	struct hlist_node uidhash_node;
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	kuid_t uid;
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#if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL) || \
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	defined(CONFIG_NET) || defined(CONFIG_IO_URING) || \
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	defined(CONFIG_VFIO_PCI_ZDEV_KVM) || IS_ENABLED(CONFIG_IOMMUFD)
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	atomic_long_t locked_vm;
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#endif
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#ifdef CONFIG_WATCH_QUEUE
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	atomic_t nr_watches;	/* The number of watches this user currently has */
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#endif
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	/* Miscellaneous per-user rate limit */
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	struct ratelimit_state ratelimit;
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};
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extern int uids_sysfs_init(void);
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extern struct user_struct *find_user(kuid_t);
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extern struct user_struct root_user;
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#define INIT_USER (&root_user)
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/* per-UID process charging. */
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extern struct user_struct * alloc_uid(kuid_t);
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static inline struct user_struct *get_uid(struct user_struct *u)
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{
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	refcount_inc(&u->__count);
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	return u;
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}
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extern void free_uid(struct user_struct *);
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#endif /* _LINUX_SCHED_USER_H */
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