#ifndef _KERNEL_EVENTS_INTERNAL_H #define _KERNEL_EVENTS_INTERNAL_H #include #include /* Buffer handling */ #define RING_BUFFER_WRITABLE 0x01 struct ring_buffer { atomic_t refcount; struct rcu_head rcu_head; #ifdef CONFIG_PERF_USE_VMALLOC struct work_struct work; int page_order; /* allocation order */ #endif int nr_pages; /* nr of data pages */ int overwrite; /* can overwrite itself */ int paused; /* can write into ring buffer */ atomic_t poll; /* POLL_ for wakeups */ local_t head; /* write position */ local_t nest; /* nested writers */ local_t events; /* event limit */ local_t wakeup; /* wakeup stamp */ local_t lost; /* nr records lost */ long watermark; /* wakeup watermark */ long aux_watermark; /* poll crap */ spinlock_t event_lock; struct list_head event_list; atomic_t mmap_count; unsigned long mmap_locked; struct user_struct *mmap_user; /* AUX area */ local_t aux_head; local_t aux_nest; local_t aux_wakeup; unsigned long aux_pgoff; int aux_nr_pages; int aux_overwrite; atomic_t aux_mmap_count; unsigned long aux_mmap_locked; void (*free_aux)(void *); atomic_t aux_refcount; void **aux_pages; void *aux_priv; struct perf_event_mmap_page *user_page; void *data_pages[0]; }; extern void rb_free(struct ring_buffer *rb); static inline void rb_free_rcu(struct rcu_head *rcu_head) { struct ring_buffer *rb; rb = container_of(rcu_head, struct ring_buffer, rcu_head); rb_free(rb); } static inline void rb_toggle_paused(struct ring_buffer *rb, bool pause) { if (!pause && rb->nr_pages) rb->paused = 0; else rb->paused = 1; } extern struct ring_buffer * rb_alloc(int nr_pages, long watermark, int cpu, int flags); extern void perf_event_wakeup(struct perf_event *event); extern int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event, pgoff_t pgoff, int nr_pages, long watermark, int flags); extern void rb_free_aux(struct ring_buffer *rb); extern struct ring_buffer *ring_buffer_get(struct perf_event *event); extern void ring_buffer_put(struct ring_buffer *rb); static inline bool rb_has_aux(struct ring_buffer *rb) { return !!rb->aux_nr_pages; } void perf_event_aux_event(struct perf_event *event, unsigned long head, unsigned long size, u64 flags); extern struct page * perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff); #ifdef CONFIG_PERF_USE_VMALLOC /* * Back perf_mmap() with vmalloc memory. * * Required for architectures that have d-cache aliasing issues. */ static inline int page_order(struct ring_buffer *rb) { return rb->page_order; } #else static inline int page_order(struct ring_buffer *rb) { return 0; } #endif static inline unsigned long perf_data_size(struct ring_buffer *rb) { return rb->nr_pages << (PAGE_SHIFT + page_order(rb)); } static inline unsigned long perf_aux_size(struct ring_buffer *rb) { return rb->aux_nr_pages << PAGE_SHIFT; } #define __DEFINE_OUTPUT_COPY_BODY(advance_buf, memcpy_func, ...) \ { \ unsigned long size, written; \ \ do { \ size = min(handle->size, len); \ written = memcpy_func(__VA_ARGS__); \ written = size - written; \ \ len -= written; \ handle->addr += written; \ if (advance_buf) \ buf += written; \ handle->size -= written; \ if (!handle->size) { \ struct ring_buffer *rb = handle->rb; \ \ handle->page++; \ handle->page &= rb->nr_pages - 1; \ handle->addr = rb->data_pages[handle->page]; \ handle->size = PAGE_SIZE << page_order(rb); \ } \ } while (len && written == size); \ \ return len; \ } #define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \ static inline unsigned long \ func_name(struct perf_output_handle *handle, \ const void *buf, unsigned long len) \ __DEFINE_OUTPUT_COPY_BODY(true, memcpy_func, handle->addr, buf, size) static inline unsigned long __output_custom(struct perf_output_handle *handle, perf_copy_f copy_func, const void *buf, unsigned long len) { unsigned long orig_len = len; __DEFINE_OUTPUT_COPY_BODY(false, copy_func, handle->addr, buf, orig_len - len, size) } static inline unsigned long memcpy_common(void *dst, const void *src, unsigned long n) { memcpy(dst, src, n); return 0; } DEFINE_OUTPUT_COPY(__output_copy, memcpy_common) static inline unsigned long memcpy_skip(void *dst, const void *src, unsigned long n) { return 0; } DEFINE_OUTPUT_COPY(__output_skip, memcpy_skip) #ifndef arch_perf_out_copy_user #define arch_perf_out_copy_user arch_perf_out_copy_user static inline unsigned long arch_perf_out_copy_user(void *dst, const void *src, unsigned long n) { unsigned long ret; pagefault_disable(); ret = __copy_from_user_inatomic(dst, src, n); pagefault_enable(); return ret; } #endif DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user) /* Callchain handling */ extern struct perf_callchain_entry * perf_callchain(struct perf_event *event, struct pt_regs *regs); static inline int get_recursion_context(int *recursion) { int rctx; if (in_nmi()) rctx = 3; else if (in_irq()) rctx = 2; else if (in_softirq()) rctx = 1; else rctx = 0; if (recursion[rctx]) return -1; recursion[rctx]++; barrier(); return rctx; } static inline void put_recursion_context(int *recursion, int rctx) { barrier(); recursion[rctx]--; } #ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP static inline bool arch_perf_have_user_stack_dump(void) { return true; } #define perf_user_stack_pointer(regs) user_stack_pointer(regs) #else static inline bool arch_perf_have_user_stack_dump(void) { return false; } #define perf_user_stack_pointer(regs) 0 #endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */ #endif /* _KERNEL_EVENTS_INTERNAL_H */ id2=566cf877a1fcb6d6dc0126b076aad062054c2637'>diff)
perf/core: Fix use-after-free bug
Dmitry reported a KASAN use-after-free on event->group_leader. It turns out there's a hole in perf_remove_from_context() due to event_function_call() not calling its function when the task associated with the event is already dead. In this case the event will have been detached from the task, but the grouping will have been retained, such that group operations might still work properly while there are live child events etc. This does however mean that we can miss a perf_group_detach() call when the group decomposes, this in turn can then lead to use-after-free. Fix it by explicitly doing the group detach if its still required. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org # v4.5+ Cc: syzkaller <syzkaller@googlegroups.com> Fixes: 63b6da39bb38 ("perf: Fix perf_event_exit_task() race") Link: http://lkml.kernel.org/r/20170126153955.GD6515@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/usb/core/sysfs.c')