Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 416 insertions, 0 deletions

diff --git a/include/net/netmem.h b/include/net/netmem.h
new file mode 100644
index 000000000..bccacd21b
--- /dev/null
+++ b/include/net/netmem.h
@@ -0,0 +1,416 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ *	Network memory
+ *
+ *	Author:	Mina Almasry <almasrymina@google.com>
+ */
+
+#ifndef _NET_NETMEM_H
+#define _NET_NETMEM_H
+
+#include <linux/dma-mapping.h>
+#include <linux/mm.h>
+#include <net/net_debug.h>
+
+/* These fields in struct page are used by the page_pool and net stack:
+ *
+ *        struct {
+ *                unsigned long pp_magic;
+ *                struct page_pool *pp;
+ *                unsigned long _pp_mapping_pad;
+ *                unsigned long dma_addr;
+ *                atomic_long_t pp_ref_count;
+ *        };
+ *
+ * We mirror the page_pool fields here so the page_pool can access these
+ * fields without worrying whether the underlying fields belong to a
+ * page or netmem_desc.
+ *
+ * CAUTION: Do not update the fields in netmem_desc without also
+ * updating the anonymous aliasing union in struct net_iov.
+ */
+struct netmem_desc {
+	unsigned long _flags;
+	unsigned long pp_magic;
+	struct page_pool *pp;
+	unsigned long _pp_mapping_pad;
+	unsigned long dma_addr;
+	atomic_long_t pp_ref_count;
+};
+
+#define NETMEM_DESC_ASSERT_OFFSET(pg, desc)        \
+	static_assert(offsetof(struct page, pg) == \
+		      offsetof(struct netmem_desc, desc))
+NETMEM_DESC_ASSERT_OFFSET(flags, _flags);
+NETMEM_DESC_ASSERT_OFFSET(pp_magic, pp_magic);
+NETMEM_DESC_ASSERT_OFFSET(pp, pp);
+NETMEM_DESC_ASSERT_OFFSET(_pp_mapping_pad, _pp_mapping_pad);
+NETMEM_DESC_ASSERT_OFFSET(dma_addr, dma_addr);
+NETMEM_DESC_ASSERT_OFFSET(pp_ref_count, pp_ref_count);
+#undef NETMEM_DESC_ASSERT_OFFSET
+
+/*
+ * Since struct netmem_desc uses the space in struct page, the size
+ * should be checked, until struct netmem_desc has its own instance from
+ * slab, to avoid conflicting with other members within struct page.
+ */
+static_assert(sizeof(struct netmem_desc) <= offsetof(struct page, _refcount));
+
+/* net_iov */
+
+DECLARE_STATIC_KEY_FALSE(page_pool_mem_providers);
+
+/*  We overload the LSB of the struct page pointer to indicate whether it's
+ *  a page or net_iov.
+ */
+#define NET_IOV 0x01UL
+
+enum net_iov_type {
+	NET_IOV_DMABUF,
+	NET_IOV_IOURING,
+};
+
+/* A memory descriptor representing abstract networking I/O vectors,
+ * generally for non-pages memory that doesn't have its corresponding
+ * struct page and needs to be explicitly allocated through slab.
+ *
+ * net_iovs are allocated and used by networking code, and the size of
+ * the chunk is PAGE_SIZE.
+ *
+ * This memory can be any form of non-struct paged memory.  Examples
+ * include imported dmabuf memory and imported io_uring memory.  See
+ * net_iov_type for all the supported types.
+ *
+ * @pp_magic:	pp field, similar to the one in struct page/struct
+ *		netmem_desc.
+ * @pp:		the pp this net_iov belongs to, if any.
+ * @dma_addr:	the dma addrs of the net_iov. Needed for the network
+ *		card to send/receive this net_iov.
+ * @pp_ref_count: the pp ref count of this net_iov, exactly the same
+ *		usage as struct page/struct netmem_desc.
+ * @owner:	the net_iov_area this net_iov belongs to, if any.
+ * @type:	the type of the memory.  Different types of net_iovs are
+ *		supported.
+ */
+struct net_iov {
+	struct netmem_desc desc;
+	enum net_iov_type type;
+	struct net_iov_area *owner;
+};
+
+struct net_iov_area {
+	/* Array of net_iovs for this area. */
+	struct net_iov *niovs;
+	size_t num_niovs;
+
+	/* Offset into the dma-buf where this chunk starts.  */
+	unsigned long base_virtual;
+};
+
+static inline struct net_iov_area *net_iov_owner(const struct net_iov *niov)
+{
+	return niov->owner;
+}
+
+static inline unsigned int net_iov_idx(const struct net_iov *niov)
+{
+	return niov - net_iov_owner(niov)->niovs;
+}
+
+/* Initialize a niov: stamp the owning area, the memory provider type.
+ */
+static inline void net_iov_init(struct net_iov *niov,
+				struct net_iov_area *owner,
+				enum net_iov_type type)
+{
+	niov->owner = owner;
+	niov->type = type;
+}
+
+/* netmem */
+
+/**
+ * typedef netmem_ref - a nonexistent type marking a reference to generic
+ * network memory.
+ *
+ * A netmem_ref can be a struct page* or a struct net_iov* underneath.
+ *
+ * Use the supplied helpers to obtain the underlying memory pointer and fields.
+ */
+typedef unsigned long __bitwise netmem_ref;
+
+static inline bool netmem_is_net_iov(const netmem_ref netmem)
+{
+	return (__force unsigned long)netmem & NET_IOV;
+}
+
+/**
+ * __netmem_to_page - unsafely get pointer to the &page backing @netmem
+ * @netmem: netmem reference to convert
+ *
+ * Unsafe version of netmem_to_page(). When @netmem is always page-backed,
+ * e.g. when it's a header buffer, performs faster and generates smaller
+ * object code (no check for the LSB, no WARN). When @netmem points to IOV,
+ * provokes undefined behaviour.
+ *
+ * Return: pointer to the &page (garbage if @netmem is not page-backed).
+ */
+static inline struct page *__netmem_to_page(netmem_ref netmem)
+{
+	return (__force struct page *)netmem;
+}
+
+static inline struct page *netmem_to_page(netmem_ref netmem)
+{
+	if (WARN_ON_ONCE(netmem_is_net_iov(netmem)))
+		return NULL;
+
+	return __netmem_to_page(netmem);
+}
+
+static inline struct net_iov *netmem_to_net_iov(netmem_ref netmem)
+{
+	if (netmem_is_net_iov(netmem))
+		return (struct net_iov *)((__force unsigned long)netmem &
+					  ~NET_IOV);
+
+	DEBUG_NET_WARN_ON_ONCE(true);
+	return NULL;
+}
+
+static inline netmem_ref net_iov_to_netmem(struct net_iov *niov)
+{
+	return (__force netmem_ref)((unsigned long)niov | NET_IOV);
+}
+
+#define page_to_netmem(p)	(_Generic((p),			\
+	const struct page * :	(__force const netmem_ref)(p),	\
+	struct page * :		(__force netmem_ref)(p)))
+
+/**
+ * virt_to_netmem - convert virtual memory pointer to a netmem reference
+ * @data: host memory pointer to convert
+ *
+ * Return: netmem reference to the &page backing this virtual address.
+ */
+static inline netmem_ref virt_to_netmem(const void *data)
+{
+	return page_to_netmem(virt_to_page(data));
+}
+
+static inline int netmem_ref_count(netmem_ref netmem)
+{
+	/* The non-pp refcount of net_iov is always 1. On net_iov, we only
+	 * support pp refcounting which uses the pp_ref_count field.
+	 */
+	if (netmem_is_net_iov(netmem))
+		return 1;
+
+	return page_ref_count(netmem_to_page(netmem));
+}
+
+static inline unsigned long netmem_pfn_trace(netmem_ref netmem)
+{
+	if (netmem_is_net_iov(netmem))
+		return 0;
+
+	return page_to_pfn(netmem_to_page(netmem));
+}
+
+/* XXX: How to extract netmem_desc from page must be changed, once
+ * netmem_desc no longer overlays on page and will be allocated through
+ * slab.
+ */
+#define __pp_page_to_nmdesc(p)	(_Generic((p),				\
+	const struct page * :	(const struct netmem_desc *)(p),	\
+	struct page * :		(struct netmem_desc *)(p)))
+
+/* CAUTION: Check if the page is a pp page before calling this helper or
+ * know it's a pp page.
+ */
+#define pp_page_to_nmdesc(p)						\
+({									\
+	DEBUG_NET_WARN_ON_ONCE(!page_pool_page_is_pp(p));		\
+	__pp_page_to_nmdesc(p);						\
+})
+
+/**
+ * __netmem_to_nmdesc - unsafely get pointer to the &netmem_desc backing
+ * @netmem
+ * @netmem: netmem reference to convert
+ *
+ * Unsafe version that can be used only when @netmem is always backed by
+ * system memory, performs faster and generates smaller object code (no
+ * check for the LSB, no WARN). When @netmem points to IOV, provokes
+ * undefined behaviour.
+ *
+ * Return: pointer to the &netmem_desc (garbage if @netmem is not backed
+ * by system memory).
+ */
+static inline struct netmem_desc *__netmem_to_nmdesc(netmem_ref netmem)
+{
+	return (__force struct netmem_desc *)netmem;
+}
+
+/* netmem_to_nmdesc - convert netmem_ref to struct netmem_desc * for
+ * access to common fields.
+ * @netmem: netmem reference to get netmem_desc.
+ *
+ * All the sub types of netmem_ref (netmem_desc, net_iov) have the same
+ * pp, pp_magic, dma_addr, and pp_ref_count fields via netmem_desc.
+ *
+ * Return: the pointer to struct netmem_desc * regardless of its
+ * underlying type.
+ */
+static inline struct netmem_desc *netmem_to_nmdesc(netmem_ref netmem)
+{
+	void *p = (void *)((__force unsigned long)netmem & ~NET_IOV);
+
+	if (netmem_is_net_iov(netmem))
+		return &((struct net_iov *)p)->desc;
+
+	return __pp_page_to_nmdesc((struct page *)p);
+}
+
+/**
+ * __netmem_get_pp - unsafely get pointer to the &page_pool backing @netmem
+ * @netmem: netmem reference to get the pointer from
+ *
+ * Unsafe version of netmem_get_pp(). When @netmem is always page-backed,
+ * e.g. when it's a header buffer, performs faster and generates smaller
+ * object code (avoids clearing the LSB). When @netmem points to IOV,
+ * provokes invalid memory access.
+ *
+ * Return: pointer to the &page_pool (garbage if @netmem is not page-backed).
+ */
+static inline struct page_pool *__netmem_get_pp(netmem_ref netmem)
+{
+	return __netmem_to_nmdesc(netmem)->pp;
+}
+
+static inline struct page_pool *netmem_get_pp(netmem_ref netmem)
+{
+	return netmem_to_nmdesc(netmem)->pp;
+}
+
+static inline atomic_long_t *netmem_get_pp_ref_count_ref(netmem_ref netmem)
+{
+	return &netmem_to_nmdesc(netmem)->pp_ref_count;
+}
+
+static inline bool netmem_is_pref_nid(netmem_ref netmem, int pref_nid)
+{
+	/* NUMA node preference only makes sense if we're allocating
+	 * system memory. Memory providers (which give us net_iovs)
+	 * choose for us.
+	 */
+	if (netmem_is_net_iov(netmem))
+		return true;
+
+	return page_to_nid(netmem_to_page(netmem)) == pref_nid;
+}
+
+static inline netmem_ref netmem_compound_head(netmem_ref netmem)
+{
+	/* niov are never compounded */
+	if (netmem_is_net_iov(netmem))
+		return netmem;
+
+	return page_to_netmem(compound_head(netmem_to_page(netmem)));
+}
+
+/**
+ * __netmem_address - unsafely get pointer to the memory backing @netmem
+ * @netmem: netmem reference to get the pointer for
+ *
+ * Unsafe version of netmem_address(). When @netmem is always page-backed,
+ * e.g. when it's a header buffer, performs faster and generates smaller
+ * object code (no check for the LSB). When @netmem points to IOV, provokes
+ * undefined behaviour.
+ *
+ * Return: pointer to the memory (garbage if @netmem is not page-backed).
+ */
+static inline void *__netmem_address(netmem_ref netmem)
+{
+	return page_address(__netmem_to_page(netmem));
+}
+
+static inline void *netmem_address(netmem_ref netmem)
+{
+	if (netmem_is_net_iov(netmem))
+		return NULL;
+
+	return __netmem_address(netmem);
+}
+
+/**
+ * netmem_is_pfmemalloc - check if @netmem was allocated under memory pressure
+ * @netmem: netmem reference to check
+ *
+ * Return: true if @netmem is page-backed and the page was allocated under
+ * memory pressure, false otherwise.
+ */
+static inline bool netmem_is_pfmemalloc(netmem_ref netmem)
+{
+	if (netmem_is_net_iov(netmem))
+		return false;
+
+	return page_is_pfmemalloc(netmem_to_page(netmem));
+}
+
+static inline unsigned long netmem_get_dma_addr(netmem_ref netmem)
+{
+	return netmem_to_nmdesc(netmem)->dma_addr;
+}
+
+#if defined(CONFIG_NET_DEVMEM)
+static inline bool net_is_devmem_iov(const struct net_iov *niov)
+{
+	return niov->type == NET_IOV_DMABUF;
+}
+#else
+static inline bool net_is_devmem_iov(const struct net_iov *niov)
+{
+	return false;
+}
+#endif
+
+void __get_netmem(netmem_ref netmem);
+void __put_netmem(netmem_ref netmem);
+
+static __always_inline void get_netmem(netmem_ref netmem)
+{
+	if (netmem_is_net_iov(netmem))
+		__get_netmem(netmem);
+	else
+		get_page(netmem_to_page(netmem));
+}
+
+static __always_inline void put_netmem(netmem_ref netmem)
+{
+	if (netmem_is_net_iov(netmem))
+		__put_netmem(netmem);
+	else
+		put_page(netmem_to_page(netmem));
+}
+
+#define netmem_dma_unmap_addr_set(NETMEM, PTR, ADDR_NAME, VAL)   \
+	do {                                                     \
+		if (!netmem_is_net_iov(NETMEM))                  \
+			dma_unmap_addr_set(PTR, ADDR_NAME, VAL); \
+		else                                             \
+			dma_unmap_addr_set(PTR, ADDR_NAME, 0);   \
+	} while (0)
+
+static inline void netmem_dma_unmap_page_attrs(struct device *dev,
+					       dma_addr_t addr, size_t size,
+					       enum dma_data_direction dir,
+					       unsigned long attrs)
+{
+	if (!addr)
+		return;
+
+	dma_unmap_page_attrs(dev, addr, size, dir, attrs);
+}
+
+#endif /* _NET_NETMEM_H */