Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted

Pull io_uring fixes from Jens Axboe:

 - Fix a task_work add use-after-free with SQPOLL.

   The sqpoll thread could pop and complete the last request while
   io_req_normal_work_add() was still looking at them after the mpscq
   push.

   Use the same approach as DEFER_TASKRUN to protect from that, holding
   an RCU read lock across the add, and have exit wait for an RCU grace
   period for SQPOLL rings as well.

 - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
   big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
   rings

 - Mark the source filter table as COW when cloning bpf filters, so
   registering another filter on the source doesn't modify the shared
   table in place

 - Initialize the task context before running the BPF loop

 - Requeue zcrx multishot receives stopped by a local resource

 - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)

* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring: fix task_work add use-after-free with SQPOLL
  io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
  io_uring/zcrx: requeue multishot receives stopped by a local resource
  io_uring: initialize task context before running the BPF loop
  io_uring: zero big_cqe for aux CQEs on CQE32 rings
  io_uring: fix free entry check for 32b CQEs on CQE32 rings
  io_uring: only post the dummy skip CQE on CQE_MIXED rings
  io_uring/bpf_filter: mark source as COW when cloning filters

1 files changed, 118 insertions, 0 deletions

diff --git a/lib/extable.c b/lib/extable.c
new file mode 100644
index 000000000..9c9f40bd2
--- /dev/null
+++ b/lib/extable.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Derived from arch/ppc/mm/extable.c and arch/i386/mm/extable.c.
+ *
+ * Copyright (C) 2004 Paul Mackerras, IBM Corp.
+ */
+
+#include <linux/bsearch.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sort.h>
+#include <linux/uaccess.h>
+#include <linux/extable.h>
+
+#ifndef ARCH_HAS_RELATIVE_EXTABLE
+#define ex_to_insn(x)	((x)->insn)
+#else
+static inline unsigned long ex_to_insn(const struct exception_table_entry *x)
+{
+	return (unsigned long)&x->insn + x->insn;
+}
+#endif
+
+#ifndef ARCH_HAS_RELATIVE_EXTABLE
+#define swap_ex		NULL
+#else
+static void swap_ex(void *a, void *b, int size)
+{
+	struct exception_table_entry *x = a, *y = b, tmp;
+	int delta = b - a;
+
+	tmp = *x;
+	x->insn = y->insn + delta;
+	y->insn = tmp.insn - delta;
+
+#ifdef swap_ex_entry_fixup
+	swap_ex_entry_fixup(x, y, tmp, delta);
+#else
+	x->fixup = y->fixup + delta;
+	y->fixup = tmp.fixup - delta;
+#endif
+}
+#endif /* ARCH_HAS_RELATIVE_EXTABLE */
+
+/*
+ * The exception table needs to be sorted so that the binary
+ * search that we use to find entries in it works properly.
+ * This is used both for the kernel exception table and for
+ * the exception tables of modules that get loaded.
+ */
+static int cmp_ex_sort(const void *a, const void *b)
+{
+	const struct exception_table_entry *x = a, *y = b;
+
+	/* avoid overflow */
+	if (ex_to_insn(x) > ex_to_insn(y))
+		return 1;
+	if (ex_to_insn(x) < ex_to_insn(y))
+		return -1;
+	return 0;
+}
+
+void sort_extable(struct exception_table_entry *start,
+		  struct exception_table_entry *finish)
+{
+	sort(start, finish - start, sizeof(struct exception_table_entry),
+	     cmp_ex_sort, swap_ex);
+}
+
+#ifdef CONFIG_MODULES
+/*
+ * If the exception table is sorted, any referring to the module init
+ * will be at the beginning or the end.
+ */
+void trim_init_extable(struct module *m)
+{
+	/*trim the beginning*/
+	while (m->num_exentries &&
+	       within_module_init(ex_to_insn(&m->extable[0]), m)) {
+		m->extable++;
+		m->num_exentries--;
+	}
+	/*trim the end*/
+	while (m->num_exentries &&
+	       within_module_init(ex_to_insn(&m->extable[m->num_exentries - 1]),
+				  m))
+		m->num_exentries--;
+}
+#endif /* CONFIG_MODULES */
+
+static int cmp_ex_search(const void *key, const void *elt)
+{
+	const struct exception_table_entry *_elt = elt;
+	unsigned long _key = *(unsigned long *)key;
+
+	/* avoid overflow */
+	if (_key > ex_to_insn(_elt))
+		return 1;
+	if (_key < ex_to_insn(_elt))
+		return -1;
+	return 0;
+}
+
+/*
+ * Search one exception table for an entry corresponding to the
+ * given instruction address, and return the address of the entry,
+ * or NULL if none is found.
+ * We use a binary search, and thus we assume that the table is
+ * already sorted.
+ */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *base,
+	       const size_t num,
+	       unsigned long value)
+{
+	return bsearch(&value, base, num,
+		       sizeof(struct exception_table_entry), cmp_ex_search);
+}