Merge branch 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers into asm-generic

Patches from David Howells <dhowells@redhat.com>:

This is to complete part of the UAPI disintegration for which the
preparatory patches were pulled recently.

Note that there are some fixup patches which are at the base of the
branch aimed at you, plus all arches get the asm-generic branch merged in too.

* 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers:
  UAPI: (Scripted) Disintegrate include/asm-generic
  UAPI: Fix conditional header installation handling (notably kvm_para.h on m68k)
  c6x: remove c6x signal.h
  UAPI: Split compound conditionals containing __KERNEL__ in Arm64
  UAPI: Fix the guards on various asm/unistd.h files

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 81 insertions, 0 deletions

diff --git a/arch/s390/mm/extable.c b/arch/s390/mm/extable.c
new file mode 100644
index 000000000000..4d1ee88864e8
--- /dev/null
+++ b/arch/s390/mm/extable.c
@@ -0,0 +1,81 @@
+#include <linux/module.h>
+#include <linux/sort.h>
+#include <asm/uaccess.h>
+
+/*
+ * 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 *first,
+	       const struct exception_table_entry *last,
+	       unsigned long value)
+{
+	const struct exception_table_entry *mid;
+	unsigned long addr;
+
+	while (first <= last) {
+		mid = ((last - first) >> 1) + first;
+		addr = extable_insn(mid);
+		if (addr < value)
+			first = mid + 1;
+		else if (addr > value)
+			last = mid - 1;
+		else
+			return mid;
+	}
+	return NULL;
+}
+
+/*
+ * 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(const void *a, const void *b)
+{
+	const struct exception_table_entry *x = a, *y = b;
+
+	/* This compare is only valid after normalization. */
+	return x->insn - y->insn;
+}
+
+void sort_extable(struct exception_table_entry *start,
+		  struct exception_table_entry *finish)
+{
+	struct exception_table_entry *p;
+	int i;
+
+	/* Normalize entries to being relative to the start of the section */
+	for (p = start, i = 0; p < finish; p++, i += 8)
+		p->insn += i;
+	sort(start, finish - start, sizeof(*start), cmp_ex, NULL);
+	/* Denormalize all entries */
+	for (p = start, i = 0; p < finish; p++, i += 8)
+		p->insn -= i;
+}
+
+#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(extable_insn(&m->extable[0]), m)) {
+		m->extable++;
+		m->num_exentries--;
+	}
+	/* Trim the end */
+	while (m->num_exentries &&
+	       within_module_init(extable_insn(&m->extable[m->num_exentries-1]), m))
+		m->num_exentries--;
+}
+#endif /* CONFIG_MODULES */