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authorLinus Torvalds2005-04-17 00:20:36 +0200
committerLinus Torvalds2005-04-17 00:20:36 +0200
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sparc/mm/extable.c
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Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/sparc/mm/extable.c')
-rw-r--r--arch/sparc/mm/extable.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/arch/sparc/mm/extable.c b/arch/sparc/mm/extable.c
new file mode 100644
index 000000000000..c9845c71f426
--- /dev/null
+++ b/arch/sparc/mm/extable.c
@@ -0,0 +1,77 @@
+/*
+ * linux/arch/sparc/mm/extable.c
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+
+void sort_extable(struct exception_table_entry *start,
+ struct exception_table_entry *finish)
+{
+}
+
+/* Caller knows they are in a range if ret->fixup == 0 */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *start,
+ const struct exception_table_entry *last,
+ unsigned long value)
+{
+ const struct exception_table_entry *walk;
+
+ /* Single insn entries are encoded as:
+ * word 1: insn address
+ * word 2: fixup code address
+ *
+ * Range entries are encoded as:
+ * word 1: first insn address
+ * word 2: 0
+ * word 3: last insn address + 4 bytes
+ * word 4: fixup code address
+ *
+ * See asm/uaccess.h for more details.
+ */
+
+ /* 1. Try to find an exact match. */
+ for (walk = start; walk <= last; walk++) {
+ if (walk->fixup == 0) {
+ /* A range entry, skip both parts. */
+ walk++;
+ continue;
+ }
+
+ if (walk->insn == value)
+ return walk;
+ }
+
+ /* 2. Try to find a range match. */
+ for (walk = start; walk <= (last - 1); walk++) {
+ if (walk->fixup)
+ continue;
+
+ if (walk[0].insn <= value && walk[1].insn > value)
+ return walk;
+
+ walk++;
+ }
+
+ return NULL;
+}
+
+/* Special extable search, which handles ranges. Returns fixup */
+unsigned long search_extables_range(unsigned long addr, unsigned long *g2)
+{
+ const struct exception_table_entry *entry;
+
+ entry = search_exception_tables(addr);
+ if (!entry)
+ return 0;
+
+ /* Inside range? Fix g2 and return correct fixup */
+ if (!entry->fixup) {
+ *g2 = (addr - entry->insn) / 4;
+ return (entry + 1)->fixup;
+ }
+
+ return entry->fixup;
+}