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Diffstat (limited to 'arch/ia64/kernel/unwind.c')
-rw-r--r--arch/ia64/kernel/unwind.c23
1 files changed, 19 insertions, 4 deletions
diff --git a/arch/ia64/kernel/unwind.c b/arch/ia64/kernel/unwind.c
index b6c0e63a0bf6..fed6afa2e8a9 100644
--- a/arch/ia64/kernel/unwind.c
+++ b/arch/ia64/kernel/unwind.c
@@ -1204,10 +1204,10 @@ desc_spill_sprel_p (unsigned char qp, unw_word t, unsigned char abreg, unw_word
static inline unw_hash_index_t
hash (unsigned long ip)
{
-# define hashmagic 0x9e3779b97f4a7c16UL /* based on (sqrt(5)/2-1)*2^64 */
+ /* magic number = ((sqrt(5)-1)/2)*2^64 */
+ static const unsigned long hashmagic = 0x9e3779b97f4a7c16UL;
- return (ip >> 4)*hashmagic >> (64 - UNW_LOG_HASH_SIZE);
-#undef hashmagic
+ return (ip >> 4) * hashmagic >> (64 - UNW_LOG_HASH_SIZE);
}
static inline long
@@ -1531,7 +1531,7 @@ build_script (struct unw_frame_info *info)
struct unw_labeled_state *ls, *next;
unsigned long ip = info->ip;
struct unw_state_record sr;
- struct unw_table *table;
+ struct unw_table *table, *prev;
struct unw_reg_info *r;
struct unw_insn insn;
u8 *dp, *desc_end;
@@ -1560,11 +1560,26 @@ build_script (struct unw_frame_info *info)
STAT(parse_start = ia64_get_itc());
+ prev = NULL;
for (table = unw.tables; table; table = table->next) {
if (ip >= table->start && ip < table->end) {
+ /*
+ * Leave the kernel unwind table at the very front,
+ * lest moving it breaks some assumption elsewhere.
+ * Otherwise, move the matching table to the second
+ * position in the list so that traversals can benefit
+ * from commonality in backtrace paths.
+ */
+ if (prev && prev != unw.tables) {
+ /* unw is safe - we're already spinlocked */
+ prev->next = table->next;
+ table->next = unw.tables->next;
+ unw.tables->next = table;
+ }
e = lookup(table, ip - table->segment_base);
break;
}
+ prev = table;
}
if (!e) {
/* no info, return default unwinder (leaf proc, no mem stack, no saved regs) */