[PATCH 3/3] x86/unwind/orc: Simplify unwind_init() for x86 boot

Huaixin Chang
2020-06-03T14:42:53Z

The orc fast lookup table is built by scripts/sorttable tool. All that
is left is setting lookup_num_blocks.

Signed-off-by: Huaixin Chang <changhuaixin@linux.alibaba.com>
Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
---
arch/x86/kernel/unwind_orc.c | 41 ++---------------------------------------
1 file changed, 2 insertions(+), 39 deletions(-)

diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index 7f969b2d240f..e4cf124c7a51 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -264,48 +264,11 @@ void unwind_module_init(struct module *mod, void *_orc_ip, size_t orc_ip_size,

void __init unwind_init(void)
{
- size_t orc_ip_size = (void *)__stop_orc_unwind_ip - (void *)__start_orc_unwind_ip;
- size_t orc_size = (void *)__stop_orc_unwind - (void *)__start_orc_unwind;
- size_t num_entries = orc_ip_size / sizeof(int);
- struct orc_entry *orc;
- int i;
-
- if (!num_entries || orc_ip_size % sizeof(int) != 0 ||
- orc_size % sizeof(struct orc_entry) != 0 ||
- num_entries != orc_size / sizeof(struct orc_entry)) {
- orc_warn("WARNING: Bad or missing .orc_unwind table. Disabling unwinder.\n");
- return;
- }
-
/*
- * Note, the orc_unwind and orc_unwind_ip tables were already
- * sorted at build time via the 'sorttable' tool.
- * It's ready for binary search straight away, no need to sort it.
+ * The fast lookup table is built via sorttable tool. Initialize
+ * lookup_num_blocks only.
*/
-
- /* Initialize the fast lookup table: */
lookup_num_blocks = orc_lookup_end - orc_lookup;
- for (i = 0; i < lookup_num_blocks-1; i++) {
- orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind,
- num_entries,
- LOOKUP_START_IP + (LOOKUP_BLOCK_SIZE * i));
- if (!orc) {
- orc_warn("WARNING: Corrupt .orc_unwind table. Disabling unwinder.\n");
- return;
- }
-
- orc_lookup[i] = orc - __start_orc_unwind;
- }
-
- /* Initialize the ending block: */
- orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind, num_entries,
- LOOKUP_STOP_IP);
- if (!orc) {
- orc_warn("WARNING: Corrupt .orc_unwind table. Disabling unwinder.\n");
- return;
- }
- orc_lookup[lookup_num_blocks-1] = orc - __start_orc_unwind;
-
orc_init = true;
}

--
2.14.4.44.g2045bb6