#include "unwind_i.h"
#include "offsets.h"
-PROTECTED int
-unw_handle_signal_frame (unw_cursor_t *cursor)
+/* Recognise PLT entries such as:
+ 40ddf0: b0000570 adrp x16, 4ba000 <_GLOBAL_OFFSET_TABLE_+0x2a8>
+ 40ddf4: f9433611 ldr x17, [x16,#1640]
+ 40ddf8: 9119a210 add x16, x16, #0x668
+ 40ddfc: d61f0220 br x17 */
+static int
+is_plt_entry (struct dwarf_cursor *c)
+{
+ unw_word_t w0, w1;
+ unw_accessors_t *a;
+ int ret;
+
+ a = unw_get_accessors_int (c->as);
+ if ((ret = (*a->access_mem) (c->as, c->ip, &w0, 0, c->as_arg)) < 0
+ || (ret = (*a->access_mem) (c->as, c->ip + 8, &w1, 0, c->as_arg)) < 0)
+ return 0;
+
+ ret = (((w0 & 0xff0000009f000000) == 0xf900000090000000)
+ && ((w1 & 0xffffffffff000000) == 0xd61f022091000000));
+
+ Debug (14, "ip=0x%lx => 0x%016lx 0x%016lx, ret = %d\n", c->ip, w0, w1, ret);
+ return ret;
+}
+
+static int
+aarch64_handle_signal_frame (unw_cursor_t *cursor)
{
struct cursor *c = (struct cursor *) cursor;
int ret;
dwarf_get (&c->dwarf, c->dwarf.loc[UNW_AARCH64_PC], &c->dwarf.ip);
c->dwarf.pi_valid = 0;
+ c->dwarf.use_prev_instr = 0;
return 1;
}
-PROTECTED int
+int
unw_step (unw_cursor_t *cursor)
{
struct cursor *c = (struct cursor *) cursor;
c, c->dwarf.ip, c->dwarf.cfa);
/* Check if this is a signal frame. */
- if (unw_is_signal_frame (cursor))
- return unw_handle_signal_frame (cursor);
+ if (unw_is_signal_frame (cursor) > 0)
+ return aarch64_handle_signal_frame (cursor);
ret = dwarf_step (&c->dwarf);
Debug(1, "dwarf_step()=%d\n", ret);
return ret;
if (unlikely (ret < 0))
- return 0;
+ {
+ /* DWARF failed. */
+ if (is_plt_entry (&c->dwarf))
+ {
+ Debug (2, "found plt entry\n");
+ c->frame_info.frame_type = UNW_AARCH64_FRAME_STANDARD;
+ }
+ else
+ {
+ Debug (2, "fallback\n");
+ c->frame_info.frame_type = UNW_AARCH64_FRAME_GUESSED;
+ }
+ /* Use link register (X30). */
+ c->frame_info.cfa_reg_offset = 0;
+ c->frame_info.cfa_reg_sp = 0;
+ c->frame_info.fp_cfa_offset = -1;
+ c->frame_info.lr_cfa_offset = -1;
+ c->frame_info.sp_cfa_offset = -1;
+ c->dwarf.loc[UNW_AARCH64_PC] = c->dwarf.loc[UNW_AARCH64_X30];
+ c->dwarf.loc[UNW_AARCH64_X30] = DWARF_NULL_LOC;
+ if (!DWARF_IS_NULL_LOC (c->dwarf.loc[UNW_AARCH64_PC]))
+ {
+ ret = dwarf_get (&c->dwarf, c->dwarf.loc[UNW_AARCH64_PC], &c->dwarf.ip);
+ if (ret < 0)
+ {
+ Debug (2, "failed to get pc from link register: %d\n", ret);
+ return ret;
+ }
+ Debug (2, "link register (x30) = 0x%016lx\n", c->dwarf.ip);
+ ret = 1;
+ }
+ else
+ c->dwarf.ip = 0;
+ }
return (c->dwarf.ip == 0) ? 0 : 1;
}