The {start, pc} entries are already word aligned, no need to use
read_pointer() inefficiency !
Signed-off-by: Vineet Gupta <vgu...@synopsys.com>
---
arch/arc/kernel/unwind.c | 40 +++++++++++++++++-----------------------
1 file changed, 17 insertions(+), 23 deletions(-)
diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index 9b34038a7582..6a09ffa0b697 100644
--- a/arch/arc/kernel/unwind.c
+++ b/arch/arc/kernel/unwind.c
@@ -866,7 +866,7 @@ int arc_unwind(struct unwind_frame_info *frame)
const u8 *ptr = NULL, *end = NULL;
unsigned long pc = UNW_PC(frame);
unsigned long startLoc = 0, endLoc = 0, cfa;
- unsigned i;
+ unsigned i, s, e;
signed ptrType = -1;
uleb128_t retAddrReg = 0;
const struct unwind_table *table;
@@ -874,7 +874,6 @@ int arc_unwind(struct unwind_frame_info *frame)
unsigned long *fptr;
unsigned long addr;
struct eh_frame_header *hdr;
- unsigned long hdrEntrySz;
unw_debug("\nUNWIND FRAME: -------------------------------------\n");
unw_debug("PC\t\t: 0x%lx %pS\nr31 [BLINK]\t: 0x%lx %pS\nr28 [SP]\t:
0x%lx\nr27 [FP]\t: 0x%lx\n",
@@ -903,28 +902,23 @@ int arc_unwind(struct unwind_frame_info *frame)
if (hdr == NULL)
return -EINVAL;
- hdrEntrySz = sizeof(unsigned long);
- BUILD_BUG_ON(hdrEntrySz != sizeof(hdr->table[0].start));
+ s = i = 0;
+ e = hdr->fde_count - 1;
- ptr = (const u8*)(hdr->table);
- end = (const u8*)(hdr) + table->hdrsz;
- i = hdr->fde_count;
-
- do {
- const u8 *cur = ptr + (i / 2) * (2 *
hdrEntrySz);
-
- startLoc = read_pointer(&cur, cur + hdrEntrySz,
hdr->table_enc);
- if (pc < startLoc)
- i /= 2;
- else {
- ptr = cur - hdrEntrySz;
- i = (i + 1) / 2;
- }
- } while (startLoc && i > 1);
- if (i == 1
- && (startLoc = read_pointer(&ptr, ptr + hdrEntrySz,
hdr->table_enc)) != 0
- && pc >= startLoc)
- fde = (void *)read_pointer(&ptr, ptr +
hdrEntrySz, hdr->table_enc);
+ do {
+ if (pc < startLoc)
+ e = i;
+ else
+ s = i;
+ i = s + (e - s) / 2;
+ startLoc = hdr->table[i].start;
+ unw_debug("s %d e %d i %d startLoc %lx\n", s, e, i, startLoc)
+ } while ((e - s) > 1);
+
+ if (pc >= startLoc)
+ fde = (u32 *)hdr->table[i].fde;
+ else
+ return -EINVAL;
if (fde != NULL) {
cie = cie_for_fde(fde, table);
--
1.9.1
_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc
