FDE Lookup table (eh_frame_header or it's equivalent constructed by hand)
is already setup correctly in setup_unwind_table(). There's no point
to re-parse it's header for every unwind call
Signed-off-by: Vineet Gupta <vgu...@synopsys.com>
---
arch/arc/kernel/unwind.c | 37 ++++++++-----------------------------
1 file changed, 8 insertions(+), 29 deletions(-)
diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index 9f5ed6873c52..9b34038a7582 100644
--- a/arch/arc/kernel/unwind.c
+++ b/arch/arc/kernel/unwind.c
@@ -900,35 +900,16 @@ int arc_unwind(struct unwind_frame_info *frame)
return -EINVAL;
hdr = table->header;
+ if (hdr == NULL)
+ return -EINVAL;
- smp_rmb();
- if (hdr && hdr->version == 1) {
- switch (hdr->table_enc & DW_EH_PE_FORM) {
- case DW_EH_PE_native:
- hdrEntrySz = sizeof(unsigned long);
- break;
- case DW_EH_PE_data2:
- hdrEntrySz = 2;
- break;
- case DW_EH_PE_data4:
- hdrEntrySz = 4;
- break;
- case DW_EH_PE_data8:
- hdrEntrySz = 8;
- break;
- default:
- hdrEntrySz = 0;
- break;
- }
+ hdrEntrySz = sizeof(unsigned long);
+ BUILD_BUG_ON(hdrEntrySz != sizeof(hdr->table[0].start));
+
+ ptr = (const u8*)(hdr->table);
+ end = (const u8*)(hdr) + table->hdrsz;
+ i = hdr->fde_count;
- ptr = (const u8*)(hdr->eh_frame_ptr);
- end = (const u8*)(hdr) + table->hdrsz;
- if (hdrEntrySz
- && read_pointer(&ptr, end, hdr->eh_frame_ptr_enc) /*
eh_frame_ptr */
- == (unsigned long)table->address
- && (i = read_pointer(&ptr, end, hdr->fde_count_enc)) > 0 /*
fde_count */
- && i == (end - ptr) / (2 * hdrEntrySz)
- && !((end - ptr) % (2 * hdrEntrySz))) {
do {
const u8 *cur = ptr + (i / 2) * (2 *
hdrEntrySz);
@@ -944,8 +925,6 @@ int arc_unwind(struct unwind_frame_info *frame)
&& (startLoc = read_pointer(&ptr, ptr + hdrEntrySz,
hdr->table_enc)) != 0
&& pc >= startLoc)
fde = (void *)read_pointer(&ptr, ptr +
hdrEntrySz, hdr->table_enc);
- }
- }
if (fde != NULL) {
cie = cie_for_fde(fde, table);
--
1.9.1
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