1 files changed, 28 insertions, 7 deletions

diff --git a/kernel/unwind.c b/kernel/unwind.c
index f69c804c8e62..3430475fcd88 100644
--- a/kernel/unwind.c
+++ b/kernel/unwind.c
@@ -603,6 +603,7 @@ int unwind(struct unwind_frame_info *frame)
 #define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs])
         const u32 *fde = NULL, *cie = NULL;
         const u8 *ptr = NULL, *end = NULL;
+        unsigned long pc = UNW_PC(frame) - frame->call_frame;
         unsigned long startLoc = 0, endLoc = 0, cfa;
         unsigned i;
         signed ptrType = -1;
@@ -612,7 +613,7 @@ int unwind(struct unwind_frame_info *frame)
 
         if (UNW_PC(frame) == 0)
                 return -EINVAL;
-        if ((table = find_table(UNW_PC(frame))) != NULL
+        if ((table = find_table(pc)) != NULL
             && !(table->size & (sizeof(*fde) - 1))) {
                 unsigned long tableSize = table->size;
 
@@ -647,7 +648,7 @@ int unwind(struct unwind_frame_info *frame)
                                                 ptrType & DW_EH_PE_indirect
                                                 ? ptrType
                                                 : ptrType & (DW_EH_PE_FORM|DW_EH_PE_signed));
-                        if (UNW_PC(frame) >= startLoc && UNW_PC(frame) < endLoc)
+                        if (pc >= startLoc && pc < endLoc)
                                 break;
                         cie = NULL;
                 }
@@ -657,16 +658,28 @@ int unwind(struct unwind_frame_info *frame)
                 state.cieEnd = ptr; /* keep here temporarily */
                 ptr = (const u8 *)(cie + 2);
                 end = (const u8 *)(cie + 1) + *cie;
+                frame->call_frame = 1;
                 if ((state.version = *ptr) != 1)
                         cie = NULL; /* unsupported version */
                 else if (*++ptr) {
                         /* check if augmentation size is first (and thus present) */
                         if (*ptr == 'z') {
-                                /* check for ignorable (or already handled)
-                                 * nul-terminated augmentation string */
-                                while (++ptr < end && *ptr)
-                                        if (strchr("LPR", *ptr) == NULL)
+                                while (++ptr < end && *ptr) {
+                                        switch(*ptr) {
+                                        /* check for ignorable (or already handled)
+                                         * nul-terminated augmentation string */
+                                        case 'L':
+                                        case 'P':
+                                        case 'R':
+                                                continue;
+                                        case 'S':
+                                                frame->call_frame = 0;
+                                                continue;
+                                        default:
                                                 break;
+                                        }
+                                        break;
+                                }
                         }
                         if (ptr >= end || *ptr)
                                 cie = NULL;
@@ -755,7 +768,7 @@ int unwind(struct unwind_frame_info *frame)
         state.org = startLoc;
         memcpy(&state.cfa, &badCFA, sizeof(state.cfa));
         /* process instructions */
-        if (!processCFI(ptr, end, UNW_PC(frame), ptrType, &state)
+        if (!processCFI(ptr, end, pc, ptrType, &state)
            || state.loc > endLoc
            || state.regs[retAddrReg].where == Nowhere
            || state.cfa.reg >= ARRAY_SIZE(reg_info)
@@ -763,6 +776,11 @@ int unwind(struct unwind_frame_info *frame)
            || state.cfa.offs % sizeof(unsigned long))
                 return -EIO;
         /* update frame */
+#ifndef CONFIG_AS_CFI_SIGNAL_FRAME
+        if(frame->call_frame
+           && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign))
+                frame->call_frame = 0;
+#endif
         cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs;
         startLoc = min((unsigned long)UNW_SP(frame), cfa);
         endLoc = max((unsigned long)UNW_SP(frame), cfa);
@@ -866,6 +884,7 @@ int unwind_init_frame_info(struct unwind_frame_info *info,
                            /*const*/ struct pt_regs *regs)
 {
         info->task = tsk;
+        info->call_frame = 0;
         arch_unw_init_frame_info(info, regs);
 
         return 0;
@@ -879,6 +898,7 @@ int unwind_init_blocked(struct unwind_frame_info *info,
                         struct task_struct *tsk)
 {
         info->task = tsk;
+        info->call_frame = 0;
         arch_unw_init_blocked(info);
 
         return 0;
@@ -894,6 +914,7 @@ int unwind_init_running(struct unwind_frame_info *info,
                         void *arg)
 {
         info->task = current;
+        info->call_frame = 0;
 
         return arch_unwind_init_running(info, callback, arg);
 }