11 files changed, 73 insertions, 9 deletions

diff --git a/arch/i386/Makefile b/arch/i386/Makefile
index 508cdbeb3a09..7cc0b189b82b 100644
--- a/arch/i386/Makefile
+++ b/arch/i386/Makefile
@@ -50,6 +50,10 @@ CFLAGS				+= $(shell if [ $(call cc-version) -lt 0400 ] ; then echo $(call cc-op
 cflags-y += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
 AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
 
+# is .cfi_signal_frame supported too?
+cflags-y += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
+AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
+
 CFLAGS += $(cflags-y)
 
 # Default subarch .c files
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index 284f2e908ad0..5a63d6fdb70e 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -183,18 +183,21 @@ VM_MASK		= 0x00020000
 
 #define RING0_INT_FRAME \
         CFI_STARTPROC simple;\
+        CFI_SIGNAL_FRAME;\
         CFI_DEF_CFA esp, 3*4;\
         /*CFI_OFFSET cs, -2*4;*/\
         CFI_OFFSET eip, -3*4
 
 #define RING0_EC_FRAME \
         CFI_STARTPROC simple;\
+        CFI_SIGNAL_FRAME;\
         CFI_DEF_CFA esp, 4*4;\
         /*CFI_OFFSET cs, -2*4;*/\
         CFI_OFFSET eip, -3*4
 
 #define RING0_PTREGS_FRAME \
         CFI_STARTPROC simple;\
+        CFI_SIGNAL_FRAME;\
         CFI_DEF_CFA esp, OLDESP-EBX;\
         /*CFI_OFFSET cs, CS-OLDESP;*/\
         CFI_OFFSET eip, EIP-OLDESP;\
@@ -275,6 +278,7 @@ need_resched:
         # sysenter call handler stub
 ENTRY(sysenter_entry)
         CFI_STARTPROC simple
+        CFI_SIGNAL_FRAME
         CFI_DEF_CFA esp, 0
         CFI_REGISTER esp, ebp
         movl TSS_sysenter_esp0(%esp),%esp
diff --git a/arch/x86_64/Makefile b/arch/x86_64/Makefile
index 2b8d07c70106..1c0f18d4f887 100644
--- a/arch/x86_64/Makefile
+++ b/arch/x86_64/Makefile
@@ -58,6 +58,10 @@ cflags-y += $(call cc-option,-mno-sse -mno-mmx -mno-sse2 -mno-3dnow,)
 cflags-y += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
 AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
 
+# is .cfi_signal_frame supported too?
+cflags-y += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
+AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)
+
 cflags-$(CONFIG_CC_STACKPROTECTOR) += $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) -fstack-protector )
 cflags-$(CONFIG_CC_STACKPROTECTOR_ALL) += $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) -fstack-protector-all )
 
diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index 32fd32bea07c..b4aa875e175b 100644
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -71,6 +71,7 @@
  */     
 ENTRY(ia32_sysenter_target)
         CFI_STARTPROC32 simple
+        CFI_SIGNAL_FRAME
         CFI_DEF_CFA     rsp,0
         CFI_REGISTER    rsp,rbp
         swapgs
@@ -186,6 +187,7 @@ ENDPROC(ia32_sysenter_target)
  */     
 ENTRY(ia32_cstar_target)
         CFI_STARTPROC32 simple
+        CFI_SIGNAL_FRAME
         CFI_DEF_CFA     rsp,PDA_STACKOFFSET
         CFI_REGISTER    rip,rcx
         /*CFI_REGISTER  rflags,r11*/
@@ -293,6 +295,7 @@ ia32_badarg:
 
 ENTRY(ia32_syscall)
         CFI_STARTPROC   simple
+        CFI_SIGNAL_FRAME
         CFI_DEF_CFA     rsp,SS+8-RIP
         /*CFI_REL_OFFSET        ss,SS-RIP*/
         CFI_REL_OFFSET  rsp,RSP-RIP
@@ -370,6 +373,7 @@ ENTRY(ia32_ptregs_common)
         popq %r11
         CFI_ENDPROC
         CFI_STARTPROC32 simple
+        CFI_SIGNAL_FRAME
         CFI_DEF_CFA     rsp,SS+8-ARGOFFSET
         CFI_REL_OFFSET  rax,RAX-ARGOFFSET
         CFI_REL_OFFSET  rcx,RCX-ARGOFFSET
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S
index ea32688386fd..4cbc65290ae7 100644
--- a/arch/x86_64/kernel/entry.S
+++ b/arch/x86_64/kernel/entry.S
@@ -123,6 +123,7 @@
         .macro  CFI_DEFAULT_STACK start=1
         .if \start
         CFI_STARTPROC   simple
+        CFI_SIGNAL_FRAME
         CFI_DEF_CFA     rsp,SS+8
         .else
         CFI_DEF_CFA_OFFSET SS+8
@@ -207,6 +208,7 @@ END(ret_from_fork)
 
 ENTRY(system_call)
         CFI_STARTPROC   simple
+        CFI_SIGNAL_FRAME
         CFI_DEF_CFA     rsp,PDA_STACKOFFSET
         CFI_REGISTER    rip,rcx
         /*CFI_REGISTER  rflags,r11*/
@@ -324,6 +326,7 @@ END(system_call)
  */     
 ENTRY(int_ret_from_sys_call)
         CFI_STARTPROC   simple
+        CFI_SIGNAL_FRAME
         CFI_DEF_CFA     rsp,SS+8-ARGOFFSET
         /*CFI_REL_OFFSET        ss,SS-ARGOFFSET*/
         CFI_REL_OFFSET  rsp,RSP-ARGOFFSET
@@ -484,6 +487,7 @@ END(stub_rt_sigreturn)
  */
         .macro _frame ref
         CFI_STARTPROC simple
+        CFI_SIGNAL_FRAME
         CFI_DEF_CFA rsp,SS+8-\ref
         /*CFI_REL_OFFSET ss,SS-\ref*/
         CFI_REL_OFFSET rsp,RSP-\ref
diff --git a/include/asm-i386/dwarf2.h b/include/asm-i386/dwarf2.h
index 5d1a8db5a9b0..6d66398a307d 100644
--- a/include/asm-i386/dwarf2.h
+++ b/include/asm-i386/dwarf2.h
@@ -28,6 +28,12 @@
 #define CFI_RESTORE_STATE .cfi_restore_state
 #define CFI_UNDEFINED .cfi_undefined
 
+#ifdef CONFIG_AS_CFI_SIGNAL_FRAME
+#define CFI_SIGNAL_FRAME .cfi_signal_frame
+#else
+#define CFI_SIGNAL_FRAME
+#endif
+
 #else
 
 /* Due to the structure of pre-exisiting code, don't use assembler line
@@ -48,6 +54,7 @@
 #define CFI_REMEMBER_STATE ignore
 #define CFI_RESTORE_STATE ignore
 #define CFI_UNDEFINED ignore
+#define CFI_SIGNAL_FRAME ignore
 
 #endif
 
diff --git a/include/asm-i386/unwind.h b/include/asm-i386/unwind.h
index f0ac399bae3c..5031d693b89d 100644
--- a/include/asm-i386/unwind.h
+++ b/include/asm-i386/unwind.h
@@ -18,6 +18,7 @@ struct unwind_frame_info
 {
         struct pt_regs regs;
         struct task_struct *task;
+        unsigned call_frame:1;
 };
 
 #define UNW_PC(frame)        (frame)->regs.eip
@@ -44,6 +45,10 @@ struct unwind_frame_info
         PTREGS_INFO(edi), \
         PTREGS_INFO(eip)
 
+#define UNW_DEFAULT_RA(raItem, dataAlign) \
+        ((raItem).where == Memory && \
+         !((raItem).value * (dataAlign) + 4))
+
 static inline void arch_unw_init_frame_info(struct unwind_frame_info *info,
                                             /*const*/ struct pt_regs *regs)
 {
diff --git a/include/asm-x86_64/dwarf2.h b/include/asm-x86_64/dwarf2.h
index 2b9368365fad..eedc08526b0b 100644
--- a/include/asm-x86_64/dwarf2.h
+++ b/include/asm-x86_64/dwarf2.h
@@ -28,6 +28,11 @@
 #define CFI_REMEMBER_STATE .cfi_remember_state
 #define CFI_RESTORE_STATE .cfi_restore_state
 #define CFI_UNDEFINED .cfi_undefined
+#ifdef CONFIG_AS_CFI_SIGNAL_FRAME
+#define CFI_SIGNAL_FRAME .cfi_signal_frame
+#else
+#define CFI_SIGNAL_FRAME
+#endif
 
 #else
 
@@ -45,6 +50,7 @@
 #define CFI_REMEMBER_STATE      #
 #define CFI_RESTORE_STATE       #
 #define CFI_UNDEFINED   #
+#define CFI_SIGNAL_FRAME        #
 
 #endif
 
diff --git a/include/asm-x86_64/unwind.h b/include/asm-x86_64/unwind.h
index 1f6e9bfb569e..b8fa5cb7ff88 100644
--- a/include/asm-x86_64/unwind.h
+++ b/include/asm-x86_64/unwind.h
@@ -18,6 +18,7 @@ struct unwind_frame_info
 {
         struct pt_regs regs;
         struct task_struct *task;
+        unsigned call_frame:1;
 };
 
 #define UNW_PC(frame)        (frame)->regs.rip
@@ -57,6 +58,10 @@ struct unwind_frame_info
         PTREGS_INFO(r15), \
         PTREGS_INFO(rip)
 
+#define UNW_DEFAULT_RA(raItem, dataAlign) \
+        ((raItem).where == Memory && \
+         !((raItem).value * (dataAlign) + 8))
+
 static inline void arch_unw_init_frame_info(struct unwind_frame_info *info,
                                             /*const*/ struct pt_regs *regs)
 {
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);
 }
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 7adef12a0c26..4f5ff19b992b 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -66,8 +66,8 @@ as-option = $(shell if $(CC) $(CFLAGS) $(1) -Wa,-Z -c -o /dev/null \
 # as-instr
 # Usage: cflags-y += $(call as-instr, instr, option1, option2)
 
-as-instr = $(shell if echo -e "$(1)" | $(AS) -Z -o astest$$$$.out \
-                   2>&1 >/dev/null ; then echo "$(2)"; else echo "$(3)"; fi; \
+as-instr = $(shell if echo -e "$(1)" | $(AS) >/dev/null 2>&1 -W -Z -o astest$$$$.out ; \
+                   then echo "$(2)"; else echo "$(3)"; fi; \
                    rm -f astest$$$$.out)
 
 # cc-option