[PATCH] x86-64: Fix CFI information

Being the foundation for reliable stack unwinding, this fixes CFI unwind
annotations in many low-level x86_64 routines, plus a config option
(available to all architectures, and also present in the previously sent
patch adding such annotations to i386 code) to enable them separatly
rather than only along with adding full debug information.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 47 insertions, 4 deletions

diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index 5244f803203d..e0eb0c712fe9 100644
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -55,20 +55,34 @@
  * with the int 0x80 path.
  */     
 ENTRY(ia32_sysenter_target)
-        CFI_STARTPROC
+        CFI_STARTPROC   simple
+        CFI_DEF_CFA     rsp,0
+        CFI_REGISTER    rsp,rbp
         swapgs
         movq    %gs:pda_kernelstack, %rsp
         addq    $(PDA_STACKOFFSET),%rsp 
         sti     
         movl    %ebp,%ebp               /* zero extension */
         pushq   $__USER32_DS
+        CFI_ADJUST_CFA_OFFSET 8
+        /*CFI_REL_OFFSET ss,0*/
         pushq   %rbp
+        CFI_ADJUST_CFA_OFFSET 8
+        CFI_REL_OFFSET rsp,0
         pushfq
+        CFI_ADJUST_CFA_OFFSET 8
+        /*CFI_REL_OFFSET rflags,0*/
         movl    $VSYSCALL32_SYSEXIT, %r10d
+        CFI_REGISTER rip,r10
         pushq   $__USER32_CS
+        CFI_ADJUST_CFA_OFFSET 8
+        /*CFI_REL_OFFSET cs,0*/
         movl    %eax, %eax
         pushq   %r10
+        CFI_ADJUST_CFA_OFFSET 8
+        CFI_REL_OFFSET rip,0
         pushq   %rax
+        CFI_ADJUST_CFA_OFFSET 8
         cld
         SAVE_ARGS 0,0,1
         /* no need to do an access_ok check here because rbp has been
@@ -79,6 +93,7 @@ ENTRY(ia32_sysenter_target)
         .previous       
         GET_THREAD_INFO(%r10)
         testl  $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%r10)
+        CFI_REMEMBER_STATE
         jnz  sysenter_tracesys
 sysenter_do_call:       
         cmpl    $(IA32_NR_syscalls),%eax
@@ -94,14 +109,20 @@ sysenter_do_call:
         andl  $~0x200,EFLAGS-R11(%rsp) 
         RESTORE_ARGS 1,24,1,1,1,1
         popfq
+        CFI_ADJUST_CFA_OFFSET -8
+        /*CFI_RESTORE rflags*/
         popq    %rcx                            /* User %esp */
+        CFI_ADJUST_CFA_OFFSET -8
+        CFI_REGISTER rsp,rcx
         movl    $VSYSCALL32_SYSEXIT,%edx        /* User %eip */
+        CFI_REGISTER rip,rdx
         swapgs
         sti             /* sti only takes effect after the next instruction */
         /* sysexit */
         .byte   0xf, 0x35
 
 sysenter_tracesys:
+        CFI_RESTORE_STATE
         SAVE_REST
         CLEAR_RREGS
         movq    $-ENOSYS,RAX(%rsp)      /* really needed? */
@@ -140,21 +161,28 @@ sysenter_tracesys:
  * with the int 0x80 path.      
  */     
 ENTRY(ia32_cstar_target)
-        CFI_STARTPROC
+        CFI_STARTPROC   simple
+        CFI_DEF_CFA     rsp,0
+        CFI_REGISTER    rip,rcx
+        /*CFI_REGISTER  rflags,r11*/
         swapgs
         movl    %esp,%r8d
+        CFI_REGISTER    rsp,r8
         movq    %gs:pda_kernelstack,%rsp
         sti
         SAVE_ARGS 8,1,1
         movl    %eax,%eax       /* zero extension */
         movq    %rax,ORIG_RAX-ARGOFFSET(%rsp)
         movq    %rcx,RIP-ARGOFFSET(%rsp)
+        CFI_REL_OFFSET rip,RIP-ARGOFFSET
         movq    %rbp,RCX-ARGOFFSET(%rsp) /* this lies slightly to ptrace */
         movl    %ebp,%ecx
         movq    $__USER32_CS,CS-ARGOFFSET(%rsp)
         movq    $__USER32_DS,SS-ARGOFFSET(%rsp)
         movq    %r11,EFLAGS-ARGOFFSET(%rsp)
+        /*CFI_REL_OFFSET rflags,EFLAGS-ARGOFFSET*/
         movq    %r8,RSP-ARGOFFSET(%rsp) 
+        CFI_REL_OFFSET rsp,RSP-ARGOFFSET
         /* no need to do an access_ok check here because r8 has been
            32bit zero extended */ 
         /* hardware stack frame is complete now */      
@@ -164,6 +192,7 @@ ENTRY(ia32_cstar_target)
         .previous       
         GET_THREAD_INFO(%r10)
         testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%r10)
+        CFI_REMEMBER_STATE
         jnz   cstar_tracesys
 cstar_do_call:  
         cmpl $IA32_NR_syscalls,%eax
@@ -177,12 +206,16 @@ cstar_do_call:
         jnz  int_ret_from_sys_call
         RESTORE_ARGS 1,-ARG_SKIP,1,1,1
         movl RIP-ARGOFFSET(%rsp),%ecx
+        CFI_REGISTER rip,rcx
         movl EFLAGS-ARGOFFSET(%rsp),%r11d       
+        /*CFI_REGISTER rflags,r11*/
         movl RSP-ARGOFFSET(%rsp),%esp
+        CFI_RESTORE rsp
         swapgs
         sysretl
         
 cstar_tracesys: 
+        CFI_RESTORE_STATE
         SAVE_REST
         CLEAR_RREGS
         movq $-ENOSYS,RAX(%rsp) /* really needed? */
@@ -226,11 +259,18 @@ ia32_badarg:
  */                             
 
 ENTRY(ia32_syscall)
-        CFI_STARTPROC
+        CFI_STARTPROC   simple
+        CFI_DEF_CFA     rsp,SS+8-RIP
+        /*CFI_REL_OFFSET        ss,SS-RIP*/
+        CFI_REL_OFFSET  rsp,RSP-RIP
+        /*CFI_REL_OFFSET        rflags,EFLAGS-RIP*/
+        /*CFI_REL_OFFSET        cs,CS-RIP*/
+        CFI_REL_OFFSET  rip,RIP-RIP
         swapgs  
         sti
         movl %eax,%eax
         pushq %rax
+        CFI_ADJUST_CFA_OFFSET 8
         cld
         /* note the registers are not zero extended to the sf.
            this could be a problem. */
@@ -278,6 +318,8 @@ quiet_ni_syscall:
         jmp  ia32_ptregs_common 
         .endm
 
+        CFI_STARTPROC
+
         PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn, %rdi
         PTREGSCALL stub32_sigreturn, sys32_sigreturn, %rdi
         PTREGSCALL stub32_sigaltstack, sys32_sigaltstack, %rdx
@@ -290,8 +332,9 @@ quiet_ni_syscall:
         PTREGSCALL stub32_rt_sigsuspend, sys_rt_sigsuspend, %rdx
 
 ENTRY(ia32_ptregs_common)
-        CFI_STARTPROC
         popq %r11
+        CFI_ADJUST_CFA_OFFSET -8
+        CFI_REGISTER rip, r11
         SAVE_REST
         call *%rax
         RESTORE_REST