[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>
diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index 5244f80..e0eb0c7 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 @@
.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 @@
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 @@
* 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 @@
.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 @@
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 @@
*/
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 @@
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 @@
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