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authorMarcelo Tosatti <mtosatti@redhat.com>2012-10-29 22:15:32 +0100
committerMarcelo Tosatti <mtosatti@redhat.com>2012-10-29 22:15:32 +0100
commit19bf7f8ac3f8131100027281c495dbbe00cd5ae0 (patch)
tree270b97e3ca47c0f62a1babca2ae37f79a76a309c /arch/x86/kernel/entry_32.S
parentKVM: ia64: remove unused variable in kvm_release_vm_pages() (diff)
parentMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sag... (diff)
downloadlinux-19bf7f8ac3f8131100027281c495dbbe00cd5ae0.tar.xz
linux-19bf7f8ac3f8131100027281c495dbbe00cd5ae0.zip
Merge remote-tracking branch 'master' into queue
Merge reason: development work has dependency on kvm patches merged upstream. Conflicts: arch/powerpc/include/asm/Kbuild arch/powerpc/include/asm/kvm_para.h Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kernel/entry_32.S')
-rw-r--r--arch/x86/kernel/entry_32.S54
1 files changed, 27 insertions, 27 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 0750e3ba87c0..88b725aa1d52 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -299,6 +299,21 @@ ENTRY(ret_from_fork)
CFI_ENDPROC
END(ret_from_fork)
+ENTRY(ret_from_kernel_thread)
+ CFI_STARTPROC
+ pushl_cfi %eax
+ call schedule_tail
+ GET_THREAD_INFO(%ebp)
+ popl_cfi %eax
+ pushl_cfi $0x0202 # Reset kernel eflags
+ popfl_cfi
+ movl PT_EBP(%esp),%eax
+ call *PT_EBX(%esp)
+ movl $0,PT_EAX(%esp)
+ jmp syscall_exit
+ CFI_ENDPROC
+ENDPROC(ret_from_kernel_thread)
+
/*
* Interrupt exit functions should be protected against kprobes
*/
@@ -323,8 +338,7 @@ ret_from_intr:
andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax
#else
/*
- * We can be coming here from a syscall done in the kernel space,
- * e.g. a failed kernel_execve().
+ * We can be coming here from child spawned by kernel_thread().
*/
movl PT_CS(%esp), %eax
andl $SEGMENT_RPL_MASK, %eax
@@ -616,6 +630,10 @@ work_notifysig: # deal with pending signals and
movl %esp, %eax
jne work_notifysig_v86 # returning to kernel-space or
# vm86-space
+1:
+#else
+ movl %esp, %eax
+#endif
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
movb PT_CS(%esp), %bl
@@ -626,24 +644,15 @@ work_notifysig: # deal with pending signals and
call do_notify_resume
jmp resume_userspace
+#ifdef CONFIG_VM86
ALIGN
work_notifysig_v86:
pushl_cfi %ecx # save ti_flags for do_notify_resume
call save_v86_state # %eax contains pt_regs pointer
popl_cfi %ecx
movl %eax, %esp
-#else
- movl %esp, %eax
+ jmp 1b
#endif
- TRACE_IRQS_ON
- ENABLE_INTERRUPTS(CLBR_NONE)
- movb PT_CS(%esp), %bl
- andb $SEGMENT_RPL_MASK, %bl
- cmpb $USER_RPL, %bl
- jb resume_kernel
- xorl %edx, %edx
- call do_notify_resume
- jmp resume_userspace
END(work_pending)
# perform syscall exit tracing
@@ -732,7 +741,6 @@ ENDPROC(ptregs_##name)
PTREGSCALL1(iopl)
PTREGSCALL0(fork)
PTREGSCALL0(vfork)
-PTREGSCALL3(execve)
PTREGSCALL2(sigaltstack)
PTREGSCALL0(sigreturn)
PTREGSCALL0(rt_sigreturn)
@@ -1015,16 +1023,6 @@ END(spurious_interrupt_bug)
*/
.popsection
-ENTRY(kernel_thread_helper)
- pushl $0 # fake return address for unwinder
- CFI_STARTPROC
- movl %edi,%eax
- call *%esi
- call do_exit
- ud2 # padding for call trace
- CFI_ENDPROC
-ENDPROC(kernel_thread_helper)
-
#ifdef CONFIG_XEN
/* Xen doesn't set %esp to be precisely what the normal sysenter
entrypoint expects, so fix it up before using the normal path. */
@@ -1037,7 +1035,7 @@ ENTRY(xen_sysenter_target)
ENTRY(xen_hypervisor_callback)
CFI_STARTPROC
- pushl_cfi $0
+ pushl_cfi $-1 /* orig_ax = -1 => not a system call */
SAVE_ALL
TRACE_IRQS_OFF
@@ -1079,14 +1077,16 @@ ENTRY(xen_failsafe_callback)
2: mov 8(%esp),%es
3: mov 12(%esp),%fs
4: mov 16(%esp),%gs
+ /* EAX == 0 => Category 1 (Bad segment)
+ EAX != 0 => Category 2 (Bad IRET) */
testl %eax,%eax
popl_cfi %eax
lea 16(%esp),%esp
CFI_ADJUST_CFA_OFFSET -16
jz 5f
addl $16,%esp
- jmp iret_exc # EAX != 0 => Category 2 (Bad IRET)
-5: pushl_cfi $0 # EAX == 0 => Category 1 (Bad segment)
+ jmp iret_exc
+5: pushl_cfi $-1 /* orig_ax = -1 => not a system call */
SAVE_ALL
jmp ret_from_exception
CFI_ENDPROC