mirror of
https://github.com/torvalds/linux.git
synced 2024-12-19 01:23:20 +00:00
x86: entry_64.S - trivial: space, comments fixup
Impact: cleanup Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Cyrill Gorcunov
Ingo Molnar
parent
5ae3a139cf
commit
9f1e87ea3e
@ -1020,7 +1020,7 @@ END(\sym)
|
||||
|
||||
.macro paranoidzeroentry_ist sym do_sym ist
|
||||
ENTRY(\sym)
|
||||
INTR_FRAME
|
||||
INTR_FRAME
|
||||
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
||||
pushq $-1 /* ORIG_RAX: no syscall to restart */
|
||||
CFI_ADJUST_CFA_OFFSET 8
|
||||
@ -1088,36 +1088,36 @@ zeroentry coprocessor_error do_coprocessor_error
|
||||
errorentry alignment_check do_alignment_check
|
||||
zeroentry simd_coprocessor_error do_simd_coprocessor_error
|
||||
|
||||
/* Reload gs selector with exception handling */
|
||||
/* edi: new selector */
|
||||
/* Reload gs selector with exception handling */
|
||||
/* edi: new selector */
|
||||
ENTRY(native_load_gs_index)
|
||||
CFI_STARTPROC
|
||||
pushf
|
||||
CFI_ADJUST_CFA_OFFSET 8
|
||||
DISABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI))
|
||||
SWAPGS
|
||||
SWAPGS
|
||||
gs_change:
|
||||
movl %edi,%gs
|
||||
movl %edi,%gs
|
||||
2: mfence /* workaround */
|
||||
SWAPGS
|
||||
popf
|
||||
popf
|
||||
CFI_ADJUST_CFA_OFFSET -8
|
||||
ret
|
||||
ret
|
||||
CFI_ENDPROC
|
||||
END(native_load_gs_index)
|
||||
|
||||
.section __ex_table,"a"
|
||||
.align 8
|
||||
.quad gs_change,bad_gs
|
||||
.previous
|
||||
.section .fixup,"ax"
|
||||
.section __ex_table,"a"
|
||||
.align 8
|
||||
.quad gs_change,bad_gs
|
||||
.previous
|
||||
.section .fixup,"ax"
|
||||
/* running with kernelgs */
|
||||
bad_gs:
|
||||
SWAPGS /* switch back to user gs */
|
||||
xorl %eax,%eax
|
||||
movl %eax,%gs
|
||||
jmp 2b
|
||||
.previous
|
||||
movl %eax,%gs
|
||||
jmp 2b
|
||||
.previous
|
||||
|
||||
/*
|
||||
* Create a kernel thread.
|
||||
@ -1152,7 +1152,7 @@ ENTRY(kernel_thread)
|
||||
* so internally to the x86_64 port you can rely on kernel_thread()
|
||||
* not to reschedule the child before returning, this avoids the need
|
||||
* of hacks for example to fork off the per-CPU idle tasks.
|
||||
* [Hopefully no generic code relies on the reschedule -AK]
|
||||
* [Hopefully no generic code relies on the reschedule -AK]
|
||||
*/
|
||||
RESTORE_ALL
|
||||
UNFAKE_STACK_FRAME
|
||||
@ -1231,22 +1231,24 @@ END(call_softirq)
|
||||
zeroentry xen_hypervisor_callback xen_do_hypervisor_callback
|
||||
|
||||
/*
|
||||
# A note on the "critical region" in our callback handler.
|
||||
# We want to avoid stacking callback handlers due to events occurring
|
||||
# during handling of the last event. To do this, we keep events disabled
|
||||
# until we've done all processing. HOWEVER, we must enable events before
|
||||
# popping the stack frame (can't be done atomically) and so it would still
|
||||
# be possible to get enough handler activations to overflow the stack.
|
||||
# Although unlikely, bugs of that kind are hard to track down, so we'd
|
||||
# like to avoid the possibility.
|
||||
# So, on entry to the handler we detect whether we interrupted an
|
||||
# existing activation in its critical region -- if so, we pop the current
|
||||
# activation and restart the handler using the previous one.
|
||||
*/
|
||||
* A note on the "critical region" in our callback handler.
|
||||
* We want to avoid stacking callback handlers due to events occurring
|
||||
* during handling of the last event. To do this, we keep events disabled
|
||||
* until we've done all processing. HOWEVER, we must enable events before
|
||||
* popping the stack frame (can't be done atomically) and so it would still
|
||||
* be possible to get enough handler activations to overflow the stack.
|
||||
* Although unlikely, bugs of that kind are hard to track down, so we'd
|
||||
* like to avoid the possibility.
|
||||
* So, on entry to the handler we detect whether we interrupted an
|
||||
* existing activation in its critical region -- if so, we pop the current
|
||||
* activation and restart the handler using the previous one.
|
||||
*/
|
||||
ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
|
||||
CFI_STARTPROC
|
||||
/* Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will
|
||||
see the correct pointer to the pt_regs */
|
||||
/*
|
||||
* Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will
|
||||
* see the correct pointer to the pt_regs
|
||||
*/
|
||||
movq %rdi, %rsp # we don't return, adjust the stack frame
|
||||
CFI_ENDPROC
|
||||
DEFAULT_FRAME
|
||||
@ -1264,18 +1266,18 @@ ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
|
||||
END(do_hypervisor_callback)
|
||||
|
||||
/*
|
||||
# Hypervisor uses this for application faults while it executes.
|
||||
# We get here for two reasons:
|
||||
# 1. Fault while reloading DS, ES, FS or GS
|
||||
# 2. Fault while executing IRET
|
||||
# Category 1 we do not need to fix up as Xen has already reloaded all segment
|
||||
# registers that could be reloaded and zeroed the others.
|
||||
# Category 2 we fix up by killing the current process. We cannot use the
|
||||
# normal Linux return path in this case because if we use the IRET hypercall
|
||||
# to pop the stack frame we end up in an infinite loop of failsafe callbacks.
|
||||
# We distinguish between categories by comparing each saved segment register
|
||||
# with its current contents: any discrepancy means we in category 1.
|
||||
*/
|
||||
* Hypervisor uses this for application faults while it executes.
|
||||
* We get here for two reasons:
|
||||
* 1. Fault while reloading DS, ES, FS or GS
|
||||
* 2. Fault while executing IRET
|
||||
* Category 1 we do not need to fix up as Xen has already reloaded all segment
|
||||
* registers that could be reloaded and zeroed the others.
|
||||
* Category 2 we fix up by killing the current process. We cannot use the
|
||||
* normal Linux return path in this case because if we use the IRET hypercall
|
||||
* to pop the stack frame we end up in an infinite loop of failsafe callbacks.
|
||||
* We distinguish between categories by comparing each saved segment register
|
||||
* with its current contents: any discrepancy means we in category 1.
|
||||
*/
|
||||
ENTRY(xen_failsafe_callback)
|
||||
INTR_FRAME 1 (6*8)
|
||||
/*CFI_REL_OFFSET gs,GS*/
|
||||
@ -1339,8 +1341,8 @@ paranoidzeroentry machine_check do_machine_check
|
||||
#endif
|
||||
|
||||
/*
|
||||
* "Paranoid" exit path from exception stack.
|
||||
* Paranoid because this is used by NMIs and cannot take
|
||||
* "Paranoid" exit path from exception stack.
|
||||
* Paranoid because this is used by NMIs and cannot take
|
||||
* any kernel state for granted.
|
||||
* We don't do kernel preemption checks here, because only
|
||||
* NMI should be common and it does not enable IRQs and
|
||||
@ -1445,7 +1447,7 @@ error_kernelspace:
|
||||
cmpq %rcx,RIP+8(%rsp)
|
||||
je error_swapgs
|
||||
cmpq $gs_change,RIP+8(%rsp)
|
||||
je error_swapgs
|
||||
je error_swapgs
|
||||
jmp error_sti
|
||||
END(error_entry)
|
||||
|
||||
@ -1521,7 +1523,7 @@ nmi_schedule:
|
||||
CFI_ENDPROC
|
||||
#else
|
||||
jmp paranoid_exit
|
||||
CFI_ENDPROC
|
||||
CFI_ENDPROC
|
||||
#endif
|
||||
END(nmi)
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user