[PATCH v4 14/17] x86/asm/entry/64: Migrate error and interrupt exit work to C

Andy Lutomirski
2015-06-29T19:36:29Z

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/entry/entry_64.S | 63 +++++++++++-----------------------------
arch/x86/entry/entry_64_compat.S | 5 ++++
2 files changed, 22 insertions(+), 46 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index ce2c9049abef..08a37ec049f0 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -508,7 +508,16 @@ END(irq_entries_start)

testb $3, CS(%rsp)
jz 1f
+
+ /*
+ * IRQ from user mode. Switch to kernel gsbase and inform context
+ * tracking that we're in kernel mode.
+ */
SWAPGS
+#ifdef CONFIG_CONTEXT_TRACKING
+ call enter_from_user_mode
+#endif
+
1:
/*
* Save previous stack pointer, optionally switch to interrupt stack.
@@ -547,26 +556,13 @@ ret_from_intr:

testb $3, CS(%rsp)
jz retint_kernel
- /* Interrupt came from user space */
-GLOBAL(retint_user)
- GET_THREAD_INFO(%rcx)

- /* %rcx: thread info. Interrupts are off. */
-retint_with_reschedule:
- movl $_TIF_WORK_MASK, %edi
-retint_check:
+ /* Interrupt came from user space */
LOCKDEP_SYS_EXIT_IRQ
- movl TI_flags(%rcx), %edx
- andl %edi, %edx
- jnz retint_careful
-
-retint_swapgs: /* return to user-space */
- /*
- * The iretq could re-enable interrupts:
- */
- DISABLE_INTERRUPTS(CLBR_ANY)
+GLOBAL(retint_user)
+ mov %rsp,%rdi
+ call prepare_exit_to_usermode
TRACE_IRQS_IRETQ
-
SWAPGS
jmp restore_regs_and_iret

@@ -644,35 +640,6 @@ native_irq_return_ldt:
popq %rax
jmp native_irq_return_iret
#endif
-
- /* edi: workmask, edx: work */
-retint_careful:
- bt $TIF_NEED_RESCHED, %edx
- jnc retint_signal
- TRACE_IRQS_ON
- ENABLE_INTERRUPTS(CLBR_NONE)
- pushq %rdi
- SCHEDULE_USER
- popq %rdi
- GET_THREAD_INFO(%rcx)
- DISABLE_INTERRUPTS(CLBR_NONE)
- TRACE_IRQS_OFF
- jmp retint_check
-
-retint_signal:
- testl $_TIF_DO_NOTIFY_MASK, %edx
- jz retint_swapgs
- TRACE_IRQS_ON
- ENABLE_INTERRUPTS(CLBR_NONE)
- movq $-1, ORIG_RAX(%rsp)
- xorl %esi, %esi /* oldset */
- movq %rsp, %rdi /* &pt_regs */
- call do_notify_resume
- DISABLE_INTERRUPTS(CLBR_NONE)
- TRACE_IRQS_OFF
- GET_THREAD_INFO(%rcx)
- jmp retint_with_reschedule
-
END(common_interrupt)

/*
@@ -1088,6 +1055,10 @@ error_entry_from_usermode_swapgs:
SWAPGS

error_entry_from_usermode_after_swapgs:
+#ifdef CONFIG_CONTEXT_TRACKING
+ call enter_from_user_mode
+#endif
+
error_entry_done:
TRACE_IRQS_OFF
ret
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index ac0658142ae1..566d33f17d0b 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -454,6 +454,11 @@ ia32_badarg:
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF

+ /* Now finish entering normal kernel mode. */
+#ifdef CONFIG_CONTEXT_TRACKING
+ call enter_from_user_mode
+#endif
+
/* And exit again. */
jmp retint_user

--
2.4.3