Re: [patch V4 part 3 27/29] x86/entry: Convert Alignment check exception to IDTENTRY

2020-05-13 Thread Andy Lutomirski
On Tue, May 5, 2020 at 7:15 AM Thomas Gleixner  wrote:
>
> From: Thomas Gleixner 
>
> Convert #AC to IDTENTRY_ERRORCODE:
>   - Implement the C entry point with DEFINE_IDTENTRY
>   - Emit the ASM stub with DECLARE_IDTENTRY
>   - Remove the ASM idtentry in 64bit
>   - Remove the open coded ASM entry code in 32bit
>   - Fixup the XEN/PV code
>   - Remove the old prototyoes
>   - Remove the RCU warning as the new entry macro ensures correctness
>
> No functional change.


Acked-by: Andy Lutomirski 


[patch V4 part 3 27/29] x86/entry: Convert Alignment check exception to IDTENTRY

2020-05-05 Thread Thomas Gleixner
From: Thomas Gleixner 

Convert #AC to IDTENTRY_ERRORCODE:
  - Implement the C entry point with DEFINE_IDTENTRY
  - Emit the ASM stub with DECLARE_IDTENTRY
  - Remove the ASM idtentry in 64bit
  - Remove the open coded ASM entry code in 32bit
  - Fixup the XEN/PV code
  - Remove the old prototyoes
  - Remove the RCU warning as the new entry macro ensures correctness

No functional change.

Signed-off-by: Thomas Gleixner 

---
 arch/x86/entry/entry_32.S   |6 --
 arch/x86/entry/entry_64.S   |1 -
 arch/x86/include/asm/idtentry.h |1 +
 arch/x86/include/asm/traps.h|3 ---
 arch/x86/kernel/idt.c   |2 +-
 arch/x86/kernel/traps.c |4 +---
 arch/x86/xen/enlighten_pv.c |2 +-
 arch/x86/xen/xen-asm_64.S   |2 +-
 8 files changed, 5 insertions(+), 16 deletions(-)

--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1311,12 +1311,6 @@ SYM_CODE_START(native_iret)
 SYM_CODE_END(native_iret)
 #endif
 
-SYM_CODE_START(alignment_check)
-   ASM_CLAC
-   pushl   $do_alignment_check
-   jmp common_exception
-SYM_CODE_END(alignment_check)
-
 #ifdef CONFIG_X86_MCE
 SYM_CODE_START(machine_check)
ASM_CLAC
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1074,7 +1074,6 @@ apicinterrupt IRQ_WORK_VECTOR irq_work
  */
 
 idtentry   X86_TRAP_BP int3do_int3 
has_error_code=0
-idtentry   X86_TRAP_AC alignment_check 
do_alignment_check  has_error_code=1
 idtentry   X86_TRAP_XF simd_coprocessor_error  
do_simd_coprocessor_error   has_error_code=0
 
 idtentry   X86_TRAP_PF page_fault  do_page_fault   
has_error_code=1
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -137,5 +137,6 @@ DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_TS,
 DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_NP,exc_segment_not_present);
 DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_SS,exc_stack_segment);
 DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_GP,exc_general_protection);
+DECLARE_IDTENTRY_ERRORCODE(X86_TRAP_AC,exc_alignment_check);
 
 #endif
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -19,7 +19,6 @@ asmlinkage void double_fault(void);
 #endif
 asmlinkage void page_fault(void);
 asmlinkage void async_page_fault(void);
-asmlinkage void alignment_check(void);
 #ifdef CONFIG_X86_MCE
 asmlinkage void machine_check(void);
 #endif /* CONFIG_X86_MCE */
@@ -31,7 +30,6 @@ asmlinkage void xen_xendebug(void);
 asmlinkage void xen_int3(void);
 asmlinkage void xen_double_fault(void);
 asmlinkage void xen_page_fault(void);
-asmlinkage void xen_alignment_check(void);
 #ifdef CONFIG_X86_MCE
 asmlinkage void xen_machine_check(void);
 #endif /* CONFIG_X86_MCE */
@@ -45,7 +43,6 @@ dotraplinkage void do_int3(struct pt_reg
 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, 
unsigned long cr2);
 #endif
 dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long 
error_code, unsigned long address);
-dotraplinkage void do_alignment_check(struct pt_regs *regs, long error_code);
 dotraplinkage void do_simd_coprocessor_error(struct pt_regs *regs, long 
error_code);
 #ifdef CONFIG_X86_32
 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code);
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -82,7 +82,7 @@ static const __initconst struct idt_data
INTG(X86_TRAP_GP,   asm_exc_general_protection),
INTG(X86_TRAP_SPURIOUS, asm_exc_spurious_interrupt_bug),
INTG(X86_TRAP_MF,   asm_exc_coprocessor_error),
-   INTG(X86_TRAP_AC,   alignment_check),
+   INTG(X86_TRAP_AC,   asm_exc_alignment_check),
INTG(X86_TRAP_XF,   simd_coprocessor_error),
 
 #ifdef CONFIG_X86_32
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -260,12 +260,10 @@ DEFINE_IDTENTRY_ERRORCODE(exc_stack_segm
  0, NULL);
 }
 
-dotraplinkage void do_alignment_check(struct pt_regs *regs, long error_code)
+DEFINE_IDTENTRY_ERRORCODE(exc_alignment_check)
 {
char *str = "alignment check";
 
-   RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
-
if (notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_AC, SIGBUS) == 
NOTIFY_STOP)
return;
 
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -634,7 +634,7 @@ static struct trap_array_entry trap_arra
TRAP_ENTRY(exc_general_protection,  false ),
TRAP_ENTRY(exc_spurious_interrupt_bug,  false ),
TRAP_ENTRY(exc_coprocessor_error,   false ),
-   { alignment_check, xen_alignment_check, false },
+   TRAP_ENTRY(exc_alignment_check, false ),
{ simd_coprocessor_error,  xe