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x86/entry/64: Simplify idtentry a little 

There's a bunch of duplication in idtentry, namely the
.Lfrom_usermode_switch_stack is a paranoid=0 copy of the normal flow.

Make this explicit by creating a idtentry_part helper macro.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: bp@alien8.de
Cc: torvalds@linux-foundation.org
Cc: hpa@zytor.com
Cc: dave.hansen@linux.intel.com
Cc: jgross@suse.com
Cc: zhe.he@windriver.com
Cc: joel@joelfernandes.org
Cc: devel@etsukata.com
Link: https://lkml.kernel.org/r/20190711114336.002429503@infradead.org
This commit is contained in:
Peter Zijlstra 2019-07-11 13:40:57 +02:00 committed by Thomas Gleixner
parent e67f1c11e5
commit 2fd37912cf
1 changed files with 48 additions and 54 deletions
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102
arch/x86/entry/entry_64.S
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@ -864,6 +864,52 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt
*/
#define CPU_TSS_IST(x) PER_CPU_VAR(cpu_tss_rw) + (TSS_ist + (x) * 8)
.macro idtentry_part do_sym, has_error_code:req, paranoid:req, shift_ist=-1, ist_offset=0
.if \paranoid
call paranoid_entry
/* returned flag: ebx=0: need swapgs on exit, ebx=1: don't need it */
.else
call error_entry
.endif
UNWIND_HINT_REGS
.if \paranoid
.if \shift_ist != -1
TRACE_IRQS_OFF_DEBUG /* reload IDT in case of recursion */
.else
TRACE_IRQS_OFF
.endif
.endif
movq %rsp, %rdi /* pt_regs pointer */
.if \has_error_code
movq ORIG_RAX(%rsp), %rsi /* get error code */
movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */
.else
xorl %esi, %esi /* no error code */
.endif
.if \shift_ist != -1
subq $\ist_offset, CPU_TSS_IST(\shift_ist)
.endif
call \do_sym
.if \shift_ist != -1
addq $\ist_offset, CPU_TSS_IST(\shift_ist)
.endif
.if \paranoid
/* this procedure expect "no swapgs" flag in ebx */
jmp paranoid_exit
.else
jmp error_exit
.endif
.endm
/**
* idtentry - Generate an IDT entry stub
* @sym: Name of the generated entry point
@ -934,47 +980,7 @@ ENTRY(\sym)
.Lfrom_usermode_no_gap_\@:
.endif
.if \paranoid
call paranoid_entry
.else
call error_entry
.endif
UNWIND_HINT_REGS
/* returned flag: ebx=0: need swapgs on exit, ebx=1: don't need it */
.if \paranoid
.if \shift_ist != -1
TRACE_IRQS_OFF_DEBUG /* reload IDT in case of recursion */
.else
TRACE_IRQS_OFF
.endif
.endif
movq %rsp, %rdi /* pt_regs pointer */
.if \has_error_code
movq ORIG_RAX(%rsp), %rsi /* get error code */
movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */
.else
xorl %esi, %esi /* no error code */
.endif
.if \shift_ist != -1
subq $\ist_offset, CPU_TSS_IST(\shift_ist)
.endif
call \do_sym
.if \shift_ist != -1
addq $\ist_offset, CPU_TSS_IST(\shift_ist)
.endif
/* these procedures expect "no swapgs" flag in ebx */
.if \paranoid
jmp paranoid_exit
.else
jmp error_exit
.endif
idtentry_part \do_sym, \has_error_code, \paranoid, \shift_ist, \ist_offset
.if \paranoid == 1
/*
@ -983,21 +989,9 @@ ENTRY(\sym)
* run in real process context if user_mode(regs).
*/
.Lfrom_usermode_switch_stack_\@:
call error_entry
movq %rsp, %rdi /* pt_regs pointer */
.if \has_error_code
movq ORIG_RAX(%rsp), %rsi /* get error code */
movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */
.else
xorl %esi, %esi /* no error code */
idtentry_part \do_sym, \has_error_code, paranoid=0
.endif
call \do_sym
jmp error_exit
.endif
_ASM_NOKPROBE(\sym)
END(\sym)
.endm