xen64: deal with extra words Xen pushes onto exception frames (997409d3) · Commits · 戴 / test

Xen pushes two extra words containing the values of rcx and r11. This pvop hook copies the words back into their appropriate registers, and cleans them off the stack. This leaves the stack in native form, so the normal handler can run unchanged. Signed-off-by:

Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by:

Ingo Molnar <mingo@elte.hu>

arch/x86/xen/enlighten.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1091,7 +1091,7 @@ static const struct pv_irq_ops xen_irq_ops __initdata = {
		.safe_halt = xen_safe_halt,
		.halt = xen_halt,
		#ifdef CONFIG_X86_64
		.adjust_exception_frame = paravirt_nop,
		.adjust_exception_frame = xen_adjust_exception_frame,
		#endif
		};

arch/x86/xen/xen-asm_64.S

+5 −0

Original line number	Diff line number	Diff line
		@@ -133,6 +133,11 @@ check_events:
		ret
		#endif

		ENTRY(xen_adjust_exception_frame)
		mov 8+0(%rsp),%rcx
		mov 8+8(%rsp),%r11
		ret $16

		ENTRY(xen_iret)
		pushq $0
		jmp hypercall_page + __HYPERVISOR_iret * 32

arch/x86/xen/xen-ops.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -67,7 +67,9 @@ DECL_ASM(void, xen_irq_disable_direct, void);
		DECL_ASM(unsigned long, xen_save_fl_direct, void);
		DECL_ASM(void, xen_restore_fl_direct, unsigned long);

		/* These are not functions, and cannot be called normally */
		void xen_iret(void);
		void xen_sysexit(void);
		void xen_adjust_exception_frame(void);

		#endif /* XEN_OPS_H */

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