x86/entry/entry_64.S

14  * - iret frame:	Architecture defined interrupt frame from SS to RIP
38 #include <asm/frame.h>
444  * includes early SYSCALL entry path) or back to the stack in the IRET frame if
499 	 * identical to the stack in the IRET frame or the VC fall-back stack,
577 	/* Assert that the IRET frame indicates user mode. */
594 	/* Copy the IRET frame to the trampoline stack. */
730 	 * RSP now points to an ordinary IRET frame, except that the page
780  * popping the stack frame (can't be done atomically) and so it would still
798 	movq	%rdi, %rsp			/* we don't return, adjust the stack frame */
815  * to pop the stack frame we end up in an infinite loop of failsafe callbacks.
879 	 * This is also why CS (stashed in the "iret frame" by the
1125 	 *    o Copy the interrupt frame into an "outermost" location on the
1127 	 *    o Copy the interrupt frame into an "iret" location on the stack
1136 	 * a nested NMI that updated the copy interrupt stack frame, a
1202 	 * Here's what our stack frame will look like:
1214 	 * | iret SS          } Copied from "outermost" frame        |
1223 	 * | outermost CS          } Copied to "iret" frame on each  |
1229 	 * The "original" frame is used by hardware.  Before re-enabling
1233 	 * We return by executing IRET while RSP points to the "iret" frame.
1237 	 * The "outermost" frame is copied to the "iret" frame on each
1239 	 * frame pointing to the final return target.
1247 	 * modify the "iret" frame because it's being written by
1301 	 * Modify the "iret" frame to point to repeat_nmi, forcing another
1328 	/* Leave room for the "iret" frame */
1331 	/* Copy the "original" frame to the "outermost" frame */
1363 	 * This makes it safe to copy to the stack frame that a nested
1375 	 * Copy the "outermost" frame to the "iret" frame.  NMIs that nest
1376 	 * here must not modify the "iret" frame while we're writing to
1390 	 * frame to point back to repeat_nmi.
1437 	 * Skip orig_ax and the "outermost" frame to point RSP at the "iret"
1438 	 * at the "iret" frame.
1461 	 * iretq reads the "iret" frame and exits the NMI stack in a
1523  * alone.  Therefore we unconditionally set up the frame pointer, which allows